Shoulder measurement variances on .308 Win brass?

[p5200]

would .003-.004" less on shoulder/comparator measurement than, factory ammo be too much slop to fire safely? I'm using hornady case comparator set. All the other rounds loaded are within .001" of the factory Remington Core-Lokts. Thanks!

 

[Webster]

would .003-.004" less on shoulder/comparator measurement than, factory ammo be too much slop to fire safely? I'm using hornady case comparator set. All the other rounds loaded are within .001" of the factory Remington Core-Lokts. Thanks!

You need to determine the proper bump with a fired case. It doesn't matter where the facory shoulder is.

 

[Straightshooter1]

would .003-.004" less on shoulder/comparator measurement than, factory ammo be too much slop to fire safely? I'm using hornady case comparator set. All the other rounds loaded are within .001" of the factory Remington Core-Lokts. Thanks!

It's not unusual for factory cases to have that much "slop". And having the shoulder bump .003 - .004 is often preferable for cartridges used in semi-autos. If one bumps their shoulders back that much every time when reloading, it'll shorten the life of the cases and need to keep a close eye out for case head separation. Initial fire forming will be fine and then afterwards one shouldn't see that amount of "slop" by bumping shoulders .001 - .002" when reloading.

 

[Coyotefurharvester]

Depending on primer seating depth and actual chamber dimensions, you may/could have a ftf situation. Just something to keep in mind while shooting the undersized rounds.

 

[searcher]

You asked whether safe to fire. Yes - there should be no real safety issues. As others mentioned, you may get one or more that don't fire due to poor firing pin contact. Those that do fire should blow the shoulder out at least to factory brass specs - but may not fully blow the shoulder forward on the first firing.

 

[Doom]

In perspective the SAAMI specs for Max Cartridge/Min Chamber allows for .013" difference.

 

[p5200]

I've fired the 4 rounds in question I'll have to measure them now. The factory Remington Core-Lokts cases I fired still measure about the same. I guess I should just neck size and fire a couple more times or, until it won't chamber correctly? I don't have a neck sizer. I need to look up how to neck size using FLS Die again. Thanks folks!

 

[searcher]

I've fired the 4 rounds in question I'll have to measure them now. The factory Remington Core-Lokts cases I fired still measure about the same. I guess I should just neck size and fire a couple more times or, until it won't chamber correctly? I don't have a neck sizer. I need to look up how to neck size using FLS Die again. Thanks folks!

That is one way to do it, without having to change the dynamics of your load. Another way is to seat your bullets long enough to make contact with the lands (maybe reducing charge two grains or so), thereby the case is fully supported front to rear. This is the best, fastest method to get the shoulders forward when the round is fired. There are other methods as well, but no additional dies or tooling is required to do this.

How many rounds you can fire out of a neck-sized-only case depends a lot on the load you are shooting, particularly how heavy a bullet and how warm a charge. If you are not shooting real heavy bullets and don't push the one you use hard, you can get many firings before you have chambering/extraction issues which require full-length sizing. For a hunting rifle shooting Core Lokt bullets, I'd just stick to your full-length sizer and jamb the bullets that first time - or- simply back off your die a bit to not bump so much and just don't start bumping till you are sure the cases have fully-blown-forward shoulders. You will tend to know that when you see a number of them reaching a uniform length which are longer than the rest. If any one case is longer than the others, you know the rest of the cases have that much room to move, perhaps more.

 

[p5200]

I think I used that method of seating into the lands on my 6.5 Creedmoor. I'll give that a try again. With every caliber I load for I usually pick a charge the next step back from max charge. I haven't used my Hornady bullet comparator on this new gun yet Thanks!