Forster sizing die... bad results

[Froggy1129]

So I have been reloading since 93'. I have been using redding bushing dies with great results. Only problem is that with the Hornady brass I am shooting I have to size my necks with 3 different bushings .339,.335 and the final of .332 (fired case starts at .343). I have to run my brass through my press 4 times a piece (including body die) to get the desired result... mainly low run out. I average .001-.002 runout with the Hornady brass. I averaged .001 with Lapua but I get the Hornady brass for free and its really close in quality. I have always used a Forster seating die to get this result in combo with the Redding sizers.

Just to experiment I pulled out a Forster full length die I have to see what results I could get and speed up my process. Runout is horrible, .007-.008.

What gives? I have read where many get good results with this die.

I made sure I was doing everything I could to make it work right. I cleaned the inside of the case necks with steel wool on a bore brush (mounted on a lathe no less... they are clean), chamfered the case mouth, tried several types of lube. No joy.

I notice that the die really works the brass. I measured the brass after running it through the die without the expander ball. It was .325 all the way down from .343. When the expander does its thing it pushes it back out to .332. Seems like too much. Wonder why the die is cut to bring the OD to .325 instead of something closer to .331 or so to minimize the working of the brass.

Anyway, am I the only one getting this poor of results from the Forster, or am I spoiled by the bushing dies working well for me?

Be safe,

Justin

 

[richardj]

Re: Forster sizing die... bad results

Last time I measured run-out My Lapua was less than .001" but I use the Forster Co-ax press as well as their dies and my brass comes from a custom chamber.

RJ

 

[Froggy1129]

Re: Forster sizing die... bad results

I am shooting an Accuracy International, the fired brass looks good. I know Lapua is the best but every measurement I have taken on this Hornady brass has been excellent and I have been getting great results with the Redding setup. I'll run a few pieces of Lapua through the Forster it and see what happens. I don't think my press is the issue at this point (old faithful RCBS)

RJ, does your die take the necks down to .325 before the button is pulled back through?

Thanks for the input.

Justin

 

[Froggy1129]

Re: Forster sizing die... bad results

Just tried 3 Lapua cases. Same results .007 runout.

 

[Criver600]

Re: Forster sizing die... bad results

Drastic resizing with an expander-ball die can have negative results. Go back to your multi bushing process.

 

[Fuzzball]

Re: Forster sizing die... bad results

"Wonder why the die is cut to bring the OD to .325 instead of something closer to .331 or so to minimize the working of the brass."

All conventional sizers tend to work the necks quite a bit. That's necessary to insure they actually work on thin-necked cases.

 

[former naval person]

Re: Forster sizing die... bad results

Send the die and 3 fired cases to Forster and tell them how much neck down you want. They will hone it out precisely. About $15. JMHO

 

[Froggy1129]

Re: Forster sizing die... bad results

I'll try that.

 

[dmgreene]

Re: Forster sizing die... bad results

I use some Forester dies and I have found the same thing as far as the over working the necks. I send them back to them and tell them to hone the neck out to whatever a loaded round measures minus .003".

 

[Clark]

Re: Forster sizing die... bad results

Forster FL dies honed out to the right neck size on the Forster factory Hardinge collet lathes will beat Redding bushing dies with the right size bushing, in a concentricity test.

If you use the Forster FL sizing dies with the stock factory tight necks, the brass will be plenty concentric, until the neck is expanded.

Bart Bobbit 1994

now full Professor Toby Bradshaw 1994