Hopkins & Allen underhammer pistol.

[Gtrubicon]

Just stumbled into this over the weekend. I don’t think it was shot much. It’s got a mismatched replacement screw and the bluing was scrubbed off about a 3” section of the barrel. It’s a .45 cal. Looking for starting load info and proper disassembly information. I came up with .445 across the lands, is a .440 gonna need a mallet to get it going? Thanks for your help.

 

[Nobade]

I have one of those. It shoots best with light loads, 15gr or so. A .440" ball works fine, though my rifle version likes a .433" ball. You can try both to see what is better. Disassembly is simple - unhook the trigger guard from the hammer and remove the two screws. I am planning on reshaping the grip on mine, too much palm swell. But it does shoot quite well and is very effective on rabbits.

 

[Rifleman1776]

is a .440 gonna need a mallet to get it going?

It may. I used to sell H&A undies. Most needed a .433" ball. That is what I used in mine.

 

[springfield art]

Just stumbled into this over the weekend. I don’t think it was shot much. It’s got a mismatched replacement screw and the bluing was scrubbed off about a 3” section of the barrel. It’s a .45 cal. Looking for starting load info and proper disassembly information. I came up with .445 across the lands, is a .440 gonna need a mallet to get it going? Thanks for your help.

I'm up for one of those; you really shouldn't have to "mallet" anything! They're fun!

 

[springfield art]

I gotta get one! Had one of the plastic-grip ones many years ago; want one just like that! By 'that', I mean the wood handled one shown.

 

[garypl]

I have one that I love to shoot. A patched .440 ball is very tight so I have been loading 20 gr 3F with a Durofelt wad soaked in olive oil on top of the powder followed by a bare ball - shoots great at 15-20 yards!

 

[Gtrubicon]

My barrel has zero crown, is this the norm for these pistols?