Which is better and why? Direct Impingement Gas or Piston Operated?

I think that is a tough question. In my opinion, it depends on how they are built! I have an FN-FAL match, civilian version, piston, very accurate. I have two AK piston, not as accurate. First has tight tolerances, all machined parts. Latter have loose tolerances, some stamped parts. You get very accurate M1 Garands.
I have a bunch of AR type DI, and some are very accurate...
Can you get very accurate in either? I think yes!
 
(Piston) H&K and Sig both have one, but I do not have direct experience. I doubt they would be in the price range. Wilson Comabt I believe makes one, and again, I do no thave direct experience and it would be over $3,000. I bought my FN-FAL from a friend 15 years ago. Can't touch those now for under $5K.
Perhaps the other two people here can give you advice!
 
Look at PWS. I have and have had ar10's from many different manufacturers, and my pws shoots better than anything I've ever played with. It's insane. Light recoil, not too heavy, functions like a dream, and the first day I got it, I zeroed it and shot a 10 shot group of factory ammo without letting the barrel cool, and never jumped outside of a 1" dot. It's a fine piece of equipment. American made too.
 
Look at PWS. I have and have had ar10's from many different manufacturers, and my pws shoots better than anything I've ever played with. It's insane. Light recoil, not too heavy, functions like a dream, and the first day I got it, I zeroed it and shot a 10 shot group of factory ammo without letting the barrel cool, and never jumped outside of a 1" dot. It's a fine piece of equipment. American made too.
Learned something again. It appears they have an interesting design. Is the lower a standard AR?
 
Jim Sullivan says; direct impingement, on the otherhand, H&K says piston, I've had both and I find the direct impingement works best for me, if I was shooting a full-auto (a lot) and caned up, I think I'd go with piston, and actually, If I ran piston in the semi-auto with a can I'd go piston as well. Also anything shorter than 16" inches I'm thinking piston, 16" inches and up, direct impingment for sure, just my 0.2 Cheers.
 
I just thought of one advantage two of my piston rifles have. They have a single shot position, in which they behave like a bolt. They don't cycle!
 
I have several piston drive and would prefer to never go back to gas. I see no real difference in accuracy of either system but the functionality and cleanliness is what I enjoy. Mine all have adjustable blocks as well.
 
Does anyone believe DI would provide better accuracy or smaller groups than a piston system,?
I don't claim any particular expertise though I have owned both. I asked the owner of Craddock Precision which was more likely to give me better accuracy when I was ordering from him. His recommendation hands down was for DI. He indicated he had converted a sweet shooting upper to piston and suffered significant degradation in accuracy. All the uppers I purchased from him have been DI and all shoot sub-MOA with my favorites shooting 1/2 MOA.
 
I went down this path before in the AR-15 arena. Having spent more than a few times on active duty cleaning out nearly every square inch of the upper receiver on M16A1s and M16A2s, I wanted to lean in the direction of a piston operated AR. I heard many good things about them with just a few drawbacks (higher cost and heavier were the top two). I had the opportunity to fire an H&K 416 that an operator had available for me to shoot. It was a nice weapon, but I noticed something unusual about it. It wasn't just heavier, but front heavy. I suspected that was something one had to get used to. I ultimately broke down and bought two Stag Arms (piston model). They have shot very reliably and require very little to no maintenance or cleanup (normally just clean the bore). Stag also had a feature I liked, which was it wasn't front heavy like the H&K 416. I also bought a Patriot Ordnance Factory piston model for myself. It was heavier than the stags, but not front heavy like the H&K 416. Unfortunately, it does not look like Stag makes an AR chambered in 7.62/.308. POF on the other hand does make this: https://pof-usa.com/firearm/revolution/

If the POF Revolution functions as good or better than my 5.56 AR POF, than it should be a pretty good weapon. It is relatively light for a .308 coming in at 7.3 pounds. Most decent pistons also have a gas regulator, so it makes it easier to work with a suppressor if you are going to use one.

One immediate difference you will always notice on a piston vs. DI weapon is the amount of cleaning time required post range. Pistons clean up really fast, unlike DI weapons.

My $.02 worth.
 
My two cents. Build the rifle yourself. Build it around a custom barrel from Craddock Precision with a head spaced bolt. The barrel will take you a while to get. Avoid a rifle on a proprietary AR platform. Large frame ARs are not standardized like the small frame AR platform. Some uppers will not work with some lowers. Do your research.
I would go DI.
What follows only applies to AR platform rifles. Not rifles developed from the ground up for a piston. I have several piston ARs. So I am not negative to piston AR systems. As mentioned above there are advantages when suppressed, when operating in water and other pluses.
However the AR platformed was designed as DI. This allows the BCG to move straight back in the receiver. All piston systems have a piston hitting the BCG on the perimeter. This creates tilt in the receiver. Some piston AR systems are better at compensating for this problem. Now in practical use it does not make much difference. So for hunters it is not a factor. After 10k plus rounds it might make a difference.

Look at this report from a Las Vegas range that caters to yahoo's who want to shoot. Piston ARs do not last long for them and the piston system that does the best is HK. Consider this information is for the AR15 not an AR 10. Still it seems compelling.

 
I went down this path before in the AR-15 arena. Having spent more than a few times on active duty cleaning out nearly every square inch of the upper receiver on M16A1s and M16A2s, I wanted to lean in the direction of a piston operated AR. I heard many good things about them with just a few drawbacks (higher cost and heavier were the top two). I had the opportunity to fire an H&K 416 that an operator had available for me to shoot. It was a nice weapon, but I noticed something unusual about it. It wasn't just heavier, but front heavy. I suspected that was something one had to get used to. I ultimately broke down and bought two Stag Arms (piston model). They have shot very reliably and require very little to no maintenance or cleanup (normally just clean the bore). Stag also had a feature I liked, which was it wasn't front heavy like the H&K 416. I also bought a Patriot Ordnance Factory piston model for myself. It was heavier than the stags, but not front heavy like the H&K 416. Unfortunately, it does not look like Stag makes an AR chambered in 7.62/.308. POF on the other hand does make this: https://pof-usa.com/firearm/revolution/

If the POF Revolution functions as good or better than my 5.56 AR POF, than it should be a pretty good weapon. It is relatively light for a .308 coming in at 7.3 pounds. Most decent pistons also have a gas regulator, so it makes it easier to work with a suppressor if you are going to use one.

One immediate difference you will always notice on a piston vs. DI weapon is the amount of cleaning time required post range. Pistons clean up really fast, unlike DI weapons.

My $.02 worth.
Neighbor has a POF Revolution 308. I have an Aero M5 build. I never knew the Revolution existed until the day he brought it over to my garage. Blew my mind it was a 308 in a 5.56 size and weight rifle. Made my M5 look like a fat girl. Lol.
 
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