AR Adjustable Gas Block

[theunrulychef]

So I got sucked back into ARs just a little. Since I already have a sbr upper / lower for 300 blackout, I figured I'd get a cheap sbr upper in 556 for plinking with buddies. It's got a carbine gas tube on a 10.5" barrel, and I run it with a suppressor - but I get a lot of misfeeds / stove pipes (runs like a champ without the suppressor on). I've been meaning to get an adjustable gas block for my 300 blackout, but it actually runs pretty good with my sub loads as is. I know a piston system would have many advantages here, but I'm not looking to get into all that. I also like the Noveske Switchblock sort of device since you can change it without tools, but I know that & most like it won't fit under my rail.

Here's what I want:
#1 isn't priced like it's made of gold
#2 can fit under a Seekins MCSR free float tube
#3 isn't a huge pain in the ass to set

What do people recommend?

[daschnoz]

What is the barrel diameter at the gas block?

[theunrulychef]

What is the barrel diameter at the gas block?

Sorry, should've had that in there. 0.750"

[theunrulychef]

Also, inside diameter of the rail is 1.8". I'd have to measure how much extra clearance I have at the top in the gas tube channel, but I think it's safe to say I'll be limited to low-profile gas block sized units.

[jthrelf]

Just run a lighter weight buffer? I'm not sure if that will solve the problem but it seems like you're short stroking.

[animalmother85]

Odin Works.
Syrac Ordnance.

Will fit.
Doesn't cost it's weight in gold.
Good designs.

[Hodgie]

What do you mean by miss feeds and are the stove pipes with live rounds or the spent casings? I don't have any experience with suppressors yet but if it's short stroking then adding an adjustable gas block isn't going to help it since it's already under gassed you can only turn them down not up.

[Lycanthrope]

I have two JP adjustable blocks I use for 3 gun. They fit snug and stay in adjustment.

Lycanruneverythingthrope

[theunrulychef]

I'm relatively certain that it's cycling the bcg so fast that the spent casing doesn't have time to clear the chamber before it's stripping a new round & trying to chamber it. I've verified that it will do mag dumps without a hitch when the suppressor's not on - it's just that extra pressure from the suppressor. I've actually got a rather pronounced wear spot on the lower where the back of the gas key is slamming into the buffer tube. Rather than throwing money at things like extra heavy buffers, different springs, (it's already got a heavier full auto bcg) - I figured I'd just go to the root of my ails with the gas system. Plus, if I can reduce the amazing amount of shit it's throwing back into my upper, life will be better.

I think I'm liking the idea of the detent ones instead of the JP that uses a locking set screw. Someone PM'd me that they have some Syrac ones for sale - might go that route http://forum.pafoa.org/showthread.ph...70#post3091370

[Hodgie]

I'm relatively certain that it's cycling the bcg so fast that the spent casing doesn't have time to clear the chamber before it's stripping a new round & trying to chamber it. I've verified that it will do mag dumps without a hitch when the suppressor's not on - it's just that extra pressure from the suppressor. I've actually got a rather pronounced wear spot on the lower where the back of the gas key is slamming into the buffer tube. Rather than throwing money at things like extra heavy buffers, different springs, (it's already got a heavier full auto bcg) - I figured I'd just go to the root of my ails with the gas system. Plus, if I can reduce the amazing amount of shit it's throwing back into my upper, life will be better.

I think I'm liking the idea of the detent ones instead of the JP that uses a locking set screw. Someone PM'd me that they have some Syrac ones for sale - might go that route http://forum.pafoa.org/showthread.ph...70#post3091370

Makes sense due to the blow back thanks for sharing.