Imr4451 vs h4350 6.5cm

fifdynutz

Pasture Poodle
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Minuteman
May 5, 2020
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Iowa
What differences are you guys seeing in load data for imr 4451 enduron vs your h4350 loads? Apparently the powders act the same except have different powder weight data.

I'm looking to essentially copy my h4350 140g eld-m load with the 4451 and some 140g hpbt match bullets. This powder and those bullets are the closest thing I have to work with right now.

Thanks in advance
 
Shooting Hornady 140 ELDMs, my H4350 load was Hornady case, CCI BR2, 42.5 grains of H4350 giving excellent accuracy and about 2820 fps in a 24" Rock Creek barrel.

My IMR 4451 load was the same bullet, case, and primer, 41.8 grains of IMR 4451 giving about 2700 fps and excellent accuracy.

So for me IMR 4451 worked well but H4350 gave a bit higher velocity without pushing the upper limits of pressure.
 
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any guesses to the grain range you would see to match h4350 velocity with 4451? as in, 41.5g h4350 would likely match 42.5g 4451? so anywhere from .2-1.0?
 
In my rifles when my load development went up to 42.5 gr. of 4451, my primers were still ok but they were getting pretty flat and my accuracy at 42.5 of 4451 was not as good, so I backed off to 41.8 grains. The curve of powder charge vs. velocity also was flatter at 41.8 grains indicating more forgiveness for powder weight variations.
 
may start my loads with 41.4, 41.6, 41.8, 42, 42.2, 42.4....looking to match my dope on my RPR with 4350 as close as possible so i can switch back and forth if needed. going to try and match groups at 100, 200, 300 for now
 
Thanks for the reference folks. Just bought 8 lbs of 4451 having never used it simply because Hodgdon had it in stock and it “should” work. I didn’t have great luck with 4955, so I’m still leery...good to see success out there.
 
I run a 6x47L. I know it isn’t the same case but to be prepared bought a pound about 3 years ago and worked up a load for 105 Berger Hybrid. My f-class match load for h4350 was 39.0 in lapua brass with cci 450’s at 3044 fps. When the dust settled on 4451 my load was 39.1 at 3056. I might note this load had a wider node than my h4350 node.

HTH

David