OzFclass

Has any body try a 22-250 with a 1 in 8 twist to shoot 80g mk.

I'm putting an old barrel that still as some life in her on a hunting rifles because it too short for f-class.

2209- i think thats what your old man used in his 22BR and its what I used while I was shooting 90gr bergers in my old 22br.

If your gunna hunt with it around here, load up the 75gr amax and see how it goes, the smk's zip through foxes too easily.

See ya sunday hopefully

In a 22.250 with a 1 in 8 the Amax's get unreliable around 3200fps. The jackets are too thin to handle the rotational spin rate and you will have them coming apart 50 mts or so out from the muzzle. The Sierra's are a bit thicker and stronger in the jacket but they too can have problems over 3200 fps. Hope this helps.
Regards Malcolm.

Brad Y wrote:2209- i think thats what your old man used in his 22BR and its what I used while I was shooting 90gr bergers in my old 22br.

If your gunna hunt with it around here, load up the 75gr amax and see how it goes, the smk's zip through foxes too easily.

See ya sunday hopefully

Thanks Brad the main use for this will be field rifle at the range. Look forward to catch up this Sunday

Malcolm Hill wrote:In a 22.250 with a 1 in 8 the Amax's get unreliable around 3200fps. The jackets are too thin to handle the rotational spin rate and you will have them coming apart 50 mts or so out from the muzzle. The Sierra's are a bit thicker and stronger in the jacket but they too can have problems over 3200 fps. Hope this helps.
Regards Malcolm.

thanks for that info Malcolm what powder do you think Between 2208 or 2209 for the 80grain SMK

I think it was only 2208 that was used in the 1 in 8 twist 22.250 as an experiment to see how it would go for a 300 mt rifle. The bullets could be driven faster but weren't designed for it and too many failures resulted in the barrel being re chambered back to a 223. 2209 may work very well but it is the bullet limitations that dictate the top velocity you can achieve in a 1 in 8 twist.
Regards Malcolm.

Yeah , if you do the maths, i hope i have this right.....

.22/250
80gr at 3200fps 1:8 twist
((3200x12)/8)x60 = 286000 RPM


or my...
.223
80gr at 2850fps 1:7 twist
((2850x12)/7)x60 = 293000 RPM so no wonder lightly constructed bullets are going puff the magic dragon............

are sierras the best ? how are bergers ??

cheers Andrew

Hi Andrew
The Sierras were better than the Amax's and if you section those projectiles you can see why. The Sierra is much thicker in the jacket in the ogive area and seems to hang together better at the higher spin rates. Not sure how the Nosler would go, I have sectioned them but can't remember how they compared. Someone else has posted on here that they are having problems with them at 223 velocities but I haven't seen any issues like that.
Regards Malcolm.

Hi Andrew again.
Just checked the other post and it was you having the problem with the Nosler- sorry. A friend is using them in a 1 in 7 Krieger (30 inch / 223) and hasn't had any problems, I think the load is 25.2gn of 2208 so the velocity should be getting up there. I know plenty of others using the Nosler and none have mentioned any problems.
Regards Malcolm.

Courtz

Triggy has 200 berger 90gr berger VLD's that I ordered for my 7 twist 22BR. I also saw today he has some big boxes of 90gr matchkings. If you can get the velocity up, the 8 twist might stabilise the 90gr pills...