Undersize .312 Die

[Shiloh]

The boolits run through my .312 Lyman sizer die measure .311+ after the lube/ GC seating operation. Is this encountered by you fellow cast boolit shooters?

Can the die be honed out? Can I do it with fine emery paper on a mandrel? It is brand new from Midway. I have done several and they are all just a hair over .311

Should I send it back?? I use a Midway caliper and it is accurate for my .310 die so thats why I think I have a suspect die.

Let me know folks. Thanks.

Shiloh

[Leftoverdj]

Yeah, you can hone it out, but I'd check the measurement with something more accurate than calipers first. It's a lot easier to hone one out than to send it back and hope that the next one is closer.

[NVcurmudgeon]

Shiloh, the first thing I do with a new sizing die is to run a few boolits through it and measure them with a .0001" mike. I use an alloy of wheelweights plus 2 % tin almost exclusively. All my sizers are Lyman, and while some are right on specification, some will size up to .001" larger than what is stamped on them. Recently, while gathering tools for loading 9 mm Luger ammo, I found that my .357" sizer was the closest I had to .356". So I bought a .356" and found it sized to .357" just like the other die. One of these days, tests of sizing dies with different alloys might teach me something, but trial and error seems to work OK for now. At least I am working with only one unknown.

[454PB]

I've found that different alloys will produce different sizes in the same die. I recently pushed some 50/50 lino/WW boolits through my Lee .451 die and got .452. I've sized straight WW boolits in it and got .451 exactly. Apparently some alloys "spring back".

You should be able to hone your die .001" quite quickly using the method you described.

[Moose]

Last thing I'd do would be to hone the die - take several more measurements with various known accurate devices. Also, push a few type-metal slugs through it and see what's what. But in the final stages, you want it to size your choice of boolit and metal to the size you want, no? And it won't take much to hone it out. Good luck with that one. PS i have an old 311291 that throws perfect .314 slugs and I sized for years before I slugged the bore. I don't size that one anymore..

[Buckshot]

.................When I hone a custom die if the customer wants it 'on' for their alloy I need 4 slugs. Otherwise I approch to size with pure lead and then bring it to spec with air cooled WW, as that is probably closest to standard as you can get.

Especially problematic are the larger sizes. Narurally the lube holes are drilled before honing, and driving a WW slug through without stopping to let the die set a bit will show a larger size, as the die can stretch radially. Kinda like a snake swallowing a mouse.

...............Buckshot

[Shiloh]

I honed out my die and water hardened WW boolits measures 7.92 to 7.93 mm. I used a Swiss Leveredge gage that accurately measures to 1/10 mm. I have to estimate the hundreths but am experienced and have measured gemstones for years, and can get quite close. I didn't know if there is any springyness in the metal but it there was no change from last night to this afternoon.

I figure it is .3118 to .3122. Certainly close enough for me.

That being said, what I know is that a .312 boolit has the band swaged a little from the throat area and there is some resistance in closing the bolt. This is with three dummy rounds. The .311 has resistance on one case only. I am thinking that that case neck is slightly thicker.

I'm going to load up some .311 cast boolits at 18gr of surplus 4759 and go from there. I'll post results next week as I can't shoot till Wednesday

Shiloh

[Char-Gar]

If its very common to buy Lyman or RCBS dies that size some size other than the one indicated. I bought three .313 dies and didn't get a single one that did the job. One of them is a perfect .314. I had Stillwell hone one out to .315 and had Buckshot make me a true .313.

[kywoodwrkr]

The Lyman #46(I think) haspistol and rifle bullets.
If I can get my camera and diskette drive to cooperate I will try and post a copy of the chart later.
FWIW
DaveP kywoodwrkr
Shrinkage data:
http://img.photobucket.com/albums/v127/Kywoodwrkr/MVC-002S-1.jpg

http://img.photobucket.com/albums/v127/Kywoodwrkr/MVC-003S-1.jpg

http://img.photobucket.com/albums/v127/Kywoodwrkr/MVC-001S-1.jpg

Alloy Information:
http://img.photobucket.com/albums/v127/Kywoodwrkr/MVC-004S-1.jpg

[Shiloh]

Buckshot has posted on this thread, but I don't know who Stillwell is. I assume that these fellows are machinists who do cast boolit related work?? This is good to know

Shiloh

[Char-Gar]

Stillwell can be found at www.sizingdie.com

[Shiloh]

Thanks Chargar. This is a good reference. I bookmarked the site.

Shiloh