.224 100 grain wildcats 7 twist No Go

reed mosser · #1 11-12-2006, 05:31 PM

I went out today to out my new 7 twist 22 dasher with my old load of 35 grins of ramshot hunter rem 7.5 primer and 100 grain wildcats. And they did not stablize at 3000 fps out of this 7 twist barrel. They worked great in my old 6.5 twist barrel. I was planning on shooting 90 grain berger vld's in this barrel any ways guess thats was has to happen. [img]/ubbthreads/images/graemlins/smile.gif[/img] Thanks for humoring me again

brianwinzor · #2 11-13-2006, 05:48 AM

That report does seem strange and also confusing, as I seem to recall Kirby getting good accuracy in his 7 twist barrel at velocities up to 3,100 fps. Have you measured the twist to make sure that it is in fact a 7 twist?

I just did the maths, and 3,000 fps in a 7 twist barrel produces 308,571 rpm, and in a 6.5 twist barrel it produces 332,307 rpm.

Perhaps my 6.5 twist Krieger may be the right choice for my forthcoming .224 Clark. I was beginning to wonder if I had been too conservative in my choice of twist. Regards, Brian.

Fiftydriver · #3 11-13-2006, 09:30 AM

Reed,

Is your barrel a Lilja 3 groove? Sorry I can not remember what you were using for the life of me!!!

I still think this is more of a land width issue then anything else. From the testing I have done on the 7mm with the heavy ULD RBBTs I have proven that a thinner land allows MUCH higher velocity potential with these bullets. I know the Lilja 3 groove I have has very wide lands and I suspect this is what is causing the issues and why the Krieger barrels are working better.

Just curious what barrel make your 6.5 twist was and what your 7 twist is.

Also, did you get any bullets to profile on target? Were they making it to the target intact?

Thanks for the information.

Kirby Allen(50)

reed mosser · #4 11-13-2006, 09:29 PM

They were both pac-nor barrels 3 groove. The 7 twist I just got was a number 7 countour that was sent to replace a bad polyoganial pac-nor barrel I bought in March. Kirby like you said with more bearing surface with the longer bullets less contact with thinner grooves will help. Mybe this button rifled barrel is really a 7.5 twist or something. I ordered a 7 twist and thats usually as technical as I get. The bullets were hitting the target making very large holes, not quite side ways. Needless to say accuracy was poor. I just gave them try to see what would happen. I guess that with the twist rate I got in my barrel stablization is on the very very edge [img]/ubbthreads/images/graemlins/laugh.gif[/img]