Making a chamber reamer

[homebrew .357]

Thanks again Harold-v for your very in depth reply, now I`m on the right track , I will harden and temper it and my give it to a tool grinder for sharping , as they have all the gear. I payed $120 for the plans and the wife says you better build that gun !! or you will get the , so I`v got to get on with it, The thing with a cartridge gun is that you can look down the barrel bore, so it will need to be good, very good , Cheers Guys , I`v lots to do, Homebrew 357.

[Harold_V]

Welcome! I hope I've helped in some small way.

I'm not too worried about the outcome. You've shown that you're more than capable of excellent performance.

Might be nice to see a picture of the finished reamer.

On the subject of the reamer---I don't recall the cartridge, but if it's not a (dead) straight chamber (and I assume it's not), the reamer will have to cut on the flutes, as I mentioned. I make mention because the geometry of the flute is how rake is created. You can't have a random slot cut---it must be located such that it creates modest positive rake, then transitions to negative rake (look at a tap for a good example). You can accomplish this task with a radius cutter, but it has to be presented to the reamer in the proper attitude. If you haven't paid attention to that detail, you'll find that the reamer, even with proper relief, won't cut well. Make sure you have at least modest positive rake. Emulating a tap is a pretty good way to go. Pay attention to how the cutting edge of the tap (along the straight part) relates to the radius that is ground, creating the flute.

Harold

[Msalm]

New here, but I've got a little tip an uncle told me about. He was a tool and die guy, machinist, and a hell of a gunsmith. To harden your reamer, chuck it up in chuck and spin at high rpm while heating. To quench, just lift your oil straight up to the chuck and quench vertically. It is easier to get an even heat and quench that way and it will minimize warpage.

[homebrew .357]

On the money again Harold, I had cut it square and a good look at a tap and a milling cutter I could see the radius .
Now how the heck could I do that, so a dig around in my bits of comeinhandy stuff I found thin disc grinding wheel, using my drill press and x y vice I set up the reamer with mark one eye ball and the D T I to get it set up for grinding the radius on the cutting face, The disc has rounded face edge so it would give a good under cut to the face of the reamer.
This is the way I have to do things as I have not got all the high dollar machinery, mill, grinder, shaper , cad, c n c,
Any way, doing this now and then will look at hardening it, I have a kerosene blow touch and a gas one, will use both to get it red hot , then oil dunk. The Sharps 45-70 is an American icon, slite case taper ,2.105" long .
Thanks Harold, Homebrew .357.

[Harold_V]

The radius can serve to limit cracking in heat treat, too. As an added benefit, a radius in the flute promotes chip flow. Sharp corners are to be avoided for both reasons.

Might be a good idea to observe the suggestion offered by Msalm. That method addresses the very things that most likely will be troublesome.

Harold

[homebrew .357]

Hi guys, yes I have read about that way of heating the reamer and then lifting up a tin of oil to quench, will do, but not a this time. Will do it when I have a lot of parts to heat treat, my heat source is not hot enough so will have to use oxy/cet for it..
So I`m now making a ali bullet mould for a 400/420 gr, .456' bullet and a sizing die to .453' . Sort of work my way around this gun before I get to it. The 45-70 shoots a .500gr bullet with 70grs black powder, oow my shoulder , that's why I`m using a .400/20gr bullet, I think, will not know the weigh till I start casting. Cheers, Homebrew .357.

[alphawolf45]

I payed $120 for the plans and the wife says you better build that gun !! or you will get the , so I`v got to get on with it, The thing with a cartridge gun is that you can look down the barrel bore, so it will need to be good, very good , Cheers Guys , I`v lots to do, Homebrew 357.

Homebrew.357 I am building the Sharps right now if you want to compare notes you can PM me.. I build a couple guns a year. Presently competing in BPCR silhouette matches with home built .45-70 Highwall that I built last year. Real satisfying....I made the chamber reamers for a dozen of my builds or more but now that I am more acutely serious about accuracy I think it better practice to use a good commercially produced reamer.. Can rent one from http://www.reamerrentals.com/ProductDet ... D70Gov%2Es for 26 bucks plus shipping and insurance for 3 days.

[alphawolf45]

Heck, sorry Homebrew, I forgot youre down under. You may not be able to rent a reamer in New Zealand.hmmm

[homebrew .357]

Hi Alpha Wolf, Thanks for your offer of help, building a black powder rifle with the gear I have was ok, But having a rethink on the Sharps 45-70.
The only way I could do it is to import from the US the barrel, action, and breech block as I have not got the gear to make them and for safety and accuracy as well, after all the work I would like it to shoot strait .
There is still a lot of work to do in making the rifle and even with making the reamer, I would like to get it done in the us by a gun smith for a good job. So will have to check with the NZ police for a import licence for gun parts, Cheers, homebrew.357.

[alphawolf45]

homebrew .357
It's been 17 weeks since I began my Sharps and I have an exceptionally well equipped shop and have all day everyday to work on it. Its a big project. I regret that you wont be building the rifle but I respect your decision.. It is better to decide against starting than to get deep into it with time and money and then quit.

Mine will be .40-65... I ordered the brass shell casings today at scalper prices- 4 times what theyre advertised for the same thing at the online businesses who list them but also say they are out of stock and wont even accept back orders...Most everything gun related here in the states is still in short supply..

I am making the odd offset Sharps firing pin right now...Wow, very satisfying ..Metalsworking is my obsession, love it when faced with a good challenge...Thought about buying one of them but found that theyre asking $140.00 for a firing pin.. More than I can afford...I will only have about $300.00 in the whole rifle when I am finished but several hundreds of hours working on it.

http://www.buffaloarms.com/Sharps_Firin ... x?CAT=3776

[homebrew .357]

Hi again, yes I will be still looking at building this rifle, It`s just getting those three things I carn`t make myself.
Have just finished rifling a barrel to .450" bore, 1-24" twist, 23"long a bit rough and only 1 inch od, the sharps is a larger od barrel. So as you say , It`s fun working out how to make the parts , but having those three parts would give a kick start. .Homebrew.357.