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Green mountain barrel blanks

I am looking to have a low dollar build assembled in 223 for my son on a model 700 receiver I just picked up. How are these blanks? It sounds like the reviews of the 10/22 and ar15 barrels are decent.

Thanks for any input!
 
Good. On the few builds I saw as a student at colorado school of trades the accuracy was better than most factory rifles when care was taken in the builds. I also have had excellent results with McGowen barrels BTW as an alternative. I did 2 308's one 1-12 and the other 1-7.5 twist. Both shoot very well for a non cut rifled barrel.
 
I have 3 bpcr rifles with GM barrels and they all shoot very well. My 45-90 is especially accurate. For the price a GM barrel is hard to beat.

Rpbump
Minesweeper3433 said:
Good. On the few builds I saw as a student at colorado school of trades the accuracy was better than most factory rifles when care was taken in the builds. I also have had excellent results with McGowen barrels BTW as an alternative. I did 2 308's one 1-12 and the other 1-7.5 twist. Both shoot very well for a non cut rifled barrel.
 
Green Mountain barrels shoot pretty good for the price. If you want a much higher quality barrel blank, X-Caliber barrel blanks will run you about the same price. X-Caliber offers tighter tolerances, hand lapping, proper heat treatment, more available twist rates, and 5R rifling if you so desire.

And if your forum name is states to where you actually live, you may be pleased to know that X-Caliber is a Montana company based in Kalispell.

http://x-caliber.net/main/XCAL-page.asp?P=1
 
+1 on the X caliber

they have the latest machine on hole drilling, they have the latest equipment on Honing the hole after it is drilled(prior to rifling), and they hand lap the barrel.

Little to no copper fouling, about the same as my Lilja, Brux.
 
I had some very surprisingly good results with a few GM blanks in the 12 twist .224". They do run a little loose and shallow on the lands, but you certainly can't tell on paper other than they might lag a few fps slower. I built an AR on one and after contouring I hand lapped the bore before chambering and cutting/crowning. It lapped out very easily and shot easily 1/2 MOA from a semi auto. Nothing to complain about for a $40 or $50 blank.
 
msalm said:
I had some very surprisingly good results with a few GM blanks in the 12 twist .224". They do run a little loose and shallow on the lands, but you certainly can't tell on paper other than they might lag a few fps slower. I built an AR on one and after contouring I hand lapped the bore before chambering and cutting/crowning. It lapped out very easily and shot easily 1/2 MOA from a semi auto. Nothing to complain about for a $40 or $50 blank.

Could you possibly share your lapping procedure? Thank you.
 
I am running two GM 1:7 223 barrels. One on a 20" SPR and one on my service rifle. They are 3/4 moa shooters, which is all I am with a gas gun truth be known. I have two of their 27" 6.5mm blanks stashed away for a moth balled Grendal varminting upper.

I think you'll be happy with the performance if you can do your own profiling. I would recommend the 27" 1.20" blanks for a bolt action. Gives you more meat for the threads.
 
Sure, ....cast a lead lap and use aluminum oxide, maybe 150 grit to no finer than 180/220. I mix it with plain grease. The aluminum oxide will break down over time and create the finer finish you're looking for. Pour about a 3" or a bit longer lap and use a borescope. You can start lapping from the breech end with long strokes, work more of the breech end and go to town...if you feel a tight spot, work it out with short strokes in that area...especially if there are looser spots towards the muzzle. Towards the end I may add a little Kroil but it's not necessary. I'll only do this with un chambered blanks or ones I'm cutting at least an inch off the muzzle as the abrasive will roll between the lap and the steel and gall/scuff the finish a bit. If the bore reamer marks aren't too deep it won't take too much effort to lap them out. They also don't have to all be removed though, but it's nice when they do.
 

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