View Full Version : Diamond Arms .410 single-shot - needs trigger

12-22-2010, 3:38 PM
3-digit serial on this one; it belonged to my Great-Grandfather.

I understand that this was a trademark of Shapleigh Hardware in St. Louis, but there were several manufacturers. I know it's not a Belgian import -- no crown markings (and it's an old .410!). My father refurbished the stock and drilled the bore, blued the barrel.... in 1972. He also, sadly, lost the trigger and the firing pin in the same night-school gunsmithing class.

This is my latest project, and this is the oldest gun I now own; any help in identifying where I can find a trigger, hammer spring and firing pin for this old hardware-store break-open stagecoach gun would be appreciated. I'm aware that this probably hasn't much monetary value as a collector's item, but the sentimental value is something that cannot be priced.

Thanks, guys!

- 12 Gauge Upgrade
Bay Area, Occupied California

12-22-2010, 3:40 PM
numrich (www.e-gunparts.com) there were maybe 4 mfgs /names or so,

12-22-2010, 3:41 PM


12-22-2010, 3:44 PM
Doesn't it matter which manufacturer's version I have? Or are they all standardized even at that point? Will I need to ream the chamber to a larger size to fire modern .410 shells?

The barrel stamps read "HIGH PRESSURE SINGLE-PIECE BARREL" and ".410 BORE 12 M-M"

12-22-2010, 3:46 PM
tat part I dont know. I have a 16ga same as you, and shot it a few times. Fires fine. You would need to get current chamber dimensions, maybe from ammoguide.com? & use a caliper to confirm? do not have knowledge that .410 shell has more than one variation?

12-22-2010, 3:54 PM
Do you have a schematic of any kind? I know I am missing the firing pin and the trigger, but I have the hammer in place -- which spring do I need is the question. :)

Some very old .410's (pre-WWI) as I understand it, are chambered for 2" or 2.5", and modern .410 sizes will not fit. Easiest way for me to determine this, I suppose is to get some .410 shells. All my other shotguns are 12-gauge. ;)

Thanks so much for your help!

SoCal Bob
12-22-2010, 4:01 PM
You may want to post your question in the Gunsmithing forum. I have an old, 20 gauge, Iver Johnson, Champion, single shot shotgun that will shoot modern loads because of when this version was made. Older versions of the same shotgun were designed for black powder and cannot take the pressures of the current loads.

Good luck.

12-22-2010, 4:13 PM
Yes, this is going to be quite a project either way, SoCal Bob. Thank you!

From what I have read so far, the "high-pressure barrel" stamp means it was made for post-black powder loads, but that .410 wasn't really a US standard until around 1910 or so.

12-22-2010, 4:22 PM
I believe the Champion is the same socalbob!



12-22-2010, 5:06 PM
Thanks, Freonr22!

I don't see a firing pin for sale on Numrich - is it the floating head there in #801? Is there a Legend to go with it?

Again, your help is greatly appreciated. Merry Christmas! :)

12-22-2010, 5:11 PM
They Have a pdf for $1.50 or you can call them. Also try jack first company

12-22-2010, 7:34 PM
I will call Jack First in the morning! Thanks for the ideas.

Is it just me, or is Numrich doing business on a website from 1998? ;)

12-22-2010, 7:52 PM
sorry, last post was from a phone, Jack first has zero website, other than the contact number. called 2-3x usually a woman answers, is knowledgeable, get answer in 30 seconds or less :)

Mike A
12-23-2010, 6:47 AM
The .410/12mm marking is one of the earlier designations for the 2 1/2" .410 ctg, which is still made. I wouldn't bother to rechamber the gun for 3" shells; you don't gain much--this isn't a goose buster. The short shells will kill quail and rabbits just as well as the 3" (some say better because they pattern better in many guns, especially full choke guns as this almost certainly is if it hasn't been rechoked). And the self-defense loads, should you be so inclined, are almost all 2 1/2" anyway.

You say your father "drilled the bore" in his gunsmithing course. What's that mean? Did HE perhaps rechamber to 3"? Try chambering a 3" in it (NOT shooting it). If it fits easily, it probably has been rechambered. But I'd still use the shorter shells it was made for.

This gun, as you probably know, has no collector's value now. But it obviously has family/sentimental value, and would, if in good, tight shape, be a very fun small game gun. I'm glad you're restoring it!

12-23-2010, 10:56 AM
Mike A: Thank you so much for the information!

My father said that the bore had been badly pitted and corroded, and now it's quite shiny and new-looking inside. I'll pick up some .410 shells and try them on for size, but if I can still find the original ammo for it, my goal is to return it as close to original as possible.

Thanks again! I'm going to call Jack First about a firing pin now.

12-23-2010, 12:40 PM
Don't you have to check fit of a shotgun shell with a fired shell? Seems like I remember that you have to have extra room for the shell to "unfold".
take care

Mike A
12-23-2010, 4:00 PM
Mikeb is correct in saying that the proper way to check for chamber length (unless you have a chamber guage, which most of us don't) is to use a fired shell. Unfortunately the crimp usually squishes down in the forcing cone of a too-short chamber (or too long shell) and "fits" anyway. So all this stuff is approximate, at best. Fortunately a shotgun is unlikely to blow because the shell is the wrong length, unless there are a couple of other things wrong, too. Like a 3 1/2" 12 Super Mag in an old 2 1/2" chambered damascus gun.....

.410s operate at a somewhat higher standard pressure than other guages, by the way. Odd, but true.

It sounds like your father honed out the pits in this bore. That is USUALLY OK in a .410 if the pits weren't really deep because most old .410 singles were made on a frame that could also be used for all the other old "small guages" (.44 Shot, .44 Ideal, .410, 32 ga., 28 ga., 24 ga., and 20 ga.) So the chamber area of the barrel, where the pressure is greatest, is pretty thick, owing to the smaller hole in the standard barrel shank (a .410 hole in a barrel shank that would be safe for a 20 leaves a LOT of metal). But SOME old .410s had their own "miniature" frame with a miniature barrel shank. If your gun was one of those, it might not have enough metal left for safety after honing out very deep pits. Kinda unlikely, but one more reason to have a gunsmith who knows old guns check it for safety.

BTW, this warning goes double for damascus barrels, which your .410 clearly AIN'T.

12-28-2010, 12:53 PM
Thanks again, Mike A and Mikeb!

The metal around the chamber is indeed much thicker than it seems like you'd need for a .410.... then again, all my other shotguns are 12-gauges and I don't have a fired .410 shell. Once the weather clears up, I will be hitting the trap range again and there is almost always at least one old crack-shot there for whom .410 is the only challenge. Should be no trouble finding some fired hulls, then.

Seems like most of the folks I need to talk to at Jack First are on vacation for the holidays still. Krausewerk Collectibles in San Mateo isn't that far away; I am thinking about bringing it down there for an inspection or parts-matching. This old gun has been waiting over 38 years to be fixed up, and patience is a virtue. ;)

Thanks again, guys!

12-28-2010, 5:45 PM
Check out parts for a Springfield or a old Savage.

01-24-2011, 6:53 PM
Well, I've got the trigger, trigger spring (tang-spring) and new pins in place, but the Iver Johnson #3 Williams firing pin is a no-go. It looks like this was a tapered firing pin. The original is broken clean off, and Jack First has nothing to machine as an example....

I have it to the point where the trigger clicks, hammer goes forward, firing pin -=- well, it moves, but there is no "pin" to it anymore.... I am going to send this pin and spring back to Numrich, but no one else has anything marked for the Diamond Arms .410 at all. The trigger doesn't reset by itself... I have to push it forward a little.

Bottom line is, Numrich doesn't offer a .410 Diamond Arms firing pin, and their suggestion on the phone for using the IJ Champion pin didn't work.

Either way, I want to fix it up first and then take it to a gunsmith for safety testing. I called my Father last night and he was excited to hear that I was fixing it up, but asked that I not have it next to my face the first time I pulled the trigger on a live round. I started taking his advice to heart a decade or so ago. ;)

Thanks again for your help and suggestions, guys! Would it help if I posted pictures of the busted pin? Anyone know of a machine shop for gun parts aside from Jack First?

-12ga Upgrade offered for old electronics ;)

01-25-2011, 12:13 AM
Did you try looking at savage,springfield and Stevens shotguns they look very similar.Savage bought out Crescent arms out in 1931 and they were the makers of Diamond Arms.Was your gun made in Norwich CT or Chicopee Falls?

01-25-2011, 2:46 PM
PezHead265, not 100% sure where it was made, actually. It's receiver reads "Diamond Arms, St. Louis" and the barrel stamps read "HIGH PRESSURE SINGLE-PIECE BARREL" and ".410 BORE 12 M-M".

01-25-2011, 5:51 PM
Crescent Firearms made them for Shapleigh Hardware in ST Louis MO.Diamond Arms was the tradename for them.That might be a pre KING Nitro with the 3 digit serial # they also used the KING NITRO tradename,but not 100% sure on the King Nitro I would research that it might be worth some bucks.