Berger 80.5 gr FullBore

[PopCharlie]

I've been using these bullets in my bolt gun, getting quarter MOA at 100 yards. I seat them at 1.861, which in my rifle, is jamb minus .020. I use a Wilson in line seater with an arbor press. I get very consistent seating depth with this setup. However, for this batch seating depth was all over. 1.855 to 1.875 for the first few I seated. I stopped and measured 10 random bullets out of the box. The BTO measurements ranged from .550 to .522! I set that box aside and opened a new box and measured 10 random bullets again. These measured .5285 to .5290, BTO. This is what I normally see for this bullet. I finished seating bullets from this box. All good at 1.861.
I measured all of the remaining bullets in the "bad" box. This is what I got:
1 .519
1 .521
50 .522
9 .523
13 .524
9 .525
2 .538
3 .539
2 .540
1 .550
The weight was good, between 80.4 and 80.5 gr. I had 1 @ 78.4 grs however.
I usually dont sort Berger's because, they are very consistent for weight and BTO. Very odd that none of this box measured the normal .529. WTF?
Anybody else seeing this sort of crazy?
PopCharlie

 

[grovey]

Wow... I've been tinkering with that bullet a bit myself, but haven't measured them. Mostly because I don't have a good way... I did find a few that varied .002 to .003 once seated, so you have me wondering because my load isn't compressed.

 

[Ned Ludd]

The numbers you posted might be considered normal for OAL variance within a typical Lot of Bergers, but not for BTO variance. In my hands, OAL variance within a given Lot usually falls in the .015" to .020" range. There can sometimes be very small number of extreme outliers that could possibly pushing the OAL variance to as much as .030" to .040", but I typically don't worry about those and use them for sighters/foulers.

I don't normally sort bullets BTO, using OAL sorting solely for the purpose of pointing. Nonetheless, I have measured BTO on numerous occasions for small batches of bullets as you did above and never seen variance that large (i.e. your BTO variance of ~.020" to .030"). I typically find the BTO variance to be only about 1/4 to 1/3 of the OAL variance or less, something in the range of just a few thousandths. It seems you may have gotten a bad box, maybe from the very end of a run or something like that. It happens. Have you contacted Berger about this issue? That's where I would start.

 

[PopCharlie]

Wow... I've been tinkering with that bullet a bit myself, but haven't measured them. Mostly because I don't have a good way... I did find a few that varied .002 to .003 once seated, so you have me wondering because my load isn't compressed.

My loads are not compressed either. Im testing imr 8208 xbr vs. Re 15....no compressed loads. Ive had very consistent seating up till now. Usually half to one thou.

 

[jelenko]

Berger probably would like to know your test results.

 

[PopCharlie]

The numbers you posted might be considered normal for OAL variance within a typical Lot of Bergers, but not for BTO variance. In my hands, OAL variance within a given Lot usually falls in the .015" to .020" range. There can sometimes be very small number of extreme outliers that could possibly pushing the OAL variance to as much as .030" to .040", but I typically don't worry about those and use them for sighters/foulers.

I don't normally sort bullets BTO, using OAL sorting solely for the purpose of pointing. Nonetheless, I have measured BTO on numerous occasions for small batches of bullets as you did above and never seen variance that large (i.e. your BTO variance of ~.020" to .030"). I typically find the BTO variance to be only about 1/4 to 1/3 of the OAL variance or less, something in the range of just a few thousandths. It seems you may have gotten a bad box, maybe from the very end of a run or something like that. It happens. Have you contacted Berger about this issue? That's where I would start.

Seems like there were the tail ends of a few runs that were thrown in to fill a box. Ihad 2 bullets that had bad dents i n them. I have never seen this before, having shot thousands of Berger bullets since the early 1990s.