Lee 303 British collet die for 30-40

[Paul in Oregon]

Anybody out using the Lee 303 Brit neck sizing collet die to size 30-40 brass ? My concern is that the 30-40 case is too big to fit in the die. Thanx, Paul.

[Der Gebirgsjager]

I reload for both cartridges, but have never tried it. Seems like, since the .303 takes a .311 bullet and the .30-40 uses a .308 bullet, the neck wouldn't get sized down enough running the .30-40 into the .303.

[Paul in Oregon]

I`m using .311 cast boolits in my Krag . Would you be willing to see if a Krag case would fit in your .303 die? Thank you ,Paul.

[Der Gebirgsjager]

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My equipment is RCBS, but it shouldn't make any difference. First photo, on the left, is a .303 British full length seating die with the seating plug removed. It has a full length resized .303 British empty in it. The die on the right is a .303 British neck sizing-only die, expanding plug removed, with a full length resized .30-40 Krag empty in it. Second photo, same dies in same location, empties are reversed. So as you can see, the .30-40 empty is longer--sticks out of the die farther. Third photo is a comparison of the two empties, Krag on the left, British on the right. If you click on the photos they should become larger, and it is easily observed that the Krag shoulder begins approx. 1 5/8" above the base of the rim, and the .303 begins approx. 1 3/4" above the base of the rim, a difference of approx. 1/8". There have been a number of threads lately that touched on making .30-40 cases from .303 British due to the brass shortage, the overall conclusion being that it can be done satisfactorily but that the resulting case is shorter. I understand (I think I understand) that what you're wanting to do is use the .303 die to seat the .311 cast lead boolit in the .30-40 case. I think it can be done gingerly and with care, but you probably can't shove it all the way into the .303 die because of the overall longer case length and the farther forward location of the .303's shoulder. So it would be a slow, push it in some, pull it out and examine it, carefully push it in some more, until the desired depth of seating was reached, then do the same for each succeeding case. Perhaps a way to proceed would be that once you have the first seated as desired, to mark the depth of the case in the die with a sharpie, measure the distance from the rim to the mark, and then mark all of the other cases with that measurement at that location. You could also buy a used .30-40 die and ream it out to .311. I hope this specifically answers your question. If not, we can try again.

[EDG]

You would need a .30 caliber mandrel and a spacer to make up for the length difference between the two cases. The spacer would have to be dropped over each case before it is sized.

[Paul in Oregon]

What I`m trying to find out is this,will a 30-40 case fit in a Lee Collet die that is made for a 303 British ? I think that the Krag case is too fat to fit but I don`t know how much clearance the die has since it only sizes the neck.

[Der Gebirgsjager]

I'm still scratching my head about this question. Let's try again, taking it from the top. By "Lee Collet die" I assume that you mean the sizing die, since that's the only one that normally has a collet. However, yours is apparently just a neck sizing die as you have stated above. Since you said that you are wanting to load .311 bullets in the Krag case, you must be expanding the neck to accept the bullet as the Krag case's neck would normally be .308, and unexpanded no sizing would take place. You are correct that the Krag case is "fatter" than the .303 British case. They are within .001 at the head, the Krag being .457" and the .303 being .456" which is essentially insignificant. The diameter at the shoulders is more
pronounced, Krag .423", .303 .412" for a difference of .011. The neck of the Krag is .42, the .303 is .332", a difference of .088". So, a generalization can be made that the Krag case is fatter, but the neck is longer. Most neck sizing-only dies are bored out oversize from the base up to the shoulder, because as the name says the goal is to size the neck only. The question is, how oversize is the bore in your die? You can pre-determine this with various machinists measuring tools including an inside caliper, but if you don't own one about the only way you will find out for certain is to try it out. Take a Krag case, lube it, and run it up in the die, pull it out and see what you've got. This is assuming that you have a heavy duty press like an RCBS Rock Chucker with enough leverage to pull it out again. Even with a cheaper bench mounted press you should be able to do it. If extraction from the die was difficult then measure the case and see what you've got. But, in view of the fact that the Krag neck is
longer than the .303 case it may stop well short of the location in the bore of the die where that fatter Krag shoulder would be squeezed down to .303 dimensions, especially in view of the fact that a .303 case body would not be sized by the die. It will be close. Try it. You have nothing to lose but a single case, and if its dimensions are changed it will likely blow back out to fill the Krag chamber when fired and return to its original form.

[Mk42gunner]

You could buy a Lee collet die in .30-40 and a center mandrel for the .303 British to use in said die.

Robert

[Paul in Oregon]

According to Lee Precision`s catalog they don`t make a Collet Neck sizing die in 30-40 or I would buy it. I reload .303 so I will just buy the collet die in that caliber and see if it works. I Thank all of you for your help,Paul.

[Mk42gunner]

Sorry Paul, I thought they did make a collet type .30-40 die.

Robert

[Paul in Oregon]

I received a Lee .303 BR. collet die yesterday and sized 2 boxes of 30-40 brass with it. It looks like it will size the brass just right for .309 cast but might be tight for .311 boolits. I`m going to call Lee and see if a mandrel .002 or .003 will work in it. Paul

[WebMonkey]

Back your die out a bit ?
I use a 303 expander in my 308 neck sizer.

[kbstenberg]

There is a trick to using a Lee collet sizing die for a case other than the one it is made for. It only has 2 rules.
A.. The new case has to be thinner and longer than the designated one. On this point you are correct that the 303 die will not do your 30-40.
B.. You have to make a ring type shim (any material you have wood, plastic) That is equal in thickness to the difference of the two cases. My Hornaday manual says the 303 is 1.890 from its base to the base of the neck. It also says the 30/40 is 1.830. Again you can not size the 30-40 because of the case length.
IF you had the opposite situation. You could size a 303 case in a 30-40 Collet sizing die if you had a .060 shim.
That is why I can size my 30/30 3006 cases in a lee 308 collet sizing die. The 30/30 needs no shim, and the 06 needs a .398" sshim. The 300 Sav. can't be sized because it is shorter than the 308.