Variances in brass sizes after FLS.

[GQshayne]

Had a look at a Lyman head space gauge for the first time today. Never seen one before. Here is a link for others like me that are not aware of them.

https://www.lymanproducts.com/rifle-headspace-gauges

Basically, it gives you a min and max for a sized case. So I had a look at some cases I had on hand. I am only a hunter, so not much attention has ever been paid to anything other than the basics when it comes to cases. I full length re-size after every firing, check length, clean primer pockets, and chamfer the mouth. But I have always used mixed brass.

So I have Win, Rem, Sako, PMC & WW Super. And after case prep, all done at the same time with the same die settings, they show different seating depths in the head space gauge. WW Super, Win & PMC are all in the middle, Sako is JUST under max, and the Rem cases are all under min spec. Instructions for the gauge suggest that just under the max is the place to be, so that makes the Sako about perfect, but the Rem cases all require the FLS die to be adjusted differently to what I have done since the 1980's.

No way would I have thought that a case could be under spec when sized the same as others that meet specs, in the same die, on the same run of sizing. You learn something every day.

[JohnV]

With full length sizing using a neck expander ball type die you get varying amounts of shoulder pull out as the cases are extracted . The chamber in the rifle is a better gauge and if all the ammo fits with no problems without being oversized and creating too much head space then it should be ok . If you are starting to think precision then I suggest you throw any full length sizer in the garbage bin and buy two separate dies . A Lee collet neck sizer and a Redding body die . The body die will allow you to size more easily and there is no expander ball to pull at the case shoulder on extraction and all cases end up closer to the same shoulder to base length .

[Blr243]

I second that expander ball problem , the drag. Esp if inside of neck is dry and dirty. Nothing but trouble !

[Oldbloke]

Does lubing fix it?

[straightshooter]

The things that affect repeatable dimensions in full length resizing are:
Lube - the quality of the lube and how consistently it is applied including inside the neck. Too little, the wrong type or patchy application is one extreme where you will feel variations in the force required to complete the process and in the worst case may lead to a stuck case. Too much and you will get hydraulic dents in the body of the case especially if your die does not have a weep hole or the hole is blocked.
Excessive annealing - the only part of the case that can benefit from annealing is the neck. If the anneal travels too far into the shoulder and into the body of the case then this becomes the source of dimensional variations especially if the case has a steeper shoulder angle. This is mostly due to the difference in 'springback' between annealed and work hardened brass.
Shape of the expander ball - dies with elliptical or gently tapering expander balls might reduce some but not all of the problems described.
Headspace - if it is important for you that your cases conform to standard industry dimensions then a RCBS Precision Mic gauge is a necessity as well as knowing how to use it, otherwise having your bolt close over your full length sized cases with just a little bit of 'feel' is ideal.

[JohnV]

Polishing inside the necks and proper dry lube does help to reduce shoulder pull out using expander ball type dies but a body die eliminates it completely and stuck cases are rare and very easy to punch out from the top of the die. It's also easier to size just enough to get the cases back in the chamber with minimum head clearance . You want your cases to conform to your chamber not standard industry dimensions because your guns chamber may be loose or tight and not so standard .

[in2anity]

FWIW I don't lube inside the mouth of every case. Only every few, with the thought that there'll be residual lube on the expander. I don't tumble my brass, just a wipe with isopropal in front of the footy. I clean my dies with carb cleaner after each session. Yet my Neilson will still shoot into 1/2moa and bring home the possibles. Always stick to the same headstamp.

[JohnV]

That's true If you are using a good sticky dry lube then after a while the dies coat up and you don't need to lube every case neck . Carb cleaner does are great job but there is some nasty chemicals in it so wear a mask and gloves when you use it . It usually has methanol in it which can damage your nervous system , so don't breath it and don't get it on your skin . Keeping the same brand of brass in a batch is a good idea . However for some it's not so possible so what I do is uniform the brass so the variations of different brands is minimized .

[Oldbloke]

I usually anneal every second load.
Lube inside the neck as well when FLS.
I get pretty good results.

But have never measured the shoulder head space/bump.

Abt 2 weeks ago asked SIL to make a gadget (shoulder bump guage) so I can. Next time I FLS I'll find out how I'm going.

[GQshayne]

Correct headspace for use in a lever action is the goal, not precision. We have a BLR that is misfiring, so are going to be more careful with the loads that go in it. I think it is a rifle issue rather than ammo, but it does no harm to get the ammo more regulated.

Assuming that you blokes are correct with the neck expander theory, then it suggests that the Remington cases differ from the others by a considerable margin. All brands of case are consistent (from the sample checked so far) so that rules out procedure as the problem.

The Remington cases are the only ones out of spec.

[SCJ429]

If you bought a box of brass and fired it in one chamber, the brass would have very similar dimensions. You could confirm this with your head space gauge. You could then neck size this brass 10 times without needing to push the shoulder back. If you do need to you can used your small base body die. Easiest way to entend the life of your brass and to keep it all the same size is to stop pushing it around for no reason.

[Oldbloke]

"Sako about perfect, but the Rem cases all require the FLS die to be adjusted differently to what I have done since the 1980's."

My 2c

It's only Remington. Anneal them, and see what happens.

Yr hunting, keep so continue to FLS.
Neck sizing sounds good but gains are minimal.
Yr hunting, so you lose cases in the field, so no point trying to get 20 loads out of a case.
Yr hunting, so last thing you want is a stuck case, FLS
Yr sizing system is not at fault, the other cases are ok.
If you neck size you need to keep track of them. Too much stuffing around unless your target shooting comp.
More dies cost you fuel to go hunting. Lol.

If annealing doesn't work chuck them.

[GQshayne]

Not only hunting, but pig hunting using a lever action - FLS only as far as I am concerened.

Bought 100 new cases made by PPU, so can stop using mixed brass. They will lik;ley size up just fine but if not, the die can be adjusted to tge PPU cases. Easy to do when they are all the same.

[JohnV]

Using the one brand of brass is a good idea but using expander ball type dies is hard on the brass and work hardens the necks quicker than other methods . I have 4 different brands of brass in my 223 loads and they all function the same . Why , because the die system is better and the cases are all uniformed to be closer in dimensions especially the neck wall thickness . If the neck wall thickness varies too much the expander ball sees different size holes for it to be dragged through .