RCBS 380ACP Resize Die Set For Taper?

[Digital Jedi]

Hey there fellow THR members, hope all is good with you all I have been finding tons of useful information in this forum, so I finally decided to join. Yes, I'm a noob here, so please go easy on me. I searched the forum for over an hour trying to find a thread on my issue and couldn't, so if this has already been addressed I apologize.

I have been reloading for over a year. Picked up an older RCBS Auto4X4 Progressive at a garage sale for $100. It needed a little TLC, well a lot actually, and she runs great. I have loaded 9mm Luger, 45ACP and 40 without any problems at all. I decided to give 380ACP a try, and it has been a hair pulling experience to say the least. With many calls to RCBS and additional parts ordered (special expander plug for my 20415 die set), I finally reached a point where I can load these little guys without any problems. Now, the issue is case checking...getting about 10% that are not passing with both my Wilson and Lyman checkers. I even pulled the barrel out of my Kel-Tec to use for checking and many failed. When checking, they stop in the gauge about 1/4" from dropping fully in. I am using mixed range pickup brass in good condition and no particular head stamp seems to be better than others. I even pulled out 150 casings of Federal, RWS and Speer match grade once fired...the FCC will pass but the RWS and Speer will not, which makes no sense to me at all.

So, I figured to make things easier on myself, I would run all my brass in the re-sizer/decapper and then case check them...if they pass I continue to reload them and have had no issues...this saves me from having to use a bullet puller for hours after. The problem is, I am wasting over 50% of my brass..wasted about 2% in all my other calibers, which has been normal and nothing to stress over, but the 380 has me pitching most of it. I am just a range plinker and not going for competition accuracy, so I don't really feel bad about relaoding less than perfect brass...I keep using them till they die Some of my brass has bulges that the re-sizer does not completely get rid of, but it has never been an issue with any other calibers except the 380:banghead: I know that much of range brass has potentially been reloaded, and bulged casings are not good to reload, but wasting over 50% of my brass is getting frustrating and even my quality once fired stuff is not getting past the case checkers, even before expanding or seating...WTH??

I measured 3 FCC & RWS casings after they all were re-sized...I noticed that the die is putting a taper on them...getting .368 at the top and .372 at the bottom with RWS and a little less with the FCC, which is why the FCC are all case checking. I thought that 380 was a straight wall case, am I wrong? Is there a die I can replace the RCBS with that will not taper my casings? Do you guys think that this is the reason so much of my brass is not passing the case check? ANY info you could pass along would be VERY apprecaited...don't wanna throw away good quality once fired brass if it's a die problem Sorry for the long winded story

 

[rcmodel]

Do you guys think that this is the reason so much of my brass is not passing the case check?

Your post was too long for me to read the whole thing to get to the true question.
So bear with me.

I think your problem is mixed brass.

Federal .380 cases 'may' have a step or shoulder inside them to prevent bullet setback.
All brands of straight wall cases are tapered inside toward the case head to provide additional strength closer to the end of the chamber.

So, if you are expanding and your expander is set to deep, too low?

You are expanding part of the case that should not be expanded.



The 'taper' your die is leaving is supposed to be there to provide proper case neck tension and prevent bullet set-back after you load & begin to shoot them.

rc

 

[Digital Jedi]

Your post was too long for me to read the whole thing to get to the true question.
So bear with me.

I think your problem is mixed brass.

Federal .380 cases 'may' have a step or shoulder inside them to prevent bullet setback.
All brands of straight wall cases are tapered inside toward the case head to provide additional strength closer to the end of the chamber.

So, if you are expanding and your expander is set to deep, too low?

You are expanding part of the case that should not be expanded.



The 'taper' your die is leaving is supposed to be there to provide proper case neck tension and prevent bullet set-back after you load & begin to shoot them.

rc

Thanks for taking the time to reply, I really appreciate it. Sorry for the gone with the wind post...didn't want to leave anything out. In a nut shell, loaded rounds that should be passing the gauge check, aren't, even factory once fired with zero buldges...with 2 different case checkers. I am also checking them immediately after the resizing die, and they still fail the check before they even get to the expander station. I guess my real question is: shouldn't once fired, high quality brass pass checking after resizing? 1 or 2% failure is the norm for all my other calibers...is 380 different, because over 10% seems too high. I have noticed the FCC has a step inside the case, but this is not an issue...the FCC are the ones religiously passing the case check.

 

[rcmodel]

Put it in the gage backward and see if the rim is bigger then it should be.

Other then that?

Did you adjust your sizing die down to touch the shell holder at full ram travel??

Other then that?

Color an offending resized case with a black Dry-Erase or Magic-Marker and force it in the case gage.

What is not black after you punch it back out is what is wrong.

Then we can go from there.

rc

 

[Digital Jedi]

The casings that fail to check are all stopping about 1/4" from the rim. Just for curiosity sake, I did take a few casings and put them in the checker rim first and they started, with no hang ups. The bottom of the die is touching the shell plate at full stroke...I set them all up the exact same way I did with my other calibers. I measured 3 different casings after resizing, each O.D. at the top of the casing and again at the bottom just before the rim, and have the following:

FCC: Top=.368 Bot=.371

RWS: Top=.369 Bot=.376

HDY: Top=.367 Bot=.375

Win: Top=.368 Bot=.373

Looking at the numbers, it makes sense why the FCC and Win are passing the case checking, since they are the smallest OD's. Wouldn't these results indicate that the resizing die is tapering the casing? Is the 380ACP supposed to be tapered outside? Inside sure, but outside? I have read in many different places, including here, that 380 is not tapered. I took some fresh rounds straight from the factory box and used my bullet puller on them...the casings are not tapered and have very little variance from top to bottom, maybe .001 difference, not the large numbers I am getting. Strange that a factory, unfired casing passes with flying colors, but after putting it into the resizing die, it fails.