Cast gas check for 45-70

meatgrinder

meatgrinder

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Jus started loading my 45-70, anyone know of a good manual for this sort of thing? Looking for a decent bear load for my handi rifle. Black bear that is. I have some 390 gn gas checks from bullet barn. Any advice would be greatly appreciated. Thanks
 
The ultimate source for cast bullet data is the Lyman Cast Bullet Handbook. Most recent one is the 4th edition. It has three sections (7 pages total) of 45-70 load data; one for trap door/black powder equivalent, one at higher pressure for modern lever rifles, and a third for single shot rifles and bolt actions.

Also a lot of great information about the peculiarities of reloading cast bullets that aren't encountered with jacketed bullets.

The book goes from shotgun powders for gallery loads to several for single shots that go up to 300WM energy levels (4000 ft lbs). I used to load for a handi rifle and used mostly level 2/lever action loads. The Handi Rifle can handle the level 3 loads (usually recommended only for a Ruger #1 or modern dropping block rifle like a modern Win 1885) but a couple I tried popped my action open after each shot.

I just checked and there is no data for 390gr bullets but it's close enough you could use data for 385gr, 400gr, or 405gr from the starting loads. The bullet/rifle can't tell a difference in weight of 2-3%.

The book is usually in stock at the Stittsville range store or you can order it off Amazon or various other retailers.
 
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Consult as many different printed manuals as you can find. There can be a rather wide range of min/max loads between different Co.'s manuals for the same caliber/cartridge. Check any loads you find online against those manuals. Best of luck!
 
Thanks guys, good advice. I have the 49th addition Lyman but the cast info is super limited so I will try to find the cast bullet Manuel. There is not much out there that explains how much more pressure gas checks will add. I'm looking for about 1700 fps with h4198 under a 390 gn pill.
 
Cast bullets are generally explained as having a velocity limit rather than a pressure limit. The gas check does increase the pressure it can handle but I most often see it expressed as a higher maximum velocity rather than pressure. I suppose it's just easier to think about and understand since not everyone knows what pressure equates to what velocity with what bullet in what cartridge. Also the velocity limit is often there because the bullet will eventually strip or "trip" the rifling if you push it too fast. Some dispute this is possible online and regardless of if it does or doesn't happen, something happens when a lead bullet goes too fast and they tumble and leave lots of lead flakes/chunks in the barrel.

A plain base bullet will usually be accurate to around 1500-1700fps with a hard alloy and a gas check bullet can be pushed to 2200+ fps. Some guys using super hard alloys and special lubes meant for higher velocity have pushed cast bullets to 3000fps but I've never dabbled in those things. I generally shoot GC'ed cast at 1700-2000fps to keep things simple.

1700fps in a 45-70 with a 390gr bullet would be easy with a gas checked bullet and either of the 4198's are quite popular for 45-70 in general, including cast bullets.

I've swapped IMR4198 and H4198, at starting loads only, without any issues; work up from there. The Lyman book lists loads of 40.5gr to 45.0gr of IMR4198 and a 385gr bullet to have a velocity of 1712fps to 1924fps. That's a level 3 load for a single shot or bolt action, NOT a load for a lever rifle or trap door.
 
Wow thanks, my handi will take this you say? A lot has been sai about this and most opinions are that the stage2 is for handi's but I guess if the sb2 receiver handles higher pressures in other loads that makes sense. Thanks again
 
meatgrinder said he already has the bullets and if they're meant for a 45-70 they'll be too big for paper patching.

Paper patching is a whole other thing and needs other special considerations and techniques. To paper patch for a .458" bore you'd want to start with .450" to .452" bullets (like those for a .45 LC/ACP) and use paper patching to bring them up to .459"-.460". I've dabbled in it a little but found it was really unnecessary for my personal needs.
Paper patching is usually to be able to use really soft lead that will expand when it hits the target and still bring it up to higher velocities than naked soft lead will allow without leaving lead in your bore.
Pure lead still has a velocity limit of around 2200-2500fps because it'll deform from air resistance while travelling to the target.
You can paper patch anything, not just older rifles with shallow rifling. I was paper patching cast .314" up to .325" for an 8mm rifle and it worked but was much easier to just cast 8mm bullets from a harder alloy.

Here's a neat video on paper patched bullets from Midway USA:

You'll have no issue bringing a GC'ed hard cast bullet to 1700fps.

The level 2 loads for a 400gr bullet with the same powder is:
35.5 to 39.5 for a velocity of 1535 to 1699
 
OP, (meatgrinder) you have gotten a lot of good information, from LUTNIT, and some other information that runs from so-so, to don't bother trying this.
A 45-70 is a very easy calibre to use cast bullets for and a tremendous choice of loads, all satisfactory for their purpose.
The faster powders like 2400, or even Unique, will get you very accurate, lower velocity performance.
Any of the medium burning rifle powders will get you heavy, accurate loads.
You mentioned driving your 390 grain bullet about 1700 fps, using H4198.
The answer is right in the first edition of the famous Lyman cast book.
4198 powder and a 395 grain bullet. 26 grains will get you 1350 fps, while 34 grains will get you 1785 fps.
It was all IMR 4198 when this book was written, but there is very little difference between IMR and H varieties of 4198. You could likely not detect any difference between the two, but to be super safe, just use the lower figure, 26 grains, to try it, then see how high you want to go.
The 45-70 was the only calibre I ever reloaded for where the upper loads were judged not by how much pressure the rifle could take, but the upper loads were judged by how much recoil I wanted to put up with!
 
Just remember your using a handi rifle, and recoil can be a bit of a pain!
I like a 330 HP GC that's paper patched seated ontop of 16 grain's of Trailboss. My brother was shooting thru an 18 inch poplar tree with that load.
 
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