Gunsmithing What is considered match headspacing ?

[AR15KittyKat]

Is Go-Gauge + .001 to .002" considered match head spacing ?
So using a Match Forster .308Win 1.630"(goGauge) - 1.632" gauges w/ .001" increments, bolt closes on 1.631" w/ slight resistance, and doesn't even budge on 1.632".

 

[GasLight]

Re: What is considered match headspacing ?

That would be good headspacing, but I don't think the term match is associated with headspacing, but instead a chamber, most likely designed for a match bullet. I think a match chamber is called such based on the chamber reamer.

Dave

 

[GasLight]

Re: What is considered match headspacing ?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: AR15KittyKat</div><div class="ubbcode-body">Is Go-Gauge + .001 to .002" considered match head spacing ?
So using a Match Forster .308Win 1.630"(goGauge) - 1.632" gauges w/ .001" increments, bolt closes on 1.631" w/ slight resistance, and doesn't even budge on 1.632".</div></div>

Sounds like you are set.

 

[scotharr]

Re: What is considered match headspacing ?

I'm not sure SAAMI minimum headspacing will do anything for accuracy, especially when using fireformed brass. But I am sure it will potentially cause function problems. I think "adequate" chamber headspacing should be the objective: not minimum. With minimum chamber headspace you might run into issues where your sizing die can't bump the shoulder enough or you have to bump the shoulder shorter than even new brass. To avoid headaches like this, I insist that the bolt can close without resistance on MY GO-gauge.

 

[LRI]

Re: What is considered match headspacing ?

I know of one particular case where headspace made all the difference in accuracy.

I'd built a 6mm 284 on an "Oby" barrel. It was "minute of 8.5x11 sheet of paper" at 100 yards.

The gun just sucked eggs, ass, you name it.

During the headscratching(to the skull!)I plopped a GO gauge in the chamber at the encouragement of one of my cronies. "Hmmmmph, the chamber is a smidge tight." Now how the hell did that happen?

We squeaked the chamber to GO+.002" and all the sudden that rifle went into the teens.

No chit.

I personally think it may of had something to do with using previously fired 6.5/284 brass necked to 6mm without trimming the necks. I'm betting the very end of the neck was being "crimped" by the chamber and causing all sorts of hate/discontent with release tension and whatnot.

I really don't care, what it was. The rifle shot exceptional after that and I've always tried to hold that GO+.002" value since.

Hope this helps.

C

 

[scotharr]

Re: What is considered match headspacing ?

So, your experience confirmed that "adequate" headspace was better than minimum headspace: thanks!

I'm gonna send you a rifle to build yet Chad!

PS. I'm a big fan of Defiance: not sure how you feel about that.