?Rule of Thumb for crimp on auto pistols?

[prs]

I have seen some posts here indicating that the author has evidently measured the crimped case mouth and stated the outside case mouth diameter as an indication of how much that case was crimped. Neat concept, but a couple of caveats present; one is that some brands of brass cases are thicker than others and another is that it is not easy to measure just the crimped area with a micrometer, its not even easy to do so with calipers that have one flat jaw and one knife jaw. Seems one would need two knife jaws and calipers are sort of poo-poo'd upon at this forum. But, given what ever outer diameter of brass just behind the bell after the boolit is properly seated, how much less should one "shoot for" following a proper taper crimp? .001"? More? Less?

What I am doing now with 45ACP is to seat the boolit to where it just does NOT engage the lead to the rifling, and then taper crimping to where the round "kerplunks" into the chamber with the head flush with the back of the barrel. Takes some trial and error the first time as a change in crimp depth can allow the boolit to hit the rifling lead, but not rocket science. Of course, the round also has to be short enough to work in the magazine, but that has been no problem so far.

I only have two moulds I am using for 45 Colt right now, one is Lee TL452-230-1r and the other Lee 452-230-TC. Oddly if I crimp the Truncated Cone boolits as lightly as I do the longer nosed 1R, the TC will not "kerplunk" fully; even with the TC boolit crimped as far forward as possible. The TCs need a pretty firm crimp to "kerplunk". They both seem to shoot well tumble lubed with LLA or Recluse. Both give only modest leading after about 100 rounds and I think that is because my Ruger SR1911 has pretty abrupt and sharp transition from chamber to rifling; should benefit from some tapering of that transition.

[captaint]

prs - I can only pass along my experience - which is not truly lengthy. I have one TC die set up for all my 45ACP's. Regardless of boolit or brass headstamp, they all get TC'd the same. It is possible that your lack of kerplunk is due to OAL. When I find that condition, I adjust my OAL with the seater. Just some ideas.. also, I load about 6 different boolits for the 45ACP. Now that I think of it, I do the same thing with my 9mm ammo. enjoy Mike

[6bg6ga]

Right or wrong I taper crimp my 45acps just enough that the bullet doesn't move any when the shell leaves the magazine and goes into the chamber. Over all length for me it long enough that it fits in the magazine without rubbing on the nose. This is the way I have loaded them for over 25years and my groups are always very tight.

[popper]

Are you seating and crimping in the same step? I shoot 40, not 45 but the process is the same. I seat back to where the CB cannot engrave - tolerance to allow for nose size differences. Then I crimp to remove the bell and act as a chamber checker, set the crimper so that every round will chamber. If it over crimps (long brass), live with it, or end up pogoing the slide at the range.

[MtGun44]

Calipers are fine for this measurement, most calipers have a accuracy of +/- 0.001" which
means that if you measure a .45 ACP crimp at the edge of the case at the desired .471", it
might be .470 or .472, either of which is OK, too.

The precision measuring tool needs to be matched to the job. For measuring boolits and
fitting them to the barrel, a caliper is marginal to inadequate accuracy. For this application
a .0001" micrometer is a much better tool. For many applications caliper accuracy is just
fine.

As to the original question, my personal preference is to push about half of the thickness
of the case into the boolit, just judged by eyeball. The only reason that I know that this is
around 0.471" for the .45 ACP is that somebody here asked me and I measured a few. I
normally set them by eyeball to definitely push the case into the boolit a bit beyond straight.
I drop them into the dismounted barrel as the REAL check.

Your 'kerplunk' is exactly what you should be doing.

IME, inadequate or no taper crimp has been THE most common problem with new reloaders
making ammo to work in .45 ACP guns, mostly 1911s.

Bill

[6bg6ga]

Actually a micrometer would be more useful than a vernier for a precise measurement like this in my opinion.

Measured a few of mine using my taper crimp it until it doesn't move method and mine measure .471 with a micrometer.

Never did the "kerplunk" test and probably never will. Mine work as is.

[Le Loup Solitaire]

The 45 ACP round is supposed to seat on the case mouth so some "mouth " has to be there for that to happen, at least in a 1911. Too much crimp = not enough mouth and the round will go too far forward in the chamber=FTF. Once upon a time I had to find this out on my own and did establish that a taper crimp of .471 was correct for my guns. El problemo with 45ACP cases is that they are either too short in many instances or of different lengths or that they grow shorter with successive firings. It is a condition that has to be constantly monitored and properly adjusted/accounted for. LLS

[williamwaco]

A different idea.

I measure my crimp with a 10x glass.

I set the crimp to remove the flare and just barely press the mouth of the case into the side of the bullet. Just barely means that the mouth of the case is imbedded into the bullet or crimp ring to about a third of the thickness of the brass at the mouth of the case.

You can see and judge this with the glass. About two thirds of the mouth of the case is outside of the crimp ring and available for head spacing.

RULE OF THUMB.

Here is my rule of thumb for crimping ACP style auto pistol cartridges.

"If you can see the flare, it is too little."
"If you can see the crimp, it is too much."


.

[prs]

Captaint, given the same lot of cases or similar cases, I agree and will look further for why which boolit I choose seems to be a point to differ.

6BG6GA, my OALs are on the short side according to the two most recent Lyman Cast Bullet Handbooks, but they do not list these boolits. Crimping close to the very end of the parallel sections. .471" is exactly what I noted when I measured the crimped case mouth.

Popper, NO WAY! I seat in one stage with no crimp and then crimp with a TC only die. NO carbide factory post size either.

MTGUN44, excellent! I will look to see how much case mouth is buried in the lead. I was concerned that I might be over doing it with the TC boolit, but maybe I am a bit skimpy of crimp on the hard ball look alike instead.

LLS; with the 40 S&W cases I have come upon a way to counter shortening of the cases with sucessive resizing and use. This involves running the cases assbackward through a bulge buster set-up (gotta get some use out of those darned Lee CFCDs). It seems to work. Have not noticed my Starline 45ACP cases shortening yet, but I have not been working with the 45ACP round very long and I have 2,000 cases that were new to start.

WilliamWaco, a 10X glass! That is a dandy! The one on my loading bench is a B&L 5X, but I have others with more help. Far sighted folk need all the help we can get for close work. Your rule of Thumb rools.

To all of ya, Thanks!

Rooster

[fcvan]

when i first started loading for .45 ACP I had one box of factory ammo and 500 pieces of virgin brass. I set the sizing die according to instructions. set the case expansion die to accept the boolit, and I set the seat/crimp die with a factory round. I put the cartridge in the shell holder and ran it up in the press. I then backed the seating plug way out, screwed the die body down onto the factory round until finger tight, and then adjusted the seating depth. I had a good crimp locked in with the lock ring. as I tried different boolits I would adjust the seating depth until I found what worked and then made a dummy round. Resetting the depth with a dummy round made further measurements unnecessary. Frank

[41 mag fan]

Are you sizing your casts or shooting as cast?
What are the TC's measuring after being cast? Are the TC's maybe out of round?
Are you running the TC mold hotter? This will cause the cast to be bigger, which will cause it to not kerplunk if not sized down

I've got this mold also and just started playing with it some and noticed my casts needed sized down.

[popper]

prs - couldn't tell from your original post as to your process. I adjust for shrinking cases by setting OAL to ALMOST head space on the nose. I'd like to hear the results of your bulge buster experiment. My cases are ~ 4 yrs/mixed brass - don't care how may times reloaded.

[mdi]

Rule of thumb for crimping 45 ACP ammo; don't. Many of those new to reloading semi-auto ammo get confused when the term "crimp" is tossed around. Mebbe we shouldn't use it. In my experience and many of those I've read, a taper crimp die is used to remove any flare in the case mouth. It should be called "deflaring" or "mouth straightening". I do mine by feel/sight and if ammo passes the "thunk test". A lot of folks see the SAAMI drawings ang quote the .471" mouth deminsion as how much "crimp" should be applied. Unless you have blade micrometers, a dial vernier calipers works because of the narrow blades and taper in the case.

Jes my experience...

[prs]

Are you sizing your casts or shooting as cast?
What are the TC's measuring after being cast? Are the TC's maybe out of round?
Are you running the TC mold hotter? This will cause the cast to be bigger, which will cause it to not kerplunk if not sized down

I've got this mold also and just started playing with it some and noticed my casts needed sized down.

Yes, all the boolits were sized. The TL452-230-2R boolits just "kissed" the Lee .452 push through sizer. The 452-230-TC boolits were kissed pretty hard, but still were not "fat". Both nice and round. I prefer frosty boolits. The cases were all opened with the same M die for 452 lead and mimimal belling. I am going to sit at the bench with both samples and my barrel and ponder a bit.

prs

[gray wolf]

Rule of thumb for crimping 45 ACP ammo; don't. Many of those new to reloading semi-auto ammo get confused when the term "crimp" is tossed around. Mebbe we shouldn't use it. In my experience and many of those I've read, a taper crimp die is used to remove any flare in the case mouth. It should be called "deflaring" or "mouth straightening". I do mine by feel/sight and if ammo passes the "thunk test". A lot of folks see the SAAMI drawings ang quote the .471" mouth deminsion as how much "crimp" should be applied. Unless you have blade micrometers, a dial vernier calipers works because of the narrow blades and taper in the case.

Jes my experience...
Everything he said

[prs]

prs - couldn't tell from your original post as to your process. I adjust for shrinking cases by setting OAL to ALMOST head space on the nose. I'd like to hear the results of your bulge buster experiment. My cases are ~ 4 yrs/mixed brass - don't care how may times reloaded.

I've got 40's with way many reloadings. I do not load hot. although it is a high pressure round. I have only tinkered with 45ACP cases in the bulge buster set-up and will not use it routinely unless/until I do note the shortening.

prs

[bigboredad]

I may have missed this but with that particular tc bullet it needs to be seated a lot deeper to get the desired plunk and proper fit. My guess is is the tc bullet is seated to long and your crimp if fine. I don't remember for sure because I have loaded that bullet for over 2 years but iirc it should be down around 1.18 but like I said it's been a while I just know it needs to be deep

[prs]

Grey Wolf, when my "for 452 lead boolits" M die internallty sizes the cases, the case is expanded to where bringing it back to "spec" effectively is a light crimp.

Thanks to all!

prs

[prs]

All is bliss again. With the magnifying glass I noticed that there was a tiny ridge of lead mashed forward of the case mouth edge on the 452-230-TC boolits. Very slight, but enough to interfere with the "kerplunk" fit. My crimp setting was too deep, bulging that tiny ridge forward (95/2/3 alloy not water dropped). I set the taper crimp to make firm contact with a fired case and then 1/2 turn more. "Kerplunk!"

Thanks much to all.

prs

[Fluxed]

Another thing worth doing is to make a chamber cast of the pistol using Cerrosafe to see what internal dimensions you are dealing with. Cerrosafe is not expensive and is reusable. Brownells has it.

[41 mag fan]

All is bliss again. With the magnifying glass I noticed that there was a tiny ridge of lead mashed forward of the case mouth edge on the 452-230-TC boolits. Very slight, but enough to interfere with the "kerplunk" fit. My crimp setting was too deep, bulging that tiny ridge forward (95/2/3 alloy not water dropped). I set the taper crimp to make firm contact with a fired case and then 1/2 turn more. "Kerplunk!"

Thanks much to all.

prs

You got me thinking on that one. I got an RIA compact that will not take a cast at all, but will take the j-words without a hiccup.

I'm going to check that out and see if thats the problem, beyond my thinking of a tight chamber.

[trixter]

I see a lot of folks using the "Kerplunk!" test, which I also use, but the important part of that test is will the cartridge fall back out when you turn the barrel up side down (all by its self; just gravity) ?

[pastor]

Question #1 are you getting leading in your barrel?
if not then your crimp is probably ok, if you are getting leading then pull a loaded round and measure to see if your crimp is reducing the bullet diameter (swaging)
i very lightly taper crimp, just enough to remove the flare, and i do seat and crimp in the same die, i know that is frowned upon by some, but i have never had any problem,

[prs]

pastor, I don't think there is any potential harm in seating and just ironing-out the bell in one step. So long as the boolit is no longer moving in the case when some real crimp is being applied. I used to set my seating die like you say, just to where it barely does NOT crimp, but rather eliminates the bell. Now I have it to just barely leave the tiniest trace of bell so I am sure the boolit was not scooted under crimp.

Trixter, mine fall out. Ruger is evidently pretty generous with chambers.

prs

[trixter]

Great

[trixter]

Du you size .451 or .452?

[prs]

Du you size .451 or .452?

.452"

prs

[geargnasher]

I have seen some posts here indicating that the author has evidently measured the crimped case mouth and stated the outside case mouth diameter as an indication of how much that case was crimped. Neat concept, but a couple of caveats present; one is that some brands of brass cases are thicker than others and another is that it is not easy to measure just the crimped area with a micrometer, its not even easy to do so with calipers that have one flat jaw and one knife jaw. Seems one would need two knife jaws and calipers are sort of poo-poo'd upon at this forum. But, given what ever outer diameter of brass just behind the bell after the boolit is properly seated, how much less should one "shoot for" following a proper taper crimp? .001"? More? Less?

What I am doing now with 45ACP is to seat the boolit to where it just does NOT engage the lead to the rifling, and then taper crimping to where the round "kerplunks" into the chamber with the head flush with the back of the barrel. Takes some trial and error the first time as a change in crimp depth can allow the boolit to hit the rifling lead, but not rocket science. Of course, the round also has to be short enough to work in the magazine, but that has been no problem so far.

I only have two moulds I am using for 45 Colt right now, one is Lee TL452-230-1r and the other Lee 452-230-TC. Oddly if I crimp the Truncated Cone boolits as lightly as I do the longer nosed 1R, the TC will not "kerplunk" fully; even with the TC boolit crimped as far forward as possible. The TCs need a pretty firm crimp to "kerplunk". They both seem to shoot well tumble lubed with LLA or Recluse. Both give only modest leading after about 100 rounds and I think that is because my Ruger SR1911 has pretty abrupt and sharp transition from chamber to rifling; should benefit from some tapering of that transition.

That's exactly how I do it in my autos.

Sometimes, if the boolit needs enough crimp to actually move lead or show a ring from the case mouth when pulled and inspected, I try to size a tad smaller if the groove dimension will allow, but sometimes I just crimp them enough to pass the plunk test and don't worry if the mouth 'bites' the front band a bit. IF it the situation requires enough crimp to 'bite', then I ALWAYS crimp in a separate operation or the mouth will dig up a ring of lead that will show up in the first inch of the barrel after the first two or three shots and gradually accumulate.

If the chamber is generous, and a lot of 1911 .45 ACPs are, I crimp only enough to pass the plunk test, which usually leaves a significant portion of the bellmouth intact. That might help center the boolit in the throat some, I don't know for sure how much it helps once the powder lights and the case swells, but it doesn't hurt anything. I've never had leftover flare cause any feeding issues.

Gear