First chrono test of a HB Axis .243 AI

[n4ue]

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

[yobuck]

All good stuff. A bit of the devils advocy here so consider that for what it is, no other meaning implied.
You obviously have as fine a chronagraph as is possible to obtain. That said, would you have been able
to produce the results as for accuracy without the aide of the chronagraph?

[n4ue]

At this range session, I really wasn't interested is grouping. This was more to see if my speeds were in the ball park. Mostly checking primer condition.
Only the smallest bit of flat spotting was seen. Extraction was easy and brass looked perfect.
I usually DO indeed shoot for group while measuring velocity. With the huge capture area of the Skyscreens, it's easy.

So now that I'll probably stick with the 48.0/W760, with the low SD, I'll refine it a bit. I normally shot with the 6" shoot-n-c targets at 100 yards. I just put up a bunch of the 2" florescent stickers with the 1/2" black paster in the middle. Since I was shooting 5 groups, I just wanted to see the change of POI from one load to the next. Yep, I could have used five 6" targets, BUT, I make the 2" ones for a fraction of a penny apiece.

Couple of things I left out:
- COL = 2.640"
- jump to lands = .010"
- don't care it the ctgs fit the mag. I use a Poly Sled and load all my Savages this way.
- inexpensive (but very rigid front bipod), again, like all my rifles
- rear sand bag

Although the PA scope is nice for the $, my only complaint is that at 16X it doesn't seem to magnify like my other 16X scopes. More like 12X. I have a lot of spare scopes and may swap on something different......

ron