problem with neck die

[1moa@500]

I went to the range yesterday after reloading 50rds of 257 roberts for my ruger ultralight. I use a load that I have used for years, 42grns h-4350, 100grn hornady sp, ww case, cci primer, at an oal of 2.860 which in my notes is the oal I have used for 5yrs. I used a rcbs neck die and the brass has only been reloaded twice. the problem is that the rounds were hard to chamber and I retired after only one round. I asked several of the older gentleman that all shoot together at the end of the of the range( i did not want to say old farts but it would have been faster) what the problem was. I got several different answers but nothing conclusive. I later measured the rounds only to find the shoulder dimentions were not correct. Could this have been due to running the brass to far into the die? any info would help

thanks guys

 

[Ol` Joe]

Just thought or two from another old fart

Did you lube the case mouths when you sized them? The expander ball can stretch the case shoulders out some if they drag when pulled back out. (most likely cause)
Are the cases all fired in your rifle or are they once fired in another rifle or range pick-ups?
What brand/type of neck die are you useing?

 

[1moa@500]

reply

no i did not lube the necks when i reloaded them. The brass was purchased new and once fired in this rifle. I guess i will break out the green hammer the next time the wife is not home. The die is an rcbs neck die

 

[CB900F]

1Moa;

Carefully measure all critical dimensions on a virgin brass. Run it through your neck sizer & measure again. Then, send another virgin through the neck sizer, but this time lube the inside of the neck with a little powdered graphite.

Then, compare the neck diameters & shoulder postitioning between not only the two virgins, but one of your loaded rounds that's giving you trouble. If you don't have a decent, not plastic, dial caliper, you might wish to consider getting one.

Did you change the decapping pin recently? I'm presuming that this die has been used for quite some time by you, but am looking for something that might have changed in the expander plug.

900F

 

[1moa@500]

found it

what I found after measuring the brass is that I ran the brass too far into the die. therefor causing the shoulder to expand slightly. i backed the die off a full turn and the shoulder dimention remained unchanged thanks for the help

p.s. I have a digital caliper from harbor freight, works good