Jump to content
308AR.com Community
  • Visit Aero Precision
  • Visit Brownells
  • Visit EuroOptic
  • Visit Site
  • Visit Beachin Tactical
  • Visit Rainier Arms
  • Visit Ballistic Advantage
  • Visit Palmetto State Armory
  • Visit Cabelas
  • Visit Sportsmans Guide
C7Prod

Optimum Barrel length for accuracy...

Recommended Posts

  Can anyone help shed some light on the optimum barrel length for an 800 yard dpms platform 308.

  The 24 inch is a bit on the overweight side in bull set-up and I've read that under 21 inches does not facilitate full burn on match ammo powder capacities.

  As I look around I see the army M110 is 20 inches and JP's rpecision rifle sports a 22 inch tube.

I would like to reduce the weight by trimming the barrel but I don't want to sacrifice too much accuracy in the process.

Opinions welcomed.

  C7 Prod ,  Smoke "em

Share this post


Link to post
Share on other sites

ADCO says that recontouring a barrel should have no effect on accuracy. You want your bullet to stay supersonic at the longest range you shoot at. So you will have to do a little research in the loading manuals to see what weight bullets, launched at what velocity will remain supersonic at what range. The biggest advantage to a heavy barrel is that it is less effected  by heat. Long strings of rapid fire can cause a barrel to warp. Personally I would rather shoot a medium weight 24" barrel rather than a 16" bull barrel. More velocity, less muzzle blast.

Share this post


Link to post
Share on other sites

SW Shooter,

Thanks for the response. I will most likely stay with the 24 bull and just build a tactical upper with an 18" A4 profile...Double the fun half the gun...

C7Prod

Share this post


Link to post
Share on other sites

SW,

I think you may be right. I will need only the barrel as I will order an extra upper from JD Machine tech in San Diego. It is a perfect match on my lower. Their bolt assembly are as good as any and I prefer the JP VTac hand guards. I'm not real happy with the uppers I've seen from DPMS but that is just my opinion. Besides I like it best when the upper and lower match perfectly.

  Thanks Again,

C7Prod    "Smoke 'em"

post-32-136297262805_thumb.jpg

Share this post


Link to post
Share on other sites

SW Shooter,

Thanks for the response. I will most likely stay with the 24 bull and just build a tactical upper with an 18" A4 profile...Double the fun half the gun...

C7Prod

This is what I would/will do myself.

Share this post


Link to post
Share on other sites

X2 on keeping the 24.  I have the 24" on mine and have had her out to 400 with awesome accuracy.  I think the 24 is a great fit on the rifle, although I will agree it is heavy, if you want to peel some weight you could have it fluted...  Good luck

Share this post


Link to post
Share on other sites

I have the 24" barrel on mine to and yes, the first thing everyone says when I hand it to em is Dang! that's heavy!! I would like to get a match grade barrel eventually and I will for sure get it fluted if I ever do that.  As far as accuracy goes, it'll for sure put em out there nicely.  My guess would be that the overall gun would outshoot my shooting ability.  If I ever get around to getting some pics up I have an old satallite dish that me and some buddies used as a 300+/- target holder, needless to say, I don't think it will pick up a signal very well anymore ;D

Share this post


Link to post
Share on other sites

X2 on keeping the 24.  I have the 24" on mine and have had her out to 400 with awesome accuracy.  I think the 24 is a great fit on the rifle, although I will agree it is heavy, if you want to peel some weight you could have it fluted...  Good luck

I own the .308B 18'' and I've shot clay pigeons @ 400 yds a few times now and it doesn't miss unless It's my fault. I'm not a group shooter most of the time so I usually shoot clays (deer heart size) but @ 100 yds it's sub MOA.

I probably wouldn't take a shot past 500 yds @ a deer with it because the 18'' barrel doesn't have enough energy for a clean kill past that range IMHO.

I do know a guy who owns the 24'' and he says it'll shoot MOA out to 800 yds with Amax bullets.

Share this post


Link to post
Share on other sites

Just my two cents on the barrel length thing. There was a test done by L.A. co. S.W.A.T. where they took a Tango 51 in .308 cal. and cut it down an inch at a time and test fired it at each length. What they found was that all they way down to 20 inches there was NO loss in velocity and  the federal GMM (test round) had time for a complete burn. At 18 inches there was only a loss of 32 feet per second going from 2660 fps to around 2630 fps. They also found that the shorter barrel was more rigid than the longer barrels adding to accuracy.

Share this post


Link to post
Share on other sites

I do know a guy who owns the 24'' and he says it'll shoot MOA out to 800 yds with Amax bullets.

I'm still breaking my 24" barrel in, but I already know with absolute certainty that @ 100 yards, this gun will shoot one-hole groups all day long, as long as you're doing everything correctly. I want to find out how my gun is going to perform at extreme long distance before I go cutting anything off of it, and in that same vein, would almost rather buy a different barrel for comparison than to cut the one I have.

Share this post


Link to post
Share on other sites

Hey Brother,

Without sounding like the know it all post police, I think what you meant to post was significant loss in velocity(in the author's opinion). There was something akin to twenty or so FPS per inch chopped. It wasn't until they got down past twenty inches that the velocity loss started to increase substantially...

That said, my custom quarter MOA bolt gun sports a 26" tube. Velocity is a funny thing. Atmospheric conditions play hell with it. So, I like to err on the side of extra margin of error. So if I'm shooting in some low cold location, she will still get the job done. I also live in Jersey, where suppressors are verboten. Having a 26" tube guarantees me a complete powder burn for reduced a muzzle flash and report(target indicators), since it all happens in the barrel instead of the air in front of my muzzle.

Now, to be honest, shorter barrels can still reach longer distances, provided there is ample range of travel in the scope. There will be greater adjustments needed for range and wind will also have a greater impact, but it can be done. Rounds will also matter a bit more, as you'll need a round that remains stable as it transitions to subsonic, at range. Some get very erratic during the transition...I have every intention of shooting my POF 16.5" Recon at extended range. Will it do what my bolt gun does? Nah, but it should still get the job done if the loose nut behind the trigger hangs on...

I hope this helps...

Respectfully,

Harry

Share this post


Link to post
Share on other sites

To understand range and accuracy, I have two observations.

The first has to do with the 168 grn Sierra Match King bullets shot out of the M14 which has a 22inch barrel.  The caliber is 7.62X51mm / .308 Win.  The Marines were using this bullet like the Army Marksmanship teams (till they switched to the M16A2 shooting the 80 grn SMKs.  Range was out to 1000 yards.  The 168 grn were going sub-sonic before reaching 1000 yards.  When they switched to the 175 grn bullets with a 1 in 10 twist the bullets remained supersonic at the 1000 yard range.  So the lesson here is barrel length, muzzle velocity, rifle twist, weight of the bullet.  A lot of money was spent on barrels for M14s from companies like Krieger. 

The second has to do with the requirements of the international Palma Match.  The Palma match teams can only shoot 155 grn bullets (Sierra Match Kings once again).  The barrels of the Palma rifles were 28-30 inches and the twist was 1 in 11.5 inches or thereabouts all in .308 Win or 7.62x51mm.  This combination remains very competitive at a 1000 yards plus.  Savage has a very nice intro Palma rifle at around $1000. 

Another bonus observation is the length of barrels on the Sharps rifles and the size and weight of their lead bullets.  The "Quigley" Sharps rifle has a 34 inch barrel.

Again, look at the variables, what determines effectiveness will depend on barrel length, bullet weight, rifle twist, and muzzle velocity.  The right combination determines the end result for which you are making a selection based on your purpose.

Share this post


Link to post
Share on other sites

PS as a Marine Corps sniper I would not cut the barrel if I were you I just get another Barrel and keep the 24-inch Barrel I have a bull barrel on my LR 308 stainless steel I found out that you can get a halfway decent Barrel Delta Tactical they custom make a complete upper what's the barrel you might want to check it out I myself do not like cutting barrels . Even though I'm a gunsmith I will advise you to just keep your barrel 24in and pick up another Barrel a complete upper and get it the size you want Delta Tactical has good prices I have an Sr 25 with a 20 inch barrel I also have an Sr 25 with a 24-inch Barrel I also have an Sr 25 with an 18-inch barrel I also have an LR 308 will a 24-inch bull barrel also have an LR 308 with an 18 inch bro I would advise you just to go ahead and order a upper complete upper through Delta Tactical. Wish you luck sincerely yours Master Gunnery Sergeant Velez USMC ret

Share this post


Link to post
Share on other sites
7 minutes ago, Joseph said:

PS as a Marine Corps sniper I would not cut the barrel if I were you I just get another Barrel and keep the 24-inch Barrel I have a bull barrel on my LR 308 stainless steel I found out that you can get a halfway decent Barrel Delta Tactical they custom make a complete upper what's the barrel you might want to check it out I myself do not like cutting barrels . Even though I'm a gunsmith I will advise you to just keep your barrel 24in and pick up another Barrel a complete upper and get it the size you want Delta Tactical has good prices I have an Sr 25 with a 20 inch barrel I also have an Sr 25 with a 24-inch Barrel I also have an Sr 25 with an 18-inch barrel I also have an LR 308 will a 24-inch bull barrel also have an LR 308 with an 18 inch bro I would advise you just to go ahead and order a upper complete upper through Delta Tactical. Wish you luck sincerely yours Master Gunnery Sergeant Velez USMC ret

The thread is ELEVEN YEARS OLD, Sniper.  11 years old.  Keen perception skills you got there.   :hail:

Oh, welcome to the board - go rip up the Intro Section, and tell us all about yourself. 

Edited by 98Z5V

Share this post


Link to post
Share on other sites

Rodger that I understand I was just reading the post I figure I just add on to post for anybody who wanted to read the information for information purposes hopefully it will be beneficial to someone else. Wishing you guys all the best out there safe shooting is always good to go put some input out there for someone who might come down the road and look at the article I know that the article is quite old I was looking some information is found this information on barrels I don't recommend cutting a barrel just my point of view and some Marine Corps sniper join the Marine Corps in 1977 seems like a long time ago have to push the train with Carlos Hathcock Semper Fidelis always faithful Master Gunnery Sergeant J Velez USMC forever

Share this post


Link to post
Share on other sites
9 minutes ago, Joseph said:

Rodger that I understand I was just reading the post I figure I just add on to post for anybody who wanted to read the information for information purposes hopefully it will be beneficial to someone else. Wishing you guys all the best out there safe shooting is always good to go put some input out there for someone who might come down the road and look at the article I know that the article is quite old I was looking some information is found this information on barrels I don't recommend cutting a barrel just my point of view and some Marine Corps sniper join the Marine Corps in 1977 seems like a long time ago have to push the train with Carlos Hathcock Semper Fidelis always faithful Master Gunnery Sergeant J Velez USMC forever

Lots of guys have cut barrels, and made improvements.  A former Marine Sniper runs a school out here in AZ, and he disproved this myth.  By cutting the barrel an inch at a time, and shooting 900 yards, everytime.  Zero loss of accuracy.  Maybe a change in DOPE, but no loss of accuracy. Contact GPS Defense for more info.  They used to have a very good article about it up here, and I've linked it before - they used a SawZall to cut the barrel, and re-test - and didn't even recrown the barrel.

https://www.sniperschool.com/

Share this post


Link to post
Share on other sites
7 minutes ago, 98Z5V said:

Lots of guys have cut barrels, and made improvements.  A former Marine Sniper runs a school out here in AZ, and he disproved this myth.  By cutting the barrel an inch at a time, and shooting 900 yards, everytime.  Zero loss of accuracy.  Maybe a change in DOPE, but no loss of accuracy. Contact GPS Defense for more info.  They used to have a very good article about it up here, and I've linked it before - they used a SawZall to cut the barrel, and re-test - and didn't even recrown the barrel.

https://www.sniperschool.com/

Thank you for the wonderful information sir live here in Florida have family in California thinking to relocating to Arizona I was checking up the sniper School you were talking about thank you very much for the info best wishes keeping it real

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...