How do I get oal and headspace on an M1A?

[Mag 300]

I have shot bolt rifles for years and know this for all bolt rifles , what do I have to get or buy to beasure headspace and oal for the m1A. or is it worth it on a semi auto .
Feel free to laugh I feel rather dumb asking but this is where I have gotten a lot of answers and learned a lot.
Thanks Bill

 

[C.Hazelton]

Re: How do I get oal and headspace on an M1A?

Bill, I use a RCBS precision mic for measuring once fired cases and setting my full length sizing die. You could also use a Redding instant indicator, both are caliber family specific as they index off the datum line.However the Redding product works best if you have two presses. For oal I assume you mean coal and you are limited by magazine length, for single shot loading I find the length with a Hornady (formerly Stoney Point) coal gauge and a modified case. This style is bent for use in semi-autos, levers, pumps etc. Hope this helps.

Regards, Chris

 

[308isgreat]

Re: How do I get oal and headspace on an M1A?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CVH</div><div class="ubbcode-body">Bill, I use a RCBS precision mic for measuring once fired cases and setting my full length sizing die. You could also use a Redding instant indicator, both are caliber family specific as they index off the datum line.However the Redding product works best if you have two presses. For oal I assume you mean coal and you are limited by magazine length, for single shot loading I find the length with a Hornady (formerly Stoney Point) coal gauge and a modified case. This style is bent for use in semi-autos, levers, pumps etc. Hope this helps.

Regards, Chris </div></div>


+1

 

[Mag 300]

Re: How do I get oal and headspace on an M1A?

Chris it does ,
You are correct it was COAL I have that under control but the bent stoney point was new to me
Thanks
Bill

 

[Greg Langelius *]

Re: How do I get oal and headspace on an M1A?

The proper method to set up headspace from the M1A/M14/M21 uses the rifle itself as the headspace guage. The method is to disassemble the bolt, then reassemble the barreled action only, without the recoil spring or spring guide. Lube normally.

Using a cartridge that has been fired and will not chamber because of excessive shoulder length, resize it to
shorter lengths in small increments.

When the rifle can be tilted with the muzzle 30degrees down and the bolt and oprod will slide and lock with the oprod at full forward stroke from gravity alone with the case in the chamber, headspace is correct. If you can still push the oprod further forward by hand, the case still needs to be shorter in the shoulder.

As far as seating depth and OAL are concerned, seating to magfeed length is good enough that seating longer doesn't buy enough accuracy to offset the hassle of single feeding. For matches, feeding methods are specified, and for slow fire, where single feeding is mandated, extended seating lengths are justified.

Greg

 

[TomS308]

Re: How do I get oal and headspace on an M1A?

Check out the M-14 Forums http://m14tfl.com/upload/