AR-15 BS Thread

H3 in my 11.5 H2 equivalent in my 13.7 that runs a vltor buffer system. Heck even running h2 in my 20. All cycle fine with our without the can if anything the 11.5 and 13.7 still a tad gassy with the can but not overgassed enough to impact reliability

 

yep, probably need to tune it for your can. I think I'm running H3 and Sprinco spring. Sounds like your over gassed with the can. Same thing happened to me with a 12.5".

 

Does the bolt hold open on an empty mag? Where does the brass eject? If the barrel is a Colt, I would send it back. I have 8 different DI AR calibers, the only thing that solves overgas is an adjustable block. But then a new barrel is usually cheaper than an adjustable gas block, and less Rube Goldbergish....

 

Locks back on empty mag. Only issue is bolt over base when suppressed. Runs without issue when not suppressed.

Don’t know the exact ejection pattern since it wasn’t in an area I could locate the brass vs brass already there.

 

GoPro works great to see what's happening with ejection. 95% of what you need to know will come from where the brass goes. The weight difference between H2 and H3 is only about 0.5 oz. Unless You're on the jagged edge, it won't make a difference.

 

You might consider replacing the gas block with an adjustable block like this one from Superlative Arms.

https://www.brownells.com/gun-parts...-parts/ar-15-adjustable-gas-block-.750-solid/

 

And it’s finally built. My first AR.

 

Nice! What type of trigger? Looks like a hybrid between regular and straight...

 

"First" implies more forthcoming. It sounds like you know how this works.

 

Thank you! Trigger is a LaRue Tactical MBT-2S. 2-stage trigger that breaks at 4.5 lbs (2.5 lb first stage, 2 lb second stage).

 

Thank you! And absolutely.

 

School me on AR mags. I have some Magpul designated for .223/5.56. Also Magpul .762x39 for .300BO. And some Surefeed aluminum mags designated .223,5.56,.300BO. I thought the Surefeed were .300/.762x39 specific when I ordered them. Can or should I run all 3 cartridges out of the Surefeed? Trying to keep my mags caliber specific.

 

The magpul .300 packaging says that. The mag is stamped .762x39

 

Actually it’s stamped for both.
The Surefeed may run all 3 caliber’s?

 

762x39 mags will not work with 300blk. Slanted 762x39 cases need the curved mag. 556/223/300blk dont. It says 762x35. Which is 300blk

 

300 AAC Blackout is also known as 7.62×35mm, which is what is stamped on the mag. Not 7.62x39 the AK round.

 

Is there any real diff between 300 BLK and 5.56 mags other than possibly the spring strength (300 BLK being stronger)?