When reloading 45acp, do you seat the bullet and apply the taper crimp in the same step? I have an RCBS die that will do this. I've been setting up the die per the instructions, and I think doing both steps at the same time is pushing up some of the copper jacket on the bullet. Making a little ripple. Measuring is tough, but it seems like it's making a ripple of a couple thousands, increasing the bullet from .452 to .454. I tried to take a photo with my phone and macro lens.

I'd rather not do these as separate steps as I have a single-stage press. I'd rather not back off the taper crimp as it's right about where I think it should be. Think this will cause any problems?

Specs
200gr xtreme Round Nose .452 bullets
5gr hodgdon titegroup
Federal large pistol primers
1.261 OAL
.471 diameter at bullet base
.470 -> .468 taper crimp (numbers drop off fast as sliding calipers up)

I’ve loaded a lot of .45 where I seated and crimped st the same time. That said, I’ve switched to doing it separately since it’s easier to get it right.

If you’ve got 0.468” at the case mouth, I think you’re crimping too much. Try backing off until it’s 0.470-0.472”.

Isn’t the taper supposed to be 1-2 thou under the width at bullet base? So since it’s 471 at the base the crimp should be 470-469? 468 is right before the calipers fall off the edge.

I haven't heard that before.

For 45 ACP, the maximum case mouth size is 0.473" per SAAMI specs. As long as you're below that, you've removed all flare and the bullet is held tightly, you're good.

I haven't personally ever seen anything less than 0.469" with my reloads, and I'm usually up in the 0.471" ballpark.

All of this, of course, assumes that everyone's calipers are spot-on.

With jacketed bullets, yes seat and crimp in the same step is fine. With cast bullets, you need to crimp separately. You are loading plated bullets though, not jacketed, and they need to be treated more like cast bullets, since the copper plating is very thin and the lead underneath is very soft.

With that said, you don't need to crimp that much. You should be flaring the cases before seating, and then you can set the crimp feature to just remove the flare; that's all you need. That can be done in the same step as seating.

Most likely you'll find better accuracy when you stop crimping those plated bullets so hard.

Thanks everybody. I'll back the crimp off.

I load a lot of xTreme 200 & 230 plated. As above, just crimp enough to straighten out the flare. I “plunk” test them in a removed barrel, they should drop in without needing to be pushed to seat.

Shit I'm not liking the way these primers look. They look flat to me. Pressure warning signs?

What was the load exactly?

The one I'm setting up the die for now is:

Specs
200gr xtreme Round Nose .452 bullets
5gr hodgdon titegroup
Federal large pistol primers
1.261 OAL
.471 diameter at bullet base
.471 taper crimp (Will adjust die to this)

The picture above with the flat primers is:
Specs
200gr xtreme Semi-wad cutter .451 bullets
5gr hodgdon titegroup
federal large pistol primers
1.216 OAL
.470 diameter at bullet base
.466 taper crimp (wayyyyy too much)

I loaded these too short, which caused crimping problems. Now I've got 300 of them with these specs. Don't think I'll shoot them anymore. Might be time to pull all the bullets.

Looking at this chart:
http://www.handloads.com/loaddata/defau ... er&Source=

It looks like the closest is the LSWC. Maybe my OAL isn't too short. No way to un-crimp a round though.

Those primers look flatter than what I normally see for .45, but I wouldn't consider those "flat primers."



Well, you can't JUST un-crimp a round, but you can pull the bullet if there's a problem.

I didn't have any split cases. Is pressure reflected in bullet velocity? Should I try to shoot some at over a chrono?

Usually not. The pressure spike can occur early, which can actually lead to slower MV. Seems counterintuitive at first blush but makes sense.

No, you can't trust velocity. I mean, I suppose if they came zipping out at 1300 ft/s, then that might be a clue . . . but even a "normal" velocity can occur with high pressure.



All right . . . for fun . . . here's what QuickLoad has to say about that, assuming that Rainier bullets are close enough to Xtreme for these purposes. I also assumed a 4.5" barrel, which should only matter for the velocity prediction.



Note that the max pressure for 45 ACP is 21,000 psi, and your load is at 19,753 psi per QuickLoad. If you lengthen it to 1.226", the pressure drops to 18,991 psi. At 1.236", it's 18,299 psi. At 1.246", it's 17,637 psi. Etc., just to show the effect of OAL on pressure.

This is why if you ever have a round with "bullet setback," you don't want to just blindly shove it into your gun and fire it.

EDIT: Please ignore the chamber pressure and velocity shown at the top of the chart; that's something else. For that load, the predicted chamber pressure is 19,753 psi and the velocity from a 4.5" barrel is 925 fps.