Author Topic: frame to barrel gap and headspaceing (Read 504 times)

quicksdraw45 · « **on:** December 31, 2003, 07:31:09 PM »

I have two contender frames and checked the frame to barrelgap with just one barrel, The gap on one frame is .0015 and the other .006 . Is there a point were this should become a concern ?
I havent checked any of my other break action guns to see what it is with them .
I have read about sizeing cases to minimum headspace , What are the opinions on this practice ? and is the goal .000 ?

KYODE · « **Reply #1 on:** January 01, 2004, 02:34:27 AM »

i'd guess, that i'ts just gonna vary quite a bit. out of 4 contender frames i've measured, i think my 6tcu had the most at .010", and i think the least was around .005".
i hadn't really examined what determines the barrel to frame gap. maybe it's the hinge pin placement in the frame. :?
so far, i've tried to size my cases so i have .001" less case protrusion, than the measured barrel to frame gap.
the barrel to frame gap, i measured with plasti-gage. i picked it up at an auto parts store. it's really cheap, and seems to work.
i measure the resized case protrusion from a removed barrel. this can be guessed at with feeler gage blades, but i found it to be difficult, and really just that, guessing. i bought a headspace indicator that takes this measurement. works pretty good at it too, and also gets an accurate measurement of how far the bullet is seated off the lands. i just havn't used the tool enough yet to get that far with it yet.

i was just having several issues, when i was resizing cases, that either caused misfires in my contender, or would not let the hammer cock on my encore. it was probably my inexperience at setting up the full length sizer to get slight shoulder bump. also, i think i was pulling the shoulder back out slightly with the expander ball. i'm in the process of working all these issues out. i just havn't loaded any ammo in the past couple months, since before deer season.

drdoolittle_1 · « **Reply #2 on:** January 01, 2004, 03:41:16 AM »

Hey Kyode,
I've never checked this, have you.........Does the barrel/frame gap stay the same with the same barrel when moved to different frames? ie: 7TCU barrel on frame #1 is .002 and when put on frame #2 will it still be .002 or will it change? And do you size this way with rimmed cases with a shoulder, also? I'll have to check this!
Cheers,
Dave

edited to say: Should have read quicksdraw45's post slower....apparently he has done this

KYODE · « **Reply #3 on:** January 01, 2004, 05:08:39 AM »

no, i havn't done that either. i havn't been moving from frame to frame. i've been keping each to it' own.
only rimmed one i shoot is 30-30AI. i havn't measured those yet, but yes a rimmed case will be the same.
maybe since they formed to the improved version, they are not on the shoulder yet, as they are probably still on the rim, the first firing,or two. i'll have to see as i fire more later on. :?

drichi · « **Reply #4 on:** January 01, 2004, 05:12:03 AM »

I have checked the same barrel on three different frames and the barrel to frame gap does change on different frames. It was as much as .003 different on mine. drichi

drdoolittle_1 · « **Reply #5 on:** January 01, 2004, 05:16:27 AM »

So, if we are going to take the extra time to measure and size for .001" headspace, we best keep track of which frame it was measured on!
Thanx