Crimping BEHIND the bullet.

[OD#3]

I finished cutting some 45-70 brass to 45-60 specs, and I made up a few dummy rounds to check cycling through my Uberti 1876. By the time I had loaded the rifle with them and cycled them through a few times, the bullets were starting to set back in the cases. One set back flush with the case mouth, and I had a time getting the dummy round out of the rifle (ever try cycling what amounts to an empty rimmed case through a toggle action levergun? The case mouth wants to hit everything but the chamber opening.)

Anyway, my dummy loads were 350 grainers that I cast from a 457192 mould, and I noticed that when I set the 45-60 round next to a .45 Colt casing, the .45 Colt case mouth came up to almost the same spot on the .45-60 case where the base of that 350 grainer would be. So I ran the 45-60 dummy round up through a .45 Colt Lee Factory Crimp die. That left a crimp behind the bullet, and that has prevented setback. The photos aren't the best, and the dummy round was getting pretty chewed up before I tried crimping behind the bullet.




Now, I realize that I could just stick a dowel of the proper length into the case the next time I make dummy rounds, but it got me to thinking. Bullet setback is a real concern for those folks using smokeless in these cavernous cases when their bullets don't have a crimp grove. And using a .45 Colt Lee Factory Crimp die to put a crimp behind the bullet might be just the ticket to preventing setback with those less-than-case-filling smokeless loads. It does work the brass more, and I don't know if annealing before each reloading would prevent it from shortening case life, but it might be worth experimenting with. Has anyone tried this?

[Griff]

No. But, I'd worry about an increase in pressure with that severe crimp in the case.

[AJMD429]

I've seen a guy use a little copper-pipe cutter (the kind with the carbide wheel that you twirl around the pipe and gradually tighten) for putting in a cannelure; he just dulled the wheel first on a grinding stone. I think they actually sell canneluring tools for that but not sure if they are intended for cases, bullets, or both.

[mark]

Morning,

1. Do the bullets move forward under recoil?

2. Is it possible to do a roll crimp in the top lube groove?

Mark

[OD#3]

Morning,

Is it possible to do a roll crimp in the top lube groove?

Mark

No. With this bullet, the resulting OAL would be too long. It isn't really an issue for me right now, as I load with compressed BP. But eventually, I'm going to try some smokeless loads, and unless I get another mould, I'll be using these bullets.

Morning,

1. Do the bullets move forward under recoil?

Mark

Well, these are just dummy rounds, but moving forward under recoil is never a problem for me. I put a very nice crimp at the case mouth.

No. But, I'd worry about an increase in pressure with that severe crimp in the case.

I didn't have to crimp it quite that severely, but I don't see how it would raise pressures much--if any. It would reduce case volume a very slight amount, but it isn't crimped into anything. It is just a restriction below the bullet base to prevent it from setting back into the case any further. The crimped portion wouldn't retard the bullet any, and the crimp would be free to expand to chamber diameter when the gasses expanded. It used to be very common for cartridge brass to have a cannelure below the bullet base. A lot of reloaders don't like them, because they seem to make the case grow a little upon firing and therefore require more trimming, which may be an undesirable side affect of the modification I've illustrated with this post. I don't know. I was hoping that someone here might have had some experience with this.

[Canuck Bob]

Folks report that a Lee FC die will crimp nicely on the cast bullet without a cannelure. I've not done it yet but am planning it for my cast shooting levers. That way a guy isn't hampered by the case length/cannelure relationship for seating depth. Is a 45-70 Lee FC die adjustable enough for this cartridge?

[Malamute]

Did you neck size or full length size the case first?

I havent had any bullet setback problems so long as I had decent neck tension. My RCBS 45-70 dies were expanding a bit more than ideal with jacketed bullets. They sent me a 45 Colt expander, works great and has better neck tension. Still gives some flair for starting cast bullets when desired.

[williamranks]

It looks good, especially considering the price of a cannelure tool.

http://www.buffaloarms.com/bullet_canne ... -3872.aspx

http://www.corbins.com/prices.htm (There's a tab for cannelure.)

[Carlsen Highway]

I had some ancient Kynoch made .44-40 cartridges, which had a crimp just like that behind the bullet, and I was trying to figure how to replicate it when I was having trouble with my crimp holding when loading that calibre. I got it fixed in the end without needing it, but that is how Kynoch used to crimp their
.44-40 bullets in anyway.
Impressed you managed it. I wouldn't think it would make any difference to pressures, the brass is going to get blown out anyway.

[J Miller]

Factory lead ammunition doesn't always have optimum neck tension. What you did with the cannelure behind the bullet is exactly what the ammo factories did when they switched from black to smokeless powder. The crimp keeps the bullet from moving out of the case, the cannelure keeps it from backing into the case.
I have examples of smokeless .45 Colt ammo with very loose bullets, but they can't go anywhere.

Joe

[mikld]

I've had reason to put a groove (cannalure) in small tubing (1/4"-3/4") on occasion and I used a tubing cutter as AJMD429 mentioned. Working with fuel lines and hydraulics, I had a few tubing cutters in my tool box and just rounded off the sharp edge on the cutting wheel of one. I experimented with putting a groove in cast lead bullets at one time, but the results weren't worth the trouble...

[OD#3]

Folks report that a Lee FC die will crimp nicely on the cast bullet without a cannelure. I've not done it yet but am planning it for my cast shooting levers. That way a guy isn't hampered by the case length/cannelure relationship for seating depth. Is a 45-70 Lee FC die adjustable enough for this cartridge?

A lot of guys report good results grinding down the bushing on a 45-70 FCD for use in the 45-60. Lee will also make you a 45-60 FCD, but I think they require you to send them a dummy cartridge--probably because most people make their 45-60 brass by cutting down 45-70 cases, and the resulting case lengths probably vary due to the variation in skills among the various enthusiasts.

I bought the Lee 45-60 pacesetter dies from Midway, which reportedly come with a FCD, but mine certainly didn't. At least it wasn't the collet-type I'm familiar with. It did, however, do a very good job of roll-crimping ahead of the front driving band. The dummy cartridge pictured previously was just lightly kissed. The BP rounds I assembled yesterday shown here have a nicer crimp.




But if I was using smokeless, I don't think that crimp would prevent setback. If/when I ever assemble some smokeless loads, I'll try the base crimp and report back my results.

[CowboyTutt]

OD3, I am no expert handloader by any means, but I see some alternatives here just to muddy the waters some more. Shortening the case and doing a roll crimp into the grease groove for your individual COL would be one of them if you are determined to use that bullet. I pretty much exclusively use Lee FCD's with some exceptions and I know the Lee FCD is supposed to make a cannelure right into the bullet but I have found that it sometimes does not really work that well depending on lead bullet hardness.

The other idea that would probably solve the problem with a smokeless load is floral foam filler. I know fillers are controversial and I would not use any of them but the floral foam, but that last one has even McPherson convinced that it works. You have to determine how much case volume your smokeless powder charge uses, and how deep your bullet sits into the case, then you make foam blanks that slightly compress your charge and provide support under the bullet. This filler adds virtually no mass, provides better powder charge position relative to the primer, supports the bullet until the cartridge is fired and the filler is immediately consumed upon primer/powder ignition.

I think at that point your FCD crimp in addition to the foam would support the bullet from further set-back with no other modifications with a smokeless powder charge.

Just one other way to maybe solve the problem here.

Regards,

-Tutt

[M. M. Wright]

I've noticed that some of my 45-70 brass has a canalure behind the bullet. I checked some factory smokeless loads and they have the canelure behind the bullet too. I'd probably modify a tubing cutter if it were me but then I use mostly that old nasty black stuff.

[OD#3]

All good ideas, fellas. My "solution" may very well be the worst way to skin this cat. For the time being, though, it is mute. I laid in a good supply of Olde Ensford, and it will be quite some time before I'm ready to experiment with smokeless.