Conversion for cap and ball revolvers

[ascast]

Maybe not best place to post, but here goes. Santa said I might look into the conversion kits for BP revolvers. So, who is better, Kirst or Howell or other? I am looking to upgrade a ASM Walker, a Pietta '58 and maybe a 'Uberti 1860. All steel frames. It looks like the Howell are mostly 6 shot while the Kirst are 5 shot. Most all are current back ordered. I also have a couple 36's I could do. So, wondering what folks had to say on this subject. who's better, why, best caliber to go,why ,etc. etc. Really just looking to make a better purchase going in with more info. thanks all and merry christmas

[Der Gebirgsjager]

The thing is that they're different. Not necessarily better. You have to look their features over carefully and decide which you want to live with.

DG

[Outpost75]

Writeup on the Howell Conversion from The Fouling Shot, cross-posted here with author's permission:

Cartridge Conversions Modernize the Cap & Ball Sixgun


Ken Howell turns Pietta .36 Remington into a useful small game forager


Attachment 273892
Cap & Ball revolvers can be bought in most US states and shipped mail order direct to you without going through an FFL. Cartridge conversions for the same reproduction cap & ball revolvers are considered by ATF as "parts," and can “usually” ship direct in most of the US. If you happen to live in CA, HI, NY, NJ, IL, etc. you best confirm that they are indeed legal where you live.

In Canada modern reproductions of cap & ball revolvers are not considered “antiques” in the manner that originals or reproduction single-shots are. In Canada cartridge conversions for reproduction C&B revolvers are licensed under the same provisions as a modern handgun. Giorgio tells me that in the EU you can only dream of such things. But, if a "snowbird" from a northeastern US state owned a legal C&B revolver at home and kept its cartridge conversion unit at his winter condo in Florida how is anyone really going to know?

A fellow CBA member picked up one of these in a trade. He suggested that I should test it to write up in a Fouling Shot article, so we worked out a deal. Some of you reading this may recall comments on the proposed project which appeared on the CBA Forum thread: https://castbulletassoc.org/forum/th...-36-remington/

Several US makers, Taylor & Company, Walt Kirst and Ken Howell offer cartridge conversions for the most common reproduction .36 and .44 cap & ball revolvers. The one I tested here is a Howell .38 Special version made to fit the Pietta .36 Remington. For more information on his other conversion options go to: https://www.howellarms.com/

The instructions say that as long as you keep the gun in its original configuration and just swap the cartridge cylinder for the cap & ball one, all is "Kosher" and you don't have a "firearm" according to ATF. Once you remove the cap & ball loading lever and modify the revolver frame to install a loading gate and rod ejector to permit that fast cowboy action reload, you have then manufactured "a firearm." While doing so is OK for your personal use, any further transfer to others then requires completing a Form 4473.

To use the Howell conversion, unlatch and pivot the loading lever down, pulling the cylinder pin forward. Remove the black powder C&B cylinder, then remove the backplate from the conversion cylinder, insert cartridges into the chambers, replace the backplate onto its alignment pin, substitute the cartridge conversion cylinder for the C&B cylinder, and install it into the gun. After firing, to extract empty brass the conversion cylinder must be removed, its backplate removed and fired cases poked out with a BIC pen or similar object. It is slower to reload than a modern single-action, but still faster than reloading a percussion cylinder, unless you have a spare already loaded. You retain the ability to fire either cap & ball or cartridges from the same gun. Practical field utility, if not your first choice for defense!

Howell conversions are made from 4150 steel and are safe to fire with factory, standard-pressure smokeless powder “Cowboy” loads. The instructions are clear that they should be used in steel framed guns only. This is because reproduction C&B revolvers guns are clearly marked by the manufacturer for "Black Powder Only." The maker has no control over anyone using hot handloads or +P defense loads in one, so just don’t be stupid.

Attachment 273893Attachment 273894Attachment 273895Attachment 273896

Groove diameter of the Pietta .36 cap & ball barrel is .375" vs. .358" for a .38 Special. To get anything resembling "normal" accuracy you must either use soft lead, hollow-based bullets such as .38 Special factory 148-grain wadcutters, or a "heeled" bullet with enlarged forepart which fits the cylinder throats, with a reduced diameter rear shank to fit into the cartridge case, as did .38 Long Colts of the black powder era.

Factory wadcutters in .38 Special do not exceed 13,000 psi, max., and are very accurate in the .38 Special conversions. Factory .38 Long Colt 150-grain LRN factory ammunition develops similar velocity and pressure and the bullets have a deep hollow base like HBWC wadcutters, which gives fair accuracy and they also shoot to the same point of impact.

The traditional projectile loaded in black powder .38 Long Colts was a "heeled" 150-grain bullet, of soft alloy similar to 1 to 40 tin-lead. The bullet was pressed into the case up to its enlarged nose, then the case mouth was crimped onto the bullet heel in a manner similar to .22 LR ammo. Old West Bullet Molds makes a collet-type bullet heel crimper for Cowboy Action shooters who want to be authentic. I found that I could use standard .38 Special loading dies backed off 0.135” by using a .38/.357 die spacer if the bullet heel was a tight fit when seated into the case and rounds were profiled with the Redding .38 Special Profile crimp die similarly backed off, reducing case mouth diameter to permit easy chambering.

Attachment 273897Attachment 273898

Western Super Match .38 Special wadcutters from the 1960s shot best in the Pietta with Howell conversion. I was unable to improve on their performance hand loading a heeled, bullet cast from backstop lead of about 11 BHN, in which the heel did not upset with 3.5 grains of Bullseye. Perhaps softer lead would be better.

The vintage WW2-era Rem-UMC "Police Service" 158-grain and 200-grain LRN service loads loaded with soft bullets having a shallow cup-base grouped 4-5 inches at 25 yards. Examples recovered by shooting into water jugs indicated the soft, cup-based bullets indeed upset to take the rifling OK. But groups were twice as large as those produced firing wadcutters, about 4-5 inches at 25 yards. Holes in target paper showed noticeable yaw when longer LRN bullets were fired from the slow "round-ball" twist barrel. Western 150-grain .38 Long Colts having deep hollow bases were “plinking accurate” and suitable for Cowboy Action, stringing vertically and not as accurate as factory wadcutters. Extraction of fired cases from the 200-grain Super Police loads was sticky using the BIC, a clue that their pressure is a wee bit high, so that I don't recommend them for frequent use in the conversion cylinder.

As the sights came from the factory point of impact was about 6 inches low with all ammos at 25 yards, while groups were well centered for windage. To correct zero of fixed sight guns use the expression: X = RE/D where "X" is the amount of sight correction required, "R" is the sight radius. "E" is the error in Point of Impact relative to point of aim and "D" is the target distance, ALL DIMENSIONS BEING IN INCHES!!

Initially I dressed down the front sight so that it measured exactly one inch from the bottom flat of the octagon barrel to the top of the front sight removing about 0.055". The next range session indicated that this was better, was not quite enough. After confirming zeros and also shooting hand loads I removed another 0.015” which turned out to be just right.

Velocities from the Pietta with Howell conversion averaged about 60 fps lower than the same pooled samples of ammunition fired from a 1939 Colt New Service with 5-inch barrel. This is attributable to the larger barrel-cylinder gap of the black powder gun, and also from its larger barrel groove diameter, both factors combining to reduce velocity and pressure, compared to the much tighter Colt. Results are summarized in Table 1.

The enlarged nose of bullets cast from the Accurate heeled mold cast a wee bit large to fit the cylinder throats of the Howell conversion to obtain a push-fit using the "backstop scrap of unknown composition" about 11 BHN, which I had in the pot. It just so happens that the carbide ring in a Lee .380 ACP factory crimp die works perfectly as a push-through sizer, after removing the "guts" from the die, and using a Lee push-rod from another sizer, bullets emerging .3735" which is perfect for the Howell cylinder’s .374" cylinder throats.

The Old West heel-crimper for .38 Long Colt works fine, if you prefer, with .38 Special brass after minor adjustment using a standard .38 Special shell holder. An extended shell holder which comes with the die is required to crimp .38 Short Colt or Long Colt and comes pre-adjusted for a 1.02" case length. After crimping in the Old West heel-crimper, I still found it necessary to run the rounds through my Redding .38 Special Profile crimper, backed off using a .135" thick .38/.357 ring space. This reduced case mouth diameter sufficiently so that rounds would chamber freely after being expanded by in seating the .360” diameter bullet heel into the case mouth. Backing off the roll crimp shoulder away from the case mouth is required to avoid distorting the nose of the bullet.

The Redding .38 Special Profile Crimp enables rounds to chamber freely without having to forcefully push them in, cartridges falling into and out of the chambers of their own weight, although starting them back out without firing requires a wee coaxing with the BIC. Pulling sample profiled rounds indicated adequate bullet pull and the bullet heel was uniformly reduced to .358” diameter.

When using .38 Special brass in the Howell conversion with the Redding Profile Crimp Die backed off with .135” die spacer, the heel-crimp die is really not needed to produce a secure cartridge assembly, so this makes heeled bullet loading to fit the conversion cylinder simple.

To compare the performance of different loads fired in the Pietta I used a prototype exterior ballistics program sent to me for evaluation. The program graphs predicted bullet penetration in 10% ballistic gel and closely approximates the predictions from Duncan MacPherson’s Bullet Penetration. The program also adopts MacPherson’s conservative approach to “wound mass” and approximates his wound mass predictions. Here are the results:

A .375 round ball fired from a cap & ball revolver with 21 grains of 3Fg powder achieves 740 fps from a 6-1/2-inch barrel. Predicted penetration in 10 percent ordnance gelatin is 18 inches, displacing 13 grams of wound mass and depositing 110 ft.-lbs. of energy in the first 12 inches of penetration.

Attachment 273901

Factory 150-grain .38 Long Colt LRN at 695 fps penetrates 23 inches in 10% ordnance gelatin, displacing 18 grams of wound mass and depositing 139 ft.-lbs. in its first 12 inches of penetration.

Attachment 273902

A standard pressure .38 Special handload with a 149-grain flatnosed, bullet at 800 fps penetrates 28 inches in 10% ordnance gelatin, displacing 18 grams of wound mass, while depositing 167 ft.-lbs. in its first 12 inches of penetration.

Attachment 273899

A .38 Special 148-grain full wadcutter factory load impacting 738 fps penetrates 19 inches in 10% ordnance gelatin and displaces 27 grams of wound mass while depositing 171 ft.-lbs. in its first 12 inches of penetration, a dramatic improvement in performance!

Attachment 273900

Given the current political circumstances I think that every gun owner in America should get one of these and bury it in his back yard!


Table 1 - Howell .38 Special Conversion in Pietta 36 Remington

Ammunition Type__________Pietta 6-1/2”____________Colt New Service 5”
________________________0.010” cyl. Gap__________0.005” cyl. Gap
________________________.375 groove dia._________.355” groove dia.
Western .38 Long Colt
150-grain LRN_____________640 fps, 28 Sd__________693 fps, 23 Sd

Western .38 Special
158-grain LRN_____________744 fps, 20 Sd__________787 fps 23 Sd

Western Super Match
148-grain HBWC___________738 fps, 14 Sd__________770 fps, 9 Sd

Accurate 37-149H-heeled
3.0 grs Bullseye -.38 LC_____682 fps, 6 Sd___________725 fps, 16 Sd
3.0 grs Bullseye -.38 Spl_____626 fps, 22 Sd__________706 fps, 10 Sd
3.5 grs. Bullseye - .38 Spl.___700 fps, 20 Sd__________801 fps, 7 Sd

Column Mean______________688 fps________________747 fps
∆V______________________-59 fps
 

[leadeye]

I want a cartridge Lemat.

[jdfoxinc]

It will be tough getting a conversion for your ASM.

[Markopolo]

i gotta tell you, i am a HUGE fan of the Kirst converter. I have 2, and had nothing but praise to say about the customer service as well as the product... I love mine, and love the eject lever, and I love the customer service. when the owner of the company calls you personally, and knows my name, I am pretty star stuck.

cant go wrong with Kirst!!!!

[rintinglen]

Mine are Howell, but do not think that they are drop in conversions. Of the three I have, one fit just fine, one required some polishing and and one will require major work to get it to fit. I shoot 45 Schofield loads from my 1860's and expect to use 148 HBWC if I can get around to making that the 1851 work.

[bedbugbilly]

I don't think you can go wrong with any of them - it just all depends on what you want.

Read and re-read and then re-read again what Outpost75 says. All I can say about Ed (Outpost 75) is that he is a bad influence. LOL He was very helpful and as a result, conversion cylinders just sort of got addictive! I was looking for help/advice and he sent me a copy of his article on the 36 Remington Conversion. I have always shot '51 Navies - but I ended up buying a '58 Remington Navy like he used in his testing. All of my conversion cylinders are Taylors (Howell)- I prefer the Remington for the conversion cylinder due to the ease of removing/replacing the cylinder over an open top Colt where the barrel wedge has to be utilized to remove the barrel each time you need to reload. I have two of Taylor's cylinders in 45 Colt for Uberti 1858 Remingtons - on a pistol and the other a Remington revolving carbine. They fit and function just fine. I have a 45 Colt cylinder for a Pietta '60 Army. Because of the geometry/size etc. of the Pietta '60 Army, which in percussion is a 5 chamber cylinder, the 45 Colt conversion cylinder is a 5 shot Fit and function perfect.

On my .36 conversion cylinder and the Pietta '58 Remington Navey that I have like Ed used in his testing, I chose to go with a .375 150 grain "heeled bullet". My 2 cavity mold as well as the special shell holder and the crimp die for loading 38 Colt Long came from Old West.

Just as Marco says - a lot of folks really like the Kirst conversions and I am considering going that way with another of my C & B revolvers. I'm not pushing one over the other - I know the last time I talked with Taylors, they have a number of them in stock (the same as a Howell).

Good luck whichever way you go.