Charges of IMR-4198..

[big6x6]

I'm going to weigh out some charges of IMR-4198 to see how it does... What charge weight have you guys been using for:

250gr bullet?

300gr bullet?

Thanks!

 

[savagebrother]

hey chuck,
start out with around 65 grains with a 250 grain bullet.
around 60 grains with a 300 grainer. you should only need a bare sabot.
with the 250 grain bullets work your way up, you can achieve 2700 plus fps at 75 grains of imr-4198.
sb

 

[getonit]

Chuck- Ive been useing 68 gr. H4198 with 300 gr. .458 Remington HP's this year- really shoot well at 2450fps... I know some others are pushing 76 gr.- I havent needed that speed yet.... Rick

 

[savageml10-2]

are the rem .458 fragile? i want a good bone breaker that stays together LOL THATS CHEAP! :shock:

 

[Mountain Man]

Chuck- Ive been useing 68 gr. H4198 with 300 gr. .458 Remington HP's this year- really shoot well at 2450fps... I know some others are pushing 76 gr.- I havent needed that speed yet.... Rick

I do NOT believe that anyone is using 76 grains of H4198 (or IMR 4198, for that matter) with 300 grain bullets. That is strictly with 250 grain bullets. I don't think I would exceed about 68 grains with 300 grain bullets. I have not shot 300 grain bullets very much yet at all, so this is NOT my personal recommendation, just maximum's that I will keep in mind as I do.

As with any form of reloading, I would start low and work up. 64 or 65 grains with 250 grain bullets to start, and 60 grains with 300 grain bullets.

 

[Grouse]

with the 250 grain bullets work your way up, you can achieve 2700 plus fps at 75 grains of imr-4198.
sb

Will plastic become an issue? What sabot is holding up at those speeds?

 

[Rifleman]

Mountain man, don't count on it, probably some are. I am sure plastic buildup is an issue though. You might be surprised how fast you can get away with in this rifle if you keep a clean bore and keep the barrel cool. However a 300 gr at 2700 fps would likely be a bear in the recoil department.

 

[SW]

with the 250 grain bullets work your way up, you can achieve 2700 plus fps at 75 grains of imr-4198.
sb

Will plastic become an issue? What sabot is holding up at those speeds?

Tom,
The pressure on the base of the sabot with a slow powder load is generally fairly low. H-322 at a very high loading(well over 75gs) still produced over 2700'/sec with 250SST with decent accuracy yet pressure less than almost any book load. On my rather smooth bored ML-2s, plastic fouling wasn't a problem. MMP short will handle over 2700'/sec with slower powders. The HPH series should do even better. Harvesters and Knight sabots are well respected also.

 

[savagebrother]

grouse, mmp short sabots. my gun likes hph12's but its uyp to the individual to find out which is best in his gun. plastic can be an issue, it depends on how rough your barrel is-savage barrels are known for their accuracy, but also for the roughness. my ruger has an air gaged douglas in it and it is very smoothe and consistant and doesnt ruff up the sabots hardly at all. look at this pic of a .45-.40 harvester sabot that left the barrel at 2800 fps. just dry swabbed between shots.
sb

 

[savagebrother]

sw is absolutely correct, and i think mmp is working on some better compounds so we can go even faster.
sb

 

[Mountain Man]

Mountain man, don't count on it, probably some are. I am sure plastic buildup is an issue though. You might be surprised how fast you can get away with in this rifle if you keep a clean bore and keep the barrel cool. However a 300 gr at 2700 fps would likely be a bear in the recoil department.

Perhaps some are. However, not even on the "other board" have I seen anybody post about using charges of either 4198 over 70 grains (and maybe just 69 ) in conjunction with 300 grain bullets.

As far as speed, I think you're absolutely right that keeping a clean barrel is key. Less for that reason and more for consistency's sake, between each shot I swab with one solvent-dampened patch (both sides) and then three swabs with two dry patches. It only takes about 90 seconds and I'm usually waiting at least five minutes between shots, so it gives me something to do. I think with my excessively rough and tight barrel, this helps on my gun where it wouldn't with others.

 

[savagebrother]

yes i do agree with you, i dont think a 300 grain bullet at 2700 fps with the 4198's is good. i think if your wanting to go that fast aa-2015 or h-322 would be a much better powder, but you would need a large charge of these powders and recoil would start to play a big part in accuracy.
sb

 

[big6x6]

hey chuck,
start out with around 65 grains with a 250 grain bullet.
around 60 grains with a 300 grainer. you should only need a bare sabot.
with the 250 grain bullets work your way up, you can achieve 2700 plus fps at 75 grains of imr-4198.
sb

Thanks a BUNCH SB! That's EXACTLY the loads I'm going to try!

 

[Grouse]

Hey big6x6, The first bullet i try with that powder will be these.

 

[getonit]

are the rem .458 fragile? i want a good bone breaker that stays together LOL THATS CHEAP! :shock:

seem to be tough enough- the 2 deer this year both pass through- I small buck took both shoulder blades and exited- I did find 1 small piece of lead butchering-less than 5 gr.- thats all... they're plenty cheap at Midway too....Rick

 

[Rifleman]

I loaded some .458 300 gr Rems in a 45-70 for pal who shot a pretty good black bear with it at aprox. 20yds. He got complete pass thru,broke 1 shoulder and bear didn't make it more then a couple steps. He liked it.