BCG fubar

[KBScobravert]

yikes....I hope my 10.5" 300BLK doesn't have this problem once my SBR stamp comes in

I've ran my sub sonic 300blk rounds through a 9mm pistol suppressor you'll be fine.

[Craizie]

Which? It is rare to find one that you can run with a barrel that short. Most want 11.5"

Would an adjustable gas block make it ok to shoot on a 7.5?

[KBScobravert]

Would an adjustable gas block make it ok to shoot on a 7.5?

Unburnt powder exiting that short of a barrel will wreck most suppressors.

[LANTIRN]

yikes....I hope my 10.5" 300BLK doesn't have this problem once my SBR stamp comes in

Minimum for most cans with 300blk subs is 8 inch. The round was designed around an 8 or 8.5 inch barrel. You will be fine.

[Gtracer]

Minimum for most cans with 300blk subs is 8 inch. The round was designed around an 8 or 8.5 inch barrel. You will be fine.

I noticed that most manufacturers will not warranty the suppressor if it is used on a barrel shorter than 9" (Octane HD 45)...so I opted for the extra 1.5" just to be safe. Having a suppressor fly off the end of my barrel due to lack of stabilization would just make me sick...and then of course the warranty would not cover so instant vomit.


I would move from a 7.5" to at least a 9" barrel to help avoid any issues downstream.

[Craizie]

I noticed that most manufacturers will not warranty the suppressor if it is used on a barrel shorter than 9" (Octane HD 45)...so I opted for the extra 1.5" just to be safe. Having a suppressor fly off the end of my barrel due to lack of stabilization would just make me sick...and then of course the warranty would not cover so instant vomit.


I would move from a 7.5" to at least a 9" barrel to help avoid any issues downstream.

Thanks for the info. I didnt even think about that. That would of sucked!

[BlackGT]

Complete BCG, $87.

http://www.rockriverarms.com/index.cfm?fuseaction=category.display&category_id=647

[CJ]

Not sure if this was covered, but this can also happen when the gas tube is too far into the receiver, or if the gas tube was misaligned due to being bent, or improperly flanged. This situation would also cause problems with other bcg's like you described.

As mentioned above, a loose or misaligned gas key could also impact the gas tube on the head, and cause damage to the gas tube, requiring replacement.

A DI 7.5" barrel with a suppressor is going to be harder on the bcg than a typical carbine or rifle length gas system, however it's not going to cause these kinds of problems, just quicker wear. A properly built barrel will have a smaller gas port to limit the gas back down to acceptable levels. A problem I myself have been a victim of is incorrect gas port/shelf location. The problem with pistol length gas systems is there is no standardization. Unlike rifle, mid length, and carbine, there is no set location for the shelf. In very extreme circumstances, you can experience a situation where the shelf is too far back from the muzzle, resulting in the gas tube protruding into the receiver too much, and impacting the back of the gas key.

[Craizie]

Not sure if this was covered, but this can also happen when the gas tube is too far into the receiver.

What are your thoughts on the 7.5 inch barrel?

[CJ]

Checkout my post again, I added some more info for you.

[KBScobravert]

I didn't even think about the pistol length port location and the effects it could have on how far back your gas tube would go into the gas key. Might take a look a measurement of of how much of your tube is inside the upper receiver. Someone here could do the same with one of theirs to compare against.

Sent from my SAMSUNG-SM-G890A using Tapatalk

[Craizie]

Checkout my post again, I added some more info for you.

Awesome, thanks. I'll see if I can narrow down the problem.

[CJ]

What are your thoughts on the 7.5 inch barrel?

I love them, personally. My only complaints being there are not enough pencil profile 7.5" barrels (I always have to turn them down myself), and short lifespans. The other real serious issue is the potential of shooting your hand off.

Pistol barrels have a short lifespan do to gas port erosion. But this really only affects m16's. Semi auto guns should see decent life out of them.

My preivous barrel was a red x 7.5" which I turned down to kill weight since my piston system was so heavy. It lasted approx 4,000 rounds. Eventually, the gas port erodes, think of a sharp hole turning into a funnel on the inside of the barrel. As the bullet passes by, the funnel allows a larger area, and therefore time, for the gas to pulse into the bcg. The result is a higher and higher cyclic rate until the gun out runs the magazine and starts jamming.

[CJ]

I didn't even think about the pistol length port location and the effects it could have on how far back your gas tube would go into the gas key. Might take a look a measurement of of how much of your tube is inside the upper receiver. Someone here could do the same with one of theirs to compare against.

Sent from my SAMSUNG-SM-G890A using Tapatalk

Oh, it can, I destroyed a bcg because of exactly thst issue. But that's only in extreme situations.

[KBScobravert]

Oh, it can, I destroyed a bcg because of exactly thst issue. But that's only in extreme situations.

Your piston expedition.