Leading on the outside of case mouth

[Wasalmonslayer]

Hello Guys

I had a weird scenario happen today.
I was shooting my first batch of 311041 plain base today and at the end I was looking at the cases and found lead smears that just flake off with your finger nail on the outside of the case mouth.
The loads were 30-30
311041 Sized .3105 ACWW
M die prepped cases so no shaving
Crimp just smoothed out with the Lee factory crimp.
7–8 grns of unique ladder testing
Lube was tac1 and rolled in bll
Cases were once fired remington
Rounds all shot well no leading in the barrel
Accuracy was decent at 50 yrds all groups were around an inch some smaller.
What gives???

Thanks
Max

 

[Dusty Bannister]

Probably low pressure allowed some lead to blow back along case mouth.

 

[Brad]

Probably low pressure allowed some lead to blow back along case mouth.

I agree. Bet it goes away as pressure increases.

 

[fiver]

I have seen this before too and 1-2 times I have seen thin like almost see through little grabbers stick out from in front of one side of the case.
those were from cases that needed annealing, and had a slight roll crimp.

 

[Wasalmonslayer]

What is considered low pressure for rifle??
The Lyman book shows these loads starting at low 20k and moving up from there.

 

[Brad]

Low pressure is relative. Fiver mentioned case anneal. As case necks get harder it takes more pressure to get the neck to expand and seal against the chamber wall.
Annealing cases may eliminate your issue, it may just need more powder.

 

[Wasalmonslayer]

Got it I will bump it up a little more and see what happens.

Maybe I should try my hand at annealing these guys.
Never done it before, but it sure does not look difficult.

Thanks!

 

[fiver]

it's not overly hard to do.
you just need to get the case neck to 715-f then stop adding heat.

 

[Wasalmonslayer]

I will check into the heat paint.
The name is slipping my mind but I have used it for other things.

 

[Ian]

Sell your m die to someone who things they're actually any good and buy yourself an RCBS cast bullet expanding die body, spindle rod, lock, nuts, and a .310" expanding spud. Set the depth on it so it gives enough flare that the bullet base sits in it about 1/16" and has just enough room on the mouth to not shave lead.

The Lyman m die has something like a .307" second step and it wrecks plain-based bullets. It's not so great for .310-311" gas checked bullets, either.

In case you ever have trouble seating bullets perfectly straight, (doesn't sound like you are), a Forster benchrest seating die has no equal. The ones without the micrometer adjustment cap only run about 50 bucks and it is money well spent on the thin-necked cartridges like .30-30.

 

[Ian]

I'll do you one better. Send me your m die and return postage and I'll fix it for you.

 

[fiver]

what's an M-die again?

 

[Brad]

Ok, so what should an expander for cast look like?
A straight section .002 under bullet diameter then a little flair at the top for bell the mouth? No shoulder like an Mdie to leave a shoulder in the neck.

 

[Wasalmonslayer]

It actually the Noe m die in a Lee flair tool.
It is a 311/309 step I believe.

 

[fiver]

like a pistol die or, like a powder through die on a dillon

 

[Rick]

Ok, so what should an expander for cast look like?

Like an RCBS Expander die in my opinion.

 

[Wasalmonslayer]

Here is a link to the insert tool I am using.

http://noebulletmolds.com/NV/produc...cts_id=1117&osCsid=2psgpl3elf3hdui6up1nkhet67

 

[Brad]

like a pistol die or, like a powder through die on a dillon

Ok. Simple to visualize.

 

[Brad]

Like an RCBS Expander die in my opinion.

Don't have one to compare? I will admit I always used an M die or a custom expander made to fit my Sinclair expander body that I got with my neck turning tool.

 

[Ian]

Yes, exactly like an RCBS handgun die. If you're making one from scratch, a long, tapered tip added on to that basic shape helps too.