Home Forums Hunting & Shooting Handguns Taper crimp with semi-autos

How many of you are using the Lee (or Redding) taper crimp die for your semi-autos. I load for the 45 ACP and 10mm and have been having some issues with a round or two hanging up from fully chambering. Not a good thing. Will the taper crimp die help?

I've purchased the Taper Crimp die in both 45 ACP and 9mm IIRC. Been awhile. I've never used either yet, so I can't tell you. My guess is your overall length. Have you checked it against a known good factory round?

Ricky, which brand of dies are you using now? Semi-auto die sets often come with a taper crimp die, and usually marked "TC", or "Taper Crimp", etc.

I've had more problems with not allowing a sliver of lead exposed in my .45 ACP, lead, target loads not feeding than with not enough taper crimp to remove enough of the case belling. But it can happen.
Try measuring the case mouth diameter of some factory ammo then set your dies to do that. E

i've used redding taper crimp dies and lee factory crimp dies with good sucess.

My 45 dies are Redding and RCBS. I use the seating die in the RCBS set for my Rowland kit. Standard 3 die carbide set with no taper crimp die. 10mm are Hornady and I am looking to replace them. No TC die there either. They rusted on the outside almost immediately.

In the typical auto die set, the seating die will place a taper crimp.

Ideally a taper crimp should be adjusted with the aid of a micrometer. Bullet diameter + (case wall thickness x 2) = perfect taper crimp.

BTW, except for Dillon dies*, I know of no die brand which furnishes a standard taper crimp die. Regular seating dies have a built in roll crimp and the taper crimp die must be purchased as an extra.

* Interestingly, while Dillon S-A. pistol dies come with a standard taper crimp die, their revolver dies offer their "accu-crimp", i.e. it starts with a taper crimp, which becomes a roll crimp when the die is screwed down further. Thus, one has the choice between a taper crimp for light to normal loads and/or a roll crimp for heavy recoiling loads. This option is handy as case trimming (a PITA !) is much less critical with a taper crimp than it is when roll crimping.

RCBS does.

Back to the question - no, a taper crimp probably won't help. Both the .45 ACP and the 10mm headspace on the case mouth, so you should be using a taper crimp regardless. A taper crimp leaves an 'edge' for the case to catch in the chamber for a proper headspace, so if anything, that 'edge' will cause more problems.

A possible exception is if the roll crimp you're using is causing the case to bulge slightly.

I'd compare the ogive profile of the loads you're having trouble with to a load that functions well and seat the troublesome bullet to a depth where the two ogives line up. The ogive should then hit the feed ramp in the same spot.

Good advice, JOG.

I'm using a Lee die for my 45's and it works well with never a problem........yet.

When I set it up for a given bullet, I mic the diameter over the crimp area & match that to a factory round ( or a predetermined diameter).

Also, I try to just bell the case mouth enough to get the bullet started.

MM

OK. I've looked at that but will revisit the issue. Thanks.

So, can a taper crimp lend to accuracy by giving more consistent neck tension?

The only Lee products I own are their 'factory crimp' dies. The fc die in .30 carbine has allowed me to get reloads in a .30 Blackhawk where the Redding taper crimp did not. It is possible I just have a sorry Blackhawk however, as I had the chambers bored out a few thousands before it would take any reloads.

O

I had the same issue with a Raging Bull Casull. Hated it since it shot so good!

Is it possible that every once in a while, you're taper crimp is not removing enough bell from the case mouth?

I'm not using a taper crimp die. Don't have one. I was asking if that might help my situation. I have the seating die set so it removes the bell. None of the rounds that have hung up look like it is still an issue. Thanks for the suggestion, though. Never know what a guy might overlook.

I taper crimp my auto pistol and .30 carbine loads as a separate step and to an established dimension. When I start with a new batch of cases, I first trim them all to a uniform length. Following this system I've never had feeding or headspacing problems in auto pistols, my .30 cal carbine, or my .30 cal Blackhawk.

I have been having the same problem with .45 auto. I test every round in a Wilson overall size gage. Problem rounds will slide perfectly into the gage until there is about 1/32 inch of the case left above the top of the gage. A very slight push will then seat them the rest of the way. These rounds will feed ok in the actual chamber but not headspace correctly and I get failure to return to battery. It happens more or less often depending on the brass I use.

I have been using a Redding 3 die set with the seater die also applying a taper crimp. I just bought the Lee factory taper crimp die but I haven't tried it yet.

Seating and crimping in one step can suck. I never had much luck with it. A firm crimp is almost guaranteed to distort the case mouth and/or mash the bullet tip. I switched to a progressive looong ago so it's nice to not fiddle with that.