Custom barrel specifications?

tribb

Well-Known Member
Joined
Nov 9, 2011
Messages
360
I want to build a 270 whatever is fast with a140 grain 400 + bc. at 3300 fps. Case is to be determined and is not a concern at this time! What concerns me is The "barrel" as to number of grooves,twist, shape of land grooves ie. 5r? And anything I may have forgotten about for ii! It's my first truly custom and don't want to forget or leave anything to chance! Any and all suggestions are encouraged and appreciated. Thank you Tribb
 

FEENIX

Well-Known Member
LRH Team Member
Joined
Dec 20, 2008
Messages
16,483
Location
Great Falls, MT
I want to build a 270 whatever is fast with a140 grain 400 + bc. at 3300 fps. Case is to be determined and is not a concern at this time! What concerns me is The "barrel" as to number of grooves,twist, shape of land grooves ie. 5r? And anything I may have forgotten about for ii! It's my first truly custom and don't want to forget or leave anything to chance! Any and all suggestions are encouraged and appreciated. Thank you Tribb
Barrel length? I have a 30" Lilja SS 1:8" 3G Sendero contour on my .270 AI propelling the 175 Matrix at 2993 FPS with 58 H4831SC with my current accuracy load. Others are claiming ~100 more FPS with RL-26. Most of the magnum cartridges should get you there. Good luck!
 

tribb

Well-Known Member
Joined
Nov 9, 2011
Messages
360
Barrel length? I have a 30" Lilja SS 1:8" 3G Sendero contour on my .270 AI propelling the 175 Matrix at 2993 FPS with 58 H4831SC with my current accuracy load. Others are claiming ~100 more FPS with RL-26. Most of the magnum cartridges should get you there. Good luck!
Sounds like a sweet shooting rig thanks
 

Coyote Shadow Tracker

Well-Known Member
LRH Team Member
LRH Sponsor
Joined
Dec 9, 2020
Messages
979
Location
Social Circle, GA
Not enough information on what your intended use for the .270 is. Getting to 3300 fps is hot for this caliber. Are you just looking to have a fast barrel burner? Is this for hunting or target? I am sure there are a lot more folks on this site to guide you. I shoot a 270WSM. Sierra has a 140gr SGK with .457 bc @ 2800 fps and above. A 270 Win with all hodgen powders will only get you to about 2770fps. then going with a 270WSM you can get up to 3100fps, then a 270 Weatherby Mag will get you up to 3100+. As far as barrels Bartlin cuts fine 5R barrels. Probably want an 1-8 twist with 140-150 gr bullets. You really need to think about your expectations for a .270.
 

tribb

Well-Known Member
Joined
Nov 9, 2011
Messages
360
Not enough information on what your intended use for the .270 is. Getting to 3300 fps is hot for this caliber. Are you just looking to have a fast barrel burner? Is this for hunting or target? I am sure there are a lot more folks on this site to guide you. I shoot a 270WSM. Sierra has a 140gr SGK with .457 bc @ 2800 fps and above. A 270 Win with all hodgen powders will only get you to about 2770fps. then going with a 270WSM you can get up to 3100fps, then a 270 Weatherby Mag will get you up to 3100+. As far as barrels Bartlin cuts fine 5R barrels. Probably want an 1-8 twist with 140-150 gr bullets. You really need to think about your expectations for a .270.
Roger that sir thank you
 

MagnumManiac

Well-Known Member
Joined
Feb 25, 2008
Messages
3,159
A 270 Weatherby Mag will give you the desired ballistics with a 26” barrel, or better yet, like mine a 28”. I have both lengths.
130’s at 3500fps, 140’s at 3400fps and 150’s at 3300fps are easily doable.
My 28” barrel runs a little more than this.
As to twist, a 1:9” would work, and number of grooves I went with are 4 and 6. The 4 groove barrel is a cut rifled barrel and it is so easy to clean it’s remarkable. The 6 groove is button rifled, both have been lapped. It is also easy on fouling.
A 5R really only has the advantage of staying less fouled for longer, the accuracy potential is about the same as regular rifling. I only have one 5R rifle and it is a factory Rem barrel, I haven’t even fired it yet TBH.

Cheers.
 

tribb

Well-Known Member
Joined
Nov 9, 2011
Messages
360
A 270 Weatherby Mag will give you the desired ballistics with a 26” barrel, or better yet, like mine a 28”. I have both lengths.
130’s at 3500fps, 140’s at 3400fps and 150’s at 3300fps are easily doable.
My 28” barrel runs a little more than this.
As to twist, a 1:9” would work, and number of grooves I went with are 4 and 6. The 4 groove barrel is a cut rifled barrel and it is so easy to clean it’s remarkable. The 6 groove is button rifled, both have been lapped. It is also easy on fouling.
A 5R really only has the advantage of staying less fouled for longer, the accuracy potential is about the same as regular rifling. I only have one 5R rifle and it is a factory Rem barrel, I haven’t even fired it yet TBH.

Cheers.
Thank you for your information I appreciate it! Tribb
 
Top