I built a nice 300 BLK 9" tax stamped. It has an ACOG with an RMR on it. When you shoot using the RMR, you get an unpleasant puff of smoke in your eye upon every shot. Especially with supersonics.
Is there anything that I can do to correct this problem?
Blowback In Your Face
Moderators: gds, bakerjw, renegade
-
- Silent Operator
- Posts: 80
- Joined: Sun Jan 07, 2018 9:03 pm
Re: Blowback In Your Face
The RMR is atop the ACOG, and both are offset about 25 degrees. Looks cooler and holds easier.
-
- Silent But Deadly
- Posts: 349
- Joined: Tue Aug 23, 2016 7:15 pm
Re: Blowback In Your Face
You can:
Don't shoot supers
or
Use a adjustable gas block to turn the gas down
or
Use a gas buster or similar charging handle
Or any combination of the above with differing results.
Don't shoot supers
or
Use a adjustable gas block to turn the gas down
or
Use a gas buster or similar charging handle
Or any combination of the above with differing results.
Re: Blowback In Your Face
Change powders.Boolit_Head wrote: ↑Thu Aug 08, 2019 8:28 pm You can:
Don't shoot supers
or
Use a adjustable gas block to turn the gas down
or
Use a gas buster or similar charging handle
Or any combination of the above with differing results.
Don’t know why any of it would change when using an RMR, or not, but I’ve never used one.
300 Blackout, not just for sub-sonics.
Re: Blowback In Your Face
my 9" AR pistol also used to blow back in my face when shooting. I have no idea why but it quit doing it all by itself!?
peace through superior firepower
-
- Silent Operator
- Posts: 80
- Joined: Sun Jan 07, 2018 9:03 pm
Re: Blowback In Your Face
You have to hold your head up higher when using the rmr because it sits so high above the bore. This happens to be where the gas is blowing around. I went through several powders this year looking for an accurate load. One for supers and one for subs. CFE BLK, H-4227, LilGun H-110, H-4198, and a couple others I dont remember off hand. I have dies to make the bullets, so I was able to mess around with a lot of weights, jackets and bases. I ended up with a 115 grain bullet for supers made from once fired 5.7 with 22.4 grains of CFE BLK. 1800fps. The subsonic was a copper jacketed round made from 5/16" soft copper tubing. It uses a boat tail, comes in at 205 grains, and is propelled by H-4227 at 1025fps. I finally got the rifle to function by opening up the barrel gas port to .110". Seekins Prescision gas block is wide open. Has to in order to cycle with both rounds, but the gun does work. Theres a JP captive spring, with one tungsten and one steel weight.
Only problem, is Im getting blasted with it. What charging handles were you talking about? Boolit Head?
Only problem, is Im getting blasted with it. What charging handles were you talking about? Boolit Head?
Re: Blowback In Your Face
Install a Superlative ARMS Adjustable Gas Block with Bleed Off.
It worked for me when shooting supersonic rounds suppressed.
It worked for me when shooting supersonic rounds suppressed.
- plant.one
- Silent But Deadly
- Posts: 6823
- Joined: Tue Jun 23, 2009 8:31 pm
- Location: Oakland County, MI
Re: Blowback In Your Face
have you considered something like this to vent the gas elsewhere?
https://www.rainierarms.com/ar-gas-vent/
https://www.rainierarms.com/ar-gas-vent/
Reloading info shared is based on experiences w/ my guns. Be safe and work up your loads from published data. Web data may not be accurate/safe.
This disclaimer will self destruct in 10 seconds.
This disclaimer will self destruct in 10 seconds.
Re: Blowback In Your Face
You have a problem with the rifle and how it's set up, combined with powders that produce way more gas than needed to cycle the action. Possibly poor bullet design or a loose bore.BulletFactory wrote: ↑Fri Aug 09, 2019 12:07 pm You have to hold your head up higher when using the rmr because it sits so high above the bore. This happens to be where the gas is blowing around. I went through several powders this year looking for an accurate load. One for supers and one for subs. CFE BLK, H-4227, LilGun H-110, H-4198, and a couple others I dont remember off hand. I have dies to make the bullets, so I was able to mess around with a lot of weights, jackets and bases. I ended up with a 115 grain bullet for supers made from once fired 5.7 with 22.4 grains of CFE BLK. 1800fps. The subsonic was a copper jacketed round made from 5/16" soft copper tubing. It uses a boat tail, comes in at 205 grains, and is propelled by H-4227 at 1025fps. I finally got the rifle to function by opening up the barrel gas port to .110". Seekins Prescision gas block is wide open. Has to in order to cycle with both rounds, but the gun does work. Theres a JP captive spring, with one tungsten and one steel weight.
Only problem, is Im getting blasted with it. What charging handles were you talking about? Boolit Head?
9" pistol gas with an H2 weight buffer should not need a port larger than about .085" with a suppressor. You are under buffered and over ported.
I would slug the bore and or capture a bullet. I am guessing a captured bullet would be black with carbon in front of the base. Neither of those powders in the loads you are shooting them have enough pressure to properly obturate the bullet. You might try sizing to .309". I think it's possible you are losing too much pressure past the bullet to cycle the action.
You may also have a gas leak somewhere else.
If the only time the gas is an issue is holding your head high, it's probably coming out the ejection port. Again poor powder choices and or low pressure causing a poor burn rate and lots of left over gas.
300 Blackout, not just for sub-sonics.
-
- Silent Operator
- Posts: 80
- Joined: Sun Jan 07, 2018 9:03 pm
Re: Blowback In Your Face
Ok. I will look into it pretty soon. Lots going on. What a great post sir, thank you.
I'm going to try to get the forward assist.
I'm going to try to get the forward assist.
Who is online
Users browsing this forum: No registered users and 11 guests