RCBS .380ACP Bullet Seating/Taper Crimp Die

[duffman77087]

I recently bought a set of RCBS Dies for my .380ACP, when I got ready to use them I took them apart & cleaned them with hoppe's 9 solvent. Then adjusted all the dies where I needed them. Well the case expanding/decapping die & the expander die work flawlessly & the bullet seating/Taper Crimp Die will not work properly. when I get the bullet to seat at the right depth & load the next one into the press the next one would seat anywhere between 0.008 lower or higher. For example I would adjust my first bullet to 0.960, then throw the second one into the press and it would seat 0.952, throw the third in and it would seat 0.958, throw the fourth one in and it would seat 0.964 and so on without touching the adjuster on the die. Then I even had a few bullets get pulled back out of the case by the crimp. I trimmed all my brass to 0.675" so the crimp would be the same on every round. Have you guys ever had this happen to you? I think I am going to call RCBS tomorrow & get a seater die without a crimper in it. This is my first set of dies that the bullet seating die also crimps the die & I hate it! For all my other dies I have bought a Lee Factory Crimp die & never had a single problem with them.

[312shooter]

Ideally a crimp is done seperately, I have had similar luck trying to crimp and seat at the same time. One thing you may be experiencing, which is normal, you are measuring OAL to the tip of your bullet, where in the manufacturing process of the bullets there are variances, this maybe why your OAL has a bit of difference.

I would first back off the case expandsion a tad, then back the seating die out to eliminate the crimp, then run the seating plug down to proper seating depth. In other words set up as if you are seating without a crimp. After you're done seating the bullets take the seating plug out of the die and run it down to a proper crimp and follow through with the crimping process. I would recommend purchasing a lee factory crimp die, what you are experiencing is common, hence the reason crimp dies were born.

[howlnmad]

You don't need new dies. Your problem lies in the variance in bullet length and your die adjustment. Try doing it as 312 suggested and see how that works out for you.

[mikld]

Agree with the above posters; separate the crimping from the seating. Seating and crimping can be done in one step, but I have had much better results, much less variation, when I do each step separtrely.

[duffman77087]

I did what 312 Shooter said and this is what I came up with...

Measured the length of the bullets before using them.
#1-.418"
#2-.418"
#3-.418"

I seated the 1st bullet to .960".
#1-.960"
#2-.960"
#3-.958"

Then I pulled the plug on the seating part of the die & adjusted the crimp then measured after.
#1-.961"
#2-.962"
#3-.960"

Afterwords I pulled the bullets back out of the case and measured the length one last time.
#1-.418"
#2-.418"
#3-.418"


What do you guys think about that?

[duffman77087]

Also the bullets I am using are Sierra 95Gr. FMJ Flat Nose.

[woolleyworm]

Originally Posted by duffman77087

I did what 312 Shooter said and this is what I came up with...

Measured the length of the bullets before using them.
#1-.418"
#2-.418"
#3-.418"

I seated the 1st bullet to .960".
#1-.960"
#2-.960"
#3-.958"

Then I pulled the plug on the seating part of the die & adjusted the crimp then measured after.
#1-.961"
#2-.962"
#3-.960"

Afterwords I pulled the bullets back out of the case and measured the length one last time.
#1-.418"
#2-.418"
#3-.418"


What do you guys think about that?

Well within acceptable by all accounts. PM sent also.

[howlnmad]

I wouldn't have pulled them. I'd of shot them out.

[312shooter]

Excellent, by all means load em up and shoot, those are more than common measurements. Perfection in length is not a direct relationship to accuracy, many other factors come into play before the .oo2 difference.