My last decision on my 308 build

[diderr]

I have decided on just about everything else on my 308 build, but one of the most important. Barrel length. I'm going to be using it for F-class, but also other types of shooting; maybe on occasion hunting if I feel the urge to carry an 18 lb. rifle around. I've shot GAP crusader's with 23" barrels, and really liked the feel of those.
What would be like a minimum barrel length to keep a 175 supersonic to 1k or just a hair past it with a Varget like burn rate powder? I'm looking at a Bartlein, and the blank will come at 29" with a 1in10, but I highly doubt I'll keep it at 29.

 

[ICANHITHIMMAN]

I have decided on just about everything else on my 308 build, but one of the most important. Barrel length. I'm going to be using it for F-class, but also other types of shooting; maybe on occasion hunting if I feel the urge to carry an 18 lb. rifle around. I've shot GAP crusader's with 23" barrels, and really liked the feel of those.
What would be like a minimum barrel length to keep a 175 supersonic to 1k or just a hair past it with a Varget like burn rate powder? I'm looking at a Bartlein, and the blank will come at 29" with a 1in10, but I highly doubt I'll keep it at 29.

I'm a long barrel whore, but lets forget about that for now. The great part about the 308 Winchester is the fact that it is not overly sensitive to changes in barrel length. That said the bullet is the key component to the equation in this instance. A barrel with a length of 16" will stabilize that bullet past 1k, I suspect you will get a lot of varying opinion's, this is mine and it cost you nothing so use it with that aspect in mind.

 

[teflonhunter]

I would probably go 28".

 

[rick523]

One of my friends is shooting a 20'' barrel with 175 smk's, and has no problems out beyond 1000. Actually we are shooting tomorrow if I remember I will take a picture of his 1000 yd groups and post it for you. That said mine is 26" but I just got it a few weeks ago in a trade with a member on this forum, I shot it for the first time 2 days ago so I can't tell you much about how it shoots. Tomorrow I will be trying to work out a load for it, and go from there.

He is loading IMR4895 as a side note.

 

[diderr]

One of my friends is shooting a 20'' barrel with 175 smk's, and has no problems out beyond 1000. Actually we are shooting tomorrow if I remember I will take a picture of his 1000 yd groups and post it for you. That said mine is 26" but I just got it a few weeks ago in a trade with a member on this forum, I shot it for the first time 2 days ago so I can't tell you much about how it shoots. Tomorrow I will be trying to work out a load for it, and go from there.

He is loading IMR4895 as a side note.

Nice! looking forward to that info.

 

[Bullet bumper]

It's not the lenght that stabalises a bullet it's the twist rate . The lenght helps with extra velocity per inch to utilise slower powders. Short barrels do shoot but are limited to faster powder speeds or it just burns in the air . However they have greater rigidity for their cross section and less barrel flip. I would start long and if you can't find a good load then chop off an inch and start again . At some point there has to be a sweet spot .

 

[backcountryguide]

On my recent build I went with a 28" Brux #5 contour with a 1/10 twist. We run the 185gr Berger VLD @ 2800 fps now after backing the load down a bit. We are using RL-17 in Lapua cases with a FGM210 primer. COAL is 2.875 and they just fit in the mag. The load has been very consistent with groups around the 1/4 in mark being the norm. This is the first time I have used this long a tube on a .308 but results have been great with 48.5gr of the slow RL-17 powder.

 

[diderr]

It's not the lenght that stabalises a bullet it's the twist rate . The lenght helps with extra velocity per inch to utilise slower powders. Short barrels do shoot but are limited to faster powder speeds or it just burns in the air . However they have greater rigidity for their cross section and less barrel flip. I would start long and if you can't find a good load then chop off an inch and start again . At some point there has to be a sweet spot .

Yes. I'm aware the twist stabilizes the bullet, and not the length. I'm fully confident in the 1 in 10 and the 175s. I just want a supersonic velocity slightly beyond 1k. I may try 27".