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NAPOTS
04-24-2012, 10:37 PM
My wilson combat manual has a suggested .45 auto load as follows

200 gr H&G #68 SWC
5 gr Bullseye
1.250 COL
Taper Crimp of .469 at the case mouth

My question is on the taper crimp. I set the seating/crimping die so that the diameter of the case as far forward as I can get my calliper is .469. It looks like too much crimp to me. I know the .45 headspaces on the case mouth and it doesn't leave much case mouth at all to catch on the chamber. Also with the RCBS die that I have some come out a .470 and some at .468. I know that's not much but the case isn't really that thick there. I loaded 7 of them and they all chambered and shot ok.

What are you guys doing for crimp? Am I crimping too much? If they chamber and shoot are they ok or am I just holding them onto the breechface with the extractor?

Schuetzenman
04-25-2012, 06:17 AM
First off, the typical bullet seating die puts on a Roll Crimp, not a taper crimp. Taper crimp is subtle and hard to see with the naked eye. Up to a 1/4" of the case will have the taper in it. The roll crimp is much narrower, maybe 1/8 th to 3/16ths.

Taper crimp is put in with a specific taper crimp die, you use that die after the bullet seater die naturally.

If your .45 Auto has a large enough chamber, you can load and shoot rounds with no crimp at all.

NAPOTS
04-25-2012, 07:45 AM
The RCBS .45 ACP dies I have perform bullet seating and a taper crimp (and the die itself is marked for taper crimp) in one operation. I can clearly see the crimped area of the case at the mouth. It is ~.010"-.020" in length.

O.S.O.K.
04-25-2012, 08:27 AM
I generally put just enough taper crimp on to secure the bullet and no more. As long as your rounds easily chamber and are performing well, you should be good to go.

If you want more precision in the crimp, you will need to trim the cases all to the exact same length. But in my opinion, it makes little difference with this caliber. The other thing that you can do is adjust your seating stem deeper and back-off the die so that there is no crimp - seat all of the bullets and then adjust the die so that the crimp is applied but no bullet seating and then apply the crimp - in two operations. That generally will give a more consistent crimp, but the case length is the biggy.

That load is a classic.

NAPOTS
04-25-2012, 11:37 PM
I generally put just enough taper crimp on to secure the bullet and no more. As long as your rounds easily chamber and are performing well, you should be good to go.

If you want more precision in the crimp, you will need to trim the cases all to the exact same length. But in my opinion, it makes little difference with this caliber. The other thing that you can do is adjust your seating stem deeper and back-off the die so that there is no crimp - seat all of the bullets and then adjust the die so that the crimp is applied but no bullet seating and then apply the crimp - in two operations. That generally will give a more consistent crimp, but the case length is the biggy.

That load is a classic.

O.S.O.K. I did a little reading and it seems a lot of people don't like using the RCBS die to seat and crimp in the same step. Does it matter with the .45 ACP? Should I set the crimp a little lighter and seat and crimp on the same die or go get a LEE FCD and seat in one step and crimp in the next?

The way I have the die set right now it is compressing the bullet a little because it is crimping as it seats.

Schuetzenman
04-26-2012, 06:16 AM
I've been reloading .45 ACP with RCBS dies starting in 1974. From what you're posting here they have made a new or updated product offering than what I am familar with. I would say get a seperate taper crimp die and crimp as a secondary step. This is the way I've been doing it for decades. The bullets don't get compressed this way.

abpt1
04-26-2012, 07:15 AM
RCBS dies are fine although if your loading for a glock your going to need a FL die since the bottom of the case will bulge a bit. I crimp my .45acp with about 5 thousandth's of a crimp that IMO is all you need.

NAPOTS
04-26-2012, 08:23 AM
Let me get some pictures of what I am seeing and see what you guys think.

Crimping, including roll crimping when I reload .44 mag, is something I am a little confused on in general. I am probably over thinking it.

I might also pick up the lee facotry crimp die, its not very expensive, it also has a carbide sizer ring to iron out the case walls to get rid of any bulges that result from seating the bullet.

noylj
05-28-2012, 12:28 AM
The taper crimp doesn't hold the bullet in place. Trimming cases that head space on the case mouth simply increases head space.
SAAMI specified the case mouth to be 0.473". Most aim for a taper crimp of 0.471-0.472". You can hold the round up in bright light against a white background and you can see any residual flare/bell of the case mouth.
Taper crimp is not a precise thing--otherwise, there would be actual gages to measure it. Up until maybe two decades ago, handloaders simply used their own eyes and the gun's barrel to establish the taper crimp. Only recently do people need to try and measure it. One thing I have done for decades, besides looking at the round's profile, is to look for the shiny ring around the case mouth from the taper crimp die "burnishing" it.
I prefer to separate seating and crimping. It may not make a lot of difference, but it is easier, to me, to adjust each die to do just one job than to adjust back-and-forth to have a die do two jobs at once. Also, there is the fact that the bullet is still being moved and seated as the case mouth is pushed into the bullet. This can scrape off lead and destroy accuracy.

Silicon Wolverine
05-28-2012, 06:44 AM
i use lee FCDs for my handgun ammo. it takes away any ambiguity in the crimping process. plus its that little bit of extra insurance that your rounds will fit and function in any handgun.

SW

O.S.O.K.
05-28-2012, 09:37 AM
In standard dies with either a roll crimp or a taper crimp and especially the taper crimp, the only way to get uniform crimps is to trim cases to uniform length. If you are using different brands of brass, this will not work as the brass will have small variences in case thickness... but with the same brass, trimming is sufficient to get a uniform crimp. Yes, trimming too much will increase head space... so don't trim below spec.

As SW says, the Lee factory crimp dies don't use overall case length to determin the crimp amount, so don't necessarily need uniform cases.

Roll crimping as with 44 Mags with bullets having good, deep crimp caneluers is also a matter of having uniform case lengths and you pretty much want to crimp as much as you can without causing the case to bulge behind the crimp - within reason. That's what's being referred to as a "heavy crimp". With cast boolits, that have a deep crimp groove, you can apply a very deep, firm crimp. With jacketed bullets with rolled crimp grooves, you can't apply as deep a crimp, but it works fine anyway as the gilding metal of the jacket is much harder than the cast lead and holds the crimp better. With the .44 Mag - with heavy loads, if the bullets are staying in their crimps during firing, then the crimp is enough as that requires a good firm crimp to acheive.

A good firm crimp does a lot of things - keeps the bullets in place under recoil, helps with uniform burn rates and to help keep the bullet straight while exiting the case.

Here is a pic showing a good crimp on a .44 Mag with 300 grain cast boolits:

http://farm5.staticflickr.com/4046/4351511014_507f01cf72_z.jpg

Taper crimps are much more subtle. You can measure them by using a caliper and measuring at the same point on the case head, but it's not easy. A simple jig to help with this is to drill a hole in a piece of wood, just big enough for the case to sit down in with just the neck sticking up and then lay the caliper flat and measure the case of the loaded/crimped round - this will give a good enough consistent placement for measuring your loaded case taper crimps.

NAPOTS
05-28-2012, 09:52 AM
I ran through 100 rounds .45 ACP without a hitch with the taper crimp at approximately .469 at the mouth. Should this be an indication that the loads are ok? Is there anything I should look for in the brass as a sign I might be crimping too much?

O.S.O.K.
05-28-2012, 10:42 AM
Hard for the crimp to be "too much"... if they are functioning correctly, then all is well.

If the crimp was too much, the cases would occasionally slip forward too far and fail to fire - the 1911 does hold the case head with the extractor during chambering and firing though, so this would only happen every so often.

100 rounds with good function and accuracy = you're OK to go.

If you're still concerned, then remove your barrel and place the loaded rounds into the chamber - push on the case head and see if you can get it to move forward and "stick" - if it just sits there and drop out freely when you tilt the barrel, and it's flush or almost flush with the barrel end (they stick out of the chamber a bit with the extractor groove exposed) then you are good.

NAPOTS
06-23-2012, 11:32 PM
I just picked up a .45 acp lee factory crimp die and my loads look much better. It has a size ring which will iron out any bulges in the case wall too