I thought I'd start a new thread, even though I've talked about this before...... Flame suit on....

Rifle - New Axis HB 243 rechambered into 243 AI. Round count = <50
Scope - PA 4-16
Ammo - New Winchester brass that has been fireformed, neck sized with Lee Collet die
Range - 50 yard target (too lazy to move my 'portable' bench to 100 yds) ha ha
Oehler 35P chronograph. (I said M33 in another thread. Mistake)
Conditions - 150' ASL, 85 degrees, dead calm. Took LOTS of time, loaded single shot style, bbl never got very hot.

Darn, it was hot down in my range!
I started with once fired/fireformed brass. The brass was fireformed with 44.0 gr W760 This was the second loading for all rounds. All rounds used W760 powder and Sierra #1505 HBN coated 70 gr HPBT Match bullets, CCI 200 primers. Bbl coated with HBN, also.

46.0..........3434fps mean........14fps SD
46.5..........3451fps mean........40fps SD
47.0..........3509fps mean........28fps SD
47.5..........3559fps mean........61fps SD (rifle didn't like this node)
48.0..........3583fps mean........10fps SD

At the 48.0 gr point, the slightest amount of primer flattening was seen. The AI case has a LOT of powder capacity! Even at 48.0, the powder was below the neck/shoulder junction.

Although the load could probably made better, the accuracy was excellent for the loads with the low SD. I use 1/2" 'shoot-n-c' black pasters on 2" florescent red stickers. All loads shot into the dots. Remember, this was only 50 yards.... ha ha
Make no mistake, with the 22" bbl, this thing has a 'bark'.....
BTW, when I got home, I looked closely at the bore, not one bit of copper fouling. I tried soaking and cleaning with Kroil, almost NO debris. Dried and recoated with HBN. I just love this stuff.
If you do NOT use HBN, you could expect 50+ fps increase in velocity, over my speeds.....

I've had so much fun with this build, I might do a 22-250AI HB Axis.......

Comments welcome.

ron