45-70 Brass "dimples"

[Forester]

I was trimming some Starline nickel 45-70 brass tonight and noticed that many of the cases had a strange set of dimples on them. They are football shaped more or less and about a half inch from the case mouth. the dimples are very regularly spaced and go all the way around the case. Some cases had deep obvious marks and in others they are lighter.

These cases have all been loaded 4 or 5 times each with fairly stout loads and shot through a Marlin 1895. They were sized with Hornady dies.

Has anyone seen something similar to this? What would cause it? I have already set the brass aside with no intention to load it again. It is ashame though because I was hoping to get another few light loads out of this brass.

Any ideas?

[Scrounger]

Did you crimp it with the Hornady dies or a Lee Factory Crimp?

[454PB]

A picture would sure help. The first thought that came to me is that I saw something similar when using slow burning powders at reduced pressure in my 45/70. I believe in my case it was caused by unburned powder blowing back along the case between the chamber and the brass. Sort of like the soot you see when shooting slow powders in other small rifle cases. If that is what caused it, it doesn't harm the brass.

[94Doug]

I think I have had this occur on Rem or Win cases too, from excess lube. They were used as is with no problems, the "fire forming" process blows them back into shape for the next reloading.

Doug

[Jon K]

Looks like:
The brass is being squeezed down too much, maybe too much lube or combination of both-too much too fast.
If you measure fired bass vs sized brass, you'll see how much it is changing. Hornady dies tend to be on the small size, and leverguns tend to have rather large chambers, that's why I quit using Hornady dies for levers.

Jon

[94Doug]

Hmmm, I do have Hornady RL Dies, too....

d

[montana_charlie]

Starline brass has the reputation (among BPCR shooters) of being 'hard'. Most recommend that it be annealed before the first loading.

When shooters complain of blowby on the case mouths, the first thing asked is if it has been annealed. If your 'dimples' were caused by blown back powder, trapped between the brass and steel, it seems your necks are too hard.

Being nickle-plated, I don't know a good trick for annealing that brass.

CM

[Forester]

Most of this batch of cases have been used in pretty stout loads for a 1895, it would surprise me if I was getting blowback around the case. Wouldn't these marks be more random? The depressions on these cases are so regular I almost think they were created mechanically, though I have no idea how that could be.

The lube issue could be the culprit. I didn't think I was using too much when I sized them ut that is always possible.

I tried to take pictures but my camera and I are unable to get one that really shows what I am talking about. I will try again this evening.

Most of these cases were crimped with a Lee FCD when last loaded. How would that play into things Scrounger?

[bishopgrandpa]

Too much lube. Swab out the die.

[miestro_jerry]

I agree with Bishop, too much lube in the die. Use a clean cloth or strong paper shop towels (the blue ones) soak with alcohol and then swab out your dies. Let air dry.

Jerry

[jack19512]

Too much lube. Swab out the die.






I would have to agree also. I get little dimples in some of my cases once in a while, I have always suspected too much lube was the problem.

[Forester]

Too much lube. Swab out the die.

That is the plan for this evening. Iwill load the cases the way I was planning, with light plinking type loads and keep an eye on them.

Today I have another goal, I want to cast at least 3000 .452" 200gr LSWCs. I have ~6000 sitting in the basement now and need ~20000 to feed this IPSC habit of mine for next year.

[lovedogs]

Too much lube. Lube them real lightly and then wipe with your fingers before sizing. These cases take a verrry light lube, almost none... or you'll get lenghtwise denting. It will blow out when you shoot with no ill affects.

[Bret4207]

I doubt there's anything wrong or weakened in the brass. I agree the culprit is lube, I've had the same thing when forming cases. No big deal. Shoot them and the marks iron out.