Observations on component and OAL tolerances

[lever.gun]

New to reloading, before I even go out to the range I would like to hear if others here see what I see from their presses.

I'm loading 44 mag. I am using Nosler JSP 240gr.
I recently took a 10 shell-random sample of my favorite factory ammo and found +/-0.0045. I must say there, on one of the shells, the bullet was even a little out of square with the case.

I can't seem to do any better than about +/-0.006 in. OAL, and based on my results sorting components won't reliably change that much. So it is all my dies, press and their installation. Should I accept that? Any suggestions?

Here is why I say that sorting won't help:

I recently experimented with the effect of component variation on final OAL. For 10 samples, I measured case length after trimming, case weight, bullet diameter, bullet length, and bullet weight. I then assembled the cases and bullets without powder or primer, measuring case length after sizing and expanding as well as final OAL. I ran the results in XL and SAS, and beleive me when I say that I couldn't find any significant effect from any of the case or bullet characteristics on either case length after sizing or final OAL. As might be expected, there is a small, marginally significant tendency toward longer OAL when the biggest bullets are paired with the heaviest cases. I can post my component tolerances and models for their effect on OAL elsewhere, if anyone is interested.

Thanks for any comments and advice.

 

[rick smith]

The length of the bullet and it's meplat consistancy will effect seating as will the way you work the press. You can seat a bullet 0.002 deeper by bumping the handle down harder at final seating. I don't think you will see a significant difference on target. But 0.006 is a fairly large variation. your beller may be part of the problem. As with expander balls, I polish them for smoother operation.Rick.

 

[lever.gun]

Thanks rick. I will take more care on operation, to begin with, looks like that alone might get me down near factory tolerance. It just seems a little disappointing to have to say that I am trying to get down to mass production tolerance.

But it sound like a few ten thousands won't do much to point of imapact.

The problem is, as soon as see a short, which I can see right away by where the mouth of the brass sits in the cannelure, then I put the calipers on it, then I start inkering with the die. Then it's all over.

 

[rick smith]

I load all my pistol rounds on a Dillon 550B and set the seating die so that the top of the cannelure is at the top of the case neck. When the crimp is applied, it generally is approx just above the middle of the cannelure. Load and shoot. While some 44s are quite accurate, a little difference in OAL does not change much on target. It is a short range round. I have taken deer and hogs with a 44Mag and prefer it when hunting in the swamps. Don't get too carried away with trying to get every round exactly the same for the 44. It will work just fine with some variation.Rick.