AR Barrel cut down. Now having issues. What's WRONG?

[lincoln1]

So I had a reputable gunsmith chop my Sig m400 down to 11.5". Its not bringing up the next round, probably 2-3 per 10 round mag. Also not holding open
on last shot, about 60% of the time. My gun smith is good but says he's "no expert on ARs'. Now I need to figure out whats wrong on my own. Ive asked a few people but no one really knows. Buffer, gas port..., any suggestions?

 

[Dsiwy]

Gas port needs to need bigger and HH buffer should be used

 

[lincoln1]

How do you figure out the size it needs to be? Gunsmith said he didn't know? I'm in Ottawa. Any place besides Gunco? Thanks.

 

[cadgo]

First problem would be that chopping the barrel makes it prohibited but w.e.

 

[sewktbk]

Sorry to say, but I wouldn't call your gunsmith "good" if he works on guns without knowing what the hell he's doing. Let alone that he's breaking the law.

And now, you are too...by your own admission on a public forum known to be monitored by the RCMP/CFOs.

Way to go.

 

[Throttle_monkey1]

Yup you have a prohibited gun now that doesn't even function. Good job!

 

[556NATO]

How do you figure out the size it needs to be? Gunsmith said he didn't know? I'm in Ottawa. Any place besides Gunco? Thanks.

Use google search engine and type in "AR 15 gas port hole size"

here is what I found

For 5.56mm
Colt's gas port sizes are:
* 10.5" - .093
* 11.5" - .081
* 14.5" - .063
* 16" - .063

 

[Stephen1546]

Yeah, you need to go buy a new barrel and dispose of the old one. You are in possession of a prohibited device. Your gunsmith also needs to go read up on Canadian firearms laws if he wants to continue being a gunsmith.

 

[tiriaq]

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