.243 Ackley Improved and Reloder 16

[tim1457]

Hey guys, seeking wisdom out there. I'll tell my story then post my question. I bought a rifle awhile back that came from an estate sale with no information on caliber other than it was a .243 Winchester. It's a Remington 700 action with a 29" heavy stainless barrel 1:13 twist with muzzle brake. No marking whatsoever on the barrel. I chambered some .243 Winchester brass and it chambered and ejected smoothly. I loaded up 4 test loads with Reloder 16 and Nosler 70gr. ballistic tip bullets (getting load data from Alliant website stating a max charge of 46gr) at 44.1gr, 44.6gr, 45.1gr and 45.6gr. Rifle shot well and best groups were at 44.6gr (.248 group size) and 45.1gr (.121 group size) shooting 3-shot groups. I was busy checking hits and writing down velocity and taking notes I didn't even pay attention to the brass until I shot the 4 groups. I looked at the newly fireformed brass and after doing some research and talking with Kenny Jarret at Jarret Rifles to confirm, did I realize it was a .243 Ackley Improved and not a .243 Winchester. He gave me some pointers to fireform the rest of my brass, but I need some advice on the reloading as there is hardly any info out there. None of my books have any info. Kenny did say I could increase my charge weight , but to look for pressure signs. It shoots the Nosler 70gr ballistic tips well with the 1:13 twist and I have 8lbs. of Reloder 16 so I'd like to use it. Does anyone have a max load for this combination of powder and bullet and using my rifle info? Sorry for being longwinded, but trying to give as much info as possible. I've been looking all afternoon and can't find the information I need. Any help in the right direction will be greatly appreciated.
Thanks in advance,
Tim Sanders, Sr.

 

[dwinmeade]

I owned a 243AI and never could find any loading data, so I loaded as if it was a reg 243. My best groups was w/RL17 & Sierra SBT #1515.
Also 62g Barnes VGrenade & RL10x. (Text me for the recipes & some target pics, if you want...312-617-4711.)

"The Social Regressive" on YouTube loves RL16, search his channel for RL16 load info.

 

[GLTaylor]

I've shot a 243 AI for almost 50 yrs. Mostly used 85 and 105g bullets. Just recently started shooting Hammer Bullets in lighter wts. There is some Hammer load data on this forum. Look up Hammer Hunter Load Data and Absolute Hammer Load Data. If you want some cup and core data PM me and I'll look it up.
G

 

[venatic]

My thought would be use the load 45.1 that shot well to fireform all your brass. Once you have enough formed brass then I would start at that same charge but load one or two rounds in .3 gr increases up to about 3% higher than .243 data so to around 47.4 and see how pressure signs look. You may see excessive pressure signs before you get to 47.4 but that's why you don't load too many of each.

 

[tim1457]

I've shot a 243 AI for almost 50 yrs. Mostly used 85 and 105g bullets. Just recently started shooting Hammer Bullets in lighter wts. There is some Hammer load data on this forum. Look up Hammer Hunter Load Data and Absolute Hammer Load Data. If you want some cup and core data PM me and I'll look it up.
G

If you could send me any data that would be great. I forgot to mention I'm using Hornady .243 Win. brass to fireform and Federal 210m primers. You can email any info to [email protected] or text/call 803-295-2148. Thanks, Tim Sanders Sr.

 

[tim1457]

These were my two best 3-shot groups at 100 yards during load testing. Hope it'll match or better with the "proper formed" brass.

 

[MT Southpaw]

I don't have a .243 AI, but I do have a 270 AI; same problem not much reloading info out there. I agree with what Venatic said: "use the load 45.1 that shot well to fireform all your brass". That shoots a nice pattern so you can use it for target/varmint shooting while you get a nice stockpile of fireformed brass. Then once you have all those fireformed I would start running a ladder test at .5 grain increment increases looking A: for pressure and B: for the next tight node spot, or the next 2 depending on where you start to find pressure. Hopefully you'll find at least one more tight node going up, unless you're happy with the velocity now. Generally the rule of thumb with Ackley improved rounds is the max listed load of the parent case is the new starting load for the AI case, so you should be able to start at 46 and go up a couple grains. That's what I did anyway. I'm interested in seeing what you find because I have a .243 that I plan on redoing to an AI as well.

 

[Will D]

The only advice I could find when I began loading for my 243 AI was to begin with max 243 loads and work up. My favorite bullet for rock chucks to wolves is the 85 gr. Sierra HPBT ahead of 46.5 gr IMR4350 providing 3,377 fps with 9 fps SD. No pressure signs on the brass, but bolt lift on the Sako L579 gets a bit stiff when the barrel gets hot.

 

[BallisticsGuy]

Just use max .243win data minus a full grain or you can use the cream of wheat method and not get the barrel wear from sending actual bullets down the pipe. To do the Cream of Wheat method, start with a good fast burning pistol powder like Unique, drop 6 grains in and cap with COW to the body-shoulder junction and cap the neck with polyfill, fire and work up till the shoulders are good and sharp. IIRC it's going to end up being something like 9 grains of unique (that's about where it worked best for me from what I recall). Other pistol powders for the same job, I start with a maximum .45acp 180gr jacketed load and work up till the shoulders fill out nicely. It's a bit dirty so run a patch down the barrel to knock the crud out after every few rounds.

 

[xsn10s]

These were my two best 3-shot groups at 100 yards during load testing. Hope it'll match or better with the "proper formed" brass.

Boy that rifle is a shooter. I think I'd just load for accuracy and call it good.

 

[xsn10s]

Here's a link with some load data for 243 AI. Best of luck to ya. I'm all green with envy https://www.6mmbr.com/243Win.html

 

[tim1457]

Thanks everyone for all of your help and advice. Some good information from everyone and it is greatly appreciated.
Tim Sanders Sr.

 

[Tiny Tim]

Generally fire form with faster end of the spectrum powder at near max load for parent cartridge. Seems that you already have a good load for that. Only caution is that typical pressure signs on the AI cartridge are a little more subtle. Listen to GL Taylor. He's solid and a wealth of information.

 

[Flackin Hoover]

These were my two best 3-shot groups at 100 yards during load testing. Hope it'll match or better with the "proper formed" brass.

If you match those groups, you should be happy , that barrel will shoot! I love my 243AI, I started with factory Rem. 243, shot them out to fireform! annealed,turned necks, and ended up with brass I think is pretty good . I do recommend fire forming with NEW brass, nothing that has stretched in the webb area. The load that seemed to work in my rifle ,( with a Bartlien barrel), was Barnes LRX 95 g. .070 jump,IMR 4831,@44.2 gs. ,cci 250, for 3330 fps. That powder is not neccesarily the best, but shot sub MOA, and I quit there, (for now) . Have some R16 to try , also. Hammer bullets are my next load development, 88 g. HH. Good luck!