24 March 2005, 14:05
morton3How to HEADSPACE ?
How does a gunsmith measure headspace accurately?
I`ve heard of these go/no go gauges & can get the drift of how they would work, but the more accurate rifles like bench rest stuff would rely on far more stringent tolerances than that I`m assuming ?
Also when it comes to reaming a centre fire chamber, is this done with the reamer only on the new barrel blank or do the gunsmiths machine some of the metal out to get close to the chamber size prior to using the reamer ?
How do you know when to stop boring the reamer into the barrel blank, giving the exact length you need ?
Is reaming done at a slow speed or fast ?
Is there a website that answers these sort of questions ?
Thanks in advance for your replies.
Morton
Headspace is measured with the go guages you mentioned. Some use a piece of brass, and that's OK if you're carefull. As far as methods, go to Mike Bryant's website, he has an excellent article on how he does his work. And he does excellent work.
24 March 2005, 17:19
jeffeossoGoodness Morton...
There's at least one full book in your questions. I'll hit the high points, for directional answers.
quote:
Originally posted by morton3:
How does a gunsmith measure headspace accurately?
Some dont do it s accuractely!!! this is, roughly speaking, the amount of the brass that sticks out of the barrel chank as compenstated by the other end of the breech (bolt, block, whatever)
I`ve heard of these go/no go gauges & can get the drift of how they would work, but the more accurate rifles like bench rest stuff would rely on far more stringent tolerances than that I`m assuming ?
nope.. they relay on concentricity, tight necks, perfect alignment, awesome barrels, etc.. but zero headspace is zero head space... where it's in a handirifle or a 10K benchgun
Also when it comes to reaming a centre fire chamber, is this done with the reamer only on the new barrel blank or do the gunsmiths machine some of the metal out to get close to the chamber size prior to using the reamer ?
can be done either way. most of the time when you hear of a reamer, it's a finish reamer.There are roughers. Some folks use them. Some folks use a drill or a boring bar to get "rid" of the extra material
How do you know when to stop boring the reamer into the barrel blank, giving the exact length you need ?
I aint the best in the world on this, so I bore the reamer, stop, measure the head space, repeat
Is reaming done at a slow speed or fast ?
depends on the reamer. generally 120-150 rpm
Is there a website that answers these sort of questions ?
http://www.accuratereloading.com
Thanks in advance for your replies.
Morton
25 March 2005, 05:35
Jim KobeI had a problem reaming at low speed. With the new PTG reamers, and depending on the size of the chamber, faster has always been better for me. The last 223 I did, I reamed at 280rpm and it came out great; cut like butter.