Home Forums Hunting & Shooting Ask The Gunwriters Powder for .243 & 100gr. Partitions

Imr4350 with 100gr partitions. Always shoots through whitetails for me.

I use H4350.

I did not read the whole thread so this may have been posted. Sierras accuracy load for the 100 gr bullets is H4831sc 43.2 grains for 2950. I know he was talking about partitions but the topic came up of shooting Sierras for practice.

That's what I used as well, when I was loading for a couple of .243's. (Never owned one myself.) Shot well and my brother and my friend were extremely happy and successful with the results.

Since someone decided to revive this chestnut of mine, here’s what I have loaded at present. Different rifle though.

Can't remember if I already commented on this old thread, but will again. Have tried a bunch of powders in a bunch of .243s with bullets around 100 grains since buying my first .243 in the 1970s (a Remington 700 BDL), and while several powders have worked, I started with IMR4350, and have yet to find one that didn't shoot well with it.

Lately have switched to H4350, which does just as well. An example: Eileen's lightweight Husqvarna came to us just before hunting season a few years ago. Actually I bought it off the Campfire classifieds, just because it was a great deal--but she picked it up one day, noticing it was a "new" rifle in the house, and liked the way it felt so much it became hers.)

Anyway, there wasn't much time before hunting season, so I tried 42.0 grains of H4350 and the 100-grain Partition. The first group was well under an inch, but I didn't chronograph it, after long experience guessing the muzzle velocity was around 2900. She killed a pronghorn at 243 lasered yards a couple weeks later--and a year or two afterward killed her biggest-bodied whitetail buck with the same load.

Later on I did chronograph it, and velocity was just about 2900.

I bought several pounds of IMR 4451 a while back while the getting was still good. The 4350's were already dried up around here. My 243 is doing quite well with 41.8 grains under a 95 grain Partition. This is in SIG brass and lit by a 210M.

Am not surprised!

Have gotten just about the same results from 4451 as IMR and H4350 in a bunch of rifles.

Me too, works in every 243 and 244 I've ever had so I've never gone further with load development with other powders.

I went to the range this afternoon. 4451 has the 90 grain Accubond cooking with gas too.

RL26 produces very good velocity and accuracy in three 243's and a 243 AI with 100g NPt's. I tried IMR7977 and results were mediocre, but have been tempted to try again.

Because I have a ton of H4831, I have stubbornly messed with 90 and 95g NBT's, and my pickiest 243 found a H4831 and 95g NBT load and is shooting the smallest groups it ever has. But H4831 pretty consistently runs 100-150 fps slower than what Hodgdon or Nosler claims with their load data. More powder just produces loose pockets and/or ejector marks........

My 243 shoots 95 bt cloverleaf @ 3150 FPS with 45 gr of surplus 4831. Nothing sexy but it kills chit dead. I don’t need any modern powder till the old stuff is gone. Bought it at 65 cents a pound. Got enough to outlast me. I’ll let you kids have the new stuff. HaHa MAGA

Back in my .243 days, I used a lot of H4831 and also Norma MRP, when I could find it, with 100 grain Hornady bullets.

With heavier bullets in the 243, I always used a 4350 variant, but use RL26 these days. Get a bit over 3000fps with 105gr stuff in a 21.5” barrel. 100’s should work there too.

My .243 is very happy with RL16 with 95 gr ballistic tips. Same accuracy as 4350's, but almost 100 fps more.

Like most on here I have shot a lot of 243 and 6mm rounds. Favorite powders were H4350, IMR4350, H4831, and H414. All have worked quite well with bullet weights from 75gr. up to 100gr. But now RL26 is the mac daddy when shooting 95gr. to 100gr. bullets. 4 rifles in 243 shooting Hornady Interlock 100gr. sp in front of 47.3 of RL26 attest to this. Velocity runs in the 3100 range with 22" barrels and accuracy is outstanding.

Still have a couple of pounds of I4350 I need to use up. IIRC, the data sheet from my .22 Hornet Lee Loader has a load or two listed 😛

RL-22 hits all the markers for a good load.

41.90 gns of RL 22 is good for 0.37 moa (5 shot) and 0.59 moa (10) shots at 500m/540 yards. Scope set at 10X for sporte/hunter class. Bullet 105gn Berger Hybrid.

Runs 3071 ft/s from a 26" bbl.

For many years, I shot a hot load of IMR 4350, then tried R#26 and added 150 fps where it was the most accurate, right at 3200 fps 24" Rem 700 sporter.

Don't over look the 100g Hornady flat base and btsp.