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12.5 inch Sig Barrels for $49.99!


jtallen83

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3 hours ago, shooterrex said:

11 1/8" ordered length. 1/16" drill bit was too small next size up I had was 3/32" if there was way too much gas I was going to get an adjustable gas block. New barrel will be here Monday.  Cobalt bits In 64's arrived today. Think I will Install the new barrel and mess with the stuck bit latter. Think I will drill out new barrel to 5/64" before I even install it. Now where did I put that dimpling jig?

5/64" is what I drilled the 223 barrels and the 308 barrel at, cobalt bit, WD40. The 223 (QPQ Nitride?) barrels were way worse then the 308 chrome barrel, drilled 1/16 first then 5/64.  Using the fine feed on a mill would really be the way to go using minimal protrusion from the chuck.  The 223's run fine with the $4.99 gas block at that diameter, put an adjustable on the 308 adjusted a little over a turn in from wide open so for sure plan on an adjustable if you drill 3/32". 

Just thinking, What are 12-1/2" barrels going for with a broken off bit in the gas port? I know someone who might be interested.

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3 hours ago, shooterrex said:

The new barrel arrived today. Drilled it out to 5/64. Punch did knock out the piece of bit in the 1st barrel. That port is 3/32. If I build another pistol I will use a adjustable gas block on that.

How did you clean up the burr? I was going to run a reamer through mine but the cut looked clean and didn't want to risk it. 

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7 hours ago, Slugger said:

Interesting, I come up with about .062" gas port on the barrel I have. 

I had .073 on a 7.62x51 marked barrel and it runs great. Made the measurement with chineseum  calipers using chineseum number bits for a gauge. Calipers were accurate into the 4th decimal point last I checked them on a standard.  Odd, now we have two different factory gas port sizes and two different gas tube lengths.

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  • 4 weeks later...
On 9/15/2019 at 8:44 AM, jtallen83 said:

I had .073 on a 7.62x51 marked barrel and it runs great. Made the measurement with chineseum  calipers using chineseum number bits for a gauge. Calipers were accurate into the 4th decimal point last I checked them on a standard.  Odd, now we have two different factory gas port sizes and two different gas tube lengths.

Think I found the gas tube length difference. First gas block I had was dead center of cam pin cutout. Adjustable gas block is shorter than first 1. Now gas tube is past the middle of cam pin cutout. Not by much but maybe an 1/8. I'll post pics this weekend I'm at work now.

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