I am new to pistol reloading, and for that matter, this is my first post. I apologize ahead of time.

Loading 9mm, I taper crimped my cartridge to the case mouth specs in my manual. When finished i was able to push bullets into case with my fingers.

Is there a tolerance for crimping cartridges? I am concerned about head spacing on case mouth.

Thanks in advance,

First, welcome to AR.

I am not sure what the "tolerance" you refer to is or would be for the crimp but lets assume it might be +- 0.00001 radially or something, which would not mean a lot in general reloading. While I dont load the 9mm , they can be a little tricky.

You dont say what press you are using either.

But take a factory 9mm round and maybe get an idea of the case crimp there on the mouth. It may not actaully measure any differently with your caliper or a mic and I dont expect it to.

But reset your crimp die to apply more tension to the case and bullet. Might do one, then go add a 1/8-1/4 turn, check, add a 1/4 turn, check etc until you get the crimp you want. If you bulge or start mashing it then of couse back off. You will feel the resitance on a single stage, and maybe on the progressive too. Take a note of about where the die is after each crimp, then record about where it is when you get the crimp you like.

Make sure you are getting the right COL per the book while you go as well.

If you are using the crimp in the seating die, then think about getting a dedicated crimp die. It generally works better. The Reddings are good, there are others too. Might try the Lee factory crimp as it is not too expensive, migth just be sure it will "taper" before you buy one, but I am betting it will.

D*@n it! Factory ammo. Wishin' I woulda thought of that before I asked.

For the record, RCBS single stage.

Thanks

First, crimp does NOT hold the bullet in place. Proper neck tension does that. The taper crimp is really just a finished product thing. You flare the case mouth & need to remove that flare after seating the bullet. If you pull a loaded round & can see where the bullet was crimped, it's too much. Too much crimp can do two things: It can actually reduce critical neck tension & destroy accuracy by reducing the bullet dia. So if you are sizing the case properly, check the dia of your expander & make sure it's at least 0.002" SMALLER than bullet dia.

Fred said it better.

I should not have used the word "tension." But the crimp is suppossed to help hold the bullet in the case under recoil, amd give a more consistent tension or release, and with the taper provide for smoother feeding in auto rounds, with taking the bell out of the case.

One of the problems I had using the Lee Factory Crimp was just as he described. I would pull a bullet and find that the jacket was being damaged slightly. Although I must admit that this was found with rifle bullets loading though.

I went with the Redding for the 38's slight taper crimp for the S&W Model 52 auto. But that wadcutter is a bit different too.

Were you Full Length sizing and using a separate crimp die after seating? Or using the crimp in the seater. Or other.

I appreciate the help fellas.

I have yet to check expander diameter, but out of the 200 or so cases I loaded, about 40 bullets would slip into case. others were okay.

I also have yet to pull any bullets to check for bullet damage.

Full length sizing. Using same die in two steps.
Seating bullet to c.o.l. then resetting die for crimping.

Thanks again guys

Well I have a difference outlook on crimps. Crimps are to keep the bullet from being moved because of recoil AND help keep it from being pushed back into the case when the cartridge is used in semi and full auto firearms from hitting the feed ramp, plus keep the bullet from being pushed backed into the case when the firearm has a tubular magazine such as found in lever action rifles with tubular magazines. Also helps keep the bullet from being pushed back in the magazine when the recoil of the firearm causes the cartridge bang the front of magazines in such rifles as heavy recoiling bolt actions, etc..

If it were solely for removing the flare from belling the case mouths it would be called a deflaring tool or something like and besides that most people don't flare the case mouths of rifle cartridges and many of those rifle cartridges get crimped.

The taper crimp was mainly for semi auto pistol cartridges that head space on the case mouth. Roll crimping such cartridges can roll the case mouth in too much and cause problems with the cartridge head spacing. Taper crimp leaves the case mouth intact to head space.

Hope that clears it up for you.

You dont have to actually pull any bullets. I just did it because I wanted to see, if, and at how much crimp, I might be distorting or damaging the bullet.

And while the seater and crimp method works, I'll bet if you try a dedicated crimp die, you will like it. Especially with the 9mm.

One thing you might try is not run your expander in as deep by the way.

Here is the Lee FCD and it looks like guys have good results at $18. In carbide to boot. One thing about these Lee FCD dies is that some small errors in case length, or COL, are not as critical, where with the Redding style you need more consitentcy.

http://www.midwayusa.com/produ...-crimp-die-9mm-luger

And a Redding

http://www.midwayusa.com/produ...crimp-die-9mm-luger#

I am not a real "crimp" guy anyway, so I am helping me and hopefully you some too. The 38 is not hard to crimp and the 45 taper crimp is somewhat easier to apply. The only round I load in the single stage abd really crimp is the 44 Remington Mag revolver with the full house big recoil loads. Then I crimp hard LOL. For that I use the Redding Profile crimp, and in full honesty I have a Lee FCD in the cabinet in case I need it if the Redding is not the answer that day, or if the cases varya little. While I know you can over do it, I dont think I have yet. At least I havent squashed any yet LOL - which I did one time on the 38's. I had to disassemble the die and take a punch and drive the crushed round out, so you learn on the way.

While I am spending your money freely for you LOL LOL, this is the end of seating depth problems and the tops in accuracy and consistency. I am not associated with Redding, I am just a customer.

I got a couple of these, and now have them for every caliber that I reload. It truly helped me.

With it and a crimp you will be set. Then add a progressive loader and you are churning out the 9mm almost as fast as you can shoot it.



Redding Competition Seater

http://www.midwayusa.com/produ...eater-die-9mm-luger#

I agree with Tex that you are probably over expanding you case. When you seat the bullet the die should close flare down, is your seating die set up right? A Lee crimp die is a good final step for a progressive.