Issue with 30 carbine die.

[sevt_chevelle]

I've got an issue with a 30 carbine die, its a Dillon type trim die made for the Rt1200 trimmer. Anyways, its made by CH4D, it sizes the case as you trim it in the same step.

The problem that I have is the die forms a shoulder around the case about 1/2" down from the case mouth. You can definitely feel the shoulder on the case. When you look inside the die you can see a ridge along the die.
I have NEVER seen a piece of 30 carbine with such a shoulder formed in it. I ran a piece of brass through a RCBS die, which forms no shoulder, and compared some measurements. I measured down by the extractor groove, about half way up the case and at the case mouth, I get the same measurements for the CH4D die and the RCBS die minus the shoulder from the CH die.

Am came across this die from a fellow reloader who posts on a few forums and asked if he had the same issue as I was with my die, no he was not.

I contacted CH4D and all they said was see attached SAMMI drawings.

Thoughts opinions as I am not overly pleased. Thanks...Eric

The CH die brass on the left, rcbs brass on the right.

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CH on bottom rcbs on top

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[jag2]

I think the more commonly used term is bulge, not shoulder. What ever. It is just something that happens when the brass is getting a little weaker or that particular brand is a little thinner. Keep in mind I am not an engineer so these are my interpretations of what I experience. The same thing happens when I reload 9mm and 380. Maybe it is just going to happen to all cases that are almost straight but not quite. The question is will it feed okay? If so you're good to go but you probably won't get too many more reloads out of that piece.

The good news is if you aren't aware of it is that Starline is now making .30 carbine brass and it is available. I pulled a new one and measured near that bottom area and it was .354 while a piece that I have reloaded before is .360. It went into battery okay but was a little tight coming out.

Going back to a previous point. I picked up some once fired Tula 9mm at the range but most all of it started to bulge after the second or third reload so I started tossing it while I have plenty of Win that still looks fine after umpteen reloads. Just the way it is.

You might try backing off the die, a lot, like 1/4 of an inch. You may not really need to size it that far down. That is usually more important with bottle neck cartridges. Keep trying out different setups and it may help some but I still think it's going to happen.

 

[condor bravo]

Sounds like the die is oversizing abruptly at the area of the shoulder and forming the shoulder rather than continuing with more of a taper. Perhaps not really a problem. After seating a bullet which may extend down to and iron out the shoulder, does the shoulder then disappear and the round appear normal? It may just be a cosmetic concern until bullet seating and functioning may then be fine. Loading for .30 carbines is hardly a problem, or shouldn't be, but if a problem does exist, a sizing die replacement is probably the only answer. But I agree that the shoulder probably should not be forming, or the shoulder at least just looks suspicious but may be innocent. It will have to be judged on the appearance and functioning of the final loaded round.

 

[jag2]

I think I misread your description. I thought I was seeing a bulge near the base in the photos but missed you said it was near the top. My mistake. I'm still not sure it is a problem though. It is a phenomenon that is often seen in many calibers. It looks like there is a bulge near where the base of the bullet is inside the brass. I have read an explanation of why it occurs that made sense when I read it but don't think I can repeat it. I would still advise that you don't start changing things until you know you have a problem when the round is actually fired.

 

[dahermit]

When the die company said to read the specs on the drawing they gave the answer. If that drawing is indeed SAMMI specs for the .30 Carbine, then what your die is doing is correct. It would appear from the drawing that the .30 Carbine case is not a continuous straight taper, but a straight taper until it gets to near the area that holds the bullet...then the sides of the case become parallel (see the two .336 dimensions on the drawing of the cartridge?). Firing the round "irons out" the subtle change from taper to straight, whereas you die reforms the case to the specs on the chart, leaving that subtle change that appears to you as a "shoulder". If that be true, then I guess we learn something new every day...I always considered the .30 Carbine as being a continuous, straight taper round.

 

[T. O'Heir]

Haven't ever needed to trim .30 Carbine, but that die in the giant picture isn't resizing.

 

[dahermit]

...that die in the giant picture isn't resizing.

I see no "giant picture" with a die in it. I see pictures of cases and drawings of a .30 Carbine cartridge and chamber. Please put a little more effort in what you are trying to express, your post is not clear.