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mikeg1005
04-18-2020, 12:13 AM
Hello everyone,

Back when I got into rifle reloading (casted for pistols) my old man purchased a Uberti 1876 in 45-75WCF (WCF not UCF chamber confirmed). We made some 457122 330gr bullets and H4895. The gun would not short less than a 10" group at 100yds. I feel the bullet was incorrectly sized and hardness was off that had a huge contributing factor to this. Almost a decade later with everyone in quarantine and running out of things to do I am going to develop and accurate load from this rifle. After searching the internet for the last week I've order 350gr Laser Cast RNFP as they seem to be a go to for successful 45-75WCF shooters and I was able to get a 1lb on IMR3031, IMR4198, IMR4320 and 5744. I also have on hand 2400, Varget, H4831 (and SC version) and H4895.

This caliber seems to have a lot of experimental testing with it from various shooters but I've came to realize that after comparing loads people have posted that in most cases the load range for 45-75WCF that is producing good accuracy is that of 45-70 trapdoor load data.

Comparing the size of the two cases they're almost identical. Bottled neck will increase pressure but these modern day 45-75WCF are said to be rated to 28k PSI so it would make sense that load data is similar.

49th edition Lymans book has load data for 45-75WCF but for many of the loads they're 20% lower than 45-70 and 20% than where people are find good accuracy.

So I guess my questions are as follows... for the guys load 45-75WCF, are you finding the results of your accurate loads being similar to 45-70 trapdoor pressure loads? And... here is what I've found so far in research as being promising load data worth testing.

All 350gr bullets...
22-24gr 2400 w/ a filler of some kind.
24-26gr AA5744
49-51gr IMR4320
56-58gr H4831
30-32gr IMR4198
42-45gr IMR3031
Because I have a lot of it...40gr of Varget

Any input on from those of you shooting smokeless in 45-75WCF?

Thanks,
Mike.

Tatume
04-18-2020, 09:43 AM
The reason the data are similar to 45-70 is because the 45-75 was designed to duplicate 45-70 ballistics in a shorter cartridge that would work through the Winchester 1876 action.

veeman
04-18-2020, 10:11 AM
What MY Uberti Chamber 45/75 does. Try at your own risk, but these are pretty much starter loads.
24.0 Buffalo Rifle, (pic got cut off)
https://uniim1.shutterfly.com/ng/services/mediarender/THISLIFE/010046471428/media/54670918526/medium/1564957695/enhance
https://uniim1.shutterfly.com/ng/services/mediarender/THISLIFE/010046471428/media/54670918564/medium/1564957697/enhance
https://uniim1.shutterfly.com/ng/services/mediarender/THISLIFE/010046471428/media/54670918745/medium/1564957706/enhance
https://uniim1.shutterfly.com/ng/services/mediarender/THISLIFE/010046471428/media/54670918680/small/1564957703/enhance
https://uniim1.shutterfly.com/ng/services/mediarender/THISLIFE/010046471428/media/54693555092/medium/1566142862/enhance
https://uniim1.shutterfly.com/ng/services/mediarender/THISLIFE/010046471428/media/54693555851/medium/1566142877/enhance
This last one I used about 1/3 packing peanut for filler. I don't use those anymore, but I do use laundry lint, from a load of towels. No trace of it after the shot.

veeman
04-18-2020, 04:49 PM
Did a test with Varget too, was more of a pattern than group, so no more Varget.

mikeg1005
04-18-2020, 10:55 PM
Veeman,

Thank you for the info. I noticed on the H4831sc and IMR-4198 you're load way on the low end. Did accruacy improve loading them hotter or was this your best? I'm assuming velocity are in the 1200fps range?

veeman
04-19-2020, 12:04 AM
Like I said, these are starter loads, and I haven't done anything with them yet. Too many guns to play with, not enough to time. I don't have a chroney.

mikeg1005
04-22-2020, 12:53 AM
Went to the range today and tested out my first batch of loads.

Uberti 1876 Centennial 47-75WCF (actual not UCF)
Oregon Trail Laser Cast 350gr RNFP .459" sizing.
50* temp.
Shooting at 75yds

AA5744 (High/Low/Avg/SD)
24.0gr 1218/1197/1207/6.6
25.0gr 1260/1222/1241/14.2
26.0gr 1287/1272/1278/6.3 (most accurate other than 2 fliers shot a clover leaf)

IMR-4198
26.0gr 1179/1094/1135/22.9 (had a delayed ignition on one rough)
28.0gr 1279/1163/1219/33.8 (the 1163 was an oddball low velocity by 60+ FPS)
30.0gr 1303/1253/1270/18.0 (most accurate tested, ~2" group at 75yds)

IMR-3031
42.0gr 1463/1358/1406/47.5 (this one was accurate ~3" group)
44.0gr 1540/1400/1507/28.5 (accuracy sucked)
46.0gr ... didn't bother shooting and pulled the bullets, reaching velocity/recoil I wasn't interested in

IMR-4320 (accucy was bad)
48.0gr 1539/1438/1500/34.9 (1438fps was very low rest were 50fps higher)
50.0gr 1639/1567/1600/36.0

Didn't get to try out 2400 or IMR-4227 as I need to get filler.

Recap from today... seems like this the 1300-1400fps range is the sweet spot with his bullet.

IMR-4320 left A LOT of unburnt powder, to the point the proceeding rounds had dimples as there was unburnt powder on the neck in the chamber. This powders going in the surplus stock to get burnt up in 223... plus its discontinued.

IMR-3031 looks like it has potential but no at above 1400fps.

5744 Looks VERY promising.. IMR-4198, and IMR-3031 have accuracy potential in that 1300-1400fps range. I'm going to do the following for next range visit.

AA5744 26.0gr, 26.3gr, and 26.6gr
IMR-4198 30.5gr 31.0gr 31.5gr
IMR-3031 40.5gr, 41.0gr, 42.5gr (accuracy was best on my lowest load, going to slow it down more to see what happens)