PDA

View Full Version : Chamber adapter for a trapdoor



Jedman
06-12-2021, 10:46 AM
This will be a future project because I just recently moved and don’t have my lathe and other machines working because they need 230 V power and I will have to get that done first.
My idea is to make a chamber adapter to shoot either 32 S&W long or 32 H&R magnum in the 45-70 trapdoor without any modifications except removing the ejector and adding a small spacer to take its place. The pics I posted is of a 45-100 brass with a long bullet that measures 3.6” long and this is the maximum length I can get to chamber and make the turn. I have several 30 cal. take off barrels to use and a chucking reamer the correct size for the chamber so the plan is to make a cerrosafe chamber cast and turn the adapter to look just like a 45-70 case with a extra 1.5 inch length just under groove size to fit in the bore without touching. I may add a O ring near the muzzle end so it’s a snug fit.

The plan is to remove the ejector from the rifle and add a small spacer to take up the width of the ejector and mill out a 3/16” wide slot deep (in the adapter) enough to get a small screw driver with the blade ground thin to reach in at 9 o clock to extract the fired casings. This 3.6” long adapter should give enough rifling to get some accuracy from it with the low powered shells.
A couple of years ago I made a similar adapter from a 7” piece of .451 barrel liner and turned a adapter to fit a 16 ga break action shotgun and epoxied the liner into the adapter and chambered it to 45 ACP. With some old rifle sights added to the cut down 20” barrel it was surprisingly accurate being able to hit a pop can at 50 yards regularly.

This is just a “toy” to play with that I can make in a couple hours time so it should be fun !
If anyone has suggestions let me know as it will be a while before I get to this anyway.

Jedman284391284392

Nobade
06-12-2021, 11:37 AM
Nothing wrong with that. Sounds like a fun project. Get that wiring done!

Landy88
06-12-2021, 11:49 AM
Both this project and the prior read like good and, especially with these recurrent shortages, practical fun.

Mk42gunner
06-12-2021, 07:59 PM
Been a while since I looked at a Trapdoor action, but if you didn't have a rim on the adapter I don't think you would have to take the extractor out of the rifle.

Robert

Jedman
06-13-2021, 12:09 AM
I just thought taking out the ejector was easy enough and that way it’s not trying to extract the adapter when opening the trapdoor. I could make it with a rimless adapter but the headspace would be harder to get right. I have dies ,brass and bullets for both of the 32 S&W long and the 32 H&R mag so that makes it easy also. I think with the H&R mag I should get close to 1000 FPS with the 100 gr. castboolits I have and that should have about the same trajectory as a 22 LR .

Jedman

jdfoxinc
06-13-2021, 08:04 AM
Just remove the rim at the extractor like the Chiappa shotgun adapters.

John Taylor
06-13-2021, 09:17 AM
Sounds like a fun project.

Cap'n Morgan
06-13-2021, 10:28 AM
Go ahead and give it a try. Like JD suggested, remove part of the rim for the extractor.

I once made an insert for a Martini Henry - complete with a soft soldered .22 rifled sleeve, and a spring-loaded extractor.

Unfortunately, I bored the insert parallel with the rifle bore. It should have angled slightly towards the center to keep the bullet from touching the bore wall.
Theoretical, the bullets should've just cleared the bore, but while they did not tumble, they still landed all over the place.

I couldn't muster enough energy to make another one at the time - but maybe one of these days...

https://i.imgur.com/8O6qYIE.jpg?1
https://i.imgur.com/jzXpdgI.jpg?1
https://i.imgur.com/oETppiR.jpg?2

Mk42gunner
06-13-2021, 07:33 PM
Been a while since I looked at a Trapdoor action, but if you didn't have a rim on the adapter I don't think you would have to take the extractor out of the rifle.

Robert
This is what I said.


Just remove the rim at the extractor like the Chiappa shotgun adapters.
This is what I meant to say.

Of course you would need at least a portion of rim to set you headspace for the adapter.

Robert