Playing With Fire

That’s fire and brimstone.  This is pure gun geekery, and even for gun geeks its nerdy because it’s about percussion guns of the 1800s.  You’ve been warned.

Saturday, Nephew and I tried some heavy loads for the repro 1858 Remington revolver.  I’d been using a 28 grain powder charge and a round ball with decent results, but wanted to try something with more pep.  Civil War era military loads ranged from very light, to as much powder and lead as could be stuffed in the cylinder.  To start, we tried round ball (~140 grains) over a charge of 39 grains of 3F Goex with a greased felt wad in between.  That load filled the chambers completely and delivered an average of 925 fps at 10 feet with an extreme spread of 46.  Not too bad.  The 29 grain charge was yielding a velocity of about 850 fps.

It’s like pulling teeth to find acceptable “conical” bullets (“bullet shaped” as opposed to a round ball) for these “.44” percussion revolvers unless you cast your own, which I don’t.  I did find some Buffalo Bullets 180 grain jobs that fit the chambers nicely, and ordered 100 of them to try.  Since the bullet takes up more room in the chamber, the most powder I could get in and still seat the bullet below the cylinder face was 30 grains.  But, wow.  Average velocity was 1047 fps.  That’s a tad better than a .40 S&W, and matches the V of a .45 Auto load in the Speer manual for their 185 gr GDHP.  Extreme spread was 67, with a standard deviation of 21.

That was with two different people doing the loading.  I’m going to guess that with the same person loading all the rounds, the charge weight and ramming pressure would be a little more consistent, and so too the velocity.  Groups with this load opened up slightly from last week’s all-ball venture, but not enough to be sure.  This time was in direct sunlight, which makes aiming a little more difficult.

The extra pressure it takes to move the heavier bullet, which also has more friction surface against the bore, I will assume ramps up the powder’s burn rate.  More velocity with less powder and a heavier bullet.  Neat.  We’ve found a performance, or efficiency, zone.  More pressure equals more heat, equals a faster, more complete burn inside the bore, equals yet more pressure.

This is how guns (and sometimes chemical factories, engines, etc.) blow up– things look great as you increase the pressure and temp a little.  The reaction speeds up, a little bit more, things are doing fine, a little bit more and, Boom!.  A threshold is reached and a runaway reaction takes place.  You shear some bolt lugs, or burst a cylinder, etc. and maybe you go home with slightly fewer or slightly misshapen body parts.  That can be embarrassing.

I wasn’t worried about this load in a modern repro made with modern steel.  When these revolvers were designed and built originally, metallurgy wasn’t anything like it is today, and even back then they were known to stuff the chambers full on a regular basis.  Further, it makes no sense to build a cylinder that will take more powder than it can handle with the commonly used “44-100” bullets of up to 250 grains.  That would take more material and make the gun bigger and heavier, for no other reason than to encourage over-pressure loads.  I’m also running on some faith that they wouldn’t have done that (though the much longer 1847 .44 Colt “Walker” cylinder was known to occasionally let go).  Remember that back then there was only black powder, not the wide spectrum of nitro powders we have now.  All they had to control the powder’s burn rate were different granulations of the same mixture (though brand and lot inconsistency would likely have thrown in some degree of uncertainty).  With smokeless propellants you can get into a LOT MORE TROUBLE making your own loads.

Here’s Nephew torching off one of the heavy loads.  The bullet has been on its way for about a millisecond, as the gun is still in firing position and the hot gas (I mean hot– this is in direct sunlight) has traveled a foot or so out from the muzzle;

Below is the same shot in full recoil a fraction of a second later.  Forget about quick follow-up shots.  You can’t see the target until the smoke clears. By then you’re re-cocked and ready to go.  A side wind would be a big help in this case;

Today’s rapid fire guns wouldn’t be worth as much if they had to run on black powder.  For one thing you wouldn’t be able to see squat.  It is “interesting” to take a shot, and find that your target has simply disappeared after the smoke has cleared.  There’s that moment of uncertainty.

I like the slow, frame-by-frame animations as below.  You can see the mechanics of the recoil (though a high speed camera would be nice).  You can watch the force wave travel from his wrist, into the arm, the shoulder, and whole torso.  Nephew’s grip is fairly relaxed, which isn’t a problem with a medium weight 44 revolver.  Some people hate animated gifs on a web page.  I’m one of them, but this is for science;

You shouldn’t haul off and max out your charcoal burner just because I did.  I’m not saying it’s the thing to do.  What I can say is; I still, for the moment, have all my body parts (and gun parts) and all are operating satisfactorily, thank you.  I have a load that’s within the range of those used in the 1860s for the Remington New Model Army revolver and 1860 Colt Army, and it matches some of the .45 ACP loads for a ~180 grain bullet.

Now here’s a puzzler.  I’ve had barrel leading in modern revolvers and autos firing bare lead, hard-cast or swaged bullets.  Using pure, soft lead bullets in the ’58 Remington and ’51 Colts, no leading has been observed, even with these loads that achieve modern handgun KE levels.  I don’t know why.  Is it the grease?  But we’re told in no uncertain terms never to lubricate a modern gun bore, while black powder guns are greased all to hell.  Is it the propellant temp?  But the KE is the same.

10 thoughts on “Playing With Fire

  1. Black powder guns seem to like to run near max loads. I’ve seen the same with my ’61 Navy repro. Mike Cumpston and John Bates have a good book, Percussion Pistols and Revolvers.

    I’ve wondered about the leading, too. Could cast bullets for cartridges be too hard vs. the pure lead black powder bullets?

    Regards,

  2. “Could cast bullets for cartridges be too hard vs. the pure lead black powder bullets?”
    My understanding has been that the primary, if not the only, reason for the harder alloys in modern bullets is to reduce leading in the barrel.

  3. This triggered some thoughts about something I’ve wondered about for a while; is there any data on expansion volumes for powders, specifically, black powder and an average baseline (if such a thing exists) for nitro-based smokeless powders? X grains of powder Y transforms into Z volume upon combustion, etc. I realize pressure is a component, and what I’m referencing is open air combustion where pressure effect would be zero or close to it.

  4. The main reason for hard alloy in production lead bullets is to keep them from deforming in storage and shipment. The same goes for the lube they use – hard as hell.

    If the alloy is too hard, the bullet won’t seal the bore and the blow-by will strip lead off the bullet and plate it all over your rifling. Also, the harder lube used on production bullets might be fine at rifle pressures but isn’t that great for lower pressure pistol loads.

  5. Cool writeup. I have the same 1858 and I was looking into conical bullets for fun. There isn’t much info out there about them from what I’ve searched.

    I figure I’ll get some conicals and make little premade cartridges with zig zags for when it thaws out around here.

    Question. What size caps do you use? I have a pietta from cabelas and I use #11 caps that are too large. I can’t seem to find any #10’s in SE Michigan.

  6. Personally I really don’t see the thrill in black powder, and frankly I prefer a hand-ejector Double-action if I’m going to play around with a round-gun.

    That being said I want an Uberti Walker Colt so bad it makes my teeth hurt!

  7. When you’re shooting, and the smoke gets in the way of seeing the target, you best have your dancin’ shoes on cause you’re gonna be doing the Black Powder Shuffle.

    Since I’ve been runnin’ wholly black through my Ruger’s via .38spl, I have noticed to a lack of leading and residue along the lines of what I normally would get with smokeless. I was told that the heat generated from the black powder burns it all up.

    As for lube and greasy barrels, it’s to help keep the bp fouling soft so that it can get pushed out by the next round. A few people I’ve met use bore butter on top of the boolit, instead of using a wad. They say it helps with the fouling better. But, each to his/her own I guess. Whatever makes the steel go *ding*.

  8. Pete; That ’58 rem is a Pietta, as is the ’51 Colt repro I have. Both use #10 caps. But that’s not the end of the story. I started out with CCI #10s, and they fit a little too tight, which resulted in occasional misfires. Some of the hammer’s energy was being spent seating the cap, just like what can happen in a cartridge if you don’t seat the primers all the way in. The Remington #10s have a slightly looser fit, and they’re great on these Piettas. In hundreds of shots, I don’t recall having a single misfire with them. Alternatively, some people have removed the nipples one at a time and hand fit them on a drill press using some fine sandpaper. Lots of work compared to getting the right caps. The “Treso” nipples are what I regard to be the perfect fit with the Remington 10 caps, but the stock Pietta nipples are just fine.

    If you can’t find the caps you want, Cabelas sells them. They’re not a bad deal, even with the HazMat fee, if you order them by the M lot.

    Some people say to use #11s and pinch them. No, no and no. You want, and can get, the proper fit one way or another. A good fit virtually eliminates the possibility of an unfired cap falling off, as well as the possibility of a chainfire being initiated from the back.

    Cemetery’s; “I was told that the heat generated from the black powder burns it all up.”
    I have a hard time accepting that, or as Chuck Yeager would say, “I’d have to see the gun camera film on that one.”

    I do apply grease over the bullet for that reason also, with or without a felt wad. More slop means it can all be mopped out easily. Of course most of the over-the-ball grease is blasted away from adjacent chambers upon the first firing, via the cylinder gap.

    Homer; I don’t know the numbers, but smokeless is almost 100% converted to gas, while BP is way below that. That’s where all the smoke comes from– solids leftover from the far less efficient combustion. The 30 grains I was using under the 180 grain bullet in a 7″ barrel is doing about the same amount of work that 10.6 grains of smokelles does in a 5″ .45 ACP. Major difference. Interestingly, it also means that with black, you’re pushing more mass out the barrel, which some say results in more recoil for the same projectile KE. In this particular case, I’m shoving about 20 grains more down the tube (plus the very small mass of the grease).

  9. Airgun shooters have noticed less leading with softer pellets for some time. Leading can be a real issue for them because the barrels tend to be made of softer steels, and therefore harder to clean without damaging. The harder pellets (i.e. those with antimony) will lead a barrel once you get in the 900 fps and up power range, while pure-lead pellets don’t do so as readily. It seems counter-intuitive, but there you have it.

    BTW, Tom Gaylord, who writes for Shotgun News, wrote a good article explaining this issue in airgun terms with examples from the powder-burner world as well.

    http://www.pyramydair.com/blog/2006/04/can-you-keep-clean-barrel-with-crosman.html

    Cheers,

    Bobby

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