Load increment for 45-70 with new powder (5744)

[huntinlever]

I'm not a tinkerer. I developed my previous load for my 45-70 GG, 425 WFNGC and IMR 4198 by going up 0.3 grain increments to tightest group and chrono data (they actually lined up), settling on 39.7 grains of the powder. Stiff, but really accurate load. I never changed it - it's all I went into the field with.

Now, using 5744, I'm wondering if I should take a 2-pass approach: aim is to try out c. 1335-1450 fps with a 405 WFNGC. One thought was to go up in 0.5 grain increments to 30 grains, which I estimate would bring me to about 1450 fps (no chrony yet). 3 round strings, try to find a node or so, then go in 0.2 increments up and down likely with 5 round strings, to find the accuracy load.

Or, as before, just doing 0.3 increments from 26.1 grains 5744 to 30.0 grains.

Any recommendations?

[Sgt H]

IMO .5 grain increments are fine for a large case like the 45-70, 30-06, ect.. For small cases like 223, .2-.3 grain increments. BTW your 39.7 4198 load should be close to 1700fps and 25-28k psi. Should be adequate for anything in the US, but thumps pretty good in the recoil department.

[huntinlever]

Great, thanks Sgt. You're on the money! - my 39.7 got me 1710 fps, ES of 22 and SD of 8. Loved the load but yep, these bones have asked for mercy. Looking forward to the smaller boolit and the lighter load. I think I'd love to keep the 425 grain load with the 4198 for western Elk hunting, if I can ever manage it.

[Nueces]

My black powder ballistics load with 5744 and a 405 grain lead bullet follows their advice exactly - 40% of the full BP load in 5744. This load of 28/5744 under a 405 slug chronos at 1170 fps, right where it should.

Search for online loading data from Accurate. I think you'll find it a short trip to your velocity destination. Here is a line from an Accurate manual, for 45-70 loads below 28k psi

5744 405 LC FP 30.6 1,468 34.0 1,600 27,800 2.550

I underlined the starting load, 30.6/5744 for 1468 fps. Looks to me like you could start and stop with 30 grains.

[Bigslug]

I wouldn't go bigger than 0.3 grain increments personally.

My approach is a single shot at each charge weight. I'd go 0.2gr, but if primers and powder are tight, 0.3 will most likely tell you what you want to know. What you're hoping for is that flat spot on the chronograph where you have maybe only a 20 fps spread over three to five consecutive shots, and then you pin your hopes on the middle of that. The advantage to the smaller charges is you might get a better idea where the tendency to spike up to the next plateau lies. Half a grain is a bit to coarse to really narrow that down unless you're dealing with the really big cases, but since you're only firing one shot at each charge instead of three, you narrow your search down quicker and get to your final test of the promising loads sooner. Usually, you burn less components in the long run.

[huntinlever]

I wouldn't go bigger than 0.3 grain increments personally.

My approach is a single shot at each charge weight. I'd go 0.2gr, but if primers and powder are tight, 0.3 will most likely tell you what you want to know. What you're hoping for is that flat spot on the chronograph where you have maybe only a 20 fps spread over three to five consecutive shots, and then you pin your hopes on the middle of that. The advantage to the smaller charges is you might get a better idea where the tendency to spike up to the next plateau lies. Half a grain is a bit to coarse to really narrow that down unless you're dealing with the really big cases, but since you're only firing one shot at each charge instead of three, you narrow your search down quicker and get to your final test of the promising loads sooner. Usually, you burn less components in the long run.

Thanks. I've never done it, but is this the Ladder Method? Unfortunately I don't have a chrony and won't for at least awhile as my budget is tapped, so I went ahead and loaded up at 0.5 increments from 26.0-30.0, with 3 cold fouling shots at 25.0. I'd hoped to just go on groupings and a rough approximation on velocity. A bit underwhelmed with today's outing, to be honest (another thread shows today's outing, and compares it to my previous IMR 4198 load). https://castboolits.gunloads.com/showthread.php?451498-New-Accurate-46-405VG-mold.

[StrawHat]

As mentioned by Nueces, the producer of 5477 suggested the powder be used at a charge of 40% of the black powder weight. So, in the 45-70, 50-70, 40 -72 and similar, the correct smokeless charge would be 28 grains.

It works well in my 405 WCF, Model 1895.

Kevin

[huntinlever]

As mentioned by Nueces, the producer of 5477 suggested the powder be used at a charge of 40% of the black powder weight. So, in the 45-70, 50-70, 40 -72 and simian, the correct smokeless charge would be 28 grains.

It works well in my 405 WCF, Model 1895.

Kevin

Thanks Kevin (and thanks Nueces - sorry, forgot to tell you). That's a fantastic note on the suggestion (40% of BP). I've dropped the 26.0-28.0 range and have the range trip ready with 5 each at 28-32.5 in 0.5 increments. I'll be shooting at 100 yards, since I know I'm reasonably on paper at 50. I am new to this powder obviously but am pretty excited to see its BP lineage.

Following from Blahut, when I can find some, I'd like to try using the powder with large rifle magnum primers. I understand the unburnt powder may not affect accuracy but it would be nice to get it just a touch cleaner.

From another thread, today was the first time since "coming back" I'd say my casting was up to par, and I'd also like to give the powder its due accordingly.

Thanks a bunch for the help guys.

[b67]

We have always loaded 25 grains SR4759 or 27 grains 5744 with a 405 grain bullet as the 45-70 universal black powder equivalent load. It works well in most everything...Buffalo rifle should be about the same as 5744 but I haven't worked any of that up yet...

[huntinlever]

We have always loaded 25 grains SR4759 or 27 grains 5744 with a 405 grain bullet as the 45-70 universal black powder equivalent load. It works well in most everything...Buffalo rifle should be about the same as 5744 but I haven't worked any of that up yet...

I didn't have much luck in the lower end of the trapdoor range, but I'll try again because my initial trip included cast bullets that were my first since coming back and they were not comparable to the ones I'm casting now, which are very, very consistent. I have loaded up 28-30 in .5 increments for a range trip tomorrow but it might be good to go back 27-28 as well. On the first trip 28.5 was an apparent sweet spot.