Thread: 308 case differences?

Yeah not uncommon. Grind away.

Before you grind you could try sliding a feeler gauge (I found the tips of my feeler gauges fit perfectly into a shell holder) in under the brass to lift it up a couple of thou, Size the brass and then test the sized brass in the chamber with the firing pin removed from the bolt and also measure with a headspace gauge to check. It might help you figure out roughly how much you need to grind.

Also what can happen if your case prep and neck lube isnt to flash is that the expander ball pulls the neck forward a smidge. Then it headspaces on the neck shoulder junction instead of the body shoulder junction.
Simple way to check is size one of those problem cases without the decapping rod/expander and see if it chambers.

If it does, try a larger than call bronse brush in a drill inside all the necks till clean and a quaility lube inside the neck taking care to get that neck/shoulder junction on the inside.

Both good ideas thanks guys

Some brass is stiffer than others.... If it has been fired in a real sloppy chamber it may not "spring back" to fit a small chamber after FL sizing.... especialy if it is tight on the sides not the shoulder...

Neck thickness and brass hardness.

The harder the brass, the more memory it will have.

The thicker the neck, the more likely it will be the expanding ball will pull the shoulder back out past its yield point.

Just went through the same thing with Lapua brass necking down to 7mm08.

Chris

so, if this hornady brass has a thicker neck, when i size then load, what happens if i chamber and they are toight? spose i would need to then neck turn?

You could but its more work and expense and may still give differences compared to the other brass.Id suggest picking one brand/batch set up and work with that.Once youve positivly identified the problem then you have options.
Second hand Brass is often a false economy.

so , since my probs with brass and my press broke, ive now got another one, and ive sized up using the same die, some of the same hornady brass which now seems to be chambeing fine in my remmy,,,, i had belt sanded a touch off the shell holder, think im gonna get a new shell holder and re try, to see if theres any diff,,,

possible cause "may" have been the press linkage stretching a touch, before breaking, thereby not giving me enough leverage,,,,

so i have bought a new shell holder, and primed 30 cases of the Hornady match , this brass i got from others in two batches and is once fired. after f/l sizing half chamber fine in rifle, half are tight but not too tight, but the diff is there.

then i looked at the base of the cases, and the tight ones have marks on one qtr to one half of the base, looking at the bolt face, it is dirty with brass,,, so im thinking the bolt face probably is not square, and possible with some of the brass from a sloppier chamber, or hotter loads(someone elses rifle), the un square bolt face could be shaving off some brass from the base on slightly bigger cases from the hot loads? or even just slightly diff brass batch runs,,,?

anyone else concur?

No sounds like your using hot loads and are getting case head expansion.... Measure your case heads with a decent set of calipers and see if the ones which are tight to chamber have a larger diameter... If thats the case bin the brass and back your loads of a grain or so....

Ok . I havnt loaded any yet got the brass second hand from others.

Originally Posted by ANTSMAN

Ok . I havnt loaded any yet got the brass second hand from others.

Ok id just check the case head dimensions to rule that out as a possibility....

I just gathered what you ment by the mark, as in just from u closing and openinging it I thought you had fired them....

I suggest you go back to the shoulder length and try to proper adjust the dies...

If you can get hold of a hornady headspace gauge to take some measurements of the cases that fit and also dont fit..

I have separated them into a pile of firm closing in the rifle and easy to close in the rifle. I was thinking of loading some rounds in both and trying them....

Originally Posted by ANTSMAN

I have separated them into a pile of firm closing in the rifle and easy to close in the rifle. I was thinking of loading some rounds in both and trying them....

You need personal help from someone I think.. Do you know anyone in your area that is an expert?