I was told this was the way to go, but now am getting word I need to go tighter?
Thanks,
Vu
Thanks,
Vu
F T/R Competition Will a 1:13 .299 bore work with a 155 Scenar?
- Thread starter NorCal Vu
- Start date
Palma shooters often use a .298/.308 tightbore barrel with the 155s. However, I've shot many's the 155 Scenar out of a GAP Crusader with a .299/.308 11-twist barrel and they shoot very, very well. A 13- or 12-twist should be fine for the Scenars.
Edited to add: Down South is correct on the twist rate, those Scenars are a lot longer than I had remembered. Another option would be the Berger 155.5 Fullbore. Just a tick higher BC, a tanget ogive for ease of reloading, and should work pretty well in a 12- or 11-twist barrel.
Edited to add: Down South is correct on the twist rate, those Scenars are a lot longer than I had remembered. Another option would be the Berger 155.5 Fullbore. Just a tick higher BC, a tanget ogive for ease of reloading, and should work pretty well in a 12- or 11-twist barrel.
Last edited:
I personally would shoot a 12 twist or faster with the 155 Scenars, they are a long bullet for a 155.......They shot great out of my 10 twist 30 inch barrel even though thats not ideal for that bullet.
Jack Krieger and Barret Obermeyer each have sites and contact info...... I`d write or call either...... you`ll learn more....
Vu, been shooting 155 Scenars in FTR since 2006.
Here is my experience
1x13 twist works well to 800 yards after that I see fliers I can not explain
1x12 twist works better and my best groups come with a 1x11.25 twist 5R
GAP has the chamber reamer to make these hum
Here is my experience
1x13 twist works well to 800 yards after that I see fliers I can not explain
1x12 twist works better and my best groups come with a 1x11.25 twist 5R
GAP has the chamber reamer to make these hum
Mike, that's interesting and somewhat counter-intuitive. A bullet gets evermore stable as the distance grows, provided it was statically stable at the muzzle. While the forward velocity decreases due to air resistance, the spin rate of the bullet remains constant over time and since the tendency for the bullet to overturn diminishes along with the velocity, the bullet is ever more stable. I'm wondering if the 1:13 twist barrel was somehow inducing a dynamic instability to the bullets or if some bullets were not quite perfect.
However, I am always one to err on the side of more spin, within reason, and I truly believe that the 1:11 or 1:11.25 is the very best twist rate for .308 up to 190 or even 200gr (length). I've shot 200SMKs out to 1000 yards with a 1:11.25 and they were fine, apart form the elevation issues. I didn't want to trim and/or point meplats and these bullets beat me up so I switched to something else and never looked back.
However, I am always one to err on the side of more spin, within reason, and I truly believe that the 1:11 or 1:11.25 is the very best twist rate for .308 up to 190 or even 200gr (length). I've shot 200SMKs out to 1000 yards with a 1:11.25 and they were fine, apart form the elevation issues. I didn't want to trim and/or point meplats and these bullets beat me up so I switched to something else and never looked back.
Deny, my thoughts are the 155 Scenar has a long open air space and I think as it slows down at distance it needs more spin to stabilize like a football does.
Not a scientist here just reporting what I have seen shooting many of these.
I pick 1x11.25 twist for all my 155 Scenar rifles now
Not a scientist here just reporting what I have seen shooting many of these.
I pick 1x11.25 twist for all my 155 Scenar rifles now
If you have the 13 twist it will work fine if you are ordering a barrel why limit yourself to lighter bullets. 11.25 and 12 work for a lot of bullet weights.
If you do have it no worries as I have shot 1,000's of 155 scenars out of a 1-14 twist barrel with great results at 500ASL.
Trevor
If you do have it no worries as I have shot 1,000's of 155 scenars out of a 1-14 twist barrel with great results at 500ASL.
Trevor
Similar threads
