I like the bulk of IMR SR4759 for filling up the case a bit better than other medium speed powders such as 5744 (which I use a lot). I figured I’d develop a good, accurate load for SR4759 that had a similar velocity to the original Winchester cartridges in the 1890’s (1,286 fps fifty feet from the muzzle, or 1,320 fps near the muzzle).
Rifle: Winchester 1886
Caliber: 45-70
Barrel: Octagon
Trigger: plain
Date in: July 1, 1890
Shipped: August 4, 1890
Sights: An original Lyman tang sight, here’s a photo ….
First Trial Load:
26 grains of IMR SR4759 and a Wincheter Magnum Rifle Primer under a 405 grain plain base cast bullet. I tried two, five-shot groups at 100 yards. Here are the results ….
The slightly lower velocity looked a wee bit looser and, overall, the two groups were not as tight as I was getting with 5744 at a slightly higher velocity, so I decided to boost the load by a half grain and see what happened.
Second Trial Load:
26.5 grains of SR4759 with a Winchester Magnum Rifle primer under a 405 grain plain base cast bullet for 1,378 fps and an extreme spread in velocity of 37 fps. (9 shots). The first and last shots were called flyers, both slightly high and to the left of where I should have been aiming. Unfortunately, I do not know which holes those represent. I’d like to believe they are the two at the top left corner of the group, but I do not know. Still, the group demonstrates what I would call a good, accurate load. It is slightly faster than the original 1,320 fps, but still below 19,000 CUP. Here is the target ….
http://img.photobucket.com/albums/v497/3855Win/Range%20Results/45-70_zps2cbb713a.jpg”>
IMR 4198 is the way to go, for me! I have used it in all of my ‘nitro for black’ loads for my 19th century rifles. There is a rule of thumb floating around that states…..40% of the original BP charge is a perfect starting point for the IMR 4198. Thus, 28 grains of the 4198 under a 405 grain bullet would be a good place to begin your trials. It gives great results in my Trapdoor Springfield. Good luck!
GMC(SW) - USN Retired 1978 - 2001
My main reservation about IMR 4198 with this plain base bullet is that it has a slower burn rate and lower peak pressure than 5744 or IMR SR4759, for the same velocity. Black powder has an even higher peak pressure spike than all of them which enables it to ‘bump up’ the plain base bullets. IMR SR4759 and 5744 have a bit lower peak pressure and IMR 4198 even lower still. Thus, I have found IMR 4198 to work well with gas checked bullets where, if properly sized, no bumping up is necessary, but a little more iffy on the plain base bullets. I prefer to avoid gas checked bullets simply to keep my shooting costs down. To compensate in the past, I’ve bumped up the IMR 4198 loads to give me just under 1,500 fps but I don’t want to do that with this rifle. Nevertheless, I’ve not tried IMR 4198 with this rifle. Since I’m going to the range again tomorrow, I’ll load up 10 rounds and see what it does. My bullets are properly sized and, in theory, they should not need any bumping up, yet I’ve already observed that slightly lower pressure loads of 5744 give looser groups. We shall see. If all goes well, I can report back tomorrow with the IMR 4198 results.
I was just looking through my files of last years shooting and see that I did try IMR 4198.
28 grains gave me 1,252 fps and a five-shot group of 5 & 1/2".
30 grains gave me around 1,400 fps and a five-shot group of 3 & 1/16"
Looks like it really tightened up by going to 30 grains. I imagine 32 should probably be a good load, but much too fast for me. I only have one original 1886 and I want to keep it closer to the mid-1,300’s for the 405 bullet. For lower speeds like that, I need a high enough pressure spike to bump up the bullet, so I’ll be needing to stick with slightly faster powders like 5744 and IMR SR4759.
Kirk
What’s wrong with 9 shots into 2 3/8" with a 113 year old hunting rifle?
Are you going to shoot prairie dogs? I’m not saying a guy can’t improve but in my opinion that’s pretty awesome shooting. Nice!
Looking forward to seeing an even better target tomorrow….
Brad
I learned, early in the game, about IMR 4198 and bullet diameters. I always selected bullets that did not have hollow bases, and filled the bore plus 1 or 2 thousandths. It worked well, especially in oddballs like my Beaumont and Vetterli. Cheers!
GMC(SW) - USN Retired 1978 - 2001
Win 38-55
Was curious to know why you choose the 405 grain bullet?
My understanding is that factory 45-70 Model 1886 cartridges used 350 or 330 grain flat pointed bullets. All of the 45 Gov’t rounds using 405 grains where round nosed bullets at the turn of the last century and only recently have become flat pointed as standard.
If you are trying to duplicate velocity of original Winchester cartridges of the 1890s, shouldn’t you use the 350 or 330 grain bullets those cartridges used?
Sincerely,
Maverick
WACA #8783 - Checkout my Reloading Tool Survey!
https://winchestercollector.org/forum/winchester-research-surveys/winchester-reloading-tool-survey/
The Model 1886 rifles in 45-70 were made for the heavier 405-grain bullet (the rifling twist rate). Those that were specifically made for the "W.H.V." load (with a nickel steel barrel) were made for the lighter weight bullets.
Bert
WACA Historian & Board of Director Member #6571L
Maverick, in addition to what Bert said, I have a reproduction of the Winchester 1896 catalogue. It lists the 330 HP, 350 FP, 405 and 500 grain cartridges and specifically states that all four are for the 1886 (along with other rifles too). I like to use the 405 because it was, perhaps, the most common at the time. I have used the 330 and I have tried five rounds with the 500 grain bullet (extremely accurate). My original ’86 will chamber and load the full-length, original 500 grain cartridges, which have the same O.A.L. as the 45-90. I prefer my 405 grain bullets of the flat nose variety, even if it breaks with tradition. The flat nose is a better game-stopper than the round nose, all other things being equal.
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