Handloading Blackpowder Rifle Cartridges

When handloading rifle cartridges with blackpowder, Allan suggests you should not approach it with a smokeless powder mindset.

Handloading Blackpowder Rifle Cartridges
Our ballistician in residence found out long ago that sometimes “going back” turns out to be a huge step forward.

When active in cowboy action matches, my friend Brett Olin, a retired CCI rimfire engineer, shot blackpowder ammo exclusively. He’s quipped that “smokeless propellant is a passing fancy” and had a sign on his shooting cart that read “Smokeless is for Kids!”

Historically, he makes an interesting point. Earliest references to a mechanical mix of fuels and oxidizers date to around 800 AD. This stuff was launching projectiles from tubes by the early 1200s. The final usurpation by smokeless propellants of blackpowder’s dominance in small arms did not finish until after World War I. I’d rate a 700-year service life as remarkable.

There are many forms of blackpowder, depending on its use. Propellant blackpowder intended for small arms is usually the most refined. It has high-grade potassium nitrate oxidizer and carefully prepared softwood charcoal. Although “clean burning” is seldom used in the same sentence as “blackpowder,” quality propellant-grade blackpowders produce less residue than their industrial counterparts made with lower-grade materials.

I have garnered a modest but varied experience with blackpowder firearms; the only class I’ve not tried is a flintlock. It was a blackpowder cartridge rifle that caused me the most grief.


In my youth I had a nice U.S. Model 1873/84 Springfield “Trapdoor” .45-70 rifle. Accuracy was poor, and I didn’t need a chronograph to know the loads were inconsistent. “Off” sounds in the report told a sad tale. I later owned an 1874 Sharps musket in .45-105-550 and found 90+ grains of blackpowder did not improve the situation. Experience in smokeless propellant reloading left me ill-prepared for dealing with a blackpowder cartridge rifle.


As a group, we handloaders had basically forgotten what our forebears learned and applied to the loading of blackpowder cartridges. Interest in cowboy action shooting spurred historical research that changed the way we now manage blackpowder ammunition.

There were some big names—like Paul Matthews, Spencer Wolf, Steve Garbe, and Mike Venturino—among the researchers. Olin found their research very helpful as he honed his considerable skills with blackpowder cartridges.

Olin proposed a ballistics research project on blackpowder cartridges and needed my new (expensive) .45-70 Krieger pressure barrel fitted with a PCB piezo-electric transducer (also expensive). I let him use my equipment.

His study was not intended to create loading data but rather generate statistically sound data on pressure and velocity variations that affect blackpowder internal ballistics. We shot over 1,000 rounds under highly controlled conditions. He chose the CCI Quality Assurance tunnel so we didn’t have to move the plotting gear that creates time-pressure curves to the Speer tunnel a mile down the road. Time pressure (t-p) curves go from the ballistics computer to an X-Y plotter that overlays all shots in a string on one graph. Plots showed commercial blackpowders have a pressure-rise profile very similar to modern smokeless fuels.


The plots also settled a point of contention. For years, I’d heard that magnum primers performed better in blackpowder cartridges. With one exception, the numerical data showed the opposite. Ballistic consistence was better with standard rifle primers. The t-p curves showed even more. One typical 10-shot test with everything identical except for primers showed peak pressure with magnum primers occurred from 410 to 590 microseconds after ignition, but standard primers of the same brand produced a much smaller variation: 420 to 480 microseconds. The plots are reproduced on page 171 of the Speer Reloading Manual #14.

Peak pressures with blackpowder were impressive. Some types of blackpowder exceeded 20,000 psi, about the same as modern .45 ACP ammo pressures. The effects of granulation were far more apparent than any changes in primer type. With all other factors equal, substituting the same volume of the smaller-grained Goex 3F for Goex 2F increased pressures 4,000 psi and pushed the 524-grain bullet 100 fps faster, from 1,050 to 1,150 fps. Yet pressures stayed under 21,000 psi, a number most researchers find appropriate to the 1873 Springfield action.

Today, I understand that my issues with that Trapdoor Springfield were complex. The handsome “glazed” blackpowders were largely missing from the U.S. market from World War II until some was imported from Scotland in the 1980s. Those granules had a rounded appearance from tumbling that produced a clean, silver-gray metallic appearance, and it looked quite similar to modern spherical propellants.


I’ve maintained a modest collection of 19th-century rifle ammo, including Sharps cartridges. I had a sample of UMC .45-105-550 Sharps with a loose bullet and decided to peek inside. Okay, today that single cartridge would probably cost $75 or more, but I was young and curious back then. Under a lube wad the powder had the shiny gray color common to high-grade glazed blackpowder. It was obvious the charge had been compressed to shape—and not by bulletseating. No lead bullet could remain undeformed under the pressure needed to compress that load of blackpowder. Clearly, compression preceded bulletseating.

This was something Olin applied to the tests he conducted. He built a compression die to let a steel punch do the compressing while the case body was supported to prevent its swelling under the force. This seems to be one key to better burning and uniform performance.

Olin’s study showed many factors that could have vastly improved my .45-70 experiences with that old Trapdoor. Of course, in the early 1970s, we did not have the selection of blackpowders we see today, but his approach also helped me understand that I was using overly hard bullets that were undersized and not using enough powder. I could have gotten away with a bit of seating compression, but as I’ve said, back then we approached blackpowder with a smokeless powder mindset.

Brett Olin’s strong competition performance in sanctioned long-range events convinced me that “going back” was in reality a huge step forward in understanding our history and appreciating those who came before us.

Thanks, Brett.

GET THE NEWSLETTER Join the List and Never Miss a Thing.

Recommended Articles

See More Recommendations

Popular Videos

Black Hills Evolution of Rifle Cartridge: .308 Win. 175 Gr. Match

Black Hills Evolution of Rifle Cartridge: .308 Win. 175 Gr. Match

David Fortier talks with Jeff Hoffman of Black Hills Ammunition about the evolution of the .308 Win. 175 Gr. Match bullet.

Skills Drills: 3-Second Headshot

Skills Drills: 3-Second Headshot

James Tarr runs through the 3-Second Headshot drill.

The Future Of Special Operations Small Arms

The Future Of Special Operations Small Arms

We're taking a look at what the Army's Elite Units are using for service rifles and what the future of SOCOM sniping looks like.

Hornady 6MM Creedmoor

Hornady 6MM Creedmoor

Tom Beckstrand and Neal Emery of Hornady highlight the 6MM Creedmoor ammo.

See More Popular Videos

Trending Articles

The new Bushnell FORGE riflescope is “the only choice for long-range hunting enthusiasts.” Optics

Review: Bushnell FORGE 4.5-27X 50mm

Sam Wolfenberger - May 01, 2019

The new Bushnell FORGE riflescope is “the only choice for long-range hunting enthusiasts.”

Is the SIG P320 9mm modular pistol the best polymer-frame high-capacity sidearm ever designed? Let's find out. Handguns

SIG P320 9mm Review

Joseph Von Benedikt - September 13, 2018

Is the SIG P320 9mm modular pistol the best polymer-frame high-capacity sidearm ever designed?...

Daniel Defense has blazed a new trail with its first-ever bolt-action rifle, the Daniel Defense Delta 5. Rifles

Daniel Defense Delta 5 Review

Joel J. Hutchcroft - May 31, 2019

Daniel Defense has blazed a new trail with its first-ever bolt-action rifle, the Daniel...

The new striker-fired STR-9 9mm semiautomatic pistol from Stoeger Industries is reliable, ergonomic, accurate, and priced right. Handguns

Stoeger STR-9 Review

Joel J. Hutchcroft - May 17, 2019

The new striker-fired STR-9 9mm semiautomatic pistol from Stoeger Industries is reliable,...

See More Trending Articles

More Reloading

The .270 Winchester is the first big-game cartridge the author ever handloaded for is still a great choice. Reloading

Reloading the .270 Winchester

Lane Pearce - December 26, 2019

The .270 Winchester is the first big-game cartridge the author ever handloaded for is still a...

Handloading the increasingly popular .450 Bushmaster requires some special attention. Reloading

Reloading the .450 Bushmaster

Lane Pearce - November 15, 2019

Handloading the increasingly popular .450 Bushmaster requires some special attention.

Handgun shotshells are more complicated than one might think. Developing them brought many challenges, and handloading them brings even more. Reloading

Developing Effective Handgun Shotshells

Allan Jones - July 15, 2020

Handgun shotshells are more complicated than one might think. Developing them brought many...

Some rifle handloading knowledge has become so ingrained that we rarely question it, even though it may not be true or it was once true but no longer applies. Reloading

Reloading Myths for Rifle Cartridges

John Barsness - January 17, 2020

Some rifle handloading knowledge has become so ingrained that we rarely question it, even...

See More Reloading

GET THE MAGAZINE Subscribe & Save

Digital Now Included!

SUBSCRIBE NOW

Give a Gift   |   Subscriber Services

PREVIEW THIS MONTH'S ISSUE

GET THE NEWSLETTER Join the List and Never Miss a Thing.

Get Digital Access.

All Shooting Times subscribers now have digital access to their magazine content. This means you have the option to read your magazine on most popular phones and tablets.

To get started, click the link below to visit mymagnow.com and learn how to access your digital magazine.

Get Digital Access

Not a Subscriber?
Subscribe Now