Throughout the winter, I've only fired one of my rifles, and that is this .22 ARC. It's a 1-7 twist IBI, .985" straight 26" long on a CZ 527 in a B&C stock. In the late fall, I did some messing around with the 80gr SMK, Hornady brass and VV N550. I use QuickLoad for virtually all of my starting workups base on what's going to deliver top velocity, with what I have on hand.
Previous post on 80gr SMK in the .22 ARC
The 80gr was fun, but playing with numbers showed that the 88/90's would pick up a lot more supersonic distance. I don't compete, I just like to shoot for fun now, and the farther, the better.
I scored some Alpha .22 ARC brass from Go-Big, and picked some 88's up locally. I started off with 27 gr of N550, and went up to 29.7 gr as seen on this Shotmarker plot at 365 yards. Bullets were seated at about .02" jump, and do not fit in the short CZ magazine.
I wasn't getting pressure at 29.7 gr so I went to 30.0 gr and tried a 5 shot group, at .02" jump. I don't recall what it was exactly, but I was searching for better. I typically do a .04" jump, then 'touching' and see what the trend is. In this case I went for .04", and loaded another 5. This gave me 1.31", with four of them in .74", Good enough!!
Speed was excellent, pressure wasn't an issue at all and the ES/SD was spectacular.
The day after this test, a box of 500 90gr SMK's showed up, so with any luck this week, I can use the baseline 88 data to see how the 90's work. I'm interested in the heavy for calibre bullets as they will make 1200 yards with enough speed (1250fps) to register on the Shotmarker, and recoil is very mild. I think my next .22 ARC will have a 6.5 twist to play with the 95's.
Interestingly, the Alpha brass has the exact same fired water capacity (35.4gr) as the Hornady.
Previous post on 80gr SMK in the .22 ARC
The 80gr was fun, but playing with numbers showed that the 88/90's would pick up a lot more supersonic distance. I don't compete, I just like to shoot for fun now, and the farther, the better.
I scored some Alpha .22 ARC brass from Go-Big, and picked some 88's up locally. I started off with 27 gr of N550, and went up to 29.7 gr as seen on this Shotmarker plot at 365 yards. Bullets were seated at about .02" jump, and do not fit in the short CZ magazine.
I wasn't getting pressure at 29.7 gr so I went to 30.0 gr and tried a 5 shot group, at .02" jump. I don't recall what it was exactly, but I was searching for better. I typically do a .04" jump, then 'touching' and see what the trend is. In this case I went for .04", and loaded another 5. This gave me 1.31", with four of them in .74", Good enough!!
Speed was excellent, pressure wasn't an issue at all and the ES/SD was spectacular.
The day after this test, a box of 500 90gr SMK's showed up, so with any luck this week, I can use the baseline 88 data to see how the 90's work. I'm interested in the heavy for calibre bullets as they will make 1200 yards with enough speed (1250fps) to register on the Shotmarker, and recoil is very mild. I think my next .22 ARC will have a 6.5 twist to play with the 95's.
Interestingly, the Alpha brass has the exact same fired water capacity (35.4gr) as the Hornady.
