6GT COAL 2.48 too short??

[DocRDS]

I seem to have a really short COAL for my 6GT

Using Hornady 105 BTHP + alpha brass (virgin). It seems I'm in the lands a 2.52 which is shorter than a lot of book COAL. Got some tough bolt close and rifling marks on ejected rounds (I have not officially measured as I'm still working up my loads) Brand new barrel (less than 60 rounds) from SPR and Impact action.

ANd yes, I get paranoid when things are odd...thing is a hammer though, so take my FN AI arm strength and close bolt. But thought I better ask.

 

[kilizyrag]

Mine are at 2.40 which is .023 off the lands. Of course my comparitor my differ from yours.

 

[DocRDS]

So in my OCD panic I called my barrel guy (Shout out to Bugholes/Southern Precision Rifle for talking me off a ledge).

What he was worried about is would the brass chamber (headspace). I had 0 headspace issues with raw brass and no pressure signs when I was doing load development. Also my "dummy" round was a deformed brass piece from the mfg that had a dent, so it may not have been in spec--plus I was using BTHP which of course will be shorter than ELD-Ms or other "tipped" bullets. (yes i get triggered when I have 99 pieces of brass instead of 100--I have "issues"-- Sampling brass for the AMP annealer is like sacrificing a firstborn!)

As @kilizyrag did, he recommeded i just skip to a bullet comparitor. If brass is good, find my chamber length, get the comparitor and stop worrying (good advice for me in general). Biggest problem for me at first match after taking a deep breath was wind calls....barrel is a freakin lazer beam.

I know 6GT is not a wildcat, but a lot of data out there is crazy even in reloading books and my OCD goes nuts when something doesn't match. Twas a learning experience.

Anyway for future idiots like me, headspace is what you worry about. NOT OAL.

 

[4O6shootist]

The 105bthp is a long bearing short nose junk bc bullet. That's why you're touching lands with shorter oal. If you used heavy Berger, atip, or 109 eldm your oal touching will be longer. Freebore makes a difference on this as well.