.45-70 Cartridge Length Question

[broken-mold]

I am going to start reloading some light loads for my Trapdoors, H & R Buff Classic, and '74 Sharps. Some manuals recommend 2.095" trim-to length for the brass, some recommend 2.100", and one recommendation I read was to cast the chamber and trim the brass accordingly.
I have new Rem brass and most of the fifty rounds mic to 2.094"- 2.095. Will the brass grow to 2.100" or more even when using light loads?
I have some older brass that mics to about 2.092"-2.093". What is the drawback of using brass a thousandth or two under the recommended length?

[elmacgyver0]

Zero to none.

[Randy Bohannon]

Trim to the shortest piece so their uniform in length and go shoot. Deburr inside and outside before loading.

[2TM101]

Thats not the cartridge length you need to be concerned about.

If you get ahold of any Hornaday "Leverrevolution" stuff it will be considerably shorter than standard, and if your dies are set for the real thing, like a Starline case, it won't crimp. Regular dies can't even be adjusted down far enough to do it. I got really frustrated by that until I found out their cases are shorter because of the bullets they originally come loaded with (???) and learned that - I can't crimp them at all.

Allis not lost as they can still be used in single shots. And leverrevolution 45-70 tends to be relatively cheap on Gunbroker as people with repeaters can't use them (without a lot of work). As I have a one shot CVA Scout I can still use those and I make them up as my .45-55 rounds. As a CVA Scout is a really light rifle the normal rounds really kick - and that's why the 45-55 existed in the first place.

[country gent]

In my single shots I dont crimp just take the flare off any off.I trim close to chamber length ( saves the chance of getting a lead ring there) Load just off the rifling. Most of my loads the bullets can be seated by hand onto the wad stack and compressed powder charge.

Your brass will grow but at BP pressures and velocities it will be slow. Your brass will work harden from sizing and expanding you want to anneal it. this gives a better seal and more consistent tension. Chamfer and deburring only needs to be done after trimming. Deburring flash holes can make a difference in accuracy.

[Bent Ramrod]

For grease groove boolits, the standard trim-to-length in the books (~0.005” shorter than nominal length) is fine. Your 2.095” brass is right in there.

For paper patched boolits, 2.095” is about as short as I want to see brass; 2.099”-2.100” is what I have my trimmer set for, for my .45-2.1s.

Using grease groove boolits, the shells shouldn’t lengthen, unless you leave the chamber wet after wiping. I find that paper patching tends to lengthen brass. Lubricating the inside of the shell neck with graphite or Motor Mica reduces this tendency, but doesn’t entirely eliminate it.

A chamber cast, properly measured, would positively let you know how far you could let the shells lengthen, but I myself would only make the effort if something about the shooting was off, accuracy-wise, or if it was one of the more notorious oddball chambers, like on some Sile replicas, or early Farmingdale Sharps.

[Gunlaker]

You probably will never need to trim that brass. After you shoot it, the brass will swell to the dimensions of the chamber and shorten a bit more. In a lever gun with hot loads you'll find the brass stretching to some degree, but in a black powder single shot you'll get very little to zero growth. The only time mine grows is if the chamber is a little wet, and even then, more so on the longer cartridges than the 45-70.

Chris.

[1Hawkeye]

I agree with the others and I'll pass on a tip about the hornady brass while being too short for a .45-70 it works great when sized down to a .40-65 with very little excess to trim off.

[rjmelehan]

My process;

I fire form brass before I trim, sometimes with cream of wheat or some such
Then Chamber cast, after fire forming trim to chamber length.

Neck size vs. full length size.

Depending on bullet to throat fit.
Some of my moulds shoot better with full length sizing and about .003 neck tension,
some shoot better with slip fit no neck tension.

[JSnover]

I've loaded 45-70 brass anywhere from 1.085" to 2.115" and it doesn't really seem to matter. Your flaring, de-flaring/crimpimg operation will be more consistent if they're all the same length. Randy Bohannon is right: trim your brass to the whatever the shortest case is, that way you can set your dies up for that length and not have to play with them.

[Don McDowell]

I am going to start reloading some light loads for my Trapdoors, H & R Buff Classic, and '74 Sharps. Some manuals recommend 2.095" trim-to length for the brass, some recommend 2.100", and one recommendation I read was to cast the chamber and trim the brass accordingly.
I have new Rem brass and most of the fifty rounds mic to 2.094"- 2.095. Will the brass grow to 2.100" or more even when using light loads?
I have some older brass that mics to about 2.092"-2.093". What is the drawback of using brass a thousandth or two under the recommended length?
That brass length won't matter much.
More important is each of those rifles may prefer a different seating depth of the bullets.
Light loads needs a bit of clarification, as depending on bullet length and barrel twist, combined with low velocity the bullet may be leaving the muzzle at low enough velocity they are already below stability. That won't do much for tight groups.

[hwilliam01]

Thats not the cartridge length you need to be concerned about.

If you get ahold of any Hornaday "Leverrevolution" stuff it will be considerably shorter than standard, and if your dies are set for the real thing, like a Starline case, it won't crimp. Regular dies can't even be adjusted down far enough to do it. I got really frustrated by that until I found out their cases are shorter because of the bullets they originally come loaded with (???) and learned that - I can't crimp them at all.

Allis not lost as they can still be used in single shots. And leverrevolution 45-70 tends to be relatively cheap on Gunbroker as people with repeaters can't use them (without a lot of work). As I have a one shot CVA Scout I can still use those and I make them up as my .45-55 rounds. As a CVA Scout is a really light rifle the normal rounds really kick - and that's why the 45-55 existed in the first place.

2TM101,

I have found a great way to crimp the Hornady shorter brass. Since the (I use Lee) Factor Crimp die which crimps on the circumference of the brass shell, so technically you do not need a shell holder underneath...however you can place a nickel or quarter over the shell holder and under the brass case. That happens to be the smae length that the brass shel is shorter than regular brass. The only issue is that the primer is a little exposed. If that concerns you, you can drill a hole in the nickel or quarter of he proper size to protect the primer (or find a washer of the correct thickness at the hardware store). It works great. No problems...that is assuming you buy the Hornady FTX bullets to reload with as well (as I do).

Bill

[elmacgyver0]

I just use the Lee 45-70 LEVERevolution dies.

[Good Cheer]

I neck them down to .38 so they're all good.