How many different thread ODs on 310 expanding stems for expanding dies?

I posted on here in regards to a Arisaka Type 38 6.5 X 50 project I’m working on and neededing a 310 bullet sizing die or a push through sizing die in order to set the gas checks on the boolits I’m using. I took a gander at the want to trade / need thread above and surprisingly, I found a good member here that had a 310 bullet sizing body in .264 – a fellow I had sold a mold to not too long ago. Long story short, he is sending it to me. He had a list of “needs” so I took a gnder at my box of bits and pieces of what I have for the 310 dies. He needs a expander die for the 44 Mag.

I found a nice .429 expander die stem for the 310. I’m attaching photos of it. This stem is 2.00” overall length, the plug is .429 and the threaded stem, according to my digital calipers, has a thread O.D. of .398 - .400.

I had another pistol expanding die (310) in my box of parts that had a heavy threaded stem, so, I’m thinking – good – I can just switch expanding stems out and mail him a complete expanding die and help him out on something he needs. When I removed the stem from the die – and t was for a smaller caliber than the .429 for the 44, when I went to screw the .429 expander stem into the die, I was a bit surprised as the threaded stem went right up through the threaded hole in the die case top – the threaded hole was larger than the stem on the .429 expander stem.

So several questions . . . .

Just how many different stem diameters did the 310 dies utilize? I have run into this once before. Did they change the diameters they used over the years? The stem pictured that I am sending the member who helped me out is definitely a 310 stem. I had a ratty old Rifle 310 de-priming die that the stem looked to be the same size as the .429 stem and it screwed right in. Just seems odd that on pistol expanding 310 dies that utilize the same die case length for the expanding die – that the stem for a smaller caliber than 44 would actually have a threaded expander stem with the threaded portion larger than the 44 die? Or, was this a marketing strategy of Ideal/Lyman to make people have to buy different dies?

The outside diameter, the best measurement I could get, came out a .398 - .400 for the threaded portion of the .429 expander stem. If anyone has a short expanding die case laying around that is threaded at the top for a stem this size – please PM as I’m interested in getting one to send to the member that is helping me out so he can have a complete die.

Thanks for any info you can provide on the threaded stem sizes.

Jim

Jim,
You have kicked a hornets’ nest! I’ve never been able to figure it out for sure, and like you, whenever I pull out something I just know will work… it doesn’t. I wish I had a better answer for you, but I don’t. [smilie=b:
Froggie

Thanks Froggie - I kind of figured I might be chasing an invisible rabbit. I've been using 310 sets for a number of years and at one time. would buy "lots" of dues, eventually putting together sets to use or give away - seems like there was no uniformity at times - stem diameters being one of them - thus having to have a number of lock rings im different sizes, etc. I did find a few more parts I had and was able to find a lock ring for the stem shown and a die lock ring to send to the individual so if he can find the rihjy expander die body threaded for this he can end up with a complete seating die.

Jim

I've encountered this often and it has made me about bald from tearing my hair out! I can only assume that standards were loosely followed in those days! It goes also for the seating screws and the DA dies!

I've seen 4 different in my 310 travels. I said no problem, I'll make an expander and rethread with a die. NOT! Had my machinist buddy measure the threads. Okay, done. Started looking for threading dies. Found 'em but suffered sticker shock. All are non standard fine threads and haven't been in common use for years./beagle

Friend beagle, it’s good to hear from you. You are absolutely right about those threads… I’m going to guess that Lyman “inherited” the proprietary thread (or should I say “family of threads”) from the early days of the Ideal company that operated prior to the niceties of standardized threads etc. Once committed, they retained this mind bending hodge-podge for the entire production of the 310 tool and presses that used these small sized dies. Now that even Lyman has discontinued and abandoned them and apparently the 310 Shop is defunct as well, we’ll all just have to face the fact that what we have is probably all we’ll get without the expenditure of large amounts of money or highly skilled machine time. Aren’t you glad we got into this early enough to have at least most of what we need/want? Pity the poor youngsters just starting out.

Regards from one dinosaur to another!

I asked myself the same question and ruling out mfg. tolerances, I came up with a large, medium and small thread OD of 0.458", 0.395" and 0.325". All +/- 0.004". There may be others but these are all I've run into.