Problem with RCBS .380 seating die cutting into bullets.

[slowr1der]

So I finally got around to actually charging the cases and seating the bullets for my first batch of .380 ammo. Now, I've run into yet another problem. As I try to seat the bullet, I try to sit it fairly straight on top of the case while running it up into the press, but it seems like if it's not nearly perfect, the RCBS seating die cuts into the bullet on the side. Anyone seen this?

Now this is the first time I've used RCBS pistol dies. I thought it much be something rough on the seating stem, but I took it apart and all looked fine. All I can figure is that the seating stem isn't really shaped like a funnel type shape like the Lee dies, and so it has to be nearly perfectly straight or the side of the seating stem will dig into the bullet. On the Lee dies it seems like they are more of a funnel shape, so if the bullet isn't perfectly straight instead of digging it in, it straightens the bullet. Anyone seen this? What's the solution to it? Out of 100 rounds I got about 10 that have cuts in the bullet from the seater stem.

 

[Robert101]

I do try to reasonably center the bullet. It also helps if the case is expended sufficiently to allow the bullet to self-center. Be careful not to expand the case to far on .380. Again, turn your expander down into the case maybe a little bit more.

 

[loneviking]

Do a search on 'adjusting RCBS seating die'. I'm on a phone or I would post a link. Basically, your die isn't adjusted right. Take a sized case, back off on the die all the way and run the seater plug way down. Keep experimenting until you have a bullet seated at the right OAL. Then back the plug off and repeat the process getting the crimp right by screwing the die body down in very small turns until the crimp is right. Then, with the crimp right, run the shell to the top of the stroke and then screw the plug/seater down until it hits the bullet. Lower the ram and you're good to go. Sounds complicated but its easier than it sounds.

 

[JimKirk]

Pull the seater and chuck it up in a drill... use a 600 grit sandpaper to break the sharp edge of the seater plug ....

 

[rcmodel]

Expand/bell the case enough you can hard start bullets in the charged cases and pick them up out of a loading block without the charged cases falling off the bullets.

rc

 

[T Bran]

I polish all of my seater plugs as soon as I get them. Had a Lee .223 die that would cut into the bullet and leave a ring on every one streight or not. I polished it up and ordered a RCBS die. When I put the RCBS die into service guess what I got the same line back on the bullets that the Lee die had been making. At the range I felt something odd on a 30/06 bullet as I was loading a magazene for my 760. On closer inspection it also had a faint ring from the seater plug on the ogive. When I got home I started tearing down dies and polishing seater plugs on every one I owned.
No more funkey rings since then.
LUCK
T

 

[slowr1der]

Thanks for the help guys.

Do a search on 'adjusting RCBS seating die'. I'm on a phone or I would post a link. Basically, your die isn't adjusted right. Take a sized case, back off on the die all the way and run the seater plug way down. Keep experimenting until you have a bullet seated at the right OAL. Then back the plug off and repeat the process getting the crimp right by screwing the die body down in very small turns until the crimp is right. Then, with the crimp right, run the shell to the top of the stroke and then screw the plug/seater down until it hits the bullet. Lower the ram and you're good to go. Sounds complicated but its easier than it sounds.

I'm not sure what else to do as far as adjusting the die. I've read many times how to adjust them, and I've never had a problem before. I pretty much followed your process. I screwed it in until I could feel the die touching the case mouth. Then I backed it out a full turn as I don't want it to crimp the round. Then I set the seating depth with the seating stem adjustment. I'm crimping them with a Lee FCD in a separate step.

Pull the seater and chuck it up in a drill... use a 600 grit sandpaper to break the sharp edge of the seater plug ....

Sounds like this may be what I need to do.

Expand/bell the case enough you can hard start bullets in the charged cases and pick them up out of a loading block without the charged cases falling off the bullets.

rc

I need to play with this a little more I guess. I've expanded it enough that I can just lightly start the bullet in the case, but I can't push it in there far. I've heard so many stories of people over expanding the cases, I guess I don't want to do that. Maybe I need to flare them a tad more though.

 

[murf]

what rc said. the bullets are probably seated crooked, also. more bell should cure your problem. a taper crimp after seating should take care of any excess flare.

murf

 

[joneb]

Pull the seater and chuck it up in a drill... use a 600 grit sandpaper to break the sharp edge of the seater plug ....

Why didn't RCBS think of that
Is the expander/flare stem centered in the die ? Is the seater stem centered in the die ? If not this may be part or all of the problem.

 

[aluckydog]

Did you chamfer the inside of the case mouths?

 

[ssyoumans]

I had the same problem with RCBS dies in 380 ACP. It was especially bad with lead round nose bullets, I was using Secret Agents from MBC.

I finally was so annoyed with it that I sold them and bought Lee Dies. I haven't had any problems since.

Between these and 38/357 RCBS dies, I've developed a preference for Lee dies over RCBS. Haven't ever tried Hornady yet, but I see no reason to.