Preparing for the rebarrel

[Uncut_Teeth]

So recently I bought a Savage 12BVSS ( http://www.savagearms.com/firearms/model/12bvss ) in .22-250. It's going to be used mainly for varmint, once the snow melts and the prairie dogs come out, but once the barrel's burned out I'd like to go with a .308 and get into shooting paper, steel, and if possible the occasional ground hog, at ranges anywhere from 200 to 800 (with practice) yards. I figure that I might as well be on the lookout for a nice barrel now, so when the .22-250 barrel does burn out I won't have to be without a gun for long.

I have a basic understanding of bullet weights and twist rates, the heavier the round the faster the twist rate needed, and the more accurate it will be at long ranges. With that knowledge I am willing to let the prairie dog population grow for a while if it means I'll be able to keep tighter groups at greater distances. What I don't know here is WHAT bullet weight and twist rate I'm after. Hopefully I'll have my own reloading setup by the time I burn out the .22-250 barrel, but if not I'll have access to a friend's. So what twist would be best for paper & steel at those ranges?

I also saw the thread that recently came up about .308 barrel length, and I have a few questions regarding that. I know that most of you guys stick around 20-22" barrels, with a few who like 24" and a few who like 18". From what I read it seems that the general consensus is 20" is all that you really need, but are there any disadvantages to, say, a 24" barrel? I mean I don't plan on carrying this thing very far, and if I do have to I'm young and it's good for me. It was also mentioned that at 22" it's possible to max out rounds, so a barrel any longer would just be slowing the round down. I'm not sure if this is an issue with hand-loads though, so any insight on that would be appreciated.

Additional information & questions:
-I would like a heavier contour barrel, such as a varmint, but I'll take what I can get.
-I do plan on using a brake, I shoot outside on private land so noise isn't an issue.
-I know that flutes remove material, and therefor reduce accuracy, but is it noticeable on the heavier contours?
-Will a take-off Savage barrel do me well for my first .308? The budget for all this is starving college-student, but I'd rather do it right the first time than waste money on a shit barrel and have to buy another.
-Currently I'm using a Leupy VX-III 8.5-25x50 with a Long Range reticle and 94moa max internal adjustment. However, it's attached via Leupold STD mounts, and I'm not sure if I should get rid of those and go with something like a Badger 1-piece 20MOA base and some nice rings. I think the ones that are on there now costed the previous owner $30 or so, which seems silly to put on a $1000 scope...

Sorry about all the questions, I'm doing research but sometimes it's hard to get a straight answer without just asking. Any help is appreciated!

 

[Temp9]

1:11.25" seems a very popular twist rate for custom rifles. I believe this is about optimal for 175gr SMK's. 1:10" twist is popular in factory long range rifles, although this seems to have a lot to do with the fact that factory rifles are usually either 1:10", 1:12" or even slower of a twist rate. Stay faster than 1:12" if you want to shoot 175gr bullets.

Don't believe the crap about long barrels slowing down bullets. The only common cartridge that does this is .22lr, as far as I know. .308's don't gain as much with barrel length in terms of velocity as the more overbore cartridges like the 6mm's and 6.5mm's. 20" is a good medium. If you want go with a 24" or longer, you'll still gain velocity, but the gain isn't amazing.

Heavy contour barrels are plentiful, even if you go for a pre-made custom barrel. Check Northland Shooter Supply's selection of Criterion and Shilen barrels.

Savage factory barrels are $205 from NSS, Criterion barrels are $300. I'd save up for a Criterion. Savage factory barrels aren't bad by any stretch, but they're still factory barrels.

I'd personally get a 1-piece 20MOA base and nice rings. Much nicer mounting solution the STD mounts.

 

[Uncut_Teeth]

Alright, I'll keep an eye out for 1:11.25" twists for the time being. I don't really have much of a concept of bullet weights beyond the .22-250, so I'll see what the general consensus is.

Okay, that makes sense. Would it be absurd to go with something like a 28" barrel so that I'll be able to set it back a few times, or should I stick with the more common barrel lengths. NSS has 28" for $320 and 30" for $340.

I see that NSS has the same pricing for all contours of criterion barrels, which I guess makes sense since they just turn them down from their factory diameter, so that opens up some options for contours.

I've got no problem spending $300 for a Criterion, and currently that looks like the route I'll end up going.

I'll get right on the hunt for a base and rings!

Thanks for all your help, I'm swimming in unfamiliar waters here and you've been a great help!

 

[Garyc]

I have a couple of criterion's on M12 BVSS's and really like them, one would be a good choice.

For a .308 I'd go for a 1-10 twist, you can shoot most any bullet through it. The criterion barrels can be had in the savage varmint contour, I'd suggest that since it'll perfectly fit your stock as it is.

Anybody that told you that a .308 is going to slow down in a barrel longer than 24" is someone you shouldn't be listening to, they don't what they're talking about. In any centerfire round more barrel length equals more velocity. There is a barrel length where the bullet will start slowing down, but it's much longer than 24", it'd probably be more like 5' (just guessing), for any barrel length you can carry you'll get more velocity out of a longer barrel. A M12 BVSS isn't really a carrying rifle anyway, I'd go 26 or 28" on it, but it's a personal choice.

Call Jim at NSS, he'll steer you right.

 

[Uncut_Teeth]

First-hand experience is the best kind, so that's very helpful!

1:10" you say? That's interesting. I did some research and a lot of people said to choose bullet weight, then twist rate off of that. I was thinking 175 SMKs, might venture to 185 Berger's since they have a little higher BC. From that I figured that 1:11" to 1:11.25" would be perfect, since the M24 has a 1:11.25" twist and was designed (maybe my source is full of shit, if so please let me know) to send 175 SMKs, and then the '04 National F-Class winner was running 175 SMKs with a 1:11.25" twist. Choosing a twist looks complicated, it seems like people recommend everything from 1:9 to 1:12, so I don't know if they're just full of it or if it doesn't matter THAT much. Recommendations also seem to vary according to barrel length, which I wasn't aware of.

I was thinking of going 28", mayyyyybe 30", since it's just $40 more than a 26" and then maybe I can set it back when the throat wears down and save some dough in the long run. I can't seem to find any reason not to go longer, like you said it's not really a rifle to be carried...I'll see what the estimated barrel weights are and decide from that. To make it seem lighter instead of comparing it to other rifles maybe instead I'll compare it to...bags of rocks...

 

[coldboremiracle]

-I know that flutes remove material, and therefor reduce accuracy, but is it noticeable on the heavier contours?

Where on earth did you hear that? You must be talking to some real sharp folks if this is what they are telling you. There are no down sides to a fluted barrel, or at least none that I can think of or consider.(of course someone will think of something)

As far as barrel length, the .308 does fine with short barrels, personally I consider anything over 24" to be a waste of steel, and extra weight you dont need to carry. There is another active thread currently asking the best length for a .308, and the majority of the comments are in the 18-22" range. I have two .308's, one is a 24" the other is a 16", both are extremely accurate, but I prefer the 16" mainly because of the platform, but I would go against any 24" out there without hesitation, sure it's a little slower, but just something you factor in to your dope (its a .308 for fuck sake) and for the record, identical loaded ammo from my factory 16" shoots within 50fps of a friends factory remington 22" and my 24" shoots within 25fps of my brother's 21". These and many other reasons have led me to the opinion I mentioned above, more than 24" is a waste. Now, there are plenty of folks who shoot 28-30" .308's, usually F class and Palma shooters, thats fine and dandy if they wanna squeeze a few more FPS out of it. But the majority of the .308's you will see around here for our kind of shooting are stubbies.


.308 barrel length thread:
http://www.snipershide.com/shooting/showthread.php?t=175295

 

[Uncut_Teeth]

The fluting thing is around a lot on the internet. There's a bunch of theories that it reduces accuracy. Some guys say that fluting makes the ID expand inconsistently, some think that it increases twisting of the barrel, there's a bunch of ideas and I was trying to get it straight.

Alright, maybe I'll just go for a 24" and spend the extra $40 on ammo. I'd seen the thread on .308 barrel length when it first started but didn't think to check up on it, so thanks for that.

 

[Temp9]

On twist rates, it's generally better to overstabilize than understabilize. A bullet in a barrel that is too slow will most likely shoot poorly, whereas a bullet in a barrel that is too fast will most likely still shoot pretty well. This is why a 1:10" twist is still popular, even though it overstabilizes the 175gr SMK's (the most popular .308 precision bullet). It will also allow you to shoot the 190gr+ bullets if you so desire. In theory, a proper twist rate will be more accurate, however, there are many, many .308's with 1:10" barrels that shoot incredibly well with 175gr SMK's. Don't worry about it too much, but if you're already getting a custom barrel for a 175gr dedicated build, the 1:11.25" twist is a nice feature. I wouldn't feel undergunned with a 1:10" barrel, though.

Here's a nice stability calculator to help you understand more about twist rates:

http://www.jbmballistics.com/cgi-bin/jbmstab-5.1.cgi

 

[coldboremiracle]

^this, I have an 8 twist(16") and a 10 twist(24") and they both shoot the 175 accurately, and just in case you want to shoot something a little heavier then the 10 would be ideal.
I've never heard any reputable source say anything about flutes causing accuracy issues, but I've been wrong before. But just look at most of the guns built here on SH by some of the best smith's in the world, there's an awful lot of tac driving fluted rifles out there.

 

[Uncut_Teeth]

Would an over-spun bullet be more likely to keyhole? I'm just curious. It seems like the .308 twist rate is pretty forgiving.

I wasn't making a 175gr dedicated build, per se, I just did some research and it kept coming up as the most popular round for the distances I'm planning on shooting. The 1:10 twist is tempting, just to play with some of those really heavy rounds. I'll have to think about it...

Yeah, I had noticed all the fluted barrels (my current barrel's fluted), so I was skeptical, figured I'd see if any pros knew what was what. Seems like it might be a problem for the benchrest guys or warehouse shooters, but I just want to ring steel and punch holes in stuff from a ways away.

 

[coldboremiracle]

Keyholing happens when the spin of the bullet is insufficient to keep the bullet flying straight, so theoretically, overspinning is better than underspinning. Your better off with more than you need than with just enough, you'll always wish you had more twist if you ever decide to shoot heavier bullets, but even if you dont, the faster twist wont hold you back at all.
You could compare it to having a V8 in your truck VS. a V6, sure, maybe all you need is the V6, but someday you might wish you had the bigger motor, the difference is that a 10 twist barrel doesn't cost any more than an 11.25, so the choice is simply your preference.

 

[coldboremiracle]

Don't believe the crap about long barrels slowing down bullets. The only common cartridge that does this is .22lr, as far as I know.

BTW, my Dad chopped his 20" .17HMR down to a 16", I didn't chrono them before, but the Hornady box says something like 2550FPS, afterwards we chronoed them at near 2750FPS.

 

[Uncut_Teeth]

That's good to know about keyholing, guess I had it backwards! You've persuaded me to go with a 1:10", I've made the mistake of thinking I won't want more before.

 

[chariotdriver]

Go with the tighter twist; if you ever have an itch to shoot sub-sonic stuff/mount a can on it you'll be getting more bang (technically less) for your buck. A sub-sonic 208gr Amax through a can is stupid quiet in a bolt gun.

 

[Uncut_Teeth]

I'd love to buy a can, but doubt that I'll be able to afford one in this barrel's lifetime. One day. One day...