22-243 AI & H4350

[STS]

Many years ago when I had my first 6-284 built I asked the smith that was building my rifle about barrel life with a 6-284. He was kind of a funny dry sense of humor old guy and he told me "son, I can't tell you what other gunsmiths do but I thread all my barrels so they screw on and off, I don't not weld them on." I think that was the last time I ever asked a gunsmith about barrel life.

Right, that's why they have threads. I've heard a lot of pure speculation on barrel life on cartridges like this. I have a couple of .22 Creedmoor rifles and have seen unfounded speculation as low as 800 rounds of barrel life. I intend to save bore scope images every couple hundred rounds and document the erosion in a post somewhere in the future. I can say for sure at this point, that the barrel life is considerably greater than 800 rounds. We have one barrel with >800 rounds that is still razor sharp at 500 yards.

 

[Charlie-NY]

After a 1,000 rnds in my 22-243AI the accuracy started to decline. I had two inches of barrel removed and the barrel rechambered in 22-243 (plain). The rifle shot just about as good as new.

 

[YBPS]

After a 1,000 rnds in my 22-243AI the accuracy started to decline. I had two inches of barrel removed and the barrel rechambered in 22-243 (plain). The rifle shot just about as good as new.

1000 rounds with load development is probably going to be 500-600 dead coyotes. I’m cool with that. That’s a lot of $ in fur.

 

[Charlie-NY]

1000 rounds with load development is probably going to be 500-600 dead coyotes. I’m cool with that. That’s a lot of $ in fur.

I was actually surprised to get 1,000 rounds of good accuracy from that cartridge. I'm guessing that the moly coated bore/bullets may have helped. The vast majority of those shots were at PA groundhogs where the 22-243AI was deadly out to 1,000 yds, which was about the longest shots I could get in the farming community.

The rifle continued to shoot very well after the rechambering. However, I had the hankering for a shiny new 6mmBR so that's what I've got now.

 

[YBPS]

Thoughts on a 7 twist with 75’s? Looking for a new barrel for a second one.

 

[Charlie-NY]

Thoughts on a 7 twist with 75’s? Looking for a new barrel for a second one.

I see no advantage to a 7 twist with 75gr bullets. IMO it will be harder on thin bullet jackets, possibly shoot slower and may foul faster than an 8 twist. Now if you want to shoot 90gr bullets then thats a whole different story.

 

[JohnD]

FWIW. Had a .220 Swift AI that shot very well with 7828 behind a 65 gr. SGK. Actually this thing was amazingly accurate and it didn’t matter the bullet or powder. Accuracy did start to fade at about 1300 rounds.

John