I was reading about a person wanting to use a 45 acp silencer on subsonic 45/70 rounds. Boy does this get my attention.
I have loved and hunted my #1 Ruger 45/70 in the steep rugged mountains of Oregon for Roosevelt elk for years. Hand loaded it is the hardest kicking rifle I own (including my 416 Rigby). But it worked wonders for a fast handling light rifle in heavy brush. My Barnes 300X bullet was deadly on the elk. However getting into my 70's it is not the hunt I am reluctant to pursue, it is getting that heavy carcase out of the woods and back to my truck that totally kicks my butt. So my attention has turned to playing with suppressed subsonic loads.
I am awaiting this week delivery of my new toy. http://www.boltonhardware.com/images/pdf/ha330.pdf. I have a 1:14 twist barrel blank setting here. I have all the boolit casting stuff that I use for my 300 blackout, and some 550 gr postal molds for the 45/70 and way too much reloading stuff. Besides winter is coming, and all it does here is rain for 9 months, so got to have some kind of a project.
Why can I not scale up these integral silencers I see people making for their 22 lr guns. http://www.silencertalk.com/forum3/view ... 10&t=73211 or If I went up to around 7" from the breach, and turned a thread too attach the outside of the can, cut the barrel length to 20 or 22 inches (The blank is 26'). I have a 1.3" X 18" .064" titanium tube also, so I should be able to just whittle up some K baffles, and drill some holes in the barrel, attach the tube up near the breach, and figure out where it all gets quite.
Also it seems to me that one way to lower the gas pressure it to lower the temperature of the gas (Bernoulli law), is to use a medium that transfers heat rapidly. I was thinking of machining a copper tube to fit tightly inside my titanium tube in the expansion chamber area. (Just freeze it to shrink it in OD and pop in inside, and then have a tight fit when it warms up). The thermal conductivity of Titanium is only 12, Aluminum is ~120 while Copper is 223 (Btu/(hr degrees/F ft(squared)/ft)). So if we had an internal heat sink, while we would loose some internal area, we would cool the gas 20X this reducing the volume. (Besides if it does not work, it is easy to cut the copper sleeve back out).
The dynamics of the 45/70 almost beg for something like this. You can trim the cartridge length, as we space on the rim, we like quick powders for short barrels, well it was made for black powder, and that stuff is real quick, so any pistol powders will be slower, and since I can get the 500 gr bullet moving quickly, the amount of gas the suppressor has to deal with should be minimal.
I know this is uncharted territory for my 1st project on my new lathe, and I make no claims to being a machinist, but like those famous last words...."What can go wrong??"
