A little help, please....AR gas block for 300 BO

[rabid wombat]

I have a 300 BO shooting subs that I had failure to extract issues (first shots fired). The first round fired and did not move the bolt, and the bolt remained closed. After cycling the action, all subsequent rounds fired, and partially extracted and froze. Cycle the action, wash, rinse, repeat. This happened the same for three attempts and two shooters - first round, subsequent rounds....

I am thinking a gas issue (the rifle, not me). All this said, this is set on a pistol gas tube arrangement. In the attached pictures:

• Pictures
  • One picture is the end view, one is the side view
  • On the end view, the gas tube is top center. There is a set screw lower and left.
  • On the side view, the upper right is a pin (I believe), and the lower left is a set screw.
• Questions:
  • Do I have an adjustable gas block?
  • If so, which screw to adjust?

Thank you very much for your help.

 

[greyling22]

yes, it is adjustable. Usually, the allen screw on the side is a lock screw for the adjustment screw, which is on the front. Usually, counterclockwise is more gas, clockwise is less gas.

There is also the possibility that the gas block is not on the gun right. That it is not centered over the gas port.

 

[BreechFace]

Like @greyling22 stated it looks like you have an AGB and lock screw access through the side of the handguard and adjustment on the front of the gas block.

 

[Demi-human]

Surely, there is no owners manual available...

Wait, yes, that is an adjustable gas block, which answers my first question.

What brand is it? Any ideas?

I agree with, @greyling22, except the side screw looks to be over the gas port, while the front one is not. I think it is the reverse of what was said, but yeah, there ya go.

 

[rabid wombat]

@Demi-human - I am thinking it is a Seekins based on form and the interwebs. I bought the upper compete...and it does have a Seekins floated tube...so, maybe. I have emailed Seekins a request on instructions....

https://seekinsprecision.com/parts-accessories/uppers-lowers/low-profile-adjustable-gas-block.html

 

[rabid wombat]

For anyone’s interest...an email back from Seekins in two minutes!

TWO MINUTES!

It included both a pdf as well as an YouTube video:

 

[Demi-human]

Oh, so naughty it comes with an age restriction!
Seekins, how risqué!

I hope they have the info you’re looking for.
If not, let us know.

 

[rabid wombat]

@Demi-human they hit it out of the park. The .pdf (probably a better way of doing this....)

 

[BreechFace]

So opposite of what I was thinking, just like @Demi-human told you.

 

[rabid wombat]

@BreechFace ... your original comment got me to Seekins....thank you!

 

[rabid wombat]

Everyone ... thank you! Your help is greatly appreciated!

@greyling22
@BreechFace
@Demi-human

 

[greyling22]

Glad you got the directions sorted, and sorry you're going to have to tune the block in an ammo shortage. Good luck.

 

[rabid wombat]

sorry you're going to have to tune the block in an ammo shortage

Prepared earlier

 

[BreechFace]

Prepared earlier

How dare you be a hoarder!

 

[rabid wombat]

How dare you be a hoarder!

Not hoarding, just not shooting enough!...too many to enjoy! Also, different economies on purchasing!

 

[BreechFace]

Not hoarding, just not shooting enough!...too many to enjoy! Also, different economies on purchasing!

I was hoping my sarcasm was coming across, good for you being prepared. It gets tiring getting called a hoarder.

 

[rabid wombat]

I was hoping my sarcasm was coming across, good for you being prepared. It gets tiring getting called a hoarder.

When I first started (a wee pup - 7 or 8...helping my older brother reload...with a Lee whack a mole )....50 was a good number. 50 years later: classes, purges, runs, and etc....the unit of measure is much larger.

One of the best comments I have ever read on THR...paraphrasing about a whack a mole....”you have never lived, until you realized you are setting primers with a hammer...”

 

[jbmillard]

I have a 300 BO shooting subs that I had failure to extract issues (first shots fired). The first round fired and did not move the bolt, and the bolt remained closed. After cycling the action, all subsequent rounds fired, and partially extracted and froze. Cycle the action, wash, rinse, repeat. This happened the same for three attempts and two shooters - first round, subsequent rounds....

I am thinking a gas issue (the rifle, not me). All this said, this is set on a pistol gas tube arrangement. In the attached pictures:

• Pictures
  • One picture is the end view, one is the side view
  • On the end view, the gas tube is top center. There is a set screw lower and left.
  • On the side view, the upper right is a pin (I believe), and the lower left is a set screw.
• Questions:
  • Do I have an adjustable gas block?
  • If so, which screw to adjust?

Thank you very much for your help.

As I remember, the 300 AAC Blackout was designed to run subs with a suppressor. Are you running suppressed? What length gas system are you running? It sounds like you're close to running, but if the gas block is wide open, you may not get there.

 

[rabid wombat]

As I remember, the 300 AAC Blackout was designed to run subs with a suppressor. Are you running suppressed? What length gas system are you running? It sounds like you're close to running, but if the gas block is wide open, you may not get there.

With what I have, I have to go to the range...I will post the the results!

 

[greyling22]

Prepared earlier

hurray for being prepared. I keep seeing posts on swap sites where primers are being listed for $200+ per thousand. And I think, I'm literally stepping over 12K small rifle primers I don't need that I bought 2 years ago. I'd for sure sell than for a 900% markup. heck, for that price, I'd dip into my SPP stash......

 

[Demi-human]

Your bluff has been called!
To whom shall I make the check?

 

[greyling22]

Your bluff has been called!
To whom shall I make the check?

was that to me? if so, shoot me a PM and we can talk.

 

[BreechFace]

I'd sell SPP or SRP for $200 / Thousand any day of the week, I'll clear out my private messaging box.