Load data - 75 grain Barnes X 243 Winchester

[Calvin45]

Hi all.

WARNING - this is not pressure tested data. Additionally, DO NOT BE STUPID LIKE ME and move up in 1 grain increments in such a small case capacity. I had a brain fart and treated this 243 like the belted magnums I've been loading lately…bone head move.

But I just thought I'd share some very basic load chronograph findings in case anyone on the inter webs happens to have old school 75 grain Barnes x bullets (no relief grooves) in 6mm they wanna load.

Savage 99, 22 inch barrel. About -10 Celcius at time of testing. Winchester cases, fed large rifle primers.

Also note, MY bullets are HBN treated as is the bore - for naked bullets expect to hit pressure at on average a grain or two lower charges in cases of this size - that's not set in stone, proceed with caution, practice due diligence. You are responsible for yourself.

Anyways…

IMR 4064

35 grains - 2794 fps
36 - 2882
37 - 2914
38 - 3071
39 - 3150
40 - 3268
41 - 3319
42 - 3397

That's as high as I went with 4064. No pressure signs yet. Nice linear behaviour. Love that good old powder

———-
CFE 223

39 grains - 2836 fps
40 - 3091

That's as high as I went, no where close yet, lower charges the chrono was erroring, started at 35

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SUPERFORMANCE

47.2 - 3063
48.8 - 3287
49.5 - 3328
50.2 - 3366
52.0 - 3510
53.0 - 3537

- there were some other loads in between that the chronie didn't catch, only showing charge weights with velocities.

- 52 and 53 were VERY compressed and only gained 17 fps - probably hitting the pressure node just based on that and the velocity but no signs of pressure and that's as much as can fit in the case.

————

LEVEREVOLUTION


36 - 2887
Errors to 39
40 - 3090
41 - 3154
42 - 3273
43 - 3368
44 - 3369
45 - 3532

That's as high as I went - zero pressure signs BUT the fact that there was no difference between 43 and 44 is potentially suspicious…

———-

Enduron 4955 - I got impatient and stupid here …

45 - 3140

49 - 3452
50 - 3469

51 - 3631 - WAY TOO HOT - stiff action and primer blown - yikes.

No conventional pressure signs on the brass at 49 or 50 - I understand how this can happen but also have only ever had it happen with this particular powder.

———

This is more just for anyone searching for any rudimentary ballpark numbers, not well developed load data, no accuracy figures or anything, and each velocity reading is FROM A SINGLE CHRONOGRAPH READING , not an averaging. Just wanted to get some very basic numbers from a bunch of different powders to inform further development. This doesn't tell you a lot but it does tell me enough for now

 

[Mr. Magoo]

Thanks for the info. I'm just getting back into loading the 243 for the rockchuck season. Don't have any barnes bullets but it's good comparative info.

I'll be testing the same powders as well, to find an economical high volume/ high speed 'chuck load, and a heavy longer range load.

I've always liked Imr 4064. Its one i always try to have on the shelf. Just a decent performer in a number of cartridges I load for, and has been the most accurate powder for a couple.

 

[Calvin45]

Thanks for the info. I'm just getting back into loading the 243 for the rockchuck season. Don't have any barnes bullets but it's good comparative info.

I'll be testing the same powders as well, to find an economical high volume/ high speed 'chuck load, and a heavy longer range load.

I've always liked Imr 4064. Its one i always try to have on the shelf. Just a decent performer in a number of cartridges I load for, and has been the most accurate powder for a couple.

Indeed. The only powder an old 220 swift I used to have would tolerate haha.

And while it doesn't even approach good case fill or top end velocity, for whatever reason it's stupid accurate with 130 flat bases in a 270 for around 2900 fps or with notably light recoil and muzzle blast. Great for the youngster moving up from a 243 but not ready for full power 270 blast and recoil just yet.

 

[Mr. Magoo]

My early 90s rem 700 in 22-250 really liked the 4064. Found a kinda mild load that would shoot consistent 1/4" 5 shot groups, and didn't heat the barrel as much as other powders. It was a prairie dog town's worst nightmare.

 

[Calvin45]

My early 90s rem 700 in 22-250 really liked the 4064. Found a kinda mild load that would shoot consistent 1/4" 5 shot groups, and didn't heat the barrel as much as other powders. It was a prairie dog town's worst nightmare.

That's a key thing with 4064 I've found…it's not for chasing the absolute highest velocity and energy possible…just real easy to work with mild to middle of the road performance with crazy good consistency and accuracy. Most of the people I've heard that don't like it don't like it cuz they only care about going as fast as possible (which I do understand and respect - that's what ALLIANT is for haha) - 4064 isn't the powder for that.

 

[Muddyboots]

IMR4064 and 87 V-Max are perfect match. Not a barn burner but makes up in accuracy.