Quick question on adjustable gas blocks

[Bearcatrp]

Now I know why I have been buying complete upper. This one I put together is jamming the bullet before being chambered. Been a long time since I dealt with this stuff. Its a odin works adjustable gas block. Went through this with my 300 BO years ago. Can't remember, do I close off or open up the gas block for this? It will only chamber 1 round by jamming. Its a AR10 308 with 16 inch barrel. Thanks.

[xd ED]

If I understand your issue, you should open the adjustment to allow a greater volume of gas to more completely open, and cycle the bolt.
But I may need to be corrected in my thinking.

[crbutler]

Maybe I’m misunderstanding you, but if the bullet is jamming before it goes to full lockup,it sounds like something other than a gas problem.

[Jackpine Savage]

Load one in the mag, do you get bolt hold open? If not, you need more gas.

Have you tried different magazines?

[Holland&Holland]

Waiting to hear your response to CR's question. If it truly is jambing than it is not a gas issue. If 1 round is going into battery fine but then it will not cycle the next round it COULD be a gas issue. Start simple in that case and double check that your gas block port it over the port in the barrel. It can be easy to get them misaligned depending on the barrel and block. Then I start with the block opened just a bit and shoot singles until it locks the bolt open on an empty mag. Only then do I try multiples. What you are looking for is the minimal amount of gas to make the system run reliably.

BUT, if it is jamming that is something else all together. Pics of the jamb might help. Info on what load you are using as well.

not the same thing but I have a .458 socom that hates flat point bullets but feed it anything with some taper to it and it feeds like butter. Now .308 is not going to be this issue but if it is jambing something is getting caught somewhere in the system.

[Bearcatrp]

It first started out not loading the next round. This is on the new barrel. Then periodically the next round would get jammed by the BCG. After I posted this, I think I know where I went wrong. I took the lower off my 12 inch AR10. That’s set up as a carbine tube and small buffer. Dam thing kicked like a mule. Ordered a full length lower so I can put this one back where it belongs. I’ll follow up with a range report next week to let you know if it fixed the issue or not. One thing to note, once zeroed at 50 yard range with surplus rounds, I put my pet 168 Amax rounds in it. Still one shot at a time. 3 in almost the same hole dead center bullseye. Had to stop as my shoulder was killing me. So I know the barrel is broke in and shoots great so far. Wanting to get it shooting great with my sandman s so I can put my thermal on it.

[Holland&Holland]

It first started out not loading the next round. This is on the new barrel. Then periodically the next round would get jammed by the BCG. After I posted this, I think I know where I went wrong. I took the lower off my 12 inch AR10. That’s set up as a carbine tube and small buffer. Dam thing kicked like a mule. Ordered a full length lower so I can put this one back where it belongs. I’ll follow up with a range report next week to let you know if it fixed the issue or not. One thing to note, once zeroed at 50 yard range with surplus rounds, I put my pet 168 Amax rounds in it. Still one shot at a time. 3 in almost the same hole dead center bullseye. Had to stop as my shoulder was killing me. So I know the barrel is broke in and shoots great so far. Wanting to get it shooting great with my sandman s so I can put my thermal on it.

The carbine length tube and buffer should work just fine. Try shooting with only one round in the mag and see if it locks back on an empty mag. I am guessing it is not getting enough gas and is short cycling on you.

[crbutler]

Well, since suppressors increase gas pressure, I would put the suppressor on before tuning to function if that is your intended use. If it functions without the suppressor it will be overgassed with it.

[Bearcatrp]

Was thinking about that too to try with suppressor. Have my 300BO just right so it can shoot both subs and supers without adjusting the gas block. Hoping I can get this one the same. Will wait for my lower to get in before trying it again though.

[Holland&Holland]

Was thinking about that too to try with suppressor. Have my 300BO just right so it can shoot both subs and supers without adjusting the gas block. Hoping I can get this one the same. Will wait for my lower to get in before trying it again though.

Do double check your gas block alignment. That has tripped me up before

[Bearcatrp]

I put the BCG in the upper, then slid the tube in to help align up. Seems to be fine. No marks. Think I will figure out how to open it all then way (supposed to ship that way) before trying again. Got my lower in yesterday so hope to hit the range Thursday. Will put on suppressor hoping it’s only a little adjustment needed.

[Holland&Holland]

I put the BCG in the upper, then slid the tube in to help align up. Seems to be fine. No marks. Think I will figure out how to open it all then way (supposed to ship that way) before trying again. Got my lower in yesterday so hope to hit the range Thursday. Will put on suppressor hoping it’s only a little adjustment needed.

While tube alignment is important, the more important thing is that the gas block port (inside the gas block itself) needs to be lined up over the barrel gas port. Some go as far as to use a bore scope to verify. If your barrel has a dimple it helps but Manufacturing mistakes due happen.

Once installed correctly, you would NOT start with it fully open. You would start with it near closed (should be pretty easy to adjust and there should be instructions, some have a locking screw in addition to the adjustment screw). Load one round, fire, if it does not lock back on an empty mag increase the gas until it does.

[Bearcatrp]

No dimples so I torqued down real good. Dam, I do have a bore scope but didn't think about that. Will check that out. So, just turn the screw clockwise until it stops to close the block, then back off a little? Have the directions on my reload desk that I can confirm the correct directions. Thanks for all your help.

[Holland&Holland]

No dimples so I torqued down real good. Dam, I do have a bore scope but didn't think about that. Will check that out. So, just turn the screw clockwise until it stops to close the block, then back off a little? Have the directions on my reload desk that I can confirm the correct directions. Thanks for all your help.

Yes, typically but it may have a set screw to lock in your setting as well. I have some where the adjustment is on the side with a front clocking screw and some that adjust from the front with a side locking screw, and some still will no locking screw but have clicks you can feel as you open them. What make and model is it?

[Bearcatrp]

Its a areo precision adjustable gas block. According to the little flyer, turn clockwise until it stops to fully close it. Haven't touched it so not sure where setting is now but will close it, then back off 10 clicks to start, then keep backing off until bolt locks back. But, will get out my bore scope first to see if its lined up properly. Plan on shining a light into the tube hoping I see light.

Can't tell by these pics

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PICT0026.JPG (26.49 KB) Viewed 1876 times

PICT0026.JPG (26.49 KB) Viewed 1876 times