220 Swift with a 77gr HPBT??

[Hollywood1009]

Has anybody done this?

I have both a 8tw and a 9tw.

Any help would be good, my book only goes to 70 gr bullet.

Any results long range say 800-1000 yd? I do know wind will always be a factor.

 

[johnmyers]

You have a pm

 

[40X Guy]

Use the 8 twist. My new 8 twist Swift project is showing promise. Its a .254 chamber set up for Norma brass neck turned to .014 thickness. I only have 50 rounds thru it and already shot it in a midrange match with little to no load workup. I will tell you that N550 and RL-17 are the powders you should try first. I am getting 3,605 fps with N550 and 3,652 with RL-17 under 75 A-Max. Planning on an OCW test this weekend and then play with seating depth. I played around with QL extensively and you need close to 100% powder burn, and a decent fill rate of 95% or better. Ramshot Hunter is another powder that looked good on QL, but I did not try any. Let me know via PM if you need help.

Frank

 

[wboggs]

How bad did your barrel heat up during the relays? I have a .22-6mm that is very accurate with the 80.5 berger at 3650 but have been afraid of burning out the barrel with competition shooting. It would be a dream to shoot.
Thanks

 

[Hollywood1009]

Use the 8 twist. My new 8 twist Swift project is showing promise. Its a .254 chamber set up for Norma brass neck turned to .014 thickness. I only have 50 rounds thru it and already shot it in a midrange match with little to no load workup. I will tell you that N550 and RL-17 are the powders you should try first. I am getting 3,605 fps with N550 and 3,652 with RL-17 under 75 A-Max. Planning on an OCW test this weekend and then play with seating depth. I played around with QL extensively and you need close to 100% powder burn, and a decent fill rate of 95% or better. Ramshot Hunter is another powder that looked good on QL, but I did not try any. Let me know via PM if you need help.

Frank

Thanks Frank..

 

[Hollywood1009]

TTT anybody else with some good ideas??

 

[40X Guy]

How bad did your barrel heat up during the relays? I have a .22-6mm that is very accurate with the 80.5 berger at 3650 but have been afraid of burning out the barrel with competition shooting. It would be a dream to shoot.
Thanks

6 shots per relay and then between relays there's probably at least half hour break. Plus it was 50 degrees, so heat was not an issue.

Frank

 

[Hollywood1009]

TTT anybody with a little more help?