6mm 9 twist and 107's
- Thread starter Pat B.
- Start date
Help Support Long Range Hunting Forum
CatShooter
Well-Known Member
Re: 6mm 9 twist and 107\'s
It should... it'll stabilize the 105 A-Maxs.
.
It should... it'll stabilize the 105 A-Maxs.
.
C
Chawlston
Guest
Re: 6mm 9 twist and 107\'s
[ QUOTE ]
I have a 9 twist Krieger in 6mm... Will it stabilize the 107smk's?
Thanks
[/ QUOTE ]
Hopefully you are not at a higher altitude. I have found when on the ragged edge of stability with 6/284 that loads that were great at sea level wouldn't hit target at 100 yard in ElPaso TX. Specifically, in higher altitudes, the heaviest bullet I could get to stabilize in the 1-14" twist was 70gr. Back down here in or at sea level, I can shoot the 90gr bullets without any issues. Hopefully you don't have the same issues I had. Good luck.
James
[ QUOTE ]
I have a 9 twist Krieger in 6mm... Will it stabilize the 107smk's?
Thanks
[/ QUOTE ]
Hopefully you are not at a higher altitude. I have found when on the ragged edge of stability with 6/284 that loads that were great at sea level wouldn't hit target at 100 yard in ElPaso TX. Specifically, in higher altitudes, the heaviest bullet I could get to stabilize in the 1-14" twist was 70gr. Back down here in or at sea level, I can shoot the 90gr bullets without any issues. Hopefully you don't have the same issues I had. Good luck.
James
Fiftydriver
Official LRH Sponsor
Re: 6mm 9 twist and 107\'s
My standard recommendation for the larger 6mms designed to shoot the 105 to 107 class bullets is now a 1-9 twist with at least 5 grooves. I actually like the Lilja 6 groove about the best but all should work well.
If your shooting a round in the class of a 243 AI or larger, the 1-9 should be plenty. If your shooting a smaller round like a 6 br or similiar, I may go with a 1-8 just to be safe in all conditions but it is probably not a requirement.
Kirby Allen(50)
My standard recommendation for the larger 6mms designed to shoot the 105 to 107 class bullets is now a 1-9 twist with at least 5 grooves. I actually like the Lilja 6 groove about the best but all should work well.
If your shooting a round in the class of a 243 AI or larger, the 1-9 should be plenty. If your shooting a smaller round like a 6 br or similiar, I may go with a 1-8 just to be safe in all conditions but it is probably not a requirement.
Kirby Allen(50)
CatShooter
Well-Known Member
Re: 6mm 9 twist and 107\'s
[ QUOTE ]
My standard recommendation for the larger 6mms designed to shoot the 105 to 107 class bullets is now a 1-9 twist with at least 5 grooves. I actually like the Lilja 6 groove about the best but all should work well.
Kirby Allen(50)
[/ QUOTE ]
Kirby... why you say that?
I've heard this one or two times before, and I wonder why.
Is there a problem, and if so, what is it??
I have been holding off on a 3 groove for a long range riffle because of comments like your's above.
.
[ QUOTE ]
My standard recommendation for the larger 6mms designed to shoot the 105 to 107 class bullets is now a 1-9 twist with at least 5 grooves. I actually like the Lilja 6 groove about the best but all should work well.
Kirby Allen(50)
[/ QUOTE ]
Kirby... why you say that?
I've heard this one or two times before, and I wonder why.
Is there a problem, and if so, what is it??
I have been holding off on a 3 groove for a long range riffle because of comments like your's above.
.
Fiftydriver
Official LRH Sponsor
Re: 6mm 9 twist and 107\'s
Catshooter,
I was recommended by many barrel makers to use 1-8 twist barrels on 6-284s using the 105-107 gr pills. With a 5 or 6 groove barrel, these seem to work well to a point. The 107 gr SMK can be driven to as fast as you can get them out of a 6-284. This is the case even with the 1-8 3 groove barrels. I have pushed them to 3600 fps in my personal 30" Lilja 1-8 3 groove.
That said, I wanted to shoot the 105 gr A-Max which has a much thinner jackets and with its tipped design would be a much better game bullet for light game at ranges from 800 to 1000 yards. Only problem, anything over 3200-3250 fps ripped them apart or degraded accuracy to the point that they were pretty useless. The heavier jacketed SMKs did not have this problem at all.
I did some thinking on this and my theory was that the wide three groove barrels were weakening the bond between the core and jacket and finally a good customer came in and agreed to have me build a rifle for him to test my theory.
I also felt that a 1-8 was a bit fast in twist rate when dealing with 3400-3500 fps velocity potenticals.
I ordered a 1-9 6 groove Lilja and was able to drive the 105 gr A-Max and Bergers to 3500 fps easily with no loss of accuracy at all.
To test my theory further I ordered in a 1-8 5 groove barrel and it also allowed higher velocity but still caused problems once velocity pushed near 3400 fps.
As such, from then on, I only recommend the 1-9 in either a 5 or 6 groove in the 6-284 or similiar rounds. That twist rate is plenty for the 105-107 gr bullets and the thinner lands seem to be much easier on thin jacketed bullets.
All in all top velocity potential with fine accuracy is much better with the 1-9 6 groove then any other barrel I have tested with the 6-284 and similiar rounds.
Kirby Allen(50)
Catshooter,
I was recommended by many barrel makers to use 1-8 twist barrels on 6-284s using the 105-107 gr pills. With a 5 or 6 groove barrel, these seem to work well to a point. The 107 gr SMK can be driven to as fast as you can get them out of a 6-284. This is the case even with the 1-8 3 groove barrels. I have pushed them to 3600 fps in my personal 30" Lilja 1-8 3 groove.
That said, I wanted to shoot the 105 gr A-Max which has a much thinner jackets and with its tipped design would be a much better game bullet for light game at ranges from 800 to 1000 yards. Only problem, anything over 3200-3250 fps ripped them apart or degraded accuracy to the point that they were pretty useless. The heavier jacketed SMKs did not have this problem at all.
I did some thinking on this and my theory was that the wide three groove barrels were weakening the bond between the core and jacket and finally a good customer came in and agreed to have me build a rifle for him to test my theory.
I also felt that a 1-8 was a bit fast in twist rate when dealing with 3400-3500 fps velocity potenticals.
I ordered a 1-9 6 groove Lilja and was able to drive the 105 gr A-Max and Bergers to 3500 fps easily with no loss of accuracy at all.
To test my theory further I ordered in a 1-8 5 groove barrel and it also allowed higher velocity but still caused problems once velocity pushed near 3400 fps.
As such, from then on, I only recommend the 1-9 in either a 5 or 6 groove in the 6-284 or similiar rounds. That twist rate is plenty for the 105-107 gr bullets and the thinner lands seem to be much easier on thin jacketed bullets.
All in all top velocity potential with fine accuracy is much better with the 1-9 6 groove then any other barrel I have tested with the 6-284 and similiar rounds.
Kirby Allen(50)
CatShooter
Well-Known Member
Re: 6mm 9 twist and 107\'s
Is the depth in the grooves of the three groove barrel, deeper that the 6 groove barrels??
Is the depth in the grooves of the three groove barrel, deeper that the 6 groove barrels??
