45 - 70 Frustration

[Qc Pistolero]

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Leading toward the end of the bore is a classic sign of a lube failure, not an alloy problem so if you're getting lead only in the last quarter of the bore or so, you need to improve the lubrication. Powder coating is the current fad but I'm old school and will use 1 or 2 light coats of Lee Liquid Alox.

The improved lube will then also let you use a slightly softer alloy, while an alloy that is too hard, still won't obturate properly and will still experience gas cutting.

Consequently, if in doubt improve the lube, and go softer, not harder.

I tend to use 2 light coats of LLA.
While I also am of the old school as far as powder coating is concerned,I am willing to give it a try this winter but only for higher pressure loads(.308 and 30-06).With my oldies(45-70,38-55 and 30-30),I'll stick with what I've got now.

 

[glowe]

. . . Finally, black powder gives excellent accuracy with .45-70 loads as the pressure 'curve' is in fact a fast, linear rise in pressure, which helps the bullet obturate in the bore (and also helps quickly seal the case to the chamber, keeping gas out of the action . . .

It has been demonstrated and documented that the pressure curve of BP in large caliber rifles and shotguns can be duplicated with smokeless, so one can depend on the same pressures and pressure rise gradient using the proper smokeless powders. It can be said that pressure rise is linear, but that only applies in the first 2 inches of the barrel. Beyond that distance, pressure starts to drop off rapidly, so the bullet has to expand to seal the grooves in the first few inches of the barrel. I like gas check bullets since they aid in the process, plus reduce leading. I also use liquid Alox to coat the bullets.

Sherman Bell has extensively tested shotgun loads and compared black powder to many currently available powders. The best charts he generated made identical pressure curves using the powders noted on the first image. An early 1900s DuPont powder brochure compared early smokeless powders, DuPont Oval, Ballistite, to black powder loads. Their findings were similar to Bell's work. Knowing that lead shot loadings tested were in the range of 500 grains to 550 grains, that is on the upper end of the weights offered in 45-70

Can black powder be more accurate in some rifles, absolutely, but that has a lot to do with the amount of experimentation one is willing to go through. In general, I believe that smokeless loads are available that give the exact same pressure curve and are just as or more accurate, plus are a breeze to clean up after a day at the range. My most accurate loading so far in my 45-90 is smokeless, but am still experimenting. On the other-hand, I have tried dozens of loads in my 45-70 finding the most accurate load turned out tp be 3031 powder and Puflon filler under a 350g RNFP gas check bullet. I think the key is to try everything, don't just assume one option is better for your rifles than another.

 

[Carrier]

Glowe any idea where one could find pressure curve comparing H4198 to FF black powder?

 

[glowe]

There seems to be little interest in the gunpowder manufacturing community to do the testing necessary to duplicate BP loads with smokeless powder. Only random research has been done and is available. I have not seen any pressure curves using H4198.

I assume it would be possible to mimic many BP loads with several smokeless powders if proper testing was done, but no one has stepped up. To duplicate BP pressure curves you first need to have the equipment to measure the curve. Shoot and graph a known BP load to obtain a pressure curve and experiment with specific smokeless powder loads until the curves match would be the goal.

 

[cowboy4evr]

When I started reloading my 94 Winchester in 38-55 , made in 1897 I called Accurate Powder Co for reloading data and advice . He asked if I had IMR 4198 ? I said I did but I also had his powder , Accurate 5744 , he said " perfect " . That powder came the closest to matching black powder pressure and velocity . I cast and size my bullets .379 . I tried .380 but they wouldn't chamber . I cast my bullets very soft , pure lead w/1% tin . Accuracy is great , no barrel leading . The reason for my post is to encourage you to cast your bullets soft and size you bullets the size that will just barely fit in the chamber and try Accurate 5744 powder . Good Luck , Paul

 

[Qc Pistolero]

As an update,I casted 500 of those Lee 350gr RFN for a friend;not very hard,around 10bhn.Unsized,liquid lubed(2 light coats) the pills read .458''.
My friend shot them on top of 29gr IMR 4198 at 100yds.Regular open sights in his Winchester Model 86(modern manufacture made in Japan)and went a little below 1''.
I'm gonna try his recipe in my Sharps!If I can't beat that,I think that next time he orders me some bullets,I'll sell him my damaged bases culled out!

 

[bbqncigars]

My 32" Cimarron really loves a 535gr Postell cast in new Lyman #2 alloy sized .458, lubed with Ben's Red and over 37gr of Varget. Powder coating in place of the Red opened up the groups a bunch. On the bright side, I can size/lube a LOT more boolits on the Star than using powder coating.

 

[Engineer1911]

I give a big Thank you to all the members who posted here. I've copied, pasted, and printed your posts into a single Word document that is going in my Reloading binder. This is great information that has helped me.

 

[Road_Clam]

Most of the target single shot rifles such as Rolling Blocks , and 1874's are chambered with a very long freebore to accomidate 500+ gr target bullets and a healthy dose of Bkack Powder. My Pedersoli 1874 Sharps shoots 545 Creedmoors and Postels excellent. The 405 FP's do not shoot consistient in my Sharps.

 

[Qc Pistolero]

Well,I've tried and shot a few hundreds of those Lee 350gr unsized(.458'')cast at aprox BHN10 with 29gr IMR 4198.My worst groups(5 shots)at 100 are around 3'',my best a little over 1'' with my average between 2'' and 2 1/2''.
I think my next step is to beagle the mould to try to get my bullets at .459.
But groups under 2'' start to show up more regularly...and I like that!