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Caught in a loop
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The gas hole is definitely too small. I still need to decide what to do as far as the drill bit, but I'll be widening that.


"In order to understand recursion, you must first learn the principle of recursion."
 
Posts: 3205 | Location: Memphis, TN | Registered: August 23, 2010Reply With QuoteReport This Post
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Picture of powermad
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I would at least start out with a #43 (.089") bit and work up to a #42 (.0935") if you need to.

Or if you don't want to mess with doing that you could just open it up to .098" or so and get a BRT gas drive for it.
Just select what buffer and spring you are using from the drop downs and get a gas tube sized for that.
But I wouldn't, I'd just get a couple of bits and work up.

A dimple jig for the gas block is pretty cheap and makes messing with that easier if you have it on and off.
I think the KVP one I have was $25.
 
Posts: 1211 | Location: Portland Oregon | Registered: October 01, 2011Reply With QuoteReport This Post
Caught in a loop
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I have a set of #43 drills on the way.

That BRT gas drive system intrigues me, but it doesn't come tuned for a 24" barrel, at least that I've seen yet. I'm not done looking though. I found their site and there's a configurable option that would meet my needs.

0.089" = ~2.26mm. I am really quite tempted to drill out to 2.5mm and install the adjustable gas block, simply because it's the most field-expedient means of getting the gun fully operational.


"In order to understand recursion, you must first learn the principle of recursion."
 
Posts: 3205 | Location: Memphis, TN | Registered: August 23, 2010Reply With QuoteReport This Post
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If going from over-sized the BRT tube is a solid, easy fix, good for over 5,000 rounds on a suppressed 10.5"
No parts to fiddle with to keep it working.

I had a Faxon barrel that had a huge gas port.
Cycled hard with an A5H2 buffer and Law folder adapter, which was another 2 oz.
Got a BRT tube sized accordingly and it smoothed it out.
Got it sized for full power ammo.
Tested some steel case and it choked.
Runs 5.56 like a champ.

Sold it to a buddy who of course bought steel cased ammo after being told about it.
I made a spacer for the extension and gave him a carbine buffer and spring to try out.
 
Posts: 1211 | Location: Portland Oregon | Registered: October 01, 2011Reply With QuoteReport This Post
Caught in a loop
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I've looked at both options and they cost about the same. I'm going to first try chasing the hole out with a drill and go from there.


"In order to understand recursion, you must first learn the principle of recursion."
 
Posts: 3205 | Location: Memphis, TN | Registered: August 23, 2010Reply With QuoteReport This Post
Caught in a loop
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Well, BA responded to my query about the gas hole. They drilled it at 0.086". Now wonder I'm having issues.


"In order to understand recursion, you must first learn the principle of recursion."
 
Posts: 3205 | Location: Memphis, TN | Registered: August 23, 2010Reply With QuoteReport This Post
Caught in a loop
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I ended up buying a gas block dimpling jig from SLR Rifle Works for $35 last night. I also have the aforementioned #43 bits waiting at the PO box.

I also replaced the barrel with that $300 Criterion of the same length. While I'm a little annoyed at the profile ( instead of staying at over 0.90" it's what I've seen as a a service rifle profile - it drops to 0.80" after the gas block journal) I'm okay with it because I know the gas system is good to go. I tested the gas port with my pin gage and it fits wonderfully. It's also dimpled so there's no question the block is lined up (no ghetto-ass tricks like dropping spaghetti in the barrel).

I'm going to enlarge the hole on the BA and dimple it, and I'm going to be building another rifle with a PSA kit I picked up last night, and I might even Ceracoat it if I can figure out a way to bake it.


"In order to understand recursion, you must first learn the principle of recursion."
 
Posts: 3205 | Location: Memphis, TN | Registered: August 23, 2010Reply With QuoteReport This Post
Caught in a loop
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I drilled it out over Thanksgiving break. Dunno how well it'll shoot, but I can say the gage pin fits like a glove now.

The parts to finish the new upper (minus the dimple jig) will be here Wednesday. Everything else I'm still waiting on.


"In order to understand recursion, you must first learn the principle of recursion."
 
Posts: 3205 | Location: Memphis, TN | Registered: August 23, 2010Reply With QuoteReport This Post
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