Which charging die for 7RUM (load master w/auto-disk)?

[Max Heat]

With my 7RUM due to arrive soon, I have decided to get the first rounds that will be shot through it loaded up. I picked up an RCBS carbide 2-die set, and the first 50 (new) brass cases are now sized, expanded, trimmed, chamfered, tumbled, and polished. I'm now setting up the load master press for priming, powder charging, and seating of the bullets (they will be re-sized & expanded as well). The powder measure that I have is a (chain-driven) auto-disk pro.

But there is an issue that is holding me up. What charging die am I supposed to use for charging the 7RUM cases with the auto-disk? The Lee "universal charging die" says it is for the "perfect" powder measure, not the auto-disk. And the Lee "auto-disk rifle powder charging die" says it only handles cases up to 2.015", and 7RUM cases are 2.850". That is basically putting me between a rock and a hard place, as I am unable to come up with anything else, so far.

Can someone please help me out with what charging die I am supposed to use for this particular application? (I'm not finding a 7RUM "powder through" die, either)

 

[lloydsmale]

going to be hard to get that answer. Your probably the only one in the country loading ultra mags on a lee progressive!!

 

[Max Heat]

Really? Why is it such a big deal? Isn't the load master pretty much the beefiest press out there?. It fits/handles the ultra mags with ease. I was having no problems whatsoever, until it came to dropping powder charges.

I'm not 100% sure that Lee doesn't make either a universal die that is compatible with the auto-disk, an auto-disk rifle powder charging die that handles cases longer than 2.015", or a 7RUM powder though die that fits auto-disk, or even some sort of adapter that makes for fitment of any of the above to the powder measuring/charging setup that I have. But for some reason, Midway doesn't appear to carry anything that will work. I was of the belief that if it exists, THEY are the most likely to carry it. But that could be a false assumption, I suppose.

If I do come up totally dry on something commercially available, it looks like I'm going to have resort to modding (or maybe hacking up would be the better way to put it, as I only have rudimentary tools to work with) one of my existing dies. So this is basically my plea to anyone who can think of anything that is a bolt-on solution.

 

[lloydsmale]

lee does sell a conversion for the auto disc that allows you to stack two discs on top of each other. As to it being the beafy press on out there, a lot of guys would argue with you on that one. It is plenty strong though for about anything. I had one in my early days and sure dont miss it. I spent more time tweeking things then putting out ammo.

 

[g0rd0]

in my humble opinion if you are reloading the 7mm mag and doing it with any auto indexing loader your are not only looking for problems you are asking for them. All magnum loads must have individually wieghed charges.
But, by all means go ahead use that system, and when, not if but, WHEN you have a burst chamber you will be able snatch the 2 pebbles from my hand.
Grasshopper

 

[lloydsmale]

I agree totaly. I load alot on progressives. Ive got 3 lnl hornadys and 2 550 dillons. But about the only bottlenecked rifle rounds i load progressively are 223 and 308 for the ars and then i will ONLY LOAD IT progressively using ball powders. I doubt a guy would ever shoot more then 50 rounds out of a mag rifle in a day anyway and for that kind of quanity i prefer the slow, precise and careful way.

 

[RTK]

I agree totaly. I load alot on progressives. Ive got 3 lnl hornadys and 2 550 dillons. But about the only bottlenecked rifle rounds i load progressively are 223 and 308 for the ars and then i will ONLY LOAD IT progressively using ball powders. I doubt a guy would ever shoot more then 50 rounds out of a mag rifle in a day anyway and for that kind of quanity i prefer the slow, precise and careful way.

Exactly

 

[Max Heat]

My auto-disk (pro) setup already allows for stacking of the disks without any sort of "conversion" required. But even if there WAS a problem with powder measurement, there is always the "adjustable powder charge bar" option for the auto-disk setup (it's only 10 bills), if I were to need it. I'm sure it's been designed to be compatible with the disks, in terms of stackability. This would allow for a pretty much infinite # of different (and very precise) charges to be measured out. The issue I currently seem to be having involves the dropping of the charge into the cases, after it has been measured. And since the powder I will be using is of the stick variety, I would REALLY like to have the proper die, along with the integral (but separate piece) drop-tube that goes with/inside of the die, to minimize the possibility of any powder getting hung up, and ending up being added to what is already going into the NEXT case. Obviously, the top of the die needs to be threaded on the inside to match the bottom (outside) threads of the thumbwheel on the auto-disk powder measure. I suppose that a die that does NOT use a separate drop-tube inside of it would still work, if that's the only kind that IS available for the 7RUM cartridge. But it does need to be able to funnel the powder down into the neck of the case, without the possibility of any getting hung up. The load master is not only THE only press that I have, but it is also the only one that I ever WANT to have! When I bought it (only a few years ago), it was with the intent that I would be using it for ANY rounds that I might want to load (short of .50BMG, anyways), so that I would never have to consider buying any more presses. I do have to agree, that due to it having to perform so many different operations with a single stroke of the ram, it does take some fiddling & tweaking to get it set it up for smooth, seamless operation. But so far for me, that has not been a problem. For safety reasons, I actually WOULD be looking for problems, with the most critical being those of the overcharged case variety. There is a commercially available die known as the "powder cop" (a hornady product) that is intended for the sole purpose of allowing for visual verification of the amount of charge in every case, by means of having a floating rod drop down into the charged case when the ram is brought all of the way up to the top of the stroke. Obviously, it needs to be placed between the powder charging die and the bullet seating die. The load master can accommodate this extra (4th) die, while STILL having the capacity for one more! But I am still not willing to put ALL of my faith in that alone. After I finish loading up a batch of cartridges, I ALWAYS perform a final weight check of EVERY round that was loaded. Any round that varies from the average by more than a certain amount (as determined by me, taking variations in brass weight into account), ESPECIALLY if the variation is on the over-weight side, gets pulled apart, and the powder charge that was in it is weighed.

 

[comfisherman]

Just linking thoughts.

Linking thoughts from just reading the "Throat erosion double base powder" thread and now this one.

The load you were shooting for is 96.5 of Reloader 25, behind a 120 ballistic tip. Now the goal is to load that on a lee progressive press?

Most of my experience with the 7 rum has been around retumbo, but my gut says thats on the upper end of recomended pressure. Several questions and observations come to mind.

What is the accuracy in grains the auto disc is capable of when throwing powder charges in that range with rl 25? (In my experience with a couple 7 rums, charge weight changes as high as 1 grain didn't do much to velocity but drastically altered accuracy.)

Do you feel comfortable with the ramifications of high pressure in the 7 rum? I.e. super low primer pocket life and neck failure? The brass for this critter can be short lived in the upper end of pressure. (max load in one 7 rum with a 120 b-tip had as low as 2x loads before 90% neck and primer failure... that load was lower pressure than your intended)

I love the 7 rum, am currently working on a 3rd. It just seems counter intuitive to have such a hotrod with such short barrel life loaded with a method more suited for high volume pistol. If you have a scale, maybe just use the progressive for other load stages and manually weight the powder.

Just a suggestion, hope its helpful.

 

[Max Heat]

It looks like that's what I'm going to have to do for now. According to my figures, stacking 4 disks (I don't even know if that would be possible) on the autodisk measure would still yield less than 85gr of RL25. When I read that it is "primarily" intended for pistol and smaller rifle cartridges, I over-exagerrated the meaning of the word. They should have used the word "only" instead.

But now I am seeing a potential problem with the "perfect" measure also. It will handle a large enough of a charge, but from the listing that I saw on ebay yesterday for a perfect-compatible rifle charging die, RUM cases won't fit. They state that the die will fit cases up to .520". The RUM case is .520" at the shoulder, but it tapers UP to .546" at the base. I wonder what other RUM loaders do about this situation.

And to make things clear about the 96.5gr of RL25 behind a 120, it was PM'd to me by another forum member. But the 120's that he was using were NOT nosler ballistic tips. He claimed 3950fps for that load, stating that the accuracy did go down if any higher charge than that is used. But, the "mileage" MAY vary with NBT120's. I suppose I'll find out when I get there. That is if the day ever comes that the 7mm shaw barrels from the group buy at gunshack ever get shipped out. From what I understand, they are experiencing "problems" right now.