H4895 vs IMR4895 subsonic 45/70

[Sigfla]

I have researched and want to load some subsonic 45/70’s with 410 SubX’s. No IMR to be found anywhere. Internet says they are roughly interchangeable but H4895 gives a bit more velocity so was suggested to drop a grain or 2. All the discussion however was for supersonic loads. Does anyone have any guidance or suggestions? I have been playing with my Lee classic kit and want to load a few rounds.

 

[old_heli_logger]

This from Hodgdon...I'm not sure if this will get you subsonic. Good luck

HODGDON® H4895® REDUCED RIFLE LOADS
For Youth Hunting, Informal Target, and Plinking
________________________________________
Hodgdon Powder Company has found that H4895 can be loaded to reduced levels. H4895 was chosen because it is the slowest burning propellant that ignites uniformly in reduced charges. To create reduced loads, the 60% formula is recommended.
Find the H4895 load in the Reloading Data Center for your caliber and bullet.
Take the maximum H4895 charge listed and multiply by 60% (.6). The load may
be adjusted up from there to achieve the desired velocity and accuracy.
This works only where H4895 is listed. DO NOT use in a cartridge where H4895
is not shown.
Example: 30-06 cartridge with 125 gr. Sierra SP bullet. Max load shown in the Reloading
Data Center with H4895 is 53.7 grains. 53.7 X .6 = 32.2 grains. The shooter begins with this load, and may work up from there to obtain the desired velocity and accuracy for his reduced load.

Call Hodgdon Powder Company if additional information is needed, 913-362-9455.

 

[Sigfla]

I saw that from Hodgdon. I am thinking about dropping 1-1.5 grains from the IMR 4895 data and shooting over a chronograph to see. A guy on another forum started at 29 grains with a 300 ish grain bullet and was getting very slow 850-900 fps velocity. I keep reading the H4895 is hotter but some sources say the IMR 4895 is hotter. The one thing I see agreed upon is they are close but different. I figure dropping a grain and shooting over a chronograph will tell me where I need to go.

 

[mgunderson]

Not sure what twist rate you need to keep them somewhat stable in a 4570, but watch for that. A fluffy pile of trailboss might work as well.

Please update the post as you go.

 

[Sigfla]

I have a fast twist mgm barrel I had made for my TC Encore. It thumps hard and is super quiet. In the days before controlled expansion bullets real sub hunting kill power came from big slow bullets imho. Old Buffalo hunters would be proud!!

 

[Sigfla]

Not sure what twist rate you need to keep them somewhat stable in a 4570, but watch for that. A fluffy pile of trailboss might work as well.

Please update the post as you go.

I honestly expected to use trailboss but when I searched online it seems to be discontinued. Hogden posted a few sub loads and the IMR4895 seemed to be the best of the lot based on my searches. I bought all this gear years ago to start loading with certain components in mind and now that I am actually doing it they are all gone, lol. In any case I have a bit of H4895 on the way and will prob start at 32.5 gr and work up using the chronograph. Ideally I want a hunting load with the Subx and a target load to shoot for fun (and introduce people to one of the best sub loads around imho). People always go nuts loading that huge cartridge then popping one off with the suppressor.

 

[7br]

New canisters of Trailboss are on the shelf of my LGS. New higher prices too!! I can get 1100 fps with 350gr cast, 900-1000 fps with 405gr cast. Browning 1885 and Marlin 1895.

 

[M-61]

To slow and bullet will stick in barrel
I assume you mean “TOO” slow……
Bullet stuck in barrel is why I ask

 

[quest450]

FWIW I loaded reduced loads for Henry lever action
IMR 4198, CCI BR2, SNS 405 RNFP

33.00 grains 1350 fps
34.00 grains 1383 fps

 

[Sigfla]

So I ordered some Titegroup. Hogden has a load listed in their subsonic section for modern rifles using Titegroup and the 410gr SubX