This will be the last post about this 30.06 Ackley project I have going (I hope!) but here goes. I fireformed cases in the rifle I'm loading for, neck sized subsequent rounds, and the bolt closes VERY hard on them now. I smoked the cartridges and found that the contact was being made at the outside edge of the shoulder (largest diameter portion of the shoulder.) Is this typical of the AI family of cartridges? I hate to full length size due to accuracy and case life concerns. Can anyone think of a reason why a fireformed case will "oversize" for the chamber it was formed in and what I can do about it? I'm worried about trouble with quick follow ups on game, potential loadinig of brass shavings in the chamber at the point of contact and thinning of the case at the contact point. I'll thank everyone in advance for any help you can offer (bear season is on.)

First, will the fired cases chamber easy before your neck size them?
If they do you are likely bumping the neck/shoulder junction with the neck sizing die. This will cause the unsupported ( in a neck size only die) body/shoulder junction to expand and thus cause your problem.
I would try backing the neck sizing die out a 1/4 to 1/2 turn and see what happens.

Feel free to e-mail me directly if I can be of any assistance.
milender@ictc.com

http://www.anglefire.com/nd/243ackleyimproved

Good Hunting
Jeff in ND

I had a 7x57 AI once that did basically the same thing. Neck sizing with RCBS custom die didn't bump the shoulders back enough to allow the round to chamber easily. Had to really bear down on the bolt and the groups opened up LARGE. I ended up getting a full length die that pushed the shoulder back a few thou and also the diameter at the shoulder was reduced enough to allow the round to chamber easily but firmly. The groups went back down also. I talked to one of the more knowledgeable members of the club and he suggested grinding off the bottom of the neck die or the top of the shell holder a few thou to see if it would bump the shoulder enough to get the neck die to work. I did the shell holder 0.005" and it worked. I still had to full length resize every second or third or so because I had magnumitis at the time and stuffed the hell out of the case every time. Cases didn't last more than 5 loadings either. Ended up pulling a lot of bullets and resizing because I never knew when I got too long. Finally made a tool to check the shoulder length so I would stop all the extra work. I only have a 250 Sav AI left from those days and have learned not to push it so far. Just get a bigger gun.

Thanks for the ideas--You're right, I'll try to chamber empties tomorrow (loaded everything I've got already.) And because I'm using a FL die backed off that may need tweaking also. If fit remains tight when does a guy start to worry about brass deposition in the chamber? Over the life of a rifle will this slowly build up? Anyway I'll run some test on your suggestions tomorrow and let you know--feelin like a newby--really appreciate the help.

Had the same problem with my improved 303British.
Solved by neck sizing only a portion of the neck. Back off the die and try it.

Snowcat,

Welcome to the forum.

We have built many Ackley Improved rifles, and we always full length size our case.

This has not affected the accuracy of our rifles at all - as all of them will shoot groups 1/2" or better.

What is important here is that the reamer and sizing die match each other.

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saeed@ emirates.net.ae

www.accuratereloading.com