AR 10; Short Stroking with Suppressor

243winxb said:

An adjustable gas block sounds like a good idea to me too. Hornady thinks a can makes a difference ? http://www.hornady.com/ammunition/superformance-in-gas-operated-firearms

This may apply, with other ammo or powders??

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grampajack said:

I'm stumped. In general, a can is going to increase bolt velocity by a fair amount. If it were causing extraction issues bad enough to slow down the bolt that much I would expect to see evidence of it on the case heads. Are you sure it's actually short stroking and not just cycling too fast? If you get the bolt going too fast you can end up in a situation where the bolt is going home before the magazine can feed up the next round, resulting in the bolt closing on an empty chamber. And on the last round it will also outrun the bolt catch, so there again it looks like a short stroke.

I can't even begin to explain though why it would start working after the can heats up. I would actually expect the opposite. Can you describe in more detail what it's doing that makes you think it short stroking? Is it closing on an empty chamber, double feeding, getting stuck on the next round, or what?

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grampajack said:

To my knowledge, popped primers are usually a sign that chamber pressures are too high. Are these handloads or factory ammo?

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grampajack said:

To my knowledge, popped primers are usually a sign that chamber pressures are too high. Are these handloads or factory ammo?

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grampajack said:

I wouldn't just haul off and throw money at the problem. The issues described on the Hornady website don't really explain what you're experiencing. For one thing, you're talking about a 20'' barrel, which has plenty of impingement and dwell time. That barrel and gas system gives you more than enough time for pressures to drop well below what you need for safe extraction. You can expect to experience increased bolt velocity when using the suppressor, but I don't see any way use of the suppressor explains popped primers or short stroking.

If you are in fact experiencing short stroking, then I see no way an adjustable gas block can help you in any way. All it does is mimic a smaller gas port, which is going to make any short stroking even worse. If however the bolt is going too fast, as I suspect, then an adjustable gas block is the cure. Or a heavier buffer might also work and may be cheaper. Again, what in detail is happening that makes you automatically assume it's short stroking?

At the very least, I would use some regular factory loaded ammunition. There's just no way in my mind that a suppressor on a 20'' barrel could be the cause of popped primers.

ETA: If we were talking about a 12'' barrel then maybe I could see the suppressor causing popped primers, but certainly not short stroking. On a 20'' barrel I just think that the pressure has dropped so much by the time the bullet actually gets to the suppressor that there's really not much the suppressor can do at that point to cause you any extraction problems.

My best guess at this point is that your rifle is already somewhat overgassed and the suppressor is just sending it over the edge of what your magazine spring can keep up with. But again, that doesn't explain the popped primers in my mind. I would strongly advise you to try some factory ammo just to eliminate a variable and see what happens.

Click to expand...

grampajack said:

I wouldn't just haul off and throw money at the problem. The issues described on the Hornady website don't really explain what you're experiencing. For one thing, you're talking about a 20'' barrel, which has plenty of impingement and dwell time. That barrel and gas system gives you more than enough time for pressures to drop well below what you need for safe extraction. You can expect to experience increased bolt velocity when using the suppressor, but I don't see any way use of the suppressor explains popped primers or short stroking.

If you are in fact experiencing short stroking, then I see no way an adjustable gas block can help you in any way. All it does is mimic a smaller gas port, which is going to make any short stroking even worse. If however the bolt is going too fast, as I suspect, then an adjustable gas block is the cure. Or a heavier buffer might also work and may be cheaper. Again, what in detail is happening that makes you automatically assume it's short stroking?

At the very least, I would use some regular factory loaded ammunition. There's just no way in my mind that a suppressor on a 20'' barrel could be the cause of popped primers.

ETA: If we were talking about a 12'' barrel then maybe I could see the suppressor causing popped primers, but certainly not short stroking. On a 20'' barrel I just think that the pressure has dropped so much by the time the bullet actually gets to the suppressor that there's really not much the suppressor can do at that point to cause you any extraction problems.

My best guess at this point is that your rifle is already somewhat overgassed and the suppressor is just sending it over the edge of what your magazine spring can keep up with. But again, that doesn't explain the popped primers in my mind. I would strongly advise you to try some factory ammo just to eliminate a variable and see what happens.

Click to expand...