Too much gas!!

[okiecat]

Here is what I built. 6.5 Gren, Suppressed 20” barre, rifle gas with adjustable gas block,{completely closed}, 4.8 buffer, strike flat wire 13” spring, carbine buffer tube 7” long.. Trying to shoot 120 or 90gr tnt. All brass is going forward at 12:30 to 1:00. No dents and bolt stays open firing 1 shot at a time. Was twanging bad with standard spring and 3oz buffer. Still I would like to get ejection in the 3:00 area or is it not that big a deal. I dont wont to beat the BCG or gun up. Or do I need to ditch the can and get a compensator of some kind. Tried 2 different cans. Same results

[montana]

Here is what I built. 6.5 Gren, Suppressed 20” barre, rifle gas with adjustable gas block,{completely closed}, 4.8 buffer, strike flat wire 13” spring, carbine buffer tube 7” long.. Trying to shoot 120 or 90gr tnt. All brass is going forward at 12:30 to 1:00. No dents and bolt stays open firing 1 shot at a time. Was twanging bad with standard spring and 3oz buffer. Still I would like to get ejection in the 3:00 area or is it not that big a deal. I dont wont to beat the BCG or gun up. Or do I need to ditch the can and get a compensator of some kind. Tried 2 different cans. Same results

Sounds like you're not adjusting the gas block correctly.. The rifle should not function at all with the gas block completely closed. What adj gas block do you have?

[okiecat]

Hi Montana, Just found your review of RifleSpeed block. I think mine is Odin. Have a Superlative too but haven’t tried it. Hand guard is only 1.4 or 1.5 ID. Anyway. I’m going to order the RifleSpeed. I have a 12” Grendel also. And a 300Blk Pistol too. Can Always use one. Thought I read a 20” barrel could produce enough gas in bore to run the BCG

[montana]

Hi Montana, Just found your review of RifleSpeed block. I think mine is Odin. Have a Superlative too but haven’t tried it. Hand guard is only 1.4 or 1.5 ID. Anyway. I’m going to order the RifleSpeed. I have a 12” Grendel also. And a 300Blk Pistol too. Can Always use one. Thought I read a 20” barrel could produce enough gas in bore to run the BCG

Make sure your hand guard will fit the Rifle Speed adj gas block..

Make sure you have the correct hand adjuster length when ordering..Read the instructions carefully so get exactly what you need..

The Rifle Speed requires a straight gas tube and some hand guards will not work, as they are designed for standard bent gas tubes..

I also use two adj springs to increase adjustment tension..I found using only one adj spring a little light and I prefer stronger force to turn when adjusting the gas, but you may differ..

The great thing about the Rifle Speed is the ability to use different length plungers to modify the amount of gas being regulated, the ease of maintenance and easy accessibility to the parts..It is a well designed adj gas block..

The gas block also comes pre-drilled if you want to pin the block to the barrel.. I pinned mine using the BRD Engineering Gas Block Jig..

https://www.youtube.com/watch?v=E2n5wrc7...oMx0Apd6Me

https://brdengineering.com/products/2aum...illing-jig


Rifle Speed has a company that will do it for you for about $40.00 if my memory serves, if you send them your barrel..

[okiecat]

Thanks for reply and explanation of details. I would gladly change handguards but I done a cerakote paint on this rifle. Will measure everything twice! Going to open my gas block up tomorrow evening and see what happens.

[okiecat]

Well I pulled the gas block, it is a low profile Superlative clamp on. With the screw all the way in I could still blow thru the tube and get air inside gas block hole??? So I switched to the regular clamp on Superlative with gas by pass system. Put it on, 18clicks from bottom is wide open. I went 4 clicks at a time, shooting 1 rd. Done this 6 times. All held the bolt open and all piled up at 1;00 in front of me about 4-5’? Ran out of practice ammo. So I quit and scratched my head.

[VASCAR2]

What size gas port in the barrel? It has been posted on the forum the 20” 6.5 Grendel gas port should be .0935”. I wonder if you have a really stout ejector spring in your bolt. How difficult is it to depress the ejector?

If you close the gas block completely and fire one round does the bolt unlock or move?


If it were me I’d start with the gas block 4 turns out from closed, fire one cartridge and see if case is ejected and bolt locks back on empty mag. If the bolt locks open on empty I might close the gas block one click and see if it locks back on empty. If the bolt doesn’t lock back I’d continue to open the gas block until the bolt locked back on empty magazine. Once I get the bolt to lock back on an empty mag I’d open one more click.

Is it possible the ammo is loaded to max, ammunition could be causing the 1 O Clock ejection. If you were close I’d fire a Wolf steel case cartridge and see how it ejects. Wolf 100 grain FMJ steel case has a light recoil impulse in my rifles.

Is it possible the ammo/bullet is jammed into the lands and increasing pressure. If you put a cartridge in the barrel with no bolt carrier and raise the muzzle does the cartridge fall out under gravity. Do you have to push the cartridge out with a cleaning rod?

[okiecat]

Hi Vascar2, I thought with the original gas block I was completely closed, but it was not. Port is standard I think, wthi oill check this evening. The new gas block is a Superlative that is suppose to bleed excess gas as you open it more past wide open at 18 clks. I handload all my ammo and have been trying different wits of bullets, 90gr TNT, 120 sierra and 123 Hornady. Most with 8208 or H-335. Haven’t made any difference. I’m going to screw it down and backout 4 and see what happens this evening when I get home. No bullets Jammed or anything like that. Ive been reloading for 45yrs.

[okiecat]

Results: I turned it in all the way and tried to count back 4 clicks, not as defined as I would like. 1st shot 1:00 and bolt locked open. Turned in 1clk same thing, turned in another ck and 4:00 and half shut bolt. turned back out 1ck. 2:00 and bolt open. Run it down shut and tried to count, think its 4. Anyway I can live with it. I’m running a 4.85 oz buffer and either a flat spring carbine 13” long. Or strike spring.