Springfield Trapdoor .45-70-500 Case Volume and Compaction

Original M-1881 .45-70-500 cartridge dimensions.

Introduction
I recently had a conversation about my recreation of the M-1881 .45-70-500 Springfield Trapdoor cartridge and how similar it was (or was not) to the originals, with my interlocutor arguing that the volume of original cases was different from that of modern Starline cases, meaning the powder compaction necessary to load the cartridges was different.  This led to the analysis below aimed at determining how close the cartridges actually are to one another.  Note that this applies only to the later brass solid head cases used from the 1880’s onward, not to the original copper “folded head” (what today are called “balloon head”) cases.

Original M-1881 .45-70-500 cartridge.

My reproduction M-1881 cartridges.

I use a SAECO government bullet mold that produces bullets which are very close in design, weight, and dimensions to the originals.  I load them over 70 grains of Swiss 2F powder in Starline brass, compacting the powder to a depth of 0.61 in.  You can read a detailed explanation of how I load my cartridges, including a link to a video about it, HERE.

Since water has a density of 1 ml./gram, a friend of mine filled an original UMC brass case with water and weighed it, comparing it to a Starline case to determine the volume.

Weight of a UMC solid-head .45-70 case:
Empty: 11.22 grams
W/water: 16.16 grams
Volume: 4.94 ml

Weight of a Starline .45-70 case:
Empty: 12.89 grams
W/water: 17.79 grams
Volume: 4.90 ml
(Courtesy Justin Huzuga, pers. comm. 11JUN2025.)

Difference in Volume: 0.04 ml.

Length of an original 500-grain bullet: 1.31 in.
(1877 Rules of Management p. 43.)
Length of a SAECO 500-grain bullet: 1.29 in.

Difference in Length: 0.02 in.

Analysis
Ordnance Department records say the M-1881 cartridge had a MV (muzzle velocity) of 1,315.7 fps (1887 Rules for Management p. 45), whereas my recreated cartridges have an average MV of 1,315.6 fps—an entirely negligible difference, as are the differences in case volume and bullet length noted above, all within the margin of error. I know from some of Brett Gibbons’ work that Swiss powder produces almost exactly the same MV of British RFG powder, making me think it was extremely similar to the military powder in general of the period. I know the Dupont powder used in the M-1881 cartridges might well be different from the British RFG, but it was, at least, a starting point. I hypothesized that changing the degree of compaction would significantly change the MV, and that if my Swiss 2F was at least close to the Dupont powder and gave the same MV then that would tell me the compression would be about the same. Since the volume of the cases is almost identical, as is the length of the bullets (and hence the depth to which they need to be inserted), this test seems to confirm that Swiss is very similar to Dupont and that the compaction is about the same.

Source:
U.S. Ordnance Department. Rules for the Management of the Springfield Rifle, Carbine, and Army Revolvers. Caliber .45. Washington: Government Printing Office, 1887.

Black Powder Revolvers for Modern Self Defense

I recently acquired a Pietta reproduction of the Remington New Model Army (not 1858, please!!) with a 5.5 inch barrel.  Unusually for me, this purchase had no basis in historical shooting, the Remington NMA never having been issued with shortened barrels to the best of my knowledge (although local craftsmen may have reworked some).  In this case, my intent was to step away from historical shooting for a brief moment to address the question of black-powder firearms for modern self defense.

First, the big question:  Should you use a black-powder revolver for self defense today?  The answer is not just no, but HELL NO!  Don’t do it, it’s stupid… unless, of course, you have no other choice.  However, in these sad days when many states have chosen to utterly reject the Bill of Rights and the recent Supreme Court rulings because they are ruled by tyrannical, criminal politicians and populated by mincing, sad, weak, cowardly slave voters there are places where a black powder weapon is a man’s only choice.

For those poor unfortunates, just saying “don’t do it!” is not helpful; instead, we have to ask how they can best do it.  There are really two issues facing those who choose to use black powder revolvers: Handling and effectiveness.  With regards to handling, a full-sized cap and ball revolver with a 7.5-inch barrel is not very convenient, even just for having around the house, so a smaller revolver is better as long as the effectiveness is still sufficient.  A 2- to 3-inch barrel will dramatically reduce both accuracy and terminal ballistics, so I chose to concentrate on a 5.5-inch barrel, and later in this essay we will determine whether that is sufficient for an effective revolver.

A .36-caliber revolver is smaller and easier to handle than a .44-caliber, but in period the British complained that the .36-caliber Colt Navy’s they carried in the Crimea were insufficient, which led to their abandonment in favor of the .44 Adams (although many Civil War soldiers liked the .36 just fine), and here, too, we will consider the .44-caliber revolver as the better choice.

We also have to consider whether to use modern metallic cartridges or historical paper ones or even loose powder and ball.  While paper cartridge or loose powder and ball can work, they are clumsier and less effective than metallic cartridges, so we want to be able to use the latter.

The best choice, then, would be an antique revolver, preferably double action, such as a Merwin Hulbert or Smith and Wesson, since they don’t count as firearms in most states.  Unfortunately, such weapons are expensive and hard to find, and some may be quite worn out.  We can, however, buy modern, new-made cap and ball revolvers through the mail in most states and then convert them to fire metallic cartridges.

There are two ways of converting a cap and ball revolver to metallic cartridges: the Kirst system and the Howell system.  Although the Kirst system can work very well, they require pretty advanced gunsmithing skills to install (especially since the quality these days has fallen off and they require a lot of highly skilled fitting) and are more expensive than the Howells.  Howell makes conversion cylinders for both Colts and Remingtons, but to reload Colts you have to basically disassemble the revolver, whereas with the Remingtons you simply remove the cylinder, making the Remingtons a better choice.

Therefore, taking all of that into consideration, for this effort I chose to acquire a Remington .44-caliber New Model Army revolver with a 5.5-inch barrel from Pietta; I chose Pietta because in my experience they are more functional and better shooters than Ubertis despite not have quite as nice fit and finish, but honestly, either will work.  I also chose to acquire a .45 Colt (not “Long Colt,” please!!) Howell conversion cylinder for it.

I have a mold that makes a 255-grain replica of the bullets made by the Frankford Arsenal in period because, after all, I am a historical shooter, but any good, heavy bullet will do.  I experimented with numerous charges, including modern smokeless powder.  But while the cylinders are proofed for modern powder, the revolvers themselves are not, and all the recommendations are for using light loads which are not well suited to self defense, so I chose to use black powder instead.  It is possible to load as much as 40 grains of powder; the first civilian .45 Colt cartridges had that much, and I know folks who do so today, but the first U.S. Army cartridges had only 30 grains and later they dropped to 28 because the recoil of the heavier cartridges made them more difficult to use in real combat, and my experiences with heavier charges confirmed that, so I have chosen to use 30 grains of Swiss 3F powder.

So now we have my choice for a black-powder revolver for modern self defense: A Remington New Model Army with a 5.5-inch barrel and a Howell  conversion cylinder shooting .45 Colt metallic cartridges using 255-grain lead bullets over 30 grains of Swiss 3F powder.  Is that good enough?  That’s what I sought to discover today.

The two primary factors in effectiveness are accuracy and terminal ballistics (“stopping power” is a meaningless, misleading term used by amateurs).  Accuracy is somewhat subjective, but I hold that if you can reliably shoot a String Test with an average of about 3 inches/round at 15 yards, that is sufficiently accurate—it is enough to hit a head or a heart at that range.  Studies have shown that a muzzle energy of about 200 foot-pounds is necessary for a good self-defense cartridge, so that will be our basis here:  We want a String Test of around 3 inches or less and more than 200 foot pounds of muzzle energy.  Note that the modern .45 ACP with a 230-grain FMJ bullet fired from an M1911A1 pistol has a Muzzle Energy of about 360 foot-pounds (although you can get hotter rounds) for comparison.

To understand the String Test and why you should be using it to gauge your accuracy, see my article here:  historicalshooting.blogspot.com/2020/12/the-string-test-measure-for-historical.html

The calculator I used to determine muzzle energy can be found here:  ballistics101.com/muzzle_energy_calc.php

Today I shot 4 tables of fire for this test, 2 with my full-sized Remington New Model Army, and 2 with my 5.5-inch NMA, using the exact same cartridges in both.  All shots were made from a seated supported position using a Full Sight with a 6:00 hold on the 3-inch disk on the target. I swabbed the bore and wiped down the base pin between each table of fire. Here are the results:

Table One.

Table One:  Full-Sized Remington NMA
String: 8.5 in.
Rounds: 5
String Test: 1.7 in./rd.
Average MV: 905.6 fps.
Spread: 26 fps.

Table Two.

Table Two:  Full-Sized Remington NMA
String: 11.5 in.
Rounds: 5
String Test: 2.3 in./rd.
Average MV: 906.8 fps.
Spread: 39 fps.

Table Three.

Table Three:  5.5 in. Remington NMA
String: 15.0 in.
Rounds: 5
String Test: 3.0 in./rd.
Average MV: 818.4 fps.
Spread: 27 fps.

Table Four.

Table Four:  5.5 in. Remington NMA
String: 22.0 in.
Rounds: 5
String Test: 4.4 in./rd.
Average MV: 836.0 fps.
Spread: 23 fps.

Conclusion
It should be obvious from these results that the full-sized Remington is absolutely adequate for self defense.  Averaging the String Tests, we get an average of 2.0 inches per round, well below our threshold.  Averaging the muzzle velocities, we get an average of 906.2 fps, and using the calculator linked above, we see that that gives an average of 465 foot-pounds of energy, well above what is needed.

The 5.5-inch barrel, predictably, did not perform as well.  The average of the String Tests was 3.2 inches per round, which is slightly larger than the ideal, but only slightly, and that ideal is subjective anyway; I would argue that this is more than good enough.  The average muzzle velocity of all ten rounds was 822.2 fps, for an average Muzzle Energy of 383 foot-pounds, less than with the full barrel, but still well above our threshold, and 23 foot-pounds above a modern .45 ACP!  From this, I think it is safe to say this revolver with this load is absolutely adequate for modern self defense.  Note:  I did a lot more shooting today with both revolvers and was able to significantly improve with the short-barreled revolver, getting a String Test of 2.42 in./rd. for one table of fire, even though I was firing offhand and not from a rest, once I had a chance to really focus in on the sighting for the shorter weapon and practice with it a bit.

Table Ten: 2.42 in./rd. with the 5.5 in. barrel.

Note that the full-sized Remington has been extensively reworked for accuracy and reliability by Gary Barnes of Cartridge Conversion (cartridgeconversion.com/home-page), including a trigger and action job, which made it more accurate than it was originally, while the short-barreled revolver was fired right out of the box.  I plan to have Mr. Barnes do a full workup on the new revolver, including a trigger job, forcing cone adjustment, a new and more visible front sight, and more, which will significantly improve its accuracy.

Disclaimer
I am not a lawyer, and all laws vary by state.  Take responsibility for yourself and look up your own laws, or, better yet, talk to a lawyer in your state to know what is and is not legal.  Likewise, what is and isn’t suited to self defense is something you have to decide yourself.  Don’t take my word for anything (except these results), do your own research as if your life depended upon it—because it does.

Range Report 6APR2025: Trapdoor Gallery Cartridges and .45-70-500

 Today I shot the course of fire with gallery cartirdges recommended by Stanhope Blunt in his 1889 Firing Regulations for the U.S. Army.  In addition, I shot three tables of fire with historically correct recreations of the M-1881 .45-70-500 cartridge used in the last iteration of the Springfield Trapdoor Rifle.

Gallery cartridge design after Pitman's Notes vol. 3 p. 98.

Gallery Shooting
Gallery cartridges are made by adding 7 grains of rifle powder (in this case, Swiss 2F) under a .454 round ball weighing 141 grains that had been coated in bullet grease.  As the drawing above shows, the bullet is pressed down onto the powder.  In my case, I put a card under the ball to prevent the grease from contaminating the powder during storage (you can see where some of the cards hit the target in the photo below).

In Blunt's book, after soldiers had gone through musketry instruction they would be taken to a gallery range where they would get practice using their sight settings while shooting at short range (17 yards).  They would fire three sets of five shots at a target like the one below.  The first five were shot standing offhand using the 200-yard sight setting (the lowest on the 1884 et seq. rifles) aiming at the bull using a 6:00 hold; then they would fire five more kneeling or sitting using the 300-yard setting and aiming 6 in. below the bull; and 5 more prone using the 500-yard setting while aiming at a spot 10.25 in. below the bull. The targets should be 7 in. tall and 6 in. wide, with a bull of one inch surrounded by rings at 3 and 5 inches around it.  Scoring was 5 points for a bullseye; 4 points for a center; 3 points for an inner; and 2 points for an outer (which is anywhere in the black rectangle of the target).

Gallery target setup.

I recreated this exercise in full today as exactly as I could as shown in the photo below.  Note that all fifteen rounds pretty much made one giant hole, making scoring almost impossible, but there are no bullseyes and all the hits are either in the center or inner.  What look like hits below it were made by the cards hitting the paper.

Table One: Gallery fire.

Closeup of the Gallery target.

I think it is safe to say that this is a far better than "passing" score (although Blunt does not give a minimum), and that my recreation of the gallery cartirdges worked very well.

.45-70-500 Practice
After shooting the Gallery evolution, I next turned to shooting M-1881 cartridges.  These are exact reproductions of the last military version used with the Springfield Trapdoor Rifle.  They have .45-caliber 500-grain flat-based, round-nosed bullets over 70 grains of rifle powder (Swiss 2F in my case).  I have achieved a muzzle velocity with these bullets that is within 1/100th of a percent of the originals as recorded by the Ordnance Department reports of the period.  To see how I make them, go HERE.

My recreation of the M-1881 cartridge.

For scoring, I used the String Test system commonly used in the 19th century.  Regular readers of this blog will be sick of this by now, but for anyone who isn't, you can learn more about this system HERE.

Table Two
In Table Two, I shot 10 rounds at 50 yards from a rest.  Note the blue diamond below the black bullseye--this was my aiming point.  As the photo below makes clear, most of the rounds went through the same hole, indicating marvelous precision in this excellent rifle.

Table Two.

Closeup of Table Two; note that most of the bullets went through the same hole.

10 rounds
String: 24.5 in.
String Test: 2.4 in./round

Table Three
In Table Three, I shot at 100 yards, but the target had no mark on it to use in aiming off, which resulted in "stringing" of the rounds up and down the target due to the fact that I had to aim at a blank spot below the bull by estimation, and had no mark to allow me to do so precisely.  I shot this table from a sitting unsupported position, so obviously accuracy suffered from my shaking hands and bad eyesight.

Table Three.

9 rounds (one would not feed)
String: 33.0 in.
String Test: 3.7 in./round.

Table Four
In Table Four I shot 15 rounds at my recreation of a British Snider 3rd-class target (I haven't printed up any of the ones Blunt depicted yet) which helped somewhat with aiming off.  This was also shot at 100 yards from a seated unsupported position.  I was very pleased with this table of fire as getting a String Test below 3 inches at 100 yards is something I have not achieved before with any black-powder rifle.

Table Four.

15 rounds
String: 41 in.
String Test: 2.7 in./round

Historical Shooting with the Springfield Trapdoor Rifle

I am excited to announce that I have just published the next book in my Historical Shooting series, entitled Historical Shooting with the Springfield Trapdoor Rifle.  As with the other books in the series, this is not about the history of the Trapdoor (although I do cover the subject at a high level for context) nor a military history of the period, but is, rather, a book about shooting these rifles as historically as possible.

The hobby of historical shooting helps us learn about the past in a different way, by collecting and shooting antique or re-production firearms in a manner as close as possible to the way they were used in their days of glory. The book starts with a brief history of the rifle and its ammunition and an overview of some of the uniforms and equipment associated with it, then dives deep into making historically correct ammunition and the packaging for it, the musketry theory of the period, ballistics, training, the use of the sights, and gives a detailed explanation of how to shoot the rifle the way it was used in period.

The book is perfect-bound soft cover in an 8.5x11 inch format.  It is 196 pages in length and has many full-color photographs along with dozens of charts and diagrams.  It has been published through Lulu.com, an on-demand publisher, but will shortly also be available from many online retailers such as Amazon, Barnes and Noble, and others after it has had time to work through their procurement process, but that will be several weeks after the date of this announcement.

The book can be purchased immediately from Lulu.com (my preferred vendor since I make a bit more from them) by clicking on the following link:
https://www.lulu.com/shop/hugh-knight/historical-shooting-with-the-springfield-trapdoor-rifle/paperback/product-e75nqpz.html?page=1&pageSize=4

As an independent author not affiliated with any of the major publishing houses, I would really appreciate it if anyone who reads and finds value in this book would please leave a review about it, that really helps with books like this.

Here is a preview of some of the pages from the book to give a sense of what it’s like.

Where to buy Hugh Knight's Books

It occurred to me that it would be useful to have a single linked page that I can give people to show them where to get all of my books.  I can provide a link for each book individually, but there's no single location that shows links for all of them because of the way they're sold.  They can, of course, be purchased from major online retailers such as Amazon and Barnes & Noble and can be found by simply searching for the name of the book, but that requires someone to know the book exists before looking for it.  In addition, it helps me out for people to buy the books from Lulu.com, the publisher, so I wanted to be able to give all the links to purchase the books there, as well.  To that end, I will post links here to each of my books individually on Lulu.com and Amazon so that potential purchasers can link directly to them.

Historical Shooting with Civil War Cavalry Arms

To purchase from Lulu.com, click HERE.

To Purchase from Amazon.com click HERE.

Historical Shooting with the Snider-Enfield Rifle

To purchase from Lulu.com click HERE.

To Purchase from Amazon.com click HERE.

Historical Shooting with the P-53 Enfield Rifle

To purchase from Lulu.com click HERE.

To Purchase from Amazon.com click HERE.

Making Combustible Revolver Cartridges

To purchase from Lulu.com click HERE.

To Purchase from Amazon.com click HERE.

Historical Shooting with the Springfield Trapdoor Rifle

To Purchase from Lulu.com click HERE.

To purchase from Amazon click HERE.

Making Combustible Revolver Cartridges, by Hugh T. Knight, Jr.

I am excited to announce that I have just published a new book entitled Making Combustible Revolver Cartridges.  The book is not a historical survey of revolver cartridges—for that Roundball to Rimfire remains the critical work—but rather a “how to” guide showing how to make ammunition for cap and ball revolvers and the packaging for it.  In it, I demonstrate how to recreate five different kinds of historically accurate combustible cartridges for cap and ball revolvers, including nitrated paper cartridges, skin cartridges, and compressed powder cartridges.  I also show how to make a variety of different kinds of cartridge packets for carrying those cartridges, just as it was done during the nineteenth century.  In addition, the book explores casting bullets, black powder choices and measurement, bullet grease, and more!  Lavishly illustrated with almost 200 pictures and with highly detailed, step-by-step directions, this book is a must for any reenactor or black powder enthusiast.

The book is perfect bound soft cover in an 8.5x11 inch format.  It is 146 pages in length and has many full-color photographs.  It has been published through Lulu.com, an on-demand publisher, but will shortly also be available from many online retailers such as Amazon, Barnes and Noble, and others after it has had time to work through their procurement process, but that will be several weeks after the date of this announcement.

The book can be purchased immediately from Lulu.com (my preferred vendor since I make a bit more from them) by clicking on the following link:
https://www.lulu.com/shop/hugh-knight/making-combustible-revolver-cartridges/paperback/product-w4evg2r.html?page=1&pageSize=4

As an independent author not affiliated with any of the major publishing houses, I would really appreciate it if anyone who reads and finds value in this book would please leave a review about it, that really helps with books like this.

Here is a preview of some of the pages from the book to give a sense of what it’s like.

Range Report 21SEP2024: Testing Hazard-Style Compressed Powder Cartridges

I took my shiny new Hazard compressed-powder cartridges to the range today intending to do a deep-dive analysis of their ballistics.  Unfortunately, a strong gust of wind lifted my chronograph off the ground and broke the tripod, so I couldn’t do much muzzle velocity testing.  I got five good readings before the tripod died, as shown below.  These are Hazard compressed-powder charges with .44-caliber Johnston & Dow bullets and varnished with two heavy coats of a 2:1 mixture of acetone and nitrocellulose glue.  They were made with 25 grains of Swiss 3F powder.  Compare this to my previous results with paper cartridges using a comparable load, which had an average MV of over 800 fps.

1. 499
2. 429
3. 440
4. 313
5. 477
Average: 2,158/5= 432 fps with a spread of 186 fps.

My current thinking is that the heavy layer of varnish may have slowed the combustion and thus reduced the MV, or else the compression of the powder means that the individual grains can’t deflagrate as fast as loose powder, again, thus reducing the MV.  I also made a batch using precisely the same load but varnished with two thinner layers of clear nail polish, which isn’t as thick as the nitrocellulose mixture, and had hoped to see if that made any difference in MV, but obviously the equipment prevented me from being able to determine that.  I shot those in Table of Fire Two.

Next time, I will take three sets, one with the nitrocellulose varnish, one with the clear nail polish, and one with no varnish at all.  By comparing them with a fresh batch of paper cartridges the answer should be clear.

Both batches shot fairly well given that the revolver is an Uberti Colt New Model Army, which is significantly less accurate than my Pietta Remington NMA, but I usually get a string test of around 2 to 2.5 in./rd. with a similar load in paper cartridges.  All rounds were shot standing offhand at 15 yards using a 6:00 hold.  There are only five shots in Table of Fire Two because one of the cartridges was damaged.  Note:  Ubertis suck.

The cartridges were a joy to load since they don’t put any material on the heel of the bullet and thus fit better into the chambers than paper cartridges which have a layer of paper on the heel.

Table of Fire One: Nitrocellulose Varnish
String: 13.25 in.
Rounds: 6
String Test: 2.21 in./rd.
(The blue tape marks hits from a range neighbor who wasn’t paying attention.)

Table of Fire Two: Clear Nail Polish
String: 15.5 in.
Rounds: 5
String Test: 3.1 in./rd.
(Note the red X—that was a burn mark from an unknown source, not a bullet hole.)

I also tested both .44- and .36-caliber skin cartridges, but honestly, they performed no differently from paper cartridges. I will write more about them when I can include MV results, but suffice it to say they are also very easy to load and fire.