Custom work: Lapping out neck portion of resizing dies to new specs?

[MOC031]

A question that just came to my mind:

I have my Grandpop's old Model 1895 Winchester chambered in 30 U.S. Whatever the bore dimensions were when it first left the factory in Aug 98, it now slugs as though the bore belongs on a .303 British. I've come to a work flow that leads to opening up the neck to squeeze a bullet sized .3155" (so much for Saeco saying that sizer is .314"...) into the resized and prepped case, delivering great hunting accuracy out to 200 yards with that cast bullet. Which is about as far as I'm going to shoot at deer and elk with that rifle.

That's a lot of working being applied to the brass, and regular and diligent annealing isn't going to make up for that probably shortening the life of the brass. As good 30/40 brass isn't as easily found as, say, .308 Winchester, I'd like to pamper it if I can.

I haven't started contacting the commercial companies yet about a custom neck sizing/full length sizing die. For now, just wondering if any of our members here doing custom machine work do anything like lapping out the neck portions of a full length sizing die or neck sizing die? I'd be tempted to try it myself with an inexpensive Lee die, IF I had a drill press, and a selection of lapping compounds, and a set of pin gauges to tell me where I'm at as I progress.

But I'd rather just pay somebody who knows what they're doing, who already has the toys, to do it properly the first time.

Thanks for any leads - or alternate suggestions to minimize working of the case necks.

[DougGuy]

I think you'd be much better off having a die custom made, if you can get a chamber cast or a pound cast of the chamber and throat, that would give them something to work off of.

I think the Lee dies have a neck expander that is pulled back through the neck when the brass is pulled out of the die so that would be pretty much a blind hole to try and lap, Lee dies are case hardened and a real bitch to lap it parallel without belling the neck, very difficult in a blind hole situation. If it was open at the top where you could get a hone mandrel to go through all the way it would be real easy with the Sunnen hone to hone out the neck bigger.

They make ACRO laps for blind holes, you can find them on ebay for $10 apiece used, maybe a little more for a new one, those would work but not super accurate.

[country gent]

As Dougguy said lapping the neck can get tricky and be a time consuming process. A special lap would need to be made. Running in a drill press would be a recipe for failure though.

Another option would be to have the die converted to use neck bushings. These would also give the option of adjusting neck tension for different dia bullets. Redding wilson make dies for bushings and the bushings by the .001 increments.

[MOC031]

Redding wilson make dies for bushings and the bushings by the .001 increments.

Thanks to both of you. I'm not shy about either a complete custom die (already had to go that route for my 30 Newton as one example) or the dies that use bushings (if they're available with the bushings I need) - I haven't really gone looking at that option yet. Just wondered about the lapping option, looking at some of the custom work done on other projects here over the years.

Now I'm going whitetail hunting...

[dtknowles]

I seemed to miss the part where you measured the neck of your chamber. Will a 0.3155 inch dia. bullet drop thru the neck of a piece of fired brass? You might not need to size your brass. I have a lot of .22 hornet brass that I can fire and reload with cast bullets and not have to size either the bullets or the brass. Another thing, the seating and crimping die, it might not work with the larger diameter bullet and bigger neck on the brass. The bullet seating die might even be able to function as a sizing die depending on the diameter of it's neck section. If the rifle's chamber neck is too tight you might have to neck turn your brass. Maybe neck turning your brass would solve the whole problem.

Tim

[1hole]

I've an "fixed" identical problem with one of my rifles, done in three steps.

First, I made a body die out of my FL die. I just bored the neck of my sizer (with a cheep carbide concrete bit) out about 15-20 thou over normal size. That way I can body size and de- and re-cap normally.

Second, I got a Lee Collet Neck sizer and made myself a new mandrel rod that was a couple of thou smaller than what my goal was. With normal spring back I got what I wanted the sized necks to be.

Third, I got a Lee FCD Crimp die. With a Dremel cone grinding wheel I carefully ground the sliding collets steel crimping finger tips enough wider to allow my oversized case necks to fit in them normally. Now it crimps my cast bullets exactly the way I want them.

The original seater die's bullet alignment chamber was/is loose enough that it remains unchanged but I expected I'd need to drill or lap it larger to accept the oversize bullets.

[44magLeo]

I think a neck sizer with the bushings may be the easy way to go. If no bushings the size you want it would probably be easier to open just a bushing up enough than opening up a die. You could even make or get one made.
Would a 303 Brit size die work for neck sizing the 30-40 Krag? It may as long as the shoulder isn't touched. once used a set of 22-250 dies to oad some 225 Win. The 22-250 case is larger than the 225 Win. so it only neck sized the 225.
The same idea might work with the 303 Brit Or possibly the 7.7 Jap.
Leo

[MOC031]

I seemed to miss the part where you measured the neck of your chamber.

Apologies to all - my excuse is I've been too busy hunting and fishing for bull trout these last few sunny, kinda warm days...

Short story is yes, I did a cerrosafe cast of the neck and measured, then measured a case with a .311" jacketed bullet seated to know what I had to work with before getting into interference fits. It feels like the neck/something is a friction fit at this size. Some bullets sized & cases, the rounds jam just before the bolt locks closed. For hunting, not a huge deal, for now I just ensure all rounds will chamber without a struggle. The ones that there's any suggestion of interference, they don't go out hunting.

There's numerous suggestions here to work with. However, I couldn't find anyone who currently offers a bushing die for 30/40 Krag, unless my web search skills are lacking. I see Forster offers a custom neck grinding service for dirt cheap - you just have to order their sizing die. And they don't make a 30/40 die currently.

I will contact Lee directly about a custom collet neck sizer, followed by Forster regarding a custom die with a custom ground neck.

A 303 Brit neck sizer was the initial start of trying to figure out how I could do things, currently followed by NOE's neck expanders to get exactly what I want. It isn't hard to get the necks to where you want them for seating the bullets, but I think I have a lot of excessive working of the case neck right now.

This is a 120 year old rifle with a pretty fugly looking bore, that shoots well enough to make it an honest 200 yard deer hunting rifle with the aperture sights. Not exactly a bench rest gun. So I'm not looking for and expecting precision bench rest accuracy, just a fairly easy work flow to loading fun rounds for gopher shooting in the summer to tune up for hunting season, and not working my brass to death while doing so.

I'll sit down and do some focused thinking on this when I'm not distracted with hunting and fishing every day in the last few days before winter gets here in a serious way.

[samari46]

Shorty die 7/8x14 threads and use Redding sizing bushings. Should be doable. Frank