Roll Up The Rim isn't as much fun as I remember.... Check my work?

Dark Alley Dan

Dark Alley Dan

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Howdy, all.

Started reloading 38-55 last night. Cases are sized, primed, charged, belled, and then it's time for that last satisfying step, seating the bullet. Then this happens:

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Yeesh.

I'm trying to limit belling on the case mouth to increase case life. I increased the bell on the second cartridge with the obvious results. I think I need to bell that shiznit a LOT more than I am.

20231128-203411.jpg


Am I correct in my understanding? More bell? The one dummy I made started out looking like a teeny blunderbuss, and I thought that a bit extreme. But the bullet seated well enough and the crimp ended up in the right place so maybe it's OK?

Thanks for your advice.

Cheers,

Dan
 
I would use a seperate crimp die. I messed around with 45-70 trying the bullet seat die as a crimp die and had similar results. Lee crimp die works well. I tried the Redding crimp die too but Lee was more forgiving.
 
I flare the necks on all of my straight walled cased calibers so I can easily hand fit the bullet into the case mouth. I’ve never seen what you’ve encountered. I think that your “blunderbuss” flare was probably ok. Since your crimp was fine.

Sorry, but my first reaction was to lol. Really.

Me thinks you need to adjust that die to open up that neck a wee bit further. I also use separate neck flaring, seating, and crimp dies.

Congrats on admitting a mistake and posting a picture.
 
Is hard for me to understand what the belling has to do with it - I have certainly smooshed at least my share of cases - belling seems to have something to do with getting the bullet into the case neck - those look like bullet was more than half bullet diameter down before the case walls scrunched - maybe something else?? Too soft brass?? Undersized neck mouth for bullet size? But hard to argue with an increased bell resulted in successful seating - not sure I can make the connection about "why", though.
 
Hard to tell from the pictures but it looks like the ends are rolled in. I'd say you are crimping long before you should be crimping. Backing out the die is usually the fix. I know your wildly over flared case worked so if it's not that then ??
 
Expanding with a Lyman M-die expander and then seating and crimp in two separate steps is what I would do.

As mentioned check the bullet diameter
 
B said:
Hard to tell from the pictures but it looks like the ends are rolled in. I'd say you are crimping long before you should be crimping. Backing out the die is usually the fix. I know your wildly over flared case worked so if it's not that then ??
Click to expand...

I also thought that they looked like they were crimped... back out die and screw down seater plug.
 
I think you've hit it, fellows - premature crimp (sounds medical) is probably the culprit. Gonna order a fresh crimp die. Thirty bucks from Bezos, and problem solved.

Many thanks for the input. Life's about learning stuff. :)
 
I am going from my understanding how crimp dies work - like RCBS - crimp roll ledge is at very top of inside of the seating die? So, perhaps run a belled case in with no bullet - see what happens - if die body is set too low, that "crimp ledge" will engage on the mouth of the case. So, I think supposed to set seating die body first - whether you want crimp or not determines where the die body gets locked in - then a separate step to set seating punch - how deep do you want bullet seated - without moving the die body. Unless some dies have very different system, not sure how to get a crimp going with 1/4" or more for case to yet travel up?? But, if you resolved it with new / different seating die, is done.
 
First off, some 38-55 brass are manuf shorter than older stuff ( I cant remember who makes the shorter stuff now but somebody here will) so if you set your die to one length of brass it will start to crimp the longer brass way before bullet is seated.
The other possibility is your expander plug isnt fat enough to expand cases for cast slugs that may be 2-3 thou overdia. and a commercial "hard cast" slug will not "give" as much as a soft hand cast slug so the brass wrinkles instead of expanding to accept the slug.

RCBS Cowboy die sets come with two different sized expander balls/plugs. I have some machinist machines in my shop and the most common job I do for myself is custom expander dies for different molds & calibers I have.
 
fingers284 said:
First off, some 38-55 brass are manuf shorter than older stuff ( I cant remember who makes the shorter stuff now but somebody here will) so if you set your die to one length of brass it will start to crimp the longer brass way before bullet is seated.
The other possibility is your expander plug isnt fat enough to expand cases for cast slugs that may be 2-3 thou overdia. and a commercial "hard cast" slug will not "give" as much as a soft hand cast slug so the brass wrinkles instead of expanding to accept the slug.
Click to expand...

A lot of die sets have an expander meant for jacketed bullets of 0.375. You need an expander of 0.378 minimum for lead bullets depending on what diameter bullets your using. Die sets sold for cowboy action come with a larger expander. I made mine on my lathe.
All modern made brass is to made the shorter length for factory rounds. I know Starline does offer both length of cases. Which brass used can depend on how old your rifles are. Mine are made in 1908, savage 99 and 1911 a 94 Winchester.
OP your rounds do look like your die is crimping before your bullet is fully seated.
 
, even though it may appear to be straight walled. This means that you can adjust the diameter to which the case mouth is resized with your sizing die. Instead of adjusting the sizing die to touch the shellholder as per the instructions, start with the sizing die adjusted into the press so that it only resizes about 1/2 of the case. Measure the case mouth I.D. (inside diameter). Ideally you want the case mouth I.D. to be .002 to .003 under bullet diameter.

If the case mouth I.D. is smaller than this, back the die out one turn, and try resizing another case. If the I.D. is larger, turn the die in one full turn and size the case again. Once you get the case mouth I.D. where you want it, try rechambering the cartridge case in your rifle, just to be sure before you make a bunch of ammo.
 
The Lyman expanders are very nice. I'm slowly collecting some for what I load but they can be hard to find and a bit expensive. Worth it though.
 
What size bullet and what size expander? If your bullets are 379 or 380, you might need a bigger expander. The RCBS cowboy set accounts for this and includes 2. 38-55 can be a pain in the ass until you get everything set up just right.
 
supernova said:
Are you sure you set the die up correctly? Roll crimp dies are typically not set up to touch the shell holder.
Click to expand...

Exactly.
If you set up your seater die the same way you set up a sizer die, so it makes firm contact with shell holder, this will be the result.
 
When I first looked at the pic, I thought you were going to post that you used the wrong bullet - one that was too big!
 
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