6.5 Creedmoor Bolt Closing Issue With One of My Loads

[guitarsteve]

I’m new to rifle reloading and I have an issue that’s got me puzzled. I’ve worked up 2 different loads using different brass and bullets, but one of them gives a lot of resistance when closing the bolt. The loads are Starline brass with Barnes 120 gr Match Burner BT and Peterson brass with Hornady 140 gr ELD-M. When pressing the bolt handle down with the Peterson rounds, it’s smooth with little resistance, but with the Starline rounds, I have to use a good deal of force. This is very apparent in my Sako A20, but much less so in my Bergara B14 HMR.

I’ve sized both manufacturers brass in the same Forster, full length die and the finished rounds both drop into my Wilson case gage with no resistance. The OAL of the Peterson round 2.799 and the Starline round OAL is 2.701. At the base of the Peterson and at the area just before the shoulder measures .468 and .459 respectively. The Starline measures .469 and .460.5. The Peterson brass is new and sized, while the Starline was fired once and sized.

I really have to use some force to close the bolt on the Starline. So, is this something to be concerned about?

 

[Rook 6]

The Starline probably has more spring back and the Peterson is probably softer. Annealing the Starline might address the issue.

 

[mgunderson]

Does the base to ogive measure the same? Not all factory chambers measure the same.
How are you measuring shoulder set back? Loading for multiple rifles can get tricky.

 

[guitarsteve]

Does the base to ogive measure the same? Not all factory chambers measure the same.
How are you measuring shoulder set back? Loading for multiple rifles can get tricky.

As of now, I don't have anything to make those measurements. Looks like I may have to buy something to do that. I was under the assumption that sizing at full length would make any brass sized in that die the same dimensions. I guess that's not the case?

 

[Markman]

Just for clarity, you say the Peterson is new and sized in the Forester die, has it been fired? If not, I would expect it to chamber easier in both rifles.

 

[Litespeed]

Chamber the brass after you have resized it and before loading. That will tell you whether it's a bullet seating issue or a brass springback issue. If you don't have a comparator to measure base to ogive, you can do a test where you put the loaded round in the chamber (I then push with my thumb) and point the muzzle up to see if the bullet engaged the lands or the neck is tight. It should fall out under it's own weight.

I'm guessing these two tests will point to your problem.

 

[guitarsteve]

Just for clarity, you say the Peterson is new and sized in the Forester die, has it been fired? If not, I would expect it to chamber easier in both rifles.

Yes, the Peterson is new & sized once.

 

[guitarsteve]

Chamber the brass after you have resized it and before loading. That will tell you whether it's a bullet seating issue or a brass springback issue. If you don't have a comparator to measure base to ogive, you can do a test where you put the loaded round in the chamber (I then push with my thumb) and point the muzzle up to see if the bullet engaged the lands or the neck is tight. It should fall out under it's own weight.

I'm guessing these two tests will point to your problem.

Great. I'll give that a try. Thank you.