Howell .38 Special Conversion for Pietta .36 Remington

  • Last Post 04 June 2020
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Ed Harris posted this 06 May 2020

Anybody got one of these?  Thoughts?

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 most common cap & ball revolvers are designated by ATF as "parts" and can be similarly shipped direct by US mail in most US states.

Some state laws are more restrictive, so if you live in CA, HI, NY, NJ, IL, etc. you better check first to see if they are legal. Giorgio tells me that in the EU they can only dream of such things.  If a "snowbird" in a northeastern US state already had a legal C&B revolver and kept the conversion unit at the winter condo in Florida how is anyone going to know?

A fellow CBA member had one of these and didn't have time too fool with it, but thought it would make an interesting CBA forum entry and maybe later a more comprehensive Fouling Shot article, so we worked a deal. Howell makes these for most reproduction cap & ball revolvers from the Colt 1863 Pocket to the big Colt Walkers and Dragoons. See:

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. But once you remove the cap & ball loading lever and modify the frame to install a loading gate and rod ejector to permit that fast cowboy reload, you have then manufactured "a firearm," which is still OK for your personal use, but further transfer then requires completing a Form 4473.

Using the Howell conversion requires unlatching and pivoting the loading lever down, pulling the cylinder pin out, removing the black powder C&B cylinder, then loading and substituting the cartridge conversion cylinder and installing it in the gun. The cylinder must be removed, the backplate pulled off its alignment pin and fired cases poked out with a BIC pen or similar object each time.

So yes, it is a bit slow to reload, but you can shoot either cap & ball or cartridges in the same gun.

Howell states the conversions are made from 4150 steel, but cautions that you should it in steel framed guns only, with factory "Cowboy" loads. The reason is product liability because the reproduction C&B guns are marked for "Black Powder Only" and they don't want to be sued if anyone gets stupid and puts +P or hot handloads in one.

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 HBWCs (target wadcutters), or a "heeled" bullet with enlarged forepart which fits the cylinder throats and a reduced rear shank to fit into the cartridge case, like .38 Long Colts of the black powder era.

If you want to shoot factory ammo, wadcutter loads are typically loaded to about 13,000 psi, max., which is fine in the cap & ball conversions.  The .38 Long Colt 150-grain LRN ammo is loaded to similar velocity and pressure and also has a deep hollow base like HBWC wadcutters.

The traditional alternative is to buy a mold for a "heeled" 150-grain .38 Long Colt bullet, and cast them of soft alloy like 1 to 40 tin-lead. The bullet is hand-started into the case with the fingers or by pushing its nose against a table edge. Then the case mouth is crimped onto the bullet heel in a manner similar to .22 LR ammo. This cannot be done with standard loading dies, but you can improvise with blasting cap or coax cable crimpers, or buy a collet type crimp die made just for the purpose.

I fired the Pietta .36 Remington at 25 yards with Western Super Match wadcutters from the 1960s as well as WW2-era Rem-UMC "Police Service" 158-grain lead round nose and 200-grain lead RN loads. Best grouping was with the wadcutters. Point of impact was about 6 inches low at 25 yards. However, it is MUCH easier to cut down a front sight to correct zero than to install a higher one.

The 158-grain and 200-grain LRN service loads had bullets with a shallow cup-base.  Examples recovered by shooting into water jugs indicated they upset to take the rifling OK. But accuracy was poor and group size double that obtained with the wadcutters, with the heavier bullets tipping from the slow "round-ball" twist barrel. Extraction of fired cases from the 200-grain Super Police loads was difficult using the BIC, which is a clue that pressure is a bit on the high side, so that I don't recommend them in the conversion cylinder.

While low with wadcutters at 25 yards, the group was fairly well centered for right and left. 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 IN INCHES!!

I cut down the front sight so it measured exactly one inch from the bottom flat of the octagon barrel to the top of the front sight removing about 0.055".  Next range trip I'll try the wadcutters again to confirm zero, in case I need to tweak the front sight some more, I plan also to shoot some WW2-era .38 Long Colt 150-grain LRN loads which have a deep hollow base like the wadcutter.

The 1960s Western Super Match wadcutters gave 738 fps from the 6-1/2 inch barrel, penetrated 30 inches of water jugs and grouped about 2-1/2 inches at 25 yards. 

I've ordered a heeled mold from Tom at Accurate Molds, and a collet, heel-crimp die from Old West.  A charge of 3 grains of Bullseye in .38 Long Colt brass or 3.5 grains in .38 Special brass should closely approximate the velocity and pressure of factory loads.

Stay tuned for updates.  In the meantime I'd love to hear from anyone using one of these cartridge conversions, or who loads traditional "heeled" bullets in the .38 Long Colt or .38 Special for them or the old Colt 1892 DAs.


73 de KE4SKY In Home Mix We Trust From the Home of Ed's Red in "Almost Heaven" West Virginia

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45 2.1 posted this 06 May 2020

You have a PM.....................................

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admiral posted this 06 May 2020

I have one for my Ruger Old Army in .45 ACP from Howell. It shot high but I was able to get a taller front sight blade from Ruger. I got the ACP cylinder instead of the .45 Colt because at 'cowboy" pressures the small case does everything that's needed.

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jniedbalski posted this 07 May 2020

Nice write up. Always wanted one of these cylinder’s try.

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GP Idaho posted this 07 May 2020

My conversion works just the same but is 45 Colt from an 1858 Remington 44cal. pistol. They are a little slow to reload but if you keep powder charges to a reasonable level or just load black powder cartridges they handle cased ammunition just fine. My pistol is surprisingly accurate with the cap and ball cylinder. Gp

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Ed Harris posted this 15 May 2020

Accurate mold and the Old West heel-crimp die arrived.  Stop ring for the Accurate bullet was a wee bit large to fit the cylinder throats for a push-fit using the "backstop scrap of unknown composition" about 11-12 BHN, which I already had in the pot. It just so happens that the carbide ring in a Lee .380 ACP factory crimp die works dandy as a push-through sizer, after removing the "guts" from the die, sized bullets emerging .3735" which is ideal for the .374" cylinder throats.  I'll try casting some in soft lead to see if they drop enough smaller, so that I can test soft lead vs. wheelweights for group, and to recover at least one bullet of each alloy to see if the heel is upset firing Bullseye. 

Over the weekend I plan to cast more bullets to lube, size and load with 3.5 grains of Bullseye in .38 Special brass, and 3.0 grains of Bullseye in .38 Long Colt brass.

Briefly fired the gun again today after cutting down the front sight and 12 rounds with factory wadcutters, and upon arrival home I took another 0.01 off the front sight.

.38 Long Colts strung vertically, but served to produce empty cases to load with the heeled Accurate bullet.

73 de KE4SKY In Home Mix We Trust From the Home of Ed's Red in "Almost Heaven" West Virginia

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Ed Harris posted this 17 May 2020

Today cast a bunch of Accurate 37-149H bullets from the "backstop lead of unknown composition" BHN 11.  Slobbered in LLA and sized .3735 by pushing through the carbide ring of a Lee .380 ACP Factory Crimp Die with its internal "guts" removed.  Seated bullets in regular .38 Special seater by backing die off and turning seating plug down deep so as to seat bullet firm against stop ring, without distorting the front driving band.


Old West heel-crimper for .38 Long Colt works fine in .38 Special after adjustment using a standard .38 Special shell holder.  The 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 ran the rounds through my Redding .38 Special Profile crimper, using a .135" thick .38/.357 ring spacer to back the roll crimp shoulder away from the case mouth to avoid distorting the bullet.  It works just right using only the body portion of the die to lightly size the case mouth where the .362 unsized heel bulges case mouths enough to make the rounds a bit "fat" to chamber without having to strenuously force them in.  After passing through the Redding Profile die rounds fall into and out of the chambers of their own weight, although starting them back out requires coaxing with the eraser end of a pencil.

I now have 100 test rounds assembled with 3.7 grains of 452AA, as metered in the RCBS Little Dandy Rotor #6, which is what the measure had in it.  In previous testing with various bullets in .38 Special this matched the velocity of my usual 3.5 grains of Bullseye.


I also assembled a box not using the Old West heel crimper at all, but just seating bullets to length, by backing off the crimp shoulder of a standard .38 Special seating die, turning down the seating plug in deep to push bullets  against the stop ring, without marking the enlarged stop ring of the bullet.  I then used the Redding Profile Crimp similarly backing off the roll crimp shoulder to avoid marking the bullet, profilng the case body to iron out the mouth bulge caused by seating the .360+ diameter heel.  This produces a rigid enough cartridge assembly which should reduce bullet deformation, compared to using the heel crimp. If the heel-crimper is not needed, this would enable loading heeled bullets simply by re-adjusting standard .38 Special, then using the Redding Profile crimper to produce a tight bullet assembly.  A  .135" thick .38/.357 spacer ring backs the seater and crimp dies off the correct amount and makes the transition from conventional to heeled bullet loading straight-forward and simple.

Stay tuned to this station for further updates.

73 de KE4SKY In Home Mix We Trust From the Home of Ed's Red in "Almost Heaven" West Virginia

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Slugflinger posted this 17 May 2020


Think! It's not illegal, Yet.

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Ed Harris posted this 02 June 2020

Range day today, tying the ribbons on the project.

The heeled Accurate bullet shoots OK in 11 BHN backstop lead, but the heel does not upset with 3.5 grains of Bullseye. 

Next time I cast I'll run some more in soft lead and see if it improves the accuracy.

Final sight adjustment is now a keeper.  Best accuracy is still with factory wadcutters, considering that the small sights are hard to see.  This is nice to know for anybody buying one of these who doesn't hand load. 


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

73 de KE4SKY In Home Mix We Trust From the Home of Ed's Red in "Almost Heaven" West Virginia

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JeffinNZ posted this 02 June 2020

Those holes don't look very round Ed.  Is that just my eyes?  Agree on softer alloy.  I'd go 40-1.

Cheers from New Zealand

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Ed Harris posted this 04 June 2020

Those holes don't look very round Ed.  Is that just my eyes?  Agree on softer alloy.  I'd go 40-1.


Jeff, you are correct.  Even the wadcutter holes show a wee bit of yaw.  Will try some 40 to 1 and cautiously increase the load a wee bit, but not over 800 fps.

73 de KE4SKY In Home Mix We Trust From the Home of Ed's Red in "Almost Heaven" West Virginia

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