Armstrong Breech Block Rest

In the above photograph, taken I think of a 110pr Armstrong breech loader in Canada, of a Garrison mounted gun, there are several very interesting features. The Smith’s elevating screw for instance, and the remnants of the left hand breech tangent sight. But I am particularly looking at the flat surfaced item which is attached to the top of the breech. It took me some time to work out the function of the rather complex shaped item.

The breech block, which weighed 130lbs, had to be lifted out of the breech by two strong gunners to permit swabbing of the bore from the breech aperture (also visible in the photo), then loading of the next projectile and gunpowder bag, after which the breech block was lifted back into position and screwed tightly closed prior to the next firing.

Ah….. the flat topped attachment is where the breech block was placed while the swabbing and loading took place!

So I set about making the breech block rest (as I called it) for my model.

The rest looked complex and difficult to model. The inner surface had to fit the external surface of the breech, including two convex fillets. The external surface has to fit the breech block, without denting or otherwise damaging it despite its considerable weight and frequent manhandling. And there are holes for 6 attaching screws.

First I turned a disk in LG2 bronze. The interior surface fitted closely over the breech, including the convex fillets. I used a bullnose milling cutter to turn the fillets.
Then the top surface using the scarey shell cutter. I handle this cutter with great care because it is razor sharp.
Then CNC milled the shapes which hold the breech block securely…
And finally drilled the screw holes and parted the fitting from the bronze disk. The under side.
and the top side.
Here the breech block rest is Loctited in position, ready for the screw holes to be drilled into the breech and the screws fitted.
The breech block resting in place, ready for reloading.

Now, dear readers, I must inform you that I have only enough WordPress memory for another one or two posts and a few photographs.

The Armstrong 110pr breech loader cannon model project is almost finished.

The remaining parts, including the Smith’s elevating screw, carriage wheels, rope eye bolts and capstain were all described in the build of the Armstrong 80pr rifled muzzle loading model cannon, so I will not repeat those details for the 110 pr.

I will leave the remaining small memory for the assembled model of the 110 breech loader, in a few weeks time.

And since I will not delete any more old posts, that will be my final post. (unless WordPress changes their policy of not increasing memory limits. And I do not expect that to happen.)

In the final post I will notify you, my readers, of the site where I will post photos of future projects. Not quite yet decided, but it will NOT be WordPress.