Anyone shooting an AR pistol with a can?

Sprinkman

Sprinkman

Well-known member
I put a can on my AR pistol, changed the gas block to an adjustable but couldn't get it to cycle correctly. No jams, just ejecting spent brass at 1 O'clock. I tried two different adjustable gas blocks, one from ODIN and the other from PSA. Neither worked, and as it turned out, they both said not for use with pistol length gas systems.
What adjustable gas block are you finding works with a pistol?
 
I have an SLR on my 10.5” .223 pistol upper, but haven’t shot it yet. Didn’t notice anything on the packaging or website stating it isn’t for pistol length gas systems.
Could be you need to open up gas port on your barrel to reduce pressure?
 
@Sprinkman

I have used a Seekins precision adjustable gas block.
I've used these for rifle/pistol/SBR on several with no issues. A little pricy but they have worked well so far for me.
never noticed a "not for Pistol" message
link here:
seekinsprecision.com

Select Adjustable Gas Block

Seekins Precision
seekinsprecision.com seekinsprecision.com

The other method is a heavier buffer to retard the bolt unlocking quickly. Which if you decide to go that route with the existing gas blocks you might find joy.
which you "Could" just replace the buffer weights with tungsten (but keep the little spacers should be rubber or even Teflon in the same configuration).
Or buy just buy a H3,H2,or H1 buffer assembly complete.
Which caliber are you using?
If say it is a 5.56mm /223 with a pistol length gas system My go to would be a pistol weight, with an adjustable block when a suppressor is used.
If no suppressor I would most likely use at least a H3 to start with, in the pistol length and less than 10" barrel.
for your reference so when you weigh the buffer you can surmise which one you have.
  • Pistol – 5.0-8.5 oz
  • Carbine – 3 oz
  • Heavy (H or H1) – 3.8 oz
  • H2 – 4.6-4.7 oz
  • H3 – 5.0-5.4 oz
The above is assuming your using a carbine oops I meant pistol tube set-up on the buffer tube/stock not a rifle tube with stock. Sorry I have too many SBR's, usually the pistol and carbine tube is approx same length
 
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I have an SLR on my 10" pistol but had to open the port on the Kak barrel (300BO). Also changed to a heavy buffer to slow down the BCG, standard carbine spring. I do NOT have a can on it. I used a dowel in the barrel to prevent land damage if the bit suddenly goes thru. You didn't say, I assume 223? Factory powder burn curve is too slow/flat to develop much early pressure. The adj screw on it will carbon pretty fast, give it a twist once in a while.
edit: I assume short stroking (1 o'clock) but it could also be BCG running too fast. I had an adjustable buffer but the nylon end got beat up (screwed in) pretty bad. Changed to a heavy one that was pinned.
 
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Buffer weights construction:
Aluminum, Steel and Tungsten
Above you will see the H1, H2, H3 that is the number of usually tungsten weights installed.
The 9mm dedicated buffer is approx. 6 to almost 8 ozs vendor dependent, I usually use those as last resort unless of course I'm doing a 9mm.
Primary arms does have H4,H3,H2,H1 as well as the 9mm PCC buffers. (and they aren't the only source)
the purpose of the rubber end is to prevent overtravel without damage and act as a cushion when /if contact is made. Just as Popper led to above.
In the past when I had to actually change weights vs being able to just buy them as offered today. I also had to obtain the buffer rubber ends new for each replacement.

Overgassed is normally 12 to 3 oclock ejection angle. Short stroke is 4:30 to 6 ejection angle. 3 to 4:30 is considered perfect

Do this FIRST:
When tuning the gas Block I shut it off 1st ,then start opening it each shot until the mag catch locks the bolt to the rear consecutively at least twice. Load only 1 round in the mag for each time you make a adjustment (slowly opening) . I recommend this method first before doing the buffer weight. (YES have the Can on when doing this)
You will find out with a pistol that you will have two settings one for suppressed one for unsuppressed
 
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Good suggestions from everyone. I'm looking at the Seekings Adjustable Gas Block. It has 30 settings compared to the others that I have used with only 5 or so settings. This is a 556 with the pistol tube setup. Watching Seekings video on their gas block, it looks like it should do the trick. I'm using this can on 16" barrels with the adjustable gas blocks mentioned earlier with no issues. Hopefully the Seekings will do the trick, and besides they're an Idaho company.
 
And Sgt Mike, I tune my gas blocks the way you describe. I'll usually load about ten mags with one round each and then begin the adjusting.
Thanks for all your input, it helped.
 
@Sprinkman
Yeah brother if you cant adjust in with the Seekins, try weighing your existing buffer and maybe go the next step heavier. Is my only thought right now (the other plus is it "should" also lighten the recoil a little). Like you I have used the Odin and others in the past and found the Seekins easier to fine tune exactly in where it needs to be.
The other plus is when you get it the directions will show how one could do "presets" for suppressed and unsuppressed.
 
So as follow up, I wasn't able to find a Seekins AGB. Instead a went with a Superlative Arms AGB.
Got it installed this morning, and of course while I'm installing it I got an email from PSA that they had the Seekins back in stock :(.
What are you gonna do? I'm an impatient man so I ordered what I found :LOL:.
Anyway, back to the gas block. I got it installed tested it and couldn't get it to shoot better than 2 O'clock. So, I reset it with a slight twek to the rotation and now I'm consistently shooting at 3 O'clock. The can is an Otter Creek Labs 6" Polonium and it's pretty darn quite, especially when compared to just a birdcage. I may still try a heavier buffer, though, to see what kind of help it provides.

I appreciate all the comments and help with this.
 
Squirt a little carb cleaner in the 'exhaust' port and tweak the screw a bit every once in a while. I did break mine, sent it in and got a replacement though.
 
Sprinkman said:
I put a can on my AR pistol, changed the gas block to an adjustable but couldn't get it to cycle correctly. No jams, just ejecting spent brass at 1 O'clock. I tried two different adjustable gas blocks, one from ODIN and the other from PSA. Neither worked, and as it turned out, they both said not for use with pistol length gas systems.
What adjustable gas block are you finding works with a pistol?
Click to expand...
The Kitty Kat is a pistol they say,I run a Velos Lbp on it with no problems whatsoever.
 
RifleSpeed is the only gas block I use now. Running cans on 300Blk, 6.5 Grendel and 9mm ar pistols. The adjustment is unlimited. And no tools required.
 
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