Case sizing problems?

[bigedp51]

Below from the SAAMI .300 WM drawing and between the shortest case length and the longest chamber to the shoulder measurement you can have .026 clearance.

You need a new gunsmith and a Hornady cartridge case headspace gauge.

Plus just above the belt you can have a difference of .010 and why they sell the belted magnum collet resizing die.

 

[MagnumManiac]

I'm shooting a Rem 700 in .300WM. It has the 26" 5r barrel. My load is WW brass, 76gr H1000, WLRM primer, 208 AMax bullet and a COAL of 3.420".

The load has proven accurate in my rifle. Making one hole groups at 100yds and 4" groups at 500yds shooting off a backpack.

The problem... I ran out of loaded rounds so I made more. About 100 more. But I used once fired Rem brass. Probably shouldn't have switched but I had it on hand. The bolt was quite sticky when I ejected the fired cases. Rubber mallet sticky. I knew there was a problem so I went home and pulled a bunch of bullets and the powder charges were correct. So I loaded ten more in WW brass thinking that's all it is. This brass had been fired five times before. The first two shots left cases stuck in chamber, same as the ones in Rem brass. So I put those away and fired three different brands of factory ammo and it was perfect. No problems.

Is my FL sizing die out of adjustment? Would the Hornady headspace gauge kit show me what is out of whack?

Thoughts?

The simple answer to your problem is this, you have a short chamber and a die that isn't pushing the shoulder back far enough. Your chamber isn't the issue, on average, belted magnum cases will grow in the shoulder up to .026", some sloppy chambers will be more than this.
The easiest fix, if you aren't camming over due to press design, is you can take .010" off the TOP of the shellholder, allowing the case to enter the die further. This is exactly what I do when I run into this problem.
Also, I have run many belted cases in many different cals, not once, have I found this so called bulge above the belt that hampers chambering. If you adjust your die so that the case headspaces solely off the shoulder, you should have no problems with bulges or case head separations.
Your gunsmith doesn't have a clue!!

Cheers.
gun)