.45 ACP taper crimp update

Pistolero

Well-Known Member
A while back, we were discussing loading the .45 ACP and after loading it in large quantities for a sport which
is absolutely unforgiving of any malfunction, IPSC shooting, I have definite opinions on the correct way to make
ammo the absolutely WILL run in any properly made 1911 platform. The standard bullet used by me
and the overwhelming majority of folks in that game (and in the target game, too, although not quite as
much to the exclusion of others) was the H&G 68 200 gr SWC. This will feed with 100% reliability in almost
any 1911 if loaded properly.

One of the most critical things that I have found for making reliable .45 ACP ammo with the H&G 68 is to taper
crimp the case mouth so that there is a definite, measurable crimp of about .005" diameter smaller than the
cylindrical portion of the case, which is at .470" diameter. So, I always tell people to taper crimp to .465 or so at the
case mouth for proper reliability. This is at odds with the conventional wisdom of taper crimping "just enough to
remove the flare, to .470 diameter". IME, this does NOT work with 100% reliability in many guns, you need the extra
crimp to ensure perfect feeding of the round in to chamber.

Brad and Ian were having trouble even approaching this crimp, and were telling me that it was crunching the
bullet and all sorts of things that I couldn't quite understand, so we had to back off and try to figure out why
we were seeing such different results with a simple taper crimp die. It turns out that the type of taper crimp
die that I have been using since about 1980 is NOT what Hornady and Redding are selling these days as a
taper crimp die.
I have been using an RCBS taper crimp from about 1980 production, which has a rapidly
tapered step inside, probably tapering from .473-ish down to .455-ish (not measured!) in about .10 axial length or so. The
Hornady and Redding taper crimp dies are entirely featureless inside - a perfectly smooth taper from the
die mouth to the opposite end! So, with an RCBS die, it is a matter of turning the die in another quarter turn
or half turn to get the case mouth from .470 to .465, where in the straight-thru dies, it may not even be
possible to get to .465 at all within the case length, and you are likely to size down the whole bullet inside
the case due to the extremely gradual taper.

I am not sure whether RCBS even makes a separate taper crimp die any more, they are selling "taper crimp
seaters" now, which sound problematic to me. However - I just purchased a Lee taper crimp die for .45
ACP and it appears to be just like my old RCBS die. I haven't actually tried it yet, but a visual inspection
looks perfect. I did know that many of the shooters that I helped get their ammo working properly in
the 80s and 90s did use Lee taper crimp dies with good results, so I wanted to know if Lee was sticking
to the original design, and they appear to be.

So - when I say "taper crimp to .465" realize that this dimension only exists exactly at the case mouth
and the case is at .470 within .030 or less of the case mouth. I cannot yet recommend the current
production Lee TC dies, but when I get a chance to load with it, I will report here, and I am about
90% sure it will be fine.

Bill
 
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smokeywolf

Well-Known Member
Very interesting Bill. Never thought of the taper crimp taking place over a .030 to .060 span like that, but it makes perfect sense and seems like it would be less likely to cause a loss of dia. on the bullet's band(s) and base. Going to have to check my Redding die; betting it's a full length taper.
 

Pistolero

Well-Known Member
It took quite a bit of discussion to finally figure out that an apparently simple term like "taper crimp" was NOT
the same thing in different die company's lexicons. I had been using a TC die from RCBS and another from
Dillon, and another from Lee and so I "knew" what a TC die was, and I was really puzzled and repeatedly
posted my confusion on why people spent so much effort resisting my suggestions to just increase their TC
tightness until they hit .465, on the other site and now on this one.

Finally figured out what the heck is going on..... Taper Crimp is not always the same thing, at all.

Hey, another light bulb just went on in my head!

Now I see what Redding means by their "contour crimp" ...... which I own one of and it was a real shrug when I
got it, I tried it on .44 Mag and was not particularly impressed, just looked like an entirely ordinary TC die for
revolver cartridges to me. Tried it a bit, and since I largely use bullets with nice crimp grooves in revolvers,
went largely back to the std roll crimp dies without grasping what they were getting at. Now I see it.

Redding thinks a TC die is something WAY different than a roll crimp, so when they came up with essentially a
RCBS/Dillon/Lee TC die for revolver cartridges, they needed to invent a new name for it. Not sure Redding makes
a Contour Crimp die for semi-auto pistol cartridges, though, I think it is revolver only, for where the bullet does not
have a crimp groove-- exactly what I use it for in the .45 ACP.

Bill
 

Pistolero

Well-Known Member
I sat down and did some accurate measuring of a current production Lee and 1977 production
RCBS taper crimp dies for .45 ACP. They are both .470 before they start to taper, with a bit
of shallow taper to make it easier to hit the die with the cartridge, maybe .005 total below the
start of the real crimp. Since the case diam is .470, this does nothing except aid alignment.
The Lee is .453 diam above the taper area, and the RCBS is .456 above the taper area. The
Lee tapers from .470 to .453 in 0.190" axially and the RCBS tapers from .470 to .456 in 0.231"
axially. Basically they are very similar in design, although if you want fat bullets, say to fit
the throats of a .45 ACP 1917 Colt or S&W revolver, you may have issues with the .453 diam
on the Lee, where the RCBS will let you seat a .456 bullet without molesting it.

So, with the Lee the total length of crimp which is less than .470 is 0.059" if I crimp to .465,
and for the RCBS it is 0.082 for the same crimp diameter. This short crimp shouldn't (and
doesn't) injure the bullet enough to cause problems.

Possibly someone seeking the best possible accuracy, esp with a soft bullet alloy, may not
find this to be optimum, if alibis are permitted. With hard commercial H&G 68s, this causes
no harm to "IPSC accuracy" which is admittedly less critical than reliable functioning.

Hope this adds to your understanding of the issues of loading reliable .45 ACP ammo.

Bill
 

GaryN

Active Member
I got a Hornady 45 Acp. taper crimp die. I bought it about a year ago. I have not measured it but it works like my RCBS taper crimp die. I can crimp from .472 down to .465 (the lowest I have tried) in a relatively short distance. In other words, less than one turn of the die.
 

fiver

Well-Known Member
I kinda solved this problem a little differently by using a set of 45 acp/AR dies.
they have a roll crimp feature.
I would just bump the acp rounds against the roll crimp portion of the die and it would give me that little extra bit of diameter reduction.

now,, remember that I also seat my 200gr swc's so that the case mouth and the shoulder are square to each other so the little tick of a roll doesn't hurt anything [bullet wise]
this also makes the case go into the chamber as deep as possible, and removes the possibility of the round trying to headspace on the boolits shoulder.
 

Ian

Notorious member
I have used the RCBS roll crimp die a lot in the past. If you don't overdo it, it's fine for autos but a little too abrupt to completely turn in a fairly healthy bellmouth, and virtually useless at re-forming a case to normal body diameter when it has been expanded even a little bit with a stepped "M" die spud.

So I got a care package in the mail from Bill today (THANK YOU SIR!!), and after supper will embark on some TC experiments.
 

Pistolero

Well-Known Member
Great news, Ian. You are welcome.

I think you will like it, and the slight surface roughness inside on the taper puts a bright ring where
it contacts the brass - shows how little of the case is actually deformed in the TC. Not something intentional
on Lee's part, I am sure, but particularly useful for our experimentation. And yes, you can 'kinda sorta'
do some good with a roll crimp die, but it requires precise case LOA for consistency and I have never trimmed a single
.45 ACP case and not about to start. Plus it wouldn't really do what you need, only a very rough approximation.

GaryN --- Can you put an estimated date of manufacture on your Hornady TC die? Brad has one -- which I assume is
pretty new (Uh-OH! You what assume means.....) which is the straight taper. If yours has a visible rapid taper over
maybe .2 inches axially, I would love to know when it was made - and before or after Brad's die. I know you bought it
about a year ago - but is it new production or was it used, or possibly on the shelf in a store for a while?

Bill
 
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Bret4207

At the casting bench in the sky. RIP Bret.
IME "kinda sorta" is how many of us unconsciously approach the myriad of issues we find in this game. Most don't have the perfect tool or, in my case at least, the innate and complete understanding of the perfect solution to a problem. So we "kinda sorta" flail about trying different approaches until we find a solution that works for us, kinda sorta at least. That's where groups like this one shine because we can bonuce ideas and observations of one another and find someone who can look at the problem from a different angle.

I find things like this fascinating.
 
9

9.3X62AL

Guest
"Kinda sorta" is my usual paradigm in most venues of life. Exactness and insistence upon same goes against my grain structure MARKEDLY.

I have used sizing dies as K/S taper crimpers by letting the die mouth "kiss" the loaded round's case mouth between .010" to .035". Just take out the decapping assembly first.
 

Pistolero

Well-Known Member
No problems with 'kinda sorta' approach, and no question that I use it a lot in reloading.
'Close enough' usually is just fine for most reloading projects - other than safety issues like
pushing the powder up past the recommended maximums.


There are some special cases. I do know that for a straight case semiauto round like the
.45 ACP, IF one or two failures to close in 100 is a serious problem (like in no-alibi IPSC competition)
causing a big reduction in the score you get, even if you shot well and quickly (other than that
darned jam) you want to do more than just remove the bell, which is the "normal" approach.

A taper crimp with about .005 reduction at just the mouth of the case with a 'short taper' taper
crimp die will eliminate those niggling failures to feed and failures to close. Shooting 150 to 200
rounds in a competition, or 200-300 in a practice session makes a 1 in 100 malfunction into
something that is "happening all the time". You get a jam (or two!) every match, blowing your score.
Or a couple per practice session. It is infuriating to blow a great match run with an avoidable
malfunction which is due to your own ammo.

To the more casual plinker or moderate rounds casual target shooter who may shoot 25 or 50 rounds
in a session, having one failure to close every other visit to the range may not rise to anything to
get at all worried about. IME, a very large part of the problems with failures of handloaded
.45 ACP SWC ammo in 1911s was solved by tightening up the taper crimp, with too long LOA letting
the shoulder of the bullet hit the rifling as the second most common cause. Setting LOA correctly
and a good tight TC almost always solved feeding issues for myself and compatriots in the IPSC
shooting game.

But, only now, decades later do I find that "taper crimp" does not always mean the same thing
to various equipment makers.

Bill
 

Ian

Notorious member
Bill, I got distracted sorting through all the stuff that magically piles itself up against my dedicated .45 ACP progressive press and never did get to the die, but hopefully will get to it tonight now that I can actually see the press. I also rounded up some lube for you to try. One of the things I'm going to compare is how the Lee seat/crimp die compares to the Lee taper crimp die.
 

Pistolero

Well-Known Member
Sounds good. Isn't it amazine how a bunch of reloaders with collectively hundreds of years of
experience are still learning about it? :)

Bill
 
9

9.3X62AL

Guest
A little procedural thing from my cop-work days........always ask The Next Question. Turn your curiosity dog loose, let him run, and see what he brings back.
 

fiver

Well-Known Member
it is amazing how much we all know and still don't know about reloading.
I use an old school steel taper crimp die for my 45's now days [as the 4th die in the set] and never gave the matter a whole lot of thought or study.


I'm of the opinion that a semi-automatic anything has to operate [feed/fire/eject] 100% of the time 100% of the time.
accuracy is a secondary cosideration.
 

Pistolero

Well-Known Member
Yes, Fiver - that is the IPSC view, since the game is oriented towards self defense. In that
environment, no excuses. You have a TC much like mine, and frankly, I never gave it much thought
beyond the knowledge learned that "inadequate TC is likely to cause a failure to close"....... never
really thought much that "taper crimp" and "Taper Crimp Die" were undefined terms!

Al - good point. Those of us who haven't spent a career trying discover the truth in odd & intentionally
deceptive situations are not so used to "unleashed curiosity" as you are.

Bill
 

Ian

Notorious member
My personality is obsessive and endlessly curious. Oddly, this usually does not have the effect of success and satisfaction. I envy some of you, I really do.
 

Brad

Benevolent Overlord and site owner
Staff member
Obsession without limits is a bad, bad thing. It leads to never being satisfied. Yikes Ian, that must be hell.
The key is to decide what level of precision is required and how much trade off for function you are willing to make.
 

Pistolero

Well-Known Member
I am not too obsessive, but building an aircraft from scratch and maintaining it flightworthy for
1000 hours does take some serious focus, but I do have the ability (to a significant extent,
NOT perfect by any means) to prioritize. I still go off on wild goose chases "just because it is
interesting and fun" - but can pull myself back in line, usually. Definitely learned that "do it
right" is critically important when working on an airplane which will have you and your wife
flying all over the country in it. I get pretty obsessive about that! Loading ammo is a piece of
cake by comparison, as far as need to sweat making mistakes which "could be bad".

Bill
 
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