Roll Crimp in the .45 acp Colt auto

[Dutchman]

Offered in the spirit of who said you can't roll crimp .45 acp?

Not only can you but in my early years of shooting Colt LW Commander starting in 1968. Mostly was purchasing HG68 as they fed most of the time so I switched to 220-230 gr RN also purchased. Didn't start casting until 1970. Standard operating procedure was roll crimp. I didn't know how to ~spell~ taper crimp let alone have one at the tender age of 16. The Commander was private purchased for 100 smackers with original box and bill of sale from 1956. It was very nice but I learned to dislike aluminum frame automatics. They just wear out. From then on it was Gov't Models or 1911A1. What do I use now for .45 acp? Taper crimp!

These two files are scanned from NRA Handloaders Digest circa 1969ish.





The time honored method of dealing with bullet seating depth in the Colt auto is to use the barrel hood as a depth gauge.This is where you learn the definition of *flush*. You can use what the loading manuals say as to seating depth or you can do it the traditional method.

[Dutchman]

My former Colt 1911A1 1944. It became too valuable to use as a holster gun so I bundled it together with everything I'd collected, pistol belt, Carlisle bandage, 1944 canteen, spare mag pouch, etc. The M3 holster was marked by the US Army colonel during WW2. This gun was not a rebuild, no rebuild marks. It ran like a champion race horse never skipped a beat long as I fed it round nose cast bullets. I'm very fond of Colts.

[Dutchman]

My current and most likely final Colt Gov't .45 auto. Mfg circa 1934 and sent to Argentina for the Police Federal. They were roughly re-finished, blued and imported back to the USA at which point I purchased from FFL JL Denter of Connecticut.

I installed:
Nowlin reduced power main spring
Nowlin reduced power sear spring
20 lb recoil spring & shock buffer
long trigger with over travel screw
ancient Bianchi wrap around grips
new grip screw bushings, all 4
drop-in match grade bbl bushing
Pachmayr flat rubber mainspring housing
high profile white dot sites

It functions perfect with all magazines including USGI, Chip McCormik 8r, and others. Considing it has the original barrel it shoots quite accurate, tactical accuracy. I felt good enough about this gun that I carried it CCW when I lived in Indiana for a time. (a free state). Holster is an original Bianchi Askins Avenger.

[M-Tecs]

I am not sure when taper crimping got to be a thing, but I purchased a Colt Gold Cup National Match in 1974 and roll crimping was standard operating procedures at that time. I didn't start using a taper crimp until the early 80's for 9mm and 45 ACP.

I do know for a fact that a light roll crimp shoots better than a heavy taper crimp with cast. If not overdone, both the roll crimp and taper crimp shot equal for me in National Match 1911's

[Bowdrie]

The part of that article where it says "of rather doubtful worth" is certainly not someone into competitive shooting would say about taper crimps.
When you can lose a match in one shot most guys are running taper crimps at ~.457>.458.
JMB designed both pistol and ammo to use a taper crimp, that square-edged case mouth was to stop against the square-edged chamber bottom without the extractor having to withstand the forward inertia load of the round as it moves forward.
Nor is the extractor supposed to hold the case back against the impact of the firing pin.
You can crimp without using a separate taper-crimp die, but you must have your brass all the same length and then you VERY carefully adjust the die so that it just takes out the bell and BARELY starts a crimp.
You'll get a crimp that isn't "rolled" and isn't totally "tapered", it'll have just a tiny bit of inward "bump".

[LabGuy]

My first set of RCBS 45 Auto dies came with a role crimp, early 1980s. I remember when they started marketing a tapper crimp a few years later, and I quickly purchased one. I prefer separate dies for seating and crimping anyway. Having said that I never had a problem with my reloads with a very light roll crimp, just enough the remove the belling.

[M-Tecs]

JMB designed both pistol and ammo to use a taper crimp,

Do you have reference for that? Yes, the 45 ACP headspaces on the case mouth but until the 80's I am not aware of any 45 ACP die sets that came standard with a taper crimp. I had to purchase both my 9mm and 45 ACP taper crimps separately. I only have a couple of old 45 ACP cartridges in my collection. They are not taper crimped or roll crimped.

I do have one 45 Automatic Pistol Ball marked FA 4 - 12. It has zero crimp, but it does have cannelure at the base of the bullet. That was very common until the late 1930's or early 1940's

[M-Tecs]

My first set of RCBS 45 Auto dies came with a role crimp, early 1980s. I remember when they started marketing a tapper crimp a few years later, and I quickly purchased one. I prefer separate dies for seating and crimping anyway. Having said that I never had a problem with my reloads with a very light roll crimp, just enough the remove the belling.

As a kid I was a huge gun geek. I subscribed to ever major gun rag and read and reread every word. I don't remember when taper crimps became a thing, but I know I had a hard time finding one in 1981.

[Mk42gunner]

The Bianchi Askins Avenger is one of the most comfortable holsters to wear. You can lock it in position on your belt by threading your belt into the slot, then through the belt loop on your pants and then through the tunnel on the back of the holster. Works very well, and when the holster is bent around the waist, it is a fairly secure holster.

I used to buy a lot of Bianchi seconds at guns shows in SoCal for $20 IIRC. Mainly cosmetic seconds.

Robert

[Bowdrie]

We, (me too,) sometimes need to go back and see what was going on in past times.
Well into the '70s reloading was a niche pastime, except for the magazine writer guys not that many people did it, it was mostly relegated to shooters wanting more consistent accuracy than what the factory loads offered, and primarily orientated to rifles.
.45 ball ammo was dirt cheap, hardly anybody saved brass, and even the mid-level competitors would only use once-fired brass from their own gun of the brand they preferred when they went to a match.
They controlled bullet security in the case just like the hot shooters do today, not by roll crimps, but with case tension.
It became popular to reduce the expander die to get ~.003 of interference fit, (that's why the bevel-base bullets).
When Joe Average has 10 different brands of brass of unknown numbers of firings, with case dimensions/wall thickness, and brass hardness all over the map he can't blame bullet retention on the lack of a roll crimp.
Roll crimps are for revolvers and heavy recoil rifles.

[M-Tecs]

That's the total opposite of where I grew up. Almost every small-town hardware store carried reloading supplies. Even the big city stores like Woolworths had an extensive reloading section. As a kid I would ride my bicycle all the way across town (11 blocks) to the Coast to Coast to buy surplus H4895 powder out of a barrel. They would but a brown paper nail bag on the scale and scoop in the amount you wanted with a 1/2 pound minimum ($0.50).

After hours there was at least one reloading class at the school per year. In my HS graduating class there were 29 boys and 31 girls. About half the boys and a couple of the girls reloaded themselves or with their dad.

I started reloading at 8 years old and casting at 9 or 10. At 11 I started reloading for a 7th Cavalry reenactment group. By the time I was 15 I loaded and cast for around 50K total with about 85% 45 Colt and 15% 45/70. I was also the biggest user. All on a single station hence my love for progressives.

When I started bullseye in 1982 everyone that I shot with reloaded. A friend of mine had a good side hustle selling H&G hand cast bullets to the bullseye shooters.

[35remington]

If you are taper crimping to .457-.458” you are horribly overdoing it. Check your numbers.

[M-Tecs]

If you are taper crimping to .457-.458” you are horribly overdoing it. Check your numbers.

.468" is the normal recommended starting point.

[35remington]

Given SAAMI chamber specs are often expressed in minimums on a number of dimensions, a look at a chamber drawing should be a big clue that taper crimping to .457” is not a good idea.

Since case tension is primarily what holds the bullet in place no amount of taper crimp will make up for loose bullet fit.

[Sandspider500]

I wonder if a .457 crimp would create a kind of muffin top effect to the bullet.

[Bowdrie]

A thousand pardons I beg.
Yes I did make a big mistake.
I meant to type .467>.468,,, oh well, like Chief Inspector Clouseau said.
"If you've seen one Stradivarius you've seen them all".

[45DUDE]

I have a couple boxes of 1942 ammo and just looked and they measure .468 in the middle and taper crimped .470 on the end. I taper crimp .472 and have several target 1911's.

[nicholst55]

I, too, recall when taper crimping .45 ACP ammo became a thing, and you had to buy the TC die separately. I still have (and use) mine. I probably should update my RCBS .45 ACP dies one of these years - I also had to purchase a carbide sizer separately. But... they still work.

[M-Tecs]

I, too, recall when taper crimping .45 ACP ammo became a thing, and you had to buy the TC die separately. I still have (and use) mine. I probably should update my RCBS .45 ACP dies one of these years - I also had to purchase a carbide sizer separately. But... they still work.

When I first got serious about NRA Bullseye competition was about the time taper crimping got to be a thing. I shot with two High Masters that believed a light roll crimp produced better accuracy in a National Match 1911 than a taper crimp. One of them was a past NRA National Champion.

The claim that " JMB designed both pistol and ammo to use a taper crimp" doesn't seem to be correct based on the older GI ball I have in my collection. I am having a hard time finding any GI Ball with a discernible crimp so I decided to pull a couple of bullets on issued GI Ball. If the jacketed ball bullet had been crimped, I should be able to see an indentation on the bullet using my optical comparator. Same for the case mouth on loaded GI ball??????? I do have some GI that still has slight burs on the case mouth that would have been ironed out it crimped.

I did a word search for "taper crimp" on the 1937 Complete Guide to Handloading by Philip B. Sharpe with zero hits other than this on page 416.
https://archive.org/details/Complete.../n421/mode/2up

A special note on this cartridge is that it must not be crimped when used in the automatic pistol. The mouth of the cartridge case seats against the forward shoulder of the chamber and acts as a stop. If any crimp is applied, this shoulder location is changed more or less, thus dangerously increasing headspace. This may or may not be disastrous to a gun but is inclined to give more or less misfires or hangfires, particularly since the blow of the firing pin first tends to drive the cartridge deeper into the chamber before discharging the primer.

Does anyone know when taper crimp dies first became available???

[dverna]

I have not done the testing to confirm if there is an accuracy difference. So offer a simple opinion.

A roll crimp might cause variations in pressure if there are variations in case length.

A taper crimp may have a reduced affect in pressure with variations in case length.

I do not trim pistol cases and some have been fired over 30 times.