Need Advice - Bullet Not Seating Properly

[arroyobuck]

First Post.

I have been reloading on and off for a fair amount of time (about 40 years). During that time I have never had to crimp. The bullets have always seated "tight" enough so that it was not required. However, I just started loading for the 7-08 which is a new cartridge to me. I purchased some new full resizing RCBS dies and have been loading 139 Interlocks and 140 Accubonds. Both bullets seem to not be seating as "tight" as they should. In fact the Interlocks can be moved by pulling or pushing on them. That's no good. I know Interlocks have a cannelure (sp?) and are probably intended to be crimped, but I have never had to do that before on other rounds that I load for.

What do you guys suggest I do? Do you guys crimp as a routine? I would like to stay away from it if at all possible as I know it adds another step that can affect accuracy if not performed "perfectly"

Is it possible that I have a bad re-sizing die?

Thanks for your help

AB

 

[SAPPER26]

I would say it's a bad re-sizing die. The only cartridge I've ever crimped is a 375 H&H. The only reason I did for that was that it was an exceptionally hard recoiling 375. Use a micrometer to measure the inside of the case mouth after resizing, if it's giving you less than .002 smaller than your bullet diameter, then your sizing die might be too "big". I'm not too familiar with the 7/08 and what brass it uses, could be your brass is thinner than normal too. If that doesn't get you started on a solution, I'm sure someone else on here might help you more. Good luck.

Grant

 

[Broz]

First off I have never crimped a centerfire and have no plans to. That is not your problem. I have had one bad die before that didn't size necks down enough to hold a bullet. It was a RCBS. So the first thing to do is get another die.

Also, be aware that if the brass has been loaded and sized several times the necks will work harden and spring back as they are sized. This will result in inconsistancy and loss of neck tension. In this case your brass necks need to be annealed.

Jeff

 

[boogsy]

Don't go get a new die yet! Take the expander pin out of the die and size a case without it then measure the inside of case mouth. Also measure the expander ball. If need be you can emery off .001 or so to leave a tighter grip on the bullet. This ball is hard so it will remove slowly but watch you don't remove to much or you'll be SOL.

 

[TRG300WM]

I tend to agree with Broz's last statement I have noticed inconsistency in neck tension after 5 to 6 reloads on a the same case, annealing may help here.

 

[arroyobuck]

Thanks all. Good stuff here.