Chamber help/.224 Valkyrie

[sable tireur]

Please check your PM.

 

[cohunt]

Have you tried an adjustable gas block? I doubt it would cure all your problems but it would at least meter your gas down to the proper levels.

 

[Gcan]

When you switch the barrel to different uppers are you switching the barrel only or are you switching the barrel along with the gas block and tube with it? I have to agree with you that it is a gas problem. Poorly drilled gas port to me. You didn't say if you have tried different blocks, only that the smith told you too. How does the bolt cycle? Is your brass all ending up in a nice pile? Three in a clover and the forth that far away should show up in the cycling.

Ive been changing block with barrel. Have tried different bolts. Have a bunch of 6.8s. Have not tried different block. It a 920 journal. I have one other 920. Will try that. Not going to spend for an adj that I won't have a use for when i cut this thing up for cigar holders .

Nothing I will do will fix the port inside barrel.

I catch the brass. The few that have gotten away from me all seem to fly at 3-4 o'clock

 

[Gcan]

Have you tried an adjustable gas block? I doubt it would cure all your problems but it would at least meter your gas down to the proper levels.

Was trying to avoid buying a 920 adj that i will have no other use for.
Will try the other 920 I have though.
Never thought it was seriously over gassed. It has a lot of exhaust but the bolt timing seems perfect. No marks from early movements

 

[cohunt]

Cheep "adjustable" gas block tip-- to see if less gas is the issue, loosen the set screws and move the gas block (towards muzzle) a tiny bit at a time try shooting after each move.

What this does is the gas block will start to cover the gas port in the barrel, thus limiting the gas flow back to the carrier/bolt assembly to let you know if an adjustable gas block is needed.

If you can cover part of the gas port and still get proper carrier cycling, feeding, firing, and bolt lock back on an empty mag then you know you are over gassed and should buy an adjustable gas block.

Another "band aid" fix is to try adding tungsten weight to your buffer to slow the carrier unlock just a few milliseconds

Extremely overgassed can be masked --- if the carrier tries to move too early the brass can still be expanded against the chamber walls, this extra "friction" will slow the carrier down, change ejection pattern and even sometimes show signs of being undergassed....a telltale sign of this is "cloudy" brass body after ejection

Over gassed rifles will start to move the carrier before the bullet leaves the barrel, this can show up in several ways including poor accuracy.

 

[cohunt]

Are you sure the gas block journal is .920" standard sizes are .625, .750, .875 & .936"

 

[Gcan]

Cheep "adjustable" gas block tip-- to see if less gas is the issue, loosen the set screws and move the gas block (towards muzzle) a tiny bit at a time try shooting after each move.

What this does is the gas block will start to cover the gas port in the barrel, thus limiting the gas flow back to the carrier/bolt assembly to let you know if an adjustable gas block is needed.

If you can cover part of the gas port and still get proper carrier cycling, feeding, firing, and bolt lock back on an empty mag then you know you are over gassed and should buy an adjustable gas block.

Another "band aid" fix is to try adding tungsten weight to your buffer to slow the carrier unlock just a few milliseconds

Extremely overgassed can be masked --- if the carrier tries to move too early the brass can still be expanded against the chamber walls, this extra "friction" will slow the carrier down, change ejection pattern and even sometimes show signs of being undergassed....a telltale sign of this is "cloudy" brass body after ejection

Over gassed rifles will start to move the carrier before the bullet leaves the barrel, this can show up in several ways including poor accuracy.

Do t appear to have timing problem but
Good idea. Will run it tomorrow

 

[Gcan]

Are you sure the gas block journal is .920" standard sizes are .625, .750, .875 & .936"

Yes. Transposed two numbers. .936 journal. .919/920 muzzle.
I do have another block that fits. Going to try the moving it trik

 

[Gcan]

According to Bartlein my flutes are far to deep.

 

[Gcan]

Cheep "adjustable" gas block tip-- to see if less gas is the issue, loosen the set screws and move the gas block (towards muzzle) a tiny bit at a time try shooting after each move.

What this does is the gas block will start to cover the gas port in the barrel, thus limiting the gas flow back to the carrier/bolt assembly to let you know if an adjustable gas block is needed.

If you can cover part of the gas port and still get proper carrier cycling, feeding, firing, and bolt lock back on an empty mag then you know you are over gassed and should buy an adjustable gas block.

Another "band aid" fix is to try adding tungsten weight to your buffer to slow the carrier unlock just a few milliseconds

Extremely overgassed can be masked --- if the carrier tries to move too early the brass can still be expanded against the chamber walls, this extra "friction" will slow the carrier down, change ejection pattern and even sometimes show signs of being undergassed....a telltale sign of this is "cloudy" brass body after ejection

Over gassed rifles will start to move the carrier before the bullet leaves the barrel, this can show up in several ways including poor accuracy.

Interesting. The brass is filthy. Worst I ever saw