Paper patch throat 45-70

[bearcove]

My 45-70 encore has no throat. What would be a good throat configuration for paper that would also be good for plain ol' boolits. I have a lathe and feel I could make a throating reamer,so it doesn't have to be an over the counter remedy.

[leftiye]

I'm not sure that I can completely answer your question, but maybe this will help. First, I'm starting to believe that the "no freebore" chamber may be SAAMI standard for 45/70 (I could be wrrrrrr). Marlins, and many ther guns are chambered that way.

I've thought of putting a throat on my Handi Rifle, just as you seem to be doing, and I think it will work well from an accuracy perspective. But if you plan on using smokeless powder, you will be making an already too large case larger. The amount of powder needed to fill the case almost always results in loads hot enough to be very painful, and if you seat the boolit/bullet out in effect you have a 45-90 or 45/100, and even with black powder, these kick like he!!.

The leade needs to be cut with a small angle of taper, but I'm not sure about a long freebore, though it would solve the problem of starting a paper patched boolit nicely. The only other approach that I can see is to get some thick necked brass, and shoot it unsized - neck turned to fit your chamber so that the boolits seat "thumb tight" only. It might be possible to solder the outsides of the necks, and then turn the soldered outsides down to make these cases (I'd use 95% tin solder - no lead so that it's hard enough to not flow when fired). Then your boolit in effect has a freebore inside the case that holds the boolit coaxial and ready for launch.

[HWooldridge]

I own an older .45-70 Shiloh Sharps made by Wolf Derge with a long freebore. It is exceedingly accurate with conventional lubed bullets but has a tendency to sometimes strip the paper from a patched bullet. In my rifle, I can use fired brass without sizing and seat a .450 slug that wraps to .458 finished size. With BP and lube disk, the projectile only seats about 1/4" into the case. However, the rifling ends so abrubtly that it sometimes strips the jacket. It's worse with BP unless I wipe every shot and even then, I get random fliers and barrel leading - so I usually just shoot plain old lubed pills.

I had a conversation with the new owners several years ago about changing the barrel and if I recall correctly, Shiloh is no longer cutting freebore as a habit (they may offer it as an option - I'm not sure) but they recommended swapping the barrel and that the PP be sized small enough to push fit into the bore, i.e. they should chamber just like a jacketed bullet. That way, the patch is sitting in the rifling when the charge is touched off and the boolit obturates to seal. Maybe someone with a newer rifle can chime in on how Shiloh is currently throating rifles.

So what I'm saying is that I believe you can use a smaller boolit with paper and not have to worry about freebore.

[leftiye]

But only with black powder.

[303Guy]

I have demonstrated that an undersize boolit does obturate with smokeless powder. Not pure lead but a fairly soft alloy just the same. This was with a very light charge - light enough to not show pressure on the primer. A hard alloy on the other hand ..... ?

[leftiye]

Yup. But do you want to rely on it for full length obturation into the grooves? It generally doesn't obturate enough for good accuracy.

[303Guy]

That makes sense. But what of a bore-rider? Could the nose section obturate if the lead is too soft? What happens between case neck and bore? Black powder or smokeless would have the same issue if the boolit 'bumps up' while still in the neck?

[bearcove]

I'll be shooting smokeless only. Hot with heavy boolits, 500+ gr at 1700-1800fps. 20 inch Encore, peep sights, and machined in brake.

Also shoot a .451 325gr LBT WFN PP 1400 fps for a meat load.

This is going to be a ultralight packing gun for coastal Alaska.

What would be a good leade angle. The heavy boolits are gas checked not PP. The 325gr are PP. The freebore will probably be short .005-.015? Just enough to line the boolit up with the bore.

[docone31]

I have a .308, that I paper patch for. It has a match chamber with no leade. I set my patched boolitts to SAAMI specs for a conventional load and have not had an issue yet. I have not fire lapped the chamber or bore, and I suspect, firing paper patched loads has smoothed out any sharp transition angles in it.
It fired real well right out of the gate.

[bearcove]

Yeah, I think the PP boolits might be the simplest way to lap the barrel. When it cools off a little I'll probably load up a bunch and see if that smooths things out.

[docone31]

Oh, if you want to smooth the barrel, patch some slightly undersized, about .0005.
Lightly smear some valve lapping compound on the patch. Just enough to make it grey, nothing heavy here. Do about 20.
Fire them normally.
Observe progress with the grit loads.
I had hammer chatter the entire length of my Smelly. I fired 17 of these. Chatter gone, and 1" groups at 100yds, with bedding and proper sizeing. I couldn't get two at a time on the paper at 100yds before lapping.

[montana_charlie]

I'll be shooting smokeless only. Hot with heavy boolits, 500+ gr at 1700-1800fps. 20 inch Encore, peep sights, and machined in brake.

Also shoot a .451 325gr LBT WFN PP 1400 fps for a meat load.

This is going to be a ultralight packing gun for coastal Alaska.

What would be a good leade angle. The heavy boolits are gas checked not PP. The 325gr are PP. The freebore will probably be short .005-.015? Just enough to line the boolit up with the bore.
With the chamber as you describe it, that .451 bullet probably slips right out of the case and into the rifling with no opportunity to get 'modified'.
Why don't you just make up another load using a .451 bullet that is 500+ grains. The paper patch will make the gas check unnecessary at the higher velocity, and you don't have to modify the gun's chamber.

Besides, the freebore you describe is so short (5 to 15 thousandths) I don't see why you would bother to cut it.

You call the 325 bullet your 'meat load'. In that ultralight packer, what do you intend to call the hot one...your 'self abuse' load?

CM

[bearcove]

That one is for comfort, while fishing with the bears. Most are fine company. Occasionally some aren't.

[RMulhern]

I like cornbread, black-eyed peas, fried chicken, turnip greens, and cabbage and I'm fearful that them friggin bears would see me in the same light as I see the above. If I can't catch enough white perch and bass to satisfy my 'fish needs'.....I'll just do without and let them damn bears fish by themselves!!

[303Guy]

That was funny - and clever! I love it! :mrgreen: