.308 to SBR, piston or DI?

Ape_Factory

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  • May 23, 2020
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    San Antonio, Texas
    I built a 300 BLK Form 1 with a 10.5" barrel and love it. Purchased my first suppressor and it's a relatively tidy package that makes me LOL every time I go to the range. It's short, light and with subs, is ridiculously easy to shoot.

    I also have a POF Revolution DI which Iove but with the 16.5" barrel and the suppressor attached, it's a lot of gun and a far different beast from the 300 BLK. I'm not a long-range shooter (yet) and I'd probably just get something like a Ruger Precision if I wanted to explore that end of things but I know, as is, the POF would be fine at say 600-800 yards. So I'm contemplating going SBR on the POF and going with their 12.5" upper. I'd keep the 16.5" DI upper just because. The rifle's been fantastic and very accurate.

    I'm using an OSS flow through suppressor which doesn't add much in terms of making the gun run dirtier overall since there's no discernible increase in back pressure.

    I'm now contemplating piston vs. DI and my only reason going piston would be long-term function without maintenance. Otherwise DI is a bit more accurate from my understanding and a few ounces lighter. I understand the argument revolving around proprietary parts with a piston gun and the benefits of it running cleaner when suppressed (negated by the OSS suppressor). And it's a POF so half of the major components are already proprietary. They're no Sig either. Both versions of the rifle have been around for a while.

    Given the current state of the industry, the 12.5" complete uppers may never be in stock or at least not in stock within a reasonable time frame. I could purchase the pistol version of either which would leave me the choice of either doing a form 1 on the existing rifle lower and selling the new complete pistol lower or the other way around. Either way, I'll want one SBR lower. I do this with the 300 Blackout and my 5.56 16" upper on one lower. Just like it that way and keeps things simple and consistent from a trigger and function standpoint.

    Anything I'm overlooking? Any reason to stick with DI vs. a piston upper given my operating parameters? The only benefit I see with choosing the DI upper would be redundant components.
     
    i would run a piston on a suppressed sbr, but i am nobody so there's that.

    also, fwiw...i saw a video with a di version and it ran like schiff.
     
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    I have the DI version now, longer barrel of course, and it's been a total workhorse since day one and has literally shot everything I've fed it with not one FTF that wasn't self induced. A lot of responses say run piston with a suppressor due to the increased back pressure and the fact the gun tends to run dirtier and the piston version would have an advantage in time between cleanings/FTF's.

    I avoided this by going with the OSS flow-through design. I can shoot with the can or without and I do not have to make any adjustments to the gas block. This is my first suppressor and I LOL every time I go and shoot with it, especially with the 300 black subs.

    Just think the 12.5" would be a handier barrel length with the suppressor assuming the powder has enough time to do its job and the gas port location allows it to function as well as the rifle length gas system on the 16'5" barrel.
     
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    I have the DI version now, longer barrel of course, and it's been a total workhorse since day one and has literally shot everything I've fed it with not one FTF that wasn't self induced. A lot of responses say run piston with a suppressor due to the increased back pressure and the fact the gun tends to run dirtier and the piston version would have an advantage in time between cleanings/FTF's.

    I avoided this by going with the OSS flow-through design. I can shoot with the can or without and I do not have to make any adjustments to the gas block. This is my first suppressor and I LOL every time I go and shoot with it, especially with the 300 black subs.

    Just think the 12.5" would be a handier barrel length with the suppressor assuming the powder has enough time to do its job and the gas port location allows it to function as well as the rifle length gas system on the 16'5" barrel.
    the example was the 12.5 i think, and i have not seen anything bad about the longer ones.
    i had just heard that gas coming back is even worse on sbrs, but perhaps the oss is not picky.
     
    the example was the 12.5 i think, and i have not seen anything bad about the longer ones.
    i had just heard that gas coming back is even worse on sbrs, but perhaps the oss is not picky.
    The OSS is not picky,I would opt for a piston gun vs DI but in the end as long as it works…
     
    I am not really a fan of piston AR's, they are reliable, and run a little cleaner than DI, but from a practical standpoint, they are generally heavier and have a more pronounced recoil impulse which ultimately makes a DI slightly less enjoyable to shoot. Shooting Kac and LMT's for many years now and never had one choke as a result of cleanliness. If you were running a high pressure can, I could see maybe entertaining a piston, but since you have a low pressure can, I would just go to town with a DI. Love my 13.5 barrel in my MWS with dead air can.
     
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    I am not really a fan of piston AR's, they are reliable, and run a little cleaner than DI, but from a practical standpoint, they are generally heavier and have a more pronounced recoil impulse which ultimately makes a DI slightly less enjoyable to shoot. Shooting Kac and LMT's for many years now and never had one choke as a result of cleanliness. If you were running a high pressure can, I could see maybe entertaining a piston, but since you have a low pressure can, I would just go to town with a DI. Love my 13.5 barrel in my MWS with dead air can.
    I did consider the weight difference (one of the criteria I used for purchasing the DI in the first place) but having never shot a piston gun, I wasn't sure if there'd be that much of a difference in terms of impulse with this particular platform. From everything I've read, DI is more accurate vs piston. It'd be nice to have a few redundant parts as well.

    With that said, is either one more or less likely to run reliably vs. the other due to timing/dwell? And is gas port erosion more rapid with a shorter barrel? If so, are we talking 2,000, 5000, or 10,000 rounds before port erosion starts to have an effect with the DI?
     
    I vote DI whichever route you take. Lighter, more accurate, and at the end of the day. will run just fine with an OSS suppressor or maybe an adjustable gas block. I am not sure the specifics on the Revolution barrel. So, it may not lend itself to this. But, you could look into getting the 16.5" barrel cut down to 13.5"-14'" to pin/weld muzzle device. loose a little velocity for distance shooting. But, gain some more maneuverability without having to SBR anything or go as short as 12.5".
     
    I'd just go with a complete upper as I do not think POF sells the barrel or the gas tube by itself. The 16" model has rifle-length gas and is fluted so can't really shorten it. Plus it'll be nice to be able to slap the 16" back on there for hunting. Both have adjustable gas blocks from the factory.