Loading Historically Accurate M-1881 .45-70-500 Cartridges for the Trapdoor Springfield

 

UPDATE 8-12-24
I tested the muzzle velocity of cartridges made as described below.  My goal was to exactly replicate the original M-1881 cartridge in both appearance and, more importantly, in performance.  According to the 1887 Rules of Management (pp. 44-46) cited below, the original M-1881 cartridge had a muzzle velocity of 1,341.7 f.p.s.  Using the 509-grain 17:1 bullets I cast and Swiss 2F powder, I achieved a muzzle velocity of 1,314 f.p.s., a perfect match for the original.  This is the most perfect match I have ever been able to achieve with any cartridge I have recreated.  When the muzzle velocity and bullet weight are correct, then the external and terminal ballistics should exactly match.

INTRODUCTION
The .45-70 cartridge is very popular today in various configurations, but my intent here is to attempt to recreate the specific cartridge used by the U. S. Army in the 1880s for the so-called “Trapdoor” Springfield infantry rifle in .45 caliber.  The first .45-caliber Springfield rifle round developed in 1873 used a 405-grain bullet (as the carbine continued to), but they later switched to the M-1881 cartridge with a 500-grain bullet for rifles because it gave better external and terminal ballistics.  The first cartridge cases were made of copper, but were later changed to brass as we use today.

The picture above from the 1887 U. S. Ordnance Department Rules for the Management of the Springfield Rifle, Carbine, and Army Revolvers. Caliber .45 shows the cartridge I am trying to replicate.  It shows a center-primed “solid head” cartridge, meaning one formed as we do today (rather than using the earlier “folded” Benét-style primer), containing 70 grains of rifle powder with a 500-grain round nosed (not round nosed flat point as is commonly used today) bullet with three grease grooves.

The primary source for technical information is the U. S. Ordnance Department, which published reports every year including detailed information about ammunition.  My primary source for how to reload this cartridge comes from a book by J. S. and Pat Wolf entitled Loading Cartridges for the Original .45-70Springfield Rifle and Carbine (3rd edition), privately published, 2003.

My method differs from that described in Mr. Wolf’s book in several ways.  He suggested drilling out the primer pockets to ensure better ignition, the use of magnum primers, and making bullets which are sized to 0.459 in., but I do not do those things.  I found that regular primers ignite the powder perfectly well through unmodified flash holes, and that any slight advantage gained by Mr. Wolf’s method is not enough to affect my accuracy.  I was unable to find a bullet mold of the type he recommended, but the Lyman mold I found produces an excellent copy of the original bullet with which I am well satisfied even if it is only 0.457 in diameter, and this spares me from having to use a special plug in my neck expanding die as he recommended.  My bullet does have four grease grooves instead of the three seen in the diagram above, but I hold this difference to be insignificant as the amount of grease they hold is roughly the same.  Mr. Wolf had great success with his method, and I am not criticizing it, but the method described below is perfectly valid for my purposes.

Most metallic cartridges can be loaded with three dies: a resizing die, a case-mouth expanding die, and a bullet seating and crimping die.  With this cartridge, however, I find five dies to be necessary, as you will read below.  The only truly different die is the one for compression; 70 grains of powder simply will not fit into the case with a bullet of this length, and it is necessary to compress it substantially to make it fit.  I use an extra die for crimping because the extreme length of the cartridge (particularly before the bullet is fully seated), which means I would have to reset my seating/crimping die each time I used it.

Please note that I am not recommending that anyone should attempt to copy my method, I am simply showing the reader what I do to make ammunition for my rifle.  Use this material at your own risk.

Track of the Wolf has a page on their web site for loading ammunition using Mr. Wolf’s method, and I purchased much of my specific equipment for these cartridges (except the mold) from it.  Track of the Wolf is an excellent company, and I highly recommend them:
https://www.trackofthewolf.com/Categories/PartDetail.aspx/239/1/ammo-45-70

For a video showing the loading process, please go HERE:

TOOLS AND EQUIPMENT REQUIRED

1. .45-70 cartridge cases; I used Starline brand.
2. Black powder; I used Swiss 1.5F or 2F powder.
3. Large rifle primers; I used CCI brand.
4. A powder flask and volumetric powder measure.
5. A powder scale set to weigh in grains.
6. 500-grain .45-70 bullets cast in a 1:17 tin: lead alloy; I used the Lyman #457125 mold.
7. The Lee .45-70 die set, including a resizing die, a case-mouth expansion die, a bullet-seating/crimping die, and a case holder.
8. An extra Lee bullet-seating/crimping die.
9. An extra Lee case mouth expansion die.
10. A compression plug from Track of the Wolf.
11. .45-caliber card wads; I bought mine from Track of the Wolf, but they can be punched from waxed cardboard.
12. Black powder bullet grease; I used a mixture of beeswax and lamb tallow.
13. Case lube for resizing the brass.
14. A micrometer.
15. A loading press; a single-stage press works best because of the length of the cartridges, but I use a progressive press and just have to be careful when inserting the cartridges for bullet seating.

INITIAL PREPARATIONS

1. Begin by casting the required number of bullets.
2. Weigh each bullet, discarding any which weigh less than 508 grains (my bullets normally come out at 509 grains) and any which are wrinkled or not crisp.
3. Put the cast bullets base-down in a pan and pour molten grease into the pan up to the driving band of the bullets.  Allow to cool and harden before removing.  Sizing is not required for these bullets.
4. Replace the neck size expansion plug on one of the neck sizing dies with the compression plug from Track of the Wolf and mark it as the compression die.
5. Remove the bullet seating plug and cap entirely from one of the bullet seating/crimping dies to make the crimping die.

CASE RESIZING AND PRIMING

1. Put the ram all the way up with just the shell holder in it (no case).
2. Screw the resizing die down until it touches the shell holder, then back it out two full turns because you don’t need the resize the entire case.
3. Tighten down the lock ring.
4. Grease each case very lightly with case lube then drive them into the die to size and de-prime.
5. If the cases have been fired use a tumbler to clean them.
6. Prime each cartridge case; I have an attachment which goes onto the ram of my loading press, but there are several styles available.  Make sure the primer does not sit proud of the case.

POWDER COMPRESSION

1. Fill all shells with 70 grains of powder and seat a card on top (off of the press).  Measure the powder using a flask and volumetric measure onto a powder scale, than gradually add a few granules of powder at a time until reaching exactly 70 grains.
2. Put the ram all the way up (no case).
3. Screw the compression die down until it touches the shell holder.
4. Back the die out 10 (ten) full turns.
5. Insert a filled shell into the shell holder and run it up inside the die.
6. Use a caliper to test the depth of the card.  It should be 0.63 in.; if not, lower the ram and screw the die in one half turn, then drive the shell up again, again measuring the depth.
7. Repeat, lowering the die less each time, until it is exactly 0.63 in.
8. Lock the die down and compress the remaining shells.

NB:  This must be done before expanding the case mouth or the compression die will reduce the neck flare.

CASE MOUTH EXPANSION

1. Use the original case mouth expansion die with the original plug—do not replace it with a larger Track of the Wolf expansion die unless using larger bullets.
2. Put the ram all the way up with just the shell holder (no case)
3. Screw the die down until it touches the shell holder
4. Back the die out 10 (ten) full turns.
5. Raise a case into the die and then lower it to inspect the mouth of the case to see whether a bullet will barely fit; do not expand it any more than the minimum necessary or the case may not fit into the bullet-seating die.
6. Screw the die down by 1/2 turn (or less) until the mouth is expanded sufficiently, re-ramming each time; make each adjustment smaller until the bullet will just fit.
7. Raise the case into the mouth again and then tighten down the locking ring.
8. Size all of the remaining case mouths.

BULLET SEATING

1. Back the seating plug cap out until no more than two or three threads hold it in place.
2. Insert the die body into the press and screw it in so that only about two or three threads engage.
3. Insert a bullet into a case and seat the case in the case holder.
4. Raise the ram gently until the bullet touches the seating plug, then press it in very slightly.
5. Lower the case, then inspect to see how far it has gone in.  Note that the driving band of the bullet should be just below the rim of the case mouth as a general guide for when it is getting close. Push the case up again, pushing the bullet slightly lower, then check the depth.
6. Repeat until the overall cartridge length is exactly 2.79 in. using a micrometer, making smaller adjustments each time.
7. If the ram is all the way up but the bullet is not seated deeply enough, screw the die body in slightly and try again.
8. When one full stroke of the ram seats the bullet to exactly the right depth, tighten the locking ring, then seat the bullets on the remaining cartridges.

CRIMPING

1. Loosen the locking ring of the crimping die.
2. Lift the ram fully (with a cartridge in place) and screw the die body down until it just touches the case.
3. Lower the ram then rotate the die body in one-half of a turn.
4. Raise the ram fully and drive it into the die, then check the crimp.
5. If it’s not crimped enough, lower the ram and screw the die body down slightly.
6. Ram the cartridge into the die body again and check the crimp, repeating these steps until the crimp is sufficient.
7. When the crimp is sufficient, raise the ram fully and lock the die body in place.
8. Crimp the remaining cartridges.
9. When the cartridges are completed wipe them down carefully with a dry rag to remove any remaining grease. 

Formed cartridges.

My replica cartridge packet.

The original cartridge packet I copied.