Troubleshooting a .308 Win.

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by JPG, Aug 2, 2002.

  1. JPG

    JPG New Member

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    I have a Rem. 700 M-40A3 in .308. Built by very talented smiths. It shoots .5 to .75 MOA with BHM 175. I can match the performance with my handloads, but not improve it. I figure this rifle should be good for .25. My equipment is all top notch, as well as components. Lapua brass, varget, and vit. 140 powders, Federal GMM primers, 175 SMK bullets. I have played with seating debth and velocity to no end. Changed powder, but not primer. Case prepped to the max with the exception of neckturning, necks are super consistent. I have varied my bench manners, but still cannot hit my .25 MOA goal. I shoot at a range that has near purfect conditions in the AM and PM. Loads do well at the 1000YD line with the exception of a couple of missed wind shifts. My next course of action is to try 168 & 155 SMK and then try CCI Benchrest primers, but onlr changing one variable at a time of course. Any wisdom or insight would be great. Thank You in advance.
     
  2. Dave King

    Dave King Well-Known Member

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    What size groups do you get at ranges further than 100 yards?

    What scope and power are you using?
     
  3. CatShooter

    CatShooter Well-Known Member

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    Jason...

    The 1/4", .308 rifle, while not truely rare, is NOT a common gun. Every builder of rifles swears that their guns are 1/4" shooters, but alass, one 1/4" group does not a 1/4" rifle make!

    As "Doc" asked... you have said nothing about the scope, or set-up, etc. Also, you have not said anything about your shooting skills... do you have any other rifles that you can shoot 1/4" groups out of, opn a constant and regular basis?... which is to say "Are YOU a 1/4" shooter?

    Not to disparage your shooting tallents, but.... most shooters think that if they have a 1/4" rifle, that they can shoot 1/4" groups. Unfortunatly, that is not the truth.

    To shoot 1/4 groups with any regularity, it takes everything in the system... the rifle, the scope, the ammo, and the shooter's tallents, to be melded into one shooting machine... most shooters never get there.

    CatShooter.
     
  4. *WyoWhisper*

    *WyoWhisper* Guest

    I feel your pain. I too have a 308 that should and on occasion does shoot into one hole. I have seen it done with my rifle by another person. Therein is the solution ME!! I am the reason it doesn't shoot into one hole. A 1/4" group is harder to do than most think. That is shooting into the ".2s"
    Off the top of my head I am thinking here are some of the reasons why your rifle isn't...

    1. see above
    2. What is your twist rate.
    2a, your rifle may not stablize the 175's until further down range.
    3. Trigger how light is it?
    4. optics and parallax adjustment.
     
  5. JPG

    JPG New Member

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    Dave King,
    I have shot for groups at 100,200,& 300, seems to hover around MOA. I think my 3.5-10LR and the targets that I'm using could be part of it, further out.

    Catshooter,
    I agree with you, about shooting .25 all the time being tough. But the sun has to shine on a dogs ass someday! This rifle needs to throw me a bone! Tony Boyer I'm not, but I have shot in one BR match with a loaner rifle and set up. I shot a .189 at 100, and a .232 at 200, so this leads me to believe that I can shoot to some degree.

    Wyowhisper,
    My twist rate is 1-12, in a Hart Barrel.
    I have thought to try 168 & 155 SMK to see what this does. I had bought a boat load of 175 SMK to shoot at 1000YD. I also broke down and bought a brick of CCI BR primers. About passed out when I got the bill! The trigger breaks at about 3.75lbs. The rifle is my pride and joy. I saved for a LOOONG time just for the deposite on it. It was built by Bruce at IBA. I love how durable and beefy it is. It looks nothing like the PSS that loads of people have at ranges all across the country. It's woodland cammo, so it is quite a conversation piece. The optic is a Leupold 3.5-10X LR with the side focus. I would love to put a NXS on but the grand it would take, I could use elsewhere right now.

    Thanks Guys, any help would be great!
     
  6. Dave King

    Dave King Well-Known Member

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    I've got the 3.5 x 10 M1 LR on all of my rifles and I noticed that I can't shoot as small groups as I could when I had a few 4.5 x 14 and 6.5 x 20s.

    Let the rifle breakin a while and if you're up for some new setup, borrow or try out a 6.5 x 20 on the same rifle.

    By IBA I take it to mean Iron Brigade Armory, a Chandler Rifle. It should certainly do whatever you want!!

    My new George Gardner rifle (M40A1 sortof) is just starting to settle in after about 200 rounds, it's got a Mike Rock barrel.
     
  7. *WyoWhisper*

    *WyoWhisper* Guest

    OK first thoughts are this...

    Try Fed 210 M primers
    Varget 42 - 46 grns

    I have a Nor-Cal Nighthawk. It took about 250 rounds to really shoot.. like consistient .2's. I have the 3.5 - 15 X 50 NXS on it..

    It likes the 168's ALOT better than the 175's
    I shoot .2's with the 168's and about .4's with 175's.. it also loves the J4 168 noslers!!! I shot a 15 shot .480 group with them.
    But the 175's group better at 200 than 100. so I assume they are still pitching and yawing at 100.

    Next it LIGHTEN THE TRIGGER!!!! mine is at 1 lb. exactly. It is tough to shoot .2's with a t 3-4 lb trigger...

    Check your bag setup and make sure that your rear swivel stud is not touching the rear bag. I found out the hard way this can drive a man insane!!! Also make sure you return to the same front rest point, make sure everything is level etc. etc. I know that this seems trivial but always start simple...

    Try this then do what Dave said.. try glass with a higher magnification.

    If your shoooting factory ammo and getting anything around .5 your doing pretty good!!!!

    Factory ammo even the match ammo is not very consistient to shoot groups like .2s

    Hope this helps.....
     
  8. Brent

    Brent Well-Known Member

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    Higher power glass will make the big difference. If I had 20x pieces on mine I know my groups at 200yds would be almost 1/2 the size without a doubt.

    The 155 Palma works better than any Sierra I've tried in the 12 twist 308 rifles. The 165 Gameking SPBT and HPBT right behind it. Varget and CCI's at 2.855". The 155 likes 46.4gr while the others like 43-44gr.
     
  9. Gary Rihn

    Gary Rihn Well-Known Member

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    Jason-

    Like others have said, and like you are considering, try the 168's. My 308 LOVES them, and HATES 175's. Your rifle may be the same. Mine would shoot groups over an inch at 100 yards (sometimes over an inch by a LOT), then turn around & put 168's into one hole, literally. It shot a 6" group at 300 yards with 175's, then turned around & followed it with a 1 1/4" group with 168's. At that point, I got rid of my remaing stash of 175's. (I had bought the 500 count "value pack" [​IMG]). The guy with me that day got a good deal on the remaining 175's...

    On a different note, if your rifle shots *consistent* 1/2" groups, that's nothing to sneeze at either...
     
  10. JPG

    JPG New Member

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    I think I'm headed in the right direction now with Dave King, CatShooter, WyoWhisper, Brent, and Gary's help. I have on the way some Badger ring reducers, and some Varget. I can beg the use of a 24X Leupold BR scope, and then I'll see what becomes. I also have a Shilen trigger collecting dust, so I'll install that as well. Has anyone spent the $60.00 on a Tubb Speedlock Firing pin, spring combo? Just wondering, cause most custom smiths don't list them in the parts they use? Thank you, fellas!
     
  11. Nighthawk

    Nighthawk Well-Known Member

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    Sorry to ask this here but I don't know where else to post. How much do you think I could get for a Winchester Model 70 .30-06 with a Leupold Vari-X II 3-9X?
    Thanks
     
  12. DANTEC

    DANTEC Well-Known Member

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    most of 308 WIN rifles even custom built by good gunsmith are chambered for the 308 WIN SAAMI which a broad chambering ( base case and neck 0.344 )with a broad throat

    most accurate ( under 1/2 inch 5 shots group ) are chambered in modified 308 WIN as 308 Obermayer or 308 PALMA or more tighter chambering ( 0.339 neck or 0.340 neck ) to improved accuracy ( without heavy neck turning and BR carrtridge ) and the headspace is set to 1.63 ( minimum headspace ) that help to reach the 1/4 inch group ) .

    Good shooting

    DAN TEC
     
  13. BountyHunter

    BountyHunter Writers Guild

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    Might want to stay with bullets in the 175 gr range if you are going to shoot to 1000. The palma guys get the 155s to shoot to 1000 by using 30 inch barrels and 1-13 twists. You have 1-12 and did not say what lenght but I can assume it to be 26 or max 28.

    Try the Varget powder and F210 primers with Lapua brass. Lapua seems to be one of the most consistent brass available today. Start the bullets in the lands and then come out .005 once you find a powder load that wants to shoot. Try the ladder method discussed under on this board for testing powders.

    1/4 MOA is a lofty goal, and that barrel may not be able to get there. Either way you are going to need a scope of much higher power for load development.
     
  14. kromer

    kromer New Member

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    Aug 23, 2002
    using varget use CCI BR2 primers, they have been real good to me.

    I shoot a Savage 12FVSS I use regular win brass topped with 168gr Sierra or nosler. use 42.2 or 46.6 gr of varget and I can regularly shoot 1/4 at 100yds at 300 it goes up to 2.5inch