Reloading Question

[GSPHunter64]

My rifle is a Bergara B-14 HMR in 6.5 Creedmor, I am really happy with the way it shoots but when I am reloading I am having a lot of inconsistencies with the head space measurement and not just a little. The longest is 1.5415 and the shortest is 1.5380, should I be concerned with this and what should I bump the shoulder back to when resizing?

[Dick284]

Your base to datum line is varying that much?

If that is what’s happening, it would mean you’ve got varying pressures or brass hardness.

[Faststeel]

Originally Posted by GSPHunter64

My rifle is a Bergara B-14 HMR in 6.5 Creedmor, I am really happy with the way it shoots but when I am reloading I am having a lot of inconsistencies with the head space measurement and not just a little. The longest is 1.5415 and the shortest is 1.5380, should I be concerned with this and what should I bump the shoulder back to when resizing?

Are you using more than one brand of brass for your rifle...?

[GSPHunter64]

Yes I have used Hornady, Nosler and Lapua ammo (trying to find what works best), but it’s not like all the Hornady ends up being the same or all the Nosler ends up being the same, etc. it just seems random. I would have thought (but don’t really know) that regardless of the case or pressure they all would have expanded to the chamber the same. Really all I need to know is what I should bump the shoulder back to, I would assume .002 from the longest case would be correct, or should they be shorter just to be safe.

[Dean2]

If the empty cases chamber properly with no resistance then I would neck size them and NOT bump the shoulder at all. I have cases that have 15 firings on them, always neck sized, never annealed and have never needed a shoulder bump. I test fit all reloads BEFORE taking them hunting, but I have never found ones that didn't fit, though my hunting rounds only have a max of 4 firings before they get put into the target round rotation.

[catnthehat]

If you are using a FL die and not being consistent on the speed and force you are using on your press it is possible to get those variances .
However if you are happy with the way it is shooting do not get bent out of shape about it, little stuff like that will drive a person to distraction at times .
Cat

[Salavee]

If you have a Comparator, measure BTO ( base to ogive) rather than COAL.
using the same brand of brass.

[Dean2]

Originally Posted by Salavee

If you have a Comparator, measure BTO ( base to ogive) rather than COAL.
using the same brand of brass.

He is measuring to the shoulder, and from the measurements I see he is trying to measure the shoulder datum line and getting quite a variance. That can actually be caused by all sorts of things that are very hard to diagnose unless you were right there doing the measuring, but long and short, what matters is if the case fits in the gun.

[Pathfinder76]

A couple of things. What tool are you measuring with, and are there primers in the cases?

[Twisted Canuck]

Originally Posted by chuck

A couple of things. What tool are you measuring with, and are there primers in the cases?

Wait, what? You're back! Welcome home black sheep!

[GSPHunter64]

No I removed the primers because I though that might have been giving me an inconsistent measurement. I'm using the Hornady head space comparator with a good high quality set of calipers.

[catnthehat]

Originally Posted by GSPHunter64

No I removed the primers because I though that might have been giving me an inconsistent measurement. I'm using the Hornady head space comparator with a good high quality set of calipers.

Primers should be properly seated slightly below the case head anyway .
Is the caliper a vernier scale, dial or digital?
I know most machinists and millwrights have a very big disliking for digital calipers because they can give inconsistent tea finds .
I would like to see how well that rifle shoots before anything else however .
Cat

[Pathfinder76]

These are fired cases cat. That can change things with primers.

There should not be this much variation in measurement. Three thou variation can happen between brands of brass, but with same lots I don’t think I’d see more than one thou.

[catnthehat]

Originally Posted by chuck

These are fired cases cat. That can change things with primers.

.

Ah yes forgot about that!
Cat

[pikergolf]

Are these cases being measured coming from the chamber after firing or coming out of the resizing die?

[Pathfinder76]

Are you spinning the case in the comparator?

[fps plus]

Calipers are not designed to measure accurately to 100thousandth if an inch. Need a good micrometer for that

[GSPHunter64]

I just wanted to give an update, I have gotten into reloading a lot more than I thought I would, and I really enjoy it. I ended up doing a lot of research and got myself an annealer (Annie Fluxeon Annealer) this seems to have made the biggest difference in resizing consistency and shooting consistency that I have tried.

[catnthehat]

Originally Posted by GSPHunter64

I just wanted to give an update, I have gotten into reloading a lot more than I thought I would, and I really enjoy it. I ended up doing a lot of research and got myself an annealer (Annie Fluxeon Annealer) this seems to have made the biggest difference in resizing consistency and shooting consistency that I have tried.

The big question is has your accuracy on target improved
Cat

[Ariu]

I am assuming the measurements are done on 1 time fired (not sized) brass and no caliper or other tooling problems.

The virgin brass does not always get fireformed to full chamber length. Variances on pressure, different trim lengths, or different brass properties cause the brass to be stretched differently.
Take the longest spent brass and chamber it. If it chambers OK, this is most likely your chamber length.

[GSPHunter64]

Originally Posted by catnthehat

The big question is has your accuracy on target improved
Cat

Yes accuracy on target has improved, as well as SD's and ES's have gone down.