Piston vs gas AR build?

[JR]

Guys just looking for opinions on my next AR build.

I have wanted to build a longer range AR for some time. So I just got a fluted SS 20 inch barrel chambered in 223 Wylde, 1-8 twist.

Opinions on using a piston vs gas and stock options. All my ARs are gas, and us magpul moe stocks.

Sure it is just an AR, not a real long range round. But what the heck it will be nice not have all carbines (cept one 300aac pistol)

[Higher Caliber]

Have you ever built a piston AR? Personally I'm a traditional gas guy (stoner 4 life)


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[BobbyB]

Either or will work. But the DI is simpler, lighter.

[Flyin6]

I shot the H&K 416, piston gun
Served with a ton of guys overseas who used their own custom uppers, most piston guns and I rode around with my non-optics Colt M4, with the silly 3 round burst.

My gun never failed on a mission, but most of the custom AR guns did.

The gas piston AK's haji used to shoot at us always seemed to work.

All my personal AR guns are gas

I'm staying simple...gas...unless the manufacturer made it as a piston gun

[Flyin6]

Either or will work. But the DI is simpler, lighter.

And Bobby (And Red Neck) why am I suddenly so "Quotable?"

And off topic (DOTin!) Bobbee, did you buy that 7.3 you were showing us?

[Atkinsmatt]

Don't have a lot of experience with the piston AR's but what I have seen wasn't pretty.  If it ain't broke...

[husker77c]

My buddy has a Ruger piston gun and it is stupid heavy on the front end. Great gun, but I wouldn't want to be carrying it around through the woods for very long.   But being a long range gun that wouldn't matter as much.

My two cents.  If you want an AR go DI. If you want a piston go SCAR or an AK.

And as said above. I've never seen the parts to build a piston gun. Complete uppers yes but not individual parts.  I assume your 20" has a rifle length gas system?  Does a piston for a rifle lengrh system even exist?

[BobbyB]

And Bobby (And Red Neck) why am I suddenly so "Quotable?"

And off topic (DOTin!) Bobbee, did you buy that 7.3 you were showing us?

1. You're a writer, you on occasion have quotable quotes of genius.

2. Nope it sold. Looking at an 01 LB7 CCSB w/ 262,xxx, 03 LB7 CCSB w/209,xxx, 97 ECLB 12V w/150,xxx.

If you want an AR go DI. If you want a piston go SCAR or an AK.

I want to fire a SCAR.

[EL TATE]

Bobby,

Got a little experience with these (lb7 Midwest trucks) as of late... I could write a book on what I would have looked for prior to purchase vs what my wife looked at when she got it for me. DOT'in up JR's thread here.

JR,

Everyone I've ever spoken to on the subject of AR's had the same resounding response as Don; the enemy's ak's never failed. mud, water, sand, ice didn't matter. Gas just seems more reliable. But if you're just building for fun vs. combat, will piston give you any major benefits over gas or vice versa? A hobby build should be just that IMHO, so put some rotors and optics on it and make a new piston/gas hybrid drone and some awesome gyro's to support full auto fire?

[husker77c]

And Bobby (And Red Neck) why am I suddenly so "Quotable?"

And off topic (DOTin!) Bobbee, did you buy that 7.3 you were showing us?

1. You're a writer, you on occasion have quotable quotes of genius.

2. Nope it sold. Looking at an 01 LB7 w/ 262,xxx, 03 LB7 w/209,xxx, 97 12V w/150,xxx.

If you want an AR go DI. If you want a piston go SCAR or an AK.

I want to fire a SCAR.

My scar is definately a favorite.  I have the 17 and it is the softest shooting .308 you will ever handle IMO.   I want a 16 so bad I can taste it. To the point of starting to do a mental inventory of what I can stand selling to fund the purchase. 

[BobbyB]

My scar is definately a favorite.  I have the 17 and it is the softest shooting .308 you will ever handle IMO.   I want a 16 so bad I can taste it. To the point of starting to do a mental inventory of what I can stand selling to fund the purchase.

No one I know within a reasonable distance has one. I want to shoot one and see if I like it. I do know, just by the looks that I hate the butt stock. But that's just a minor aesthetic point.

[JR]

OK, looks like its pretty solid, leave it gas as designed. Option is more than the barrel anyway.

The AK works because it was designed that way from the start, same for the AR, which all of mine work fine too.

Next is the stock and scope, vortex?

[BobbyB]

Next is the stock and scope, vortex?

Since it's a precision build I'd go with:

Stock
A2 style - It's simple, you can find them cheap, they work. Can't adjust the LOP or cheek rest, unless you add an aftermarket rest.
MagPul PRS - Not so cheap, but you can adjust the LOP and the cheek rest.

Scope
Vortex - Good quality optics, good price, lifetime no questions asked warranty.

Those are my thoughts.

[Higher Caliber]

Vortex is putting out some quality stuff these days... I used to hate on the nikons but I think they are pretty solid anymore as well. I love their caliber specific scopes. I recently converted my 16" gun to a 1-4 variable power vortex so I have a P-223 Nikon with rings I'll sell you... 3-9. It's in perfect condition.

Then there is always leupold which you can't beat with a stick... Any of those will prolly suit your purposes just fine but if you want a real scope with a real price tag... Nightforce NXS
http://www.opticsplanet.com/nightforce-nxs-35-15x-tactical-riflescope.html#

For stocks you just can't go wrong with magpul PRS

http://www.midwayusa.com/product/2319159496/magpul-stock-prs-precision-rifle-adjustable-ar-15-synthetic




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[husker77c]

My scar is definately a favorite.  I have the 17 and it is the softest shooting .308 you will ever handle IMO.   I want a 16 so bad I can taste it. To the point of starting to do a mental inventory of what I can stand selling to fund the purchase.

No one I know within a reasonable distance has one. I want to shoot one and see if I like it. I do know, just by the looks that I hate the butt stock. But that's just a minor aesthetic point.

Well if you haven't shot one by the time winter rolls around we can arrange to shoot mine.   It's  looking like when I get laid off this winter I'm going to bring my truck up da UP to do the swap eh. See what I did there lol.   My dad has a big garage I can use for the swap and I need to spend some time with him.

If you're around GB I'll bring it up and we can go beat on it for awhile if you've got a place to shoot.

As for the thread. I've also heard good things about the Vortex. I'm actually thinking that might be what I use on my SCAR  the 2.5x10 variety.

The stock. Another vote for a basic A2. I have one on a lower that I need to decide on an upper for and I really like it. Limited experience though.

I have a PRS on a 20" groundhog gun I built and I like it but as said it's pricey and I hardly ever shoot the gun so can't really say it was worth it.

[TexasRedNeck]

Either or will work. But the DI is simpler, lighter.

And Bobby (And Red Neck) why am I suddenly so "Quotable?"

And off topic (DOTin!) Bobbee, did you buy that 7.3 you were showing us?

Don, real simple. It's because of the gray hair..

My 2 centavos

When the owner of LMT was asked about piston and gas AR, he said. I build it because there is a demand for it. Otherwise, it's pointless.

I'm a glass snob but I can say this.  What ever it is that you buy, make sure it is first focal plane and the turrets match the reticle, e.g. Mil/mil, or moa/moa. Then make a decision on whether you like calculating your dope in mil or moa and stick with that on all your optics.  I get way too confuzzed trying to go back and forth between mil and moa. Then again, you may be smarter than your average redneck....

Oh, and Bobby, get an 03 or newer LB7 if you can.  The can bus communication protocol changed in 03.  Anything ever goes seriously wrong you can swap in later model engines without much trouble.  Not easy at all on the 01&02


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[JR]

Lots of good input guys. But who the heck is this DOT asking about trucks in my AR thread??

The PRS is pricey, as is the the Nightforce, but like em both. I do like the idea of the A1 stock and something I had been thinking of, well a regular full A1 build really.

I have several lowers, one registered with my old Sheriffs logo and SN. Another billet unfinished and a finished forged. Registered I don't need a BB.

It will have a floating shroud and maybe a bypod.

[BobbyB]

Nightforce NXS
http://www.opticsplanet.com/nightforce-nxs-35-15x-tactical-riflescope.html#

I want one.

Well if you haven't shot one by the time winter rolls around we can arrange to shoot mine.   It's  looking like when I get laid off this winter I'm going to bring my truck up da UP to do the swap eh. See what I did there lol.   My dad has a big garage I can use for the swap and I need to spend some time with him.

If you're around GB I'll bring it up and we can go beat on it for awhile if you've got a place to shoot.

Vortex. I'm actually thinking that might be what I use on my SCAR  the 2.5x10 variety.

Sounds good, winter shoots are always fun. the 2.5-10 is a good choice. What do you run on the SCAR now?

I'm a glass snob but I can say this.  What ever it is that you buy, make sure it is first focal plane and the turrets match the reticle, e.g. Mil/mil, or moa/moa.

Oh, and Bobby, get an 03 or newer LB7 if you can.  The can bus communication protocol changed in 03.  Anything ever goes seriously wrong you can swap in later model engines without much trouble.  Not easy at all on the 01&02

I agree with FFP , matching turrets.

As for the truck, it really depends on what I see when I go look at them. I'd like the 03 as it's a 1 owner, 3" stack of maintenance records, however we shall see.

[KensAuto]

I've been pretty happy with the trijicon accupoint. I wanted a nightforce, looked at some Vortex's, and I think I have something in the middle....still not cheap by any means:
http://www.amazon.com/Trijicon-AccuPoint-5-20x50-Riflescope-Crosshair/dp/B002YF3NXK/ref=sr_1_1?s=sporting-goods&ie=UTF8&qid=1438296703&sr=1-1&keywords=trijicon+accupoint

[TexasRedNeck]

You really have to ask yourself how you will use the scope. Lots of money goes into repeatability, ruggedness and the glass itself. No one can touch German glass, but the japs have some good stuff. German glass can set you back $3000 or more. The construction of the turret system, erector, etc including materials and tolerances determine repeat ability. If you dial a lot and expect your rifle to return to THE EXACT spot every time without fail? Or is a tenth of a mil accurate enough? Will you be tossing your rifle around on the rocks?  Will you be shooting at extreme distance or in near darkness?

Based in the average shooter, a Nikon and Lupy are more than enough. Stay away from the pacific rim stuff, eg barska, bushnell etc. Their internals are almost always nylon gears.

If your livelihood or life depends on it, or the lives of others. Step up to night force , US Optics, Schmidt and Bender, or Hensholt for tactical or Zeiss, Swarovski, or the like for hunting. I'll take Kens word for it on the Triji. I have only shot their ACOG, which quite frankly are superb purpose built optics for the AR.

Quite frankly, if you shoot an AR past 300 it's not that accurate or deadly unless you have a 7.62.  I'd buy a Nikon and shoot with it and see how you like it. The resale value is good and you can always sell it later and buy a more expensive piece of glass. If they have the features you want, they are some of the best bang per dollar.

I've not personally owned a Vortex but I'd look at their HD stuff. I have a few friends runnin them and they like them. Another example of good jap glass.

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[husker77c]

Well if you haven't shot one by the time winter rolls around we can arrange to shoot mine.   It's  looking like when I get laid off this winter I'm going to bring my truck up da UP to do the swap eh. See what I did there lol.   My dad has a big garage I can use for the swap and I need to spend some time with him.

If you're around GB I'll bring it up and we can go beat on it for awhile if you've got a place to shoot.

Vortex. I'm actually thinking that might be what I use on my SCAR  the 2.5x10 variety.

Sounds good, winter shoots are always fun. the 2.5-10 is a good choice. What do you run on the SCAR now?



I don't have anything on it now.  I can't decide what I want to use it for really.   The 2.5-10 is probably the most useful but not good for close range.  I've been considering a T1 and magnifier also.  Then there's the .308 specific ACOGS.  That's why it has open sights.  I can't make a decision.

[BobbyB]

I don't have anything on it now.  I can't decide what I want to use it for really.   The 2.5-10 is probably the most useful but not good for close range.  I've been considering a T1 and magnifier also.  Then there's the .308 specific ACOGS.  That's why it has open sights.  I can't make a decision.

The struggle is real. I like the T1 for battery life, but like the EoTech's reticle more.

[TexasRedNeck]

http://www.amazon.com/Trijicon-TA31RMR-Illuminated-Crosshair-Ballistic/dp/B0035M1HNY

If your young and have good eyesight, this might fit the bill

I've also seen guys run long range scopes and a 45 degree mount with a small red dot like a dr. Optic. Up close , you simply chicken wing a bit to can't the rifle to make your up close shots.


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[BobbyB]

http://www.amazon.com/Trijicon-TA31RMR-Illuminated-Crosshair-Ballistic/dp/B0035M1HNY

If your young and have good eyesight, this might fit the bill

I've also seen guys run long range scopes and a 45 degree mount with a small red dot like a dr. Optic. Up close , you simply chicken wing a bit to can't the rifle to make your up close shots.


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I like those. I just like the EoTech with the magnifier behind it. Best of both worlds with just a flip of the magnifier.

[wilsonphil]

After wasting more time(lots of money) testing WAY to many different configs, this is my rule and I have never had a failure following this

1.  If you are running shorter than a 14" barrel then I strongly suggest piston driven.

2.  If you are running over a 14" barrel stay with the gas system.

As far as AK's go I have seen a few failures but typically not related to the design,  poor metal, ammo or just worn completely out.  Interestingly enough I have personally seen a AK re-chambered for 8mm Mauser but did not get the time to study it in detail as I had more pressing things happening around me. 


 My latest upper is a 6mm turbo which I am very happy with for the long range shooting I am doing right now, for optics I used to always buy Nightforce but they have taken some of their manufacturing over seas so I do not buy them anymore, all optics I buy now are Leupold they have the best customer service and have extremely fast turn around currently I am using a VeriX 3, 8.5 X 25 with 50mm objective and varmint reticle.  All of my current lowers start out as 80% and I truly enjoy building them, I just started to get into 1911’s and I have learned way more about 1911 than I ever wanted to know

Picture of my latest build, Coyote was taken at 350yrds, dropped instantly 

[KensAuto]

Awesome looking gun. :2thumbsup

[JR]

Thx, it will not be an extreme range rifle. The round is just to light, cept for squirrels and such. But it is cheap to shoot compared to dedicated hunting rifle.

Mossberg actually makes a nice 223 bolt action rifle, flutted barrel, takes AR mags. But it has a toyish feel to it and the mags fit sloppy and you still have to get a scope.

Think I will run up to Cabelas (do for a solo trip) and look at scopes. They also are just finishing a Bass Pro Shops near Sac. Just got a Nikon range finder and like it, very clear!!

[husker77c]

I don't have anything on it now.  I can't decide what I want to use it for really.   The 2.5-10 is probably the most useful but not good for close range.  I've been considering a T1 and magnifier also.  Then there's the .308 specific ACOGS.  That's why it has open sights.  I can't make a decision.

The struggle is real. I like the T1 for battery life, but like the EoTech's reticle more.

I have a T1 on my go to AR.  I've started changing my battery once a year just because.  It was in storage at my dads house for close to three years while I was moving around for work and when I got it back I realized I had left it on.  Still running.   Stellar battery life.

Contributing to this thread.  I was surprised how much the .223 drops off after 400 or so yards.   We got into prairie dog hunting pretty heavy in MT a few years ago.  I had my 20" AR and my girl had a .223 bolt gun.  We'd take shots at 400-800 yards at the little buggers.  Very rarely made a hit though. Heck you can't even see them at that range without a powerful spotting scope.  The holdovers were ridiculous.  That's why I got my .243. Similar velocity and a very satisfying thud when you hit one compared to no thud and just seeing the dog fall over. Or into pieces   That's why I don't shoot my 20" anymore and am probably going to sell it. I have better rifles for the ranges it competes in.

[BobbyB]

I was surprised how much the .223 drops off after 400 or so yards.   

You can stretch it out further. Granted there's not much umph left but it can reach out there. Slightly easier with a bolt as more gas is behind the round, but a gas rifle will do it.

[JR]

Scopes o plenty to look at, but I want power and repeatability for sure. Leaning towards a Vortex, just like what I hear about them.

Twist and ammo will play a big part and why I went with a 1-8 twist. Gives me options for light and heavy rounds. I think 62-69 will work the best plus the Wylde has tighter chamber.

Oh and it came in today, looks great,,,,,,,,

[BobbyB]

Scopes o plenty to look at, but I want power and repeatability for sure. Leaning towards a Vortex, just like what I hear about them.

Twist and ammo will play a big part and why I went with a 1-8 twist. Gives me options for light and heavy rounds. I think 62-69 will work the best plus the Wylde has tighter chamber.

Oh and it came in today, looks great,,,,,,,,

Looks like a good barrel. Figure out what stock and etc you are going with?

[Flyin6]

I think I am going to go for one of those 1:8 twist barrels on my next M4

[TexasRedNeck]

After wasting more time(lots of money) testing WAY to many different configs, this is my rule and I have never had a failure following this

1.  If you are running shorter than a 14" barrel then I strongly suggest piston driven.

2.  If you are running over a 14" barrel stay with the gas system.

As far as AK's go I have seen a few failures but typically not related to the design,  poor metal, ammo or just worn completely out.  Interestingly enough I have personally seen a AK re-chambered for 8mm Mauser but did not get the time to study it in detail as I had more pressing things happening around me. 


 My latest upper is a 6mm turbo which I am very happy with for the long range shooting I am doing right now, for optics I used to always buy Nightforce but they have taken some of their manufacturing over seas so I do not buy them anymore, all optics I buy now are Leupold they have the best customer service and have extremely fast turn around currently I am using a VeriX 3, 8.5 X 25 with 50mm objective and varmint reticle.  All of my current lowers start out as 80% and I truly enjoy building them, I just started to get into 1911’s and I have learned way more about 1911 than I ever wanted to know

Picture of my latest build, Coyote was taken at 350yrds, dropped instantly

Phil, nice stick and nice pelt. Genuinely curious about the short vs long point of view on piston vs gas with more detail. My LMT 10.5 gas gun eats any ammo I throw at it and never misses a beat, suppressed or not. Like Don mentioned before, a lot of guys that build their own uppers experience failures and I can only hypothesize why. Most gas SBRs reliability issues stem from the lack of appropriate sizing of the gas port and location on the barrel.

From a purely mechanical point of view the AK was designed from the beginning to be a piston gun and the bolt carrier and piston is very robust and made to fit solidly together. And the mating surface of the piston to carrier is one piece.

The AR, on the other hand has very limited room under the hand guard for a robust piece of machinery and the striking surface of the rod to the bolt carrier takes a lot of abuse, especially on auto.   (That's where most problems occur) That striking surface is bolted to the bolt carrier (in place of the original gas key) and not made integrally nor is the piston solidly mounted to the bolt carrier as it is in the AK

The failures of the piston guns have been primarily around that weakness from what I understand. I've not studied the HK, but they probably purpose built from the ground up to address that problem.

In the end, the reason many people want a piston AR is not having to deal with the carbon fouling and cleaning, or guys who run too much lube in the sand, which is just the price you pay for that system as it was designed.

Look forward to continued banter and different points of view.


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[JR]

I think I am going to go for one of those 1:8 twist barrels on my next M4

They are 270 at Midway, got this for 186 from; http://sandersarmoryusa.com/ on their ebay store. Looks like they have lots of good stuff.

[wilsonphil]

After wasting more time(lots of money) testing WAY to many different configs, this is my rule and I have never had a failure following this

1.  If you are running shorter than a 14" barrel then I strongly suggest piston driven.

2.  If you are running over a 14" barrel stay with the gas system.

As far as AK's go I have seen a few failures but typically not related to the design,  poor metal, ammo or just worn completely out.  Interestingly enough I have personally seen a AK re-chambered for 8mm Mauser but did not get the time to study it in detail as I had more pressing things happening around me. 


 My latest upper is a 6mm turbo which I am very happy with for the long range shooting I am doing right now, for optics I used to always buy Nightforce but they have taken some of their manufacturing over seas so I do not buy them anymore, all optics I buy now are Leupold they have the best customer service and have extremely fast turn around currently I am using a VeriX 3, 8.5 X 25 with 50mm objective and varmint reticle.  All of my current lowers start out as 80% and I truly enjoy building them, I just started to get into 1911’s and I have learned way more about 1911 than I ever wanted to know

Picture of my latest build, Coyote was taken at 350yrds, dropped instantly

Phil, nice stick and nice pelt. Genuinely curious about the short vs long point of view on piston vs gas with more detail. My LMT 10.5 gas gun eats any ammo I throw at it and never misses a beat, suppressed or not. Like Don mentioned before, a lot of guys that build their own uppers experience failures and I can only hypothesize why. Most gas SBRs reliability issues stem from the lack of appropriate sizing of the gas port and location on the barrel.

From a purely mechanical point of view the AK was designed from the beginning to be a piston gun and the bolt carrier and piston is very robust and made to fit solidly together. And the mating surface of the piston to carrier is one piece.

The AR, on the other hand has very limited room under the hand guard for a robust piece of machinery and the striking surface of the rod to the bolt carrier takes a lot of abuse, especially on auto.   (That's where most problems occur) That striking surface is bolted to the bolt carrier (in place of the original gas key) and not made integrally nor is the piston solidly mounted to the bolt carrier as it is in the AK

The failures of the piston guns have been primarily around that weakness from what I understand. I've not studied the HK, but they probably purpose built from the ground up to address that problem.

In the end, the reason many people want a piston AR is not having to deal with the carbon fouling and cleaning, or guys who run too much lube in the sand, which is just the price you pay for that system as it was designed.

Look forward to continued banter and different points of view.


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Well it really comes down to reliability, a little gas dynamics and a lot to do with bullet weight, type of powder and then all kind of wonderful things happen with the bolt when you go from a gas system to piston system.  If you are shooting a heaver bullet in a gas gun then the powder has time to burn in the shorter barrel, this few mili-seconds is enough time to for the powder to fully combust and not foul the gas system, this can still be an issue in piston gun but if the port is sized correctly you won’t have the issue or is not as sensitive to the issue.  Bolt issues are the next big failure item on the piston driven system I will explain the bolt issues in a couple min.
 
 If you always run commercial quality ammo from a known source I agree you will most likely never have a problem BUT that being said you never know what you will be shooting in all cases and the weapon will fail when you need it most.  So if you run unknown ammo in a barrel shorter than 14” I highly recommend the piston system is not necessary but I don’t want a failure.

Ok lets listen to the crazy redneck that only went to the third grade for just a few seconds,
 
One of the major things is that in a gas system, when the gas pressurizes the chamber in the bolt carrier, it actually pushes the bolt forward, and that pushing of the bolt forward, as it unlocks, takes a good amount of load off the back of the locking lugs as it’s unlocking, I know this sounds counterintuitive but this is what is going on in that area.

With a piston system, as you’re pushing back on the bolt carrier, you not only have tilting pressure which is uneven, it’s pulling the bolt backwards, which adds more load to the locking lugs of the bolt as the bolt carrier’s going to the rear, and the faster you drive it to the rear, the worse off it is. If you use an M4/AR15 in its conventional barrel length, which is 14-1/2 inches(16 for the civilians of course), I don’t think a piston gives you any advantage over a gas impingement gun. I think that an M4 in a 14-1/2 inch barrel military configuration it is just as reliable as a piston gun with the 14-1/2 inch barrel. The piston driven in this configuration will give/develop different problems.

It really comes down to time the bolt/carrier is under pressure, if you are able to have the luxury of having a barrel with 7 or more inches of barrel in front of the gas port, it gets the job done before the bullet leaves the end of the barrel. When you go to a 10-inch barrel or an 11-1/2 inch barrel, that time significantly drops, along with your reliability. The only way to do that is to open up the gas port, and you get a big gulp of air immediately. The rifle becomes sporadic at that point. The advantage on a piston system might come in with a shorter barrel.
If you look at the bolt carrier velocity, and you shoot ten rounds with a gas system, and you look at the velocity and you look at the standard deviation of that velocity, the standard deviation, meaning the velocities, and you overlay those velocity curves over the top of each other, the gas impingement system is much, much more concise and reliable than the velocity is for a piston-driven AR type rifle. The piston-driven gun is all over the place as far as its bolt carrier velocity, and its bolt carrier velocity at the back of the gun. The AR system likes a gas impingement system much better when the barrels are over the 14”, because it’s a much better utilization of the gas.

Do you get what I am saying?  Or do you think I am a fruit loop

[TexasRedNeck]

Redneck 3rd grade?  You're talking my language!  No fruit loop. Interesting observations.  My contention is that the piston system in an AR is an afterthought and is not as robust as the AK. Thus the failure and limitation of the piston driven AR.  As for SBR reliability, I've shot most commercially available ammo and my hand loads in my SBR and it eats it all. Unless you get some way out of spec ammo, I wouldn't expect a failure. Which would afflict all, regardless of barrel length.  Most people that build ARs bolt parts together and don't u derstand theory of operations. As you clearly do. Thanks for sharing.

The weak part,of the piston gun is the beating the bolted on piston stricking surface takes, especially on a FA weapon. Occasional use semi weapons function fine.  Run the snot out of them and failures happen. Regardless of barrel length.


So I guess theoretically I agree that pistons are a great design, but in practical application,the piston AR is a novelty and not a life or limb weapon because it was not built that way from the ground up.


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[JR]

Like it all, keep it coming and yes it makes sense to this FL also.

20 in barrel with a rifle length gas system I should be fine. I also don't plan on shooting to much if any light rounds through it and getting into rolling my own. I also use heavier m16 BCG and like to keep things so interchanging parts is not a huge issue and a piston is not that!

Heck, not sure about building a 1911, I have a commander already and building looks more than buying! But a 308 AR might be fun along with my FALs.

What do you think of my mill? Made my own DRO for it until I get the CNC back up after a little rebuild.

[JR]

AR I built for a friend;

[TexasRedNeck]

Uh, what's that in the first pic?


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[wilsonphil]

Its very interesting if you ever study Gene Stoner’s original design in the 1950s.  Actually all firearms development is very good research and in some cases really amazing.
It’s been said by a few people that were involved in the development  of the original AR15 that everything worked really well until they changed the powder, which threw the system out of balance. Instead of changing it by going back to the right powder that it was designed for, they started changing the system, and it’s been bouncing around ever since, fixing the symptoms.  At the same time why do we have a design that is stuck with only ONE type of powder and that is that sensitive to that change so I will argue the orginal design should of taken that possibility in to account before it was deployed.

  The idea of putting a piston system on the AR15 throws its own problems into the mess.  The piston-driven AR type rifle has created its own set of issues that are going to show up in the field in the future.

This all being said there are problems with the M4, the gas impingement system is just so much more efficient. That being said, if you don’t have a set of good gas rings on the gun, if you have a carrier key that’s worn out or if you have a gas tube that’s worn out, there’s going to be problems IE you have not maintained the weapon.  I find it interesting that we have rifles out there in the military system that, some of them have 10,000, 20,000+++++++ rounds through them, and we’re comparing them with rifle systems that are brand new. Everybody likes a new broom because it always sweeps clean, and everybody wants something new.

 These changes need a track record, you have to be able to track the changes you make and subject your setup to a known working model, these systems need to fire as many rounds before we can compare. An example of what I think that we are doing wrong in our small arms for the US military, it’s that we figuratively woke up one Monday morning, and said the M60(we can discuss this later) was a bad weapon.  When and where did we fall out of love for the M60? It was after it got worn out and after the parts were worn out, and then we went out to low-bid, small business set asides as vendors that built parts for the M60, crap parts flooded the system some of these parts that may or may not have worked or there was a huge compatibly issue with the original parts and pieces. (rant!!!!) (I blame the original manufactures for this in some aspects and the greedy board members or just plain poor management.) What we did was adopt a gun that was two years older, six pounds heavier, and much longer, and that had some other issues of its own. We adopted that gun “because it was more reliable.” If you would let me add 25% of the weight and 25% of the cost, and all the other things to any weapon system we have, sure, we could build a better weapon. When we started realizing that the M60 wasn’t going to last forever, we should’ve started a program to design a new belt-fed .308 machine gun.
 
 Ok a little rant from me about the screwed up gun laws we have, contrary to the liberal even Military belief all small arms that the military has ever used has come from the civilian side of the free market not the other way around.  The pure stupidity of 1968 and 1986 gun control acts will haunt the firearms community forever.  The only real plus if you want to call it that is the 68 GCA let you build your own firearm and its written in there so unless they want to restart negotiations we should be safe there for awhile. 

Ok back to history, when Gene Stoner and among others started working on the 7.62mm belt fed issue in 1989, the very first thing that was tried was to import a PKM. ATF said the law would not allow Gene Stoner to import a PKM - that’s just crazy total BS. It was because it was a Russian design, and it was forbidden to import Russian small arms into this country. I mean, here’s the father of our main rifle caliber weapon, and he wants to work on a new belt fed, and he can’t have access to similar designs because of politics. We just decided not to even bother going down that road, it’s just not worth it. Our country should have started designing a new replacement for the M-60 when we saw that the parts were going to be worn out, and the parts weren’t going to be compatible. I’m hearing similar things right now that soldiers are saying about the M249, that they’re unhappy with its reliability, they’re unhappy with the parts, and maybe we’re going to wake up one Tuesday morning, and say, “Let’s throw the M249 away.” Instead of letting it get to that point, let’s see if we can fix the problems and track the changes so we always put dependable systems in the field.

 The first thing to do is see if that weapon system can be improved, and if we have reached the lifecycle of those guns and they’re worn out, then let’s throw ‘em away and buy new ones. But how could a gun that we have had for 20 years, how can we wake up one Tuesday morning and that gun not be any good? What happened to it? If we have an issue, let’s start developing, let’s start thinking about a new level of M249, let’s start now, and let’s improve it. But there is not anyone that has written and told FN that they have a problem. As far as the Army’s concerned, there’s not a problem.

  I lot of this comes for the military itself, this came out of WW2 with the M3 grease gun and other designs and we are stuck with it in some ways. I will add this I don't really see the point in having a barrel shorter the 14" on the AR/M4 platform, unless you are a building a PDW and use it on a PSD I don't see the use of it being practical, but that is IMO!

[EL TATE]

Uh, what's that in the first pic?


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looks like what is left of his old mill... garage fire much there JR?

[JR]

Uh, what's that in the first pic?


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Yup, the mill after the fire. Hadn't even chipped a piece of metal on it. Cost about 3k to rebuild not including software.

[JR]

A couple pics of the rebuild. Did it on cnczone a couple years back.

Not many pics of the tear down or hours of cleaning. (love the ACE custom mixed spray cans)

Mostly just paint and the motor that cost 2k.

[JR]

Wasn't the M60 based on the German MG42 from WWII?

I have read the history of the M16, wasn't even a 5.56 at first!!

[BobbyB]

Wasn't the M60 based on the German MG42 from WWII?

Yes. and I still love the M60, and it's step-brother the 240B, and it's little bro the SAW.

[Atkinsmatt]

All 3 great tools of diplomacy.

[JR]

Made a run to Cabelas this last week. Picked up the Vortex PST. With coupons, rebate cards and a 10% discount card from Cabelas, out the door for $200.

Then I found this nice Sightmark for $75 on clearance at Wally and scored another 500 rounds of 22LR.

[TexasRedNeck]

Nice score! Let us know how you like the Vortex when you get it up and running

[BobbyB]

Nice choice on the scope.

[JR]

I wasn't thinking of the Vortex per say until it was recommended here.

The reflex is for another, probably my grab and go with BU irons of course.