Best barrel length for a .308 bolt gun?

[atalkingsausage]

I have a Remington 700 sps action with a 26" barrel chambered in .308,and I want to know what the optimum barrel length would be for taking 4 to 500 yard shots with a possibility of one day going out to a grand. I know a lot of people like the 18 to 20" range so somewhere around there is what I'm thinking. All I know is every time I look at my rifle I think to myself 'that barrel has got to be too long.
Also I need some help getting up the nerve to actually let someone go hacking away at my barrel... Any wisdom on this subject would greatly be appreciated.

 

[Captain Kirk]

Re: Best barrel length for a .308 bolt gun?

20-22, I'd opt for 22"

 

[jpspeeddemon]

Re: Best barrel length for a .308 bolt gun?

20" is very popular, definetly want a shorter barrel for a 308

 

[wildcats]

Re: Best barrel length for a .308 bolt gun?

Keep it at 26, or no shorter than 24 if you are planing to take it to 1k.
Keep in mind that for every 1` you cut off of barrel, you loose 30-50 ps.

 

[Luke]

Re: Best barrel length for a .308 bolt gun?

Seriously consider your desired use of the rifle and go from there.

If you are worried about every last drop of accuracy at 1000 yards you're probably better off leaving it at 26", or just starting over with a blueprinted custom rifle.

If you are wanting an accurate, portable field rifle that will make you happy to hammer at 800yds and an occasional 1000yd as icing on the cake, a 18"-20" will do the job quite well.

FWIW, I cut my 24" Savage 10FP down to 18.5" and went from ~2630fps to ~2500fps (-130fps). If I was making high risk cold bore shots at 1000yds that would be a big deal, but I'm not, I shoot for recreation in a civilian environment, so I simply add a couple more clicks of elevation on my scope and carry on....

 

[atalkingsausage]

Re: Best barrel length for a .308 bolt gun?

Thanks for the input. Any help with getting up the nerve to actually let someone do this? what are the dangers of the cut and the crown not being perpendicular with the bore axis? Will that effect group size or just poi or both? Are these fears unfounded since my gunsmith would be using a lathe?
I took a different rifle that i let my guy cut down to a gun shop a couple weeks ago and the guy behind the counter said it needed a new crown job because the crown wasn't square. personally I thought my smith did a great job, and the rifle shoots really well But that shop owner's comments have me questioning whether or not to take another rifle to my smith... especially a precision rifle.

 

[Luke]

Re: Best barrel length for a .308 bolt gun?

Unless the guy behind the counter used a square to check I wouldn't trust his minute-of-eyeball technique, especially if it looks fine to you. On the other hand it's always good to check and if you trust your gunsmith it never hurts to ask him, that way you get a quality product and it pushes your smith to do quality work.

Also ask your smith what technique he uses to crown. I know some smiths that simply hacksaw off the end and crown it by hand. Ensure he's using a lathe with the barrel trued to boreline and crowned correctly.

 

[atalkingsausage]

Re: Best barrel length for a .308 bolt gun?

I Know he's using a lathe. I had him cut the other rifle to 18 inches in order to make the oal of the rifle less that 40 inches. And when i picked it up he was talking about how he couldn't have cut it any shorter since the lathe didn't leave enough of the barrel sticking out to do anything with.
By the way, i don't think i mentioned that this guy is a friend of my grandfather who is doing this work for free. I suppose i could just let him cut it a half inch or so longer than I actually want it. If anything were to be wrong I wouldn't be out any money and i could just let someone else cut it correctly....

 

[Captain Kirk]

Re: Best barrel length for a .308 bolt gun?

Some people try to make others look bad to make themselves look good.

 

[Luke]

Re: Best barrel length for a .308 bolt gun?

Unless it gets cut reaaaally bad it would only take a couple 0.010" to get it re-crowned square so I wouldn't worry too much about leaving extra on. I have seen first hand and have heard of rifles with major defects in the bore and crown and they still shot great. It's mainly when you have knicked crowns and things obstructing the bullet path do things get out of hand. Unless you have a rail gun in a closed environment I doubt the bullet will notice a crown that is off by 1 or 2 degrees....

 

[atalkingsausage]

Re: Best barrel length for a .308 bolt gun?

This is true. Even in a worst case scenario it's not like it cant be fixed.... I guess I might as well go for it. I'll probably have him cut it to 20" That should be plenty long enough for my intended purpose.

 

[atalkingsausage]

Re: Best barrel length for a .308 bolt gun?

Just a little update here: I ended up cutting the barrel to 20" myself, using Larry Potterfield's hand tool method. It came out really well and even though it wasn't turned on a lathe. The rifle still produces groups that are around 1/4 MOA.
I highly doubt that the crown is perfectly square with the bore, but as someone said earlier in this thread, The rifle isn't a rail gun in an enclosed environment so it doesn't know the difference. Thank you all for your input on this. I may post another update if I find my work to be inadequate.

 

[Niles Coyote]

Re: Best barrel length for a .308 bolt gun?

If you are staying with the factory barrel, 20" will take you to 1000y, the wind will kick you in the butt and laugh, but it will take you there. I find that my 20" Remington tactical is great at 800 on in. The varmint with the 26" barrel gets 100 additional feet per second for those 6 inches when the same loads are used in both.

If I were to cut my varmint back, I would cut at 23" just so I could be over 2600fps with every combo that I like to launch.

It has been my experience that a custom barrel will get you more velocity in the same length as a factory tube. Case in point, my 21.75” rock creek 308 gets ~2650 with my 175smk load, the Remington with the 26” (4.25” longer than the custom) shooting the same load is right around the same speed and my tactical (1.75” shorter than the rock)is a full 100fps slower at 2550.

 

[XTR]

Re: Best barrel length for a .308 bolt gun?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Niles Coyote</div><div class="ubbcode-body">If you are staying with the factory barrel, 20" will take you to 1000y, the wind will kick you in the butt and laugh, but it will take you there. I find that my 20" Remington tactical is great at 800 on in. The varmint with the 26" barrel gets 100 additional feet per second for those 6 inches when the same loads are used in both.

If I were to cut my varmint back, I would cut at 23" just so I could be over 2600fps with every combo that I like to launch.

It has been my experience that a custom barrel will get you more velocity in the same length as a factory tube. Case in point, my 21.75” rock creek 308 gets ~2650 with my 175smk load, the Remington with the 26” (4.25” longer than the custom) shooting the same load is right around the same speed and my tactical (1.75” shorter than the rock)is a full 100fps slower at 2550.
</div></div>

I have the same/similar experience, my 24" Rock Creek is faster than my factory 26" Rem Varmint by close to 100 FPS with the same load.

 

[atalkingsausage]

Re: Best barrel length for a .308 bolt gun?

Well since you brought up reloading....Dare I ask what OAL you use for your handloads? I know a lot of people don't like to talk about what loads they use personally due to the potential lawsuits that could theoretically stem from doing so. However, if you don't mind talking about it I'll be working some of my own up very shortly and would love some advice on doing so. I plan to use Varget powder to push maybe a 168-175gr matchking bullet. 99.99 percent of my shots will be under 600 yards so I'm trying to decide between the lighter 168gr bullet or the better ballistic coefficient of the 175gr. The 168 gr bullets also seem to have price and availability going for them. any thoughts?

 

[XTR]

Re: Best barrel length for a .308 bolt gun?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: atalkingsausage</div><div class="ubbcode-body">Well since you brought up reloading....Dare I ask what OAL you use for your handloads? I know a lot of people don't like to talk about what loads they use personally due to the potential lawsuits that could theoretically stem from doing so. However, if you don't mind talking about it I'll be working some of my own up very shortly and would love some advice on doing so. I plan to use Varget powder to push maybe a 168-175gr matchking bullet. 99.99 percent of my shots will be under 600 yards so I'm trying to decide between the lighter 168gr bullet or the better ballistic coefficient of the 175gr. The 168 gr bullets also seem to have price and availability going for them. any thoughts? </div></div>

When it comes to OAL I really only care on my hunting loads, they have to fit in the mag. My match/target bullets are either 175SMKs or 185 Berger BTs, both are pretty forgiving of seating depth, but I seat .020 from the lands. The OAL on the Bergers is way longer than mag length, and the next time I check the erosion on my throat and move the 175s out they will be too long too.

Look in the reloading section, there is a ton of information on loading for the 308, but be warned there is also what IMO is a bunch of BS regarding MVs from short barrels. That or a lot of guys with incredible fast 20" tubes that shoot like the slow 30" tubes we put on F-TR rifles.

Work up your loads with Varget, it is a great powder. Learn to do your OCW or ladders and don't pick MV over accuracy, there was an old rule when I shot IPSC that you cant miss fast enough to win, same with this. If a load that is 50FPS slower shoots 1/4MOA tighter it is better.

While you are doing all of that learn about brass prep to get consistent loads, and what matters (like consistent neck tension). It will all come together in a few hundred rounds, and you will have had a lot of practice getting there.

 

[atalkingsausage]

Re: Best barrel length for a .308 bolt gun?

Good advice, I'm pretty new to both reloading and long range shooting So all of these minuscule measurements and adjustments are a pretty exciting new world to me.

 

[Niles Coyote]

Re: Best barrel length for a .308 bolt gun?

Both of my remingtons do well at 2.825 oal with 168, 175 and 180 smk's. My Tactical likes 44.5g varget with the 175, the varmint model a little less. I use winchester brass and primers.

If you are looking for 168 loads, I dont have my data right now but the high velocity node is around 45-46g, there is another a little slower (but more than enough for plinking at 600)around 43-44g.

 

[alpha6164]

Re: Best barrel length for a .308 bolt gun?

Stick with 20". I am not sure why people keep saying that longer barrel=accuracy? Extra length only gives you extra speed slightly and maybe even less accuracy due to flex in the barrel.

Here are the two speeds i get from exact same load 175smk, Varget 44.0gr 2.810" COAL
FNAR 20" factory barrel= 2602ft/sec
GAP 308 with 26" Bartlein barrel= 2677ft/sec

So i basically gain 75ft/sec for the additional 6" which works out to 12.5ft/sec per inch. If i had the choice, i would have had a 20" barrel for the bolt gun as well. My bolt gun looks retarded when i add a suppressor at the end of that 26" tube lol

 

[madAB]

Re: Best barrel length for a .308 bolt gun?

I wouldn't go any shorter than 20" I have the SPS tactical in 20" and it shoots great. If i would have gone custom I probably would or gone with a 22"

 

[atalkingsausage]

Re: Best barrel length for a .308 bolt gun?

Yeah, I cut it to 20" and the gun's group shrank to about 1/4 MOA. Not bad if i do say so myself. I haven't chrono-ed it yet to see how much velocity I lost but .308 seems to be fairly insensitive to barrel length, losing only 30-50 fps per inch of barrel. I can't see the projectiles flying through the air yet so i think I'm good