338 RUM problems

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by D.Camilleri, Jan 5, 2008.

  1. D.Camilleri

    D.Camilleri Well-Known Member

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    Two years ago I started having problems with my factory barreled 338 RUM model 700. Accuracy went down the drain and I was getting very frustrated. I went to my local smith and he looked in the bore of my barrel and found a crack in one of the lands, there was also an area in the barrel that was holding some copper. He recommended replacing the barrel. I had him blueprint the action and install a Douglas premium 4160 cm barrel finished at 27 3/8 and added a muzzle brake.

    Since the installation of this new barrel, I have fought this gun non stop. In the beginning, cleaning was a royal pain, as the barrel would copper foul very badly. I used the Tubbs final bore finish on the barrel and it seemed to help with the cleaning, but I still can't get the accuracy that I want. I have probably put over 250 rounds through this barrel trying to come up with a load that meets my needs, but I am still not happy. I have made several good kills on elk with the gun, one at 582 yards with 225 grain accubonds and the other at 539 with 250 grain partitions.

    At this point, I have given up on the accubonds, the best group I can get is about 3 inches. Today I went out and shot 5 more loads and to say the least, I am not happy. The only bullets that seem to shoot out of this barrel right now are 250 gr partitions. 98 gr of H-1000 is producing about 2960 with standard deviation of around 15, 1.5 to 2" group. The other load that shows promise is 96 gr of reloader 25 in front of a 250 gr partition moly. This load had standard deviation in the single digits, but still only grouped at about 1.5" velocity was about 2930 average.

    I have also shot some factory ammo through this barrel and it shoots about 2.5" at about 2800.

    This rifle has a laminate stock that is bedded and floated, the scope is a sightron 4-16 (3rd sightron scope) with burris high rings and two piece bases.

    The bullets the I shot today were shot with the bullets seated out to max length that would fit in the magazine, which is still about .090 off the lands. The OAL was 3.655. My prior loads actually shot better with the OAL at 3.580.

    I had high hopes for sierra game king 250 bt behind 98 gr of H 1000, but these seemed to print to the same height, but strung out right to left about 4".

    I am truly at wits end trying to make this gun shoot! When my original barrel was working right, 3" groups at 300 yards were the norm.

    Is it possible to have a barrel that is this finicky with bullets or did I just get a poor barrel? The finish on the inside of the barrel looks excellent now and the throat shows no errosion.

    Cases are all full length sized, primer pockets cleaned and cases trimmed.

    I love the terminal performance of this cartridge, but I need better accuracy.
    All opinions are welcome.
     

  2. davewilson

    davewilson Well-Known Member

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    you're correct, it is possible to get a bad shooting barrel. that happens once in a while. the only thing that caught my eye was when you stated the group was horizontal of 4" if that's not a wind thing ,then i would say you have receiver issues. i'm assuming you've eliminated the possibility of a bad scope and or mounting problems.that would have to be done before moving on to the gun. don't claim to be an expert, but at this point i would say the receiver wasn't trued, it was probably screwed. maybe one of our experts will chime in, i didn''t even sleep at a Holiday Inn last night!
     

  3. jwp475

    jwp475 Well-Known Member

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    Have you beded your scope bases to the action? If not try it and see if bedding them stops the horizontal stringing worked for me once..
     
  4. D.Camilleri

    D.Camilleri Well-Known Member

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    Of the loads I shot yesterday, only one load strung out, it was the sierra 250 game king bt. Both groups of nosler partitions shot actual groups, just not very tight, 2" to 3". I tried a load with 200 grain hornady's that grouped around 12" and it wasn't even close to being a hot load, only 3070fps. Today I will seat my bullets back to 3.580 and only shoot the nosler's. I have tried 3 different scopes and am on my second set of bases and rings on this gun. First set of bases and rings were dual dovetail leuopold because without the muzzle brake I kept shearing the ears off of the rear windage mount. With the dual dove tails on, it required moving the windage adjustment quite a bit off of center in the scope. After lengthly discussions with the owner of Sightron, he wanted me to use windage bases and zero the scope as close as possible to keep the cross hairs in the center.

    As far as the action being true, my gunsmith is old school and very profficient. I forgot to mention that this barrel was turned to a #5 contour with an 11 degree crown. Right now I am super cleaning the barrel to make sure there is no copper fouling and I will shoot it again today.

    What really frustrates me is that my original factory barrel shot great until the defects showed up. I recently had this same gunsmith install a take off 300RUM barrel on my old 338 win action and it shoots 1/2 moa all day and isn't picky at all.

    I am really starting to think about a different barrel, maybe a Lilja ss.
     
  5. davewilson

    davewilson Well-Known Member

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    was this barrel a heavier contour and you had it turned down to a smaller contour? if that's the case, i'm bettin on the barrel being the problem.
     
  6. jwp475

    jwp475 Well-Known Member

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    I agree with Dave it is not advisable to contour a buttom barrel.
     
  7. D.Camilleri

    D.Camilleri Well-Known Member

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    Yes, the barrel came as a straight blank at full dimension. At the time, this gunsmith was contouring all of his own. Now he has determined that it is much easier and cheaper to order the barrel with the propper contour. I watched him contour this barrel, he kept his carbide sharp and took very small cuts with plenty of cooling fluid. The barrel never got hot while he was turning it.

    Now on to the news of today. I super cleaned the barrel last night and again this morning. Got a lot of copper out of it, got it all out. Loaded up some more shells and went to the range.

    I pushed the OAL back to where I had been shooting before 3.600. Loaded some 250 gr partitions with moly behind 97 gr of Rel 25, some more behind 98 gr of Rel 25, some uncoated partitions in front of 96 gr of Rel 25 and some sierra game king 250's in front of 96 gr of Rel 25. I also shot my hunting load from the last 2 years of 98 gr of H-1000 in front of uncoated partition 250 gr.

    97 gr rel 25, 250 partition moly: 4 shots 3.5" 2960fps
    98 gr rel 25, 250 partition moly: 5 shots 1.25" with one flyer 3010fps
    96 gr rel 25, 250 partition uncoated: 5 shots just under an inch 3050fps
    96 gr rel 25, 250 sierra game king: 8" or more horrible
    98 gr H-1000 250 partition uncoated: about 1.5" three shots under an inch with two flyers 2955fps
    This is a little bit more encouraging, but this barrel still won't shoot a boat tail bullet at all and I have no idea why.

    I have several loads here that I should be able to improve on, as soon as my shoulder heals up.

    So why won't this barrel shoot boat tails? How much free bore is a 338 rum supposed to have? I know mine has a lot and seems to shoot better with the bullets having a long jump. At least now I know I can get at least a reasonable group. This barrel is still copper fouling badly. But it will be very clean for the rest of the testing.
     
  8. JD338

    JD338 Well-Known Member

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    D.Camilleri

    I have a M700LSS in 338 RUM with a Leupold VariX III 2.5x8 and get excellent accuracy with several loads.
    Here are my favorite loads for the 338 RUM. All loads were taken from the Nosler #5 manual and are safe in MY rifle. I am using R-P cases and Federal GM215M primers. I run all COL's at 3.645".

    200 gr Nosler BT
    RL22 90.0 grs
    best 3 shot group @ 100 yds .325"

    210 gr Nosler PT
    RL22 90.0 grs
    best 4 shot group @ 100 yds .425"
    best 3 shot group @ 300 yds 1.285"

    225 gr Nosler PT
    RL22 90.0 grs
    best 3 shot group @ 100 yds .450"

    225 gr Nosler AB
    RL25 96.0 grs
    best 4 shot group @ 100 yds .567"

    250 gr Nosler PT
    RL25 90.0 grs
    best 4 shot group @ 100 yds .490"

    Hope this helps.

    JD338
     
    Last edited: Jan 7, 2008
  9. rtv900

    rtv900 Well-Known Member

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    This is an interesting thread. I am in the process of trying to decide between a 300RUM and a 338RUM. I really appreciate the info on contour of a bbl and load information. You guys really know your stuff. It is a delight to read your posts.
     
  10. royinidaho

    royinidaho Writers Guild

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    Howdy Fella,

    Your situation sounds pretty much like being married to the wrong woman:D

    I took some time to study each of your posts as I'm also shooting a 338 RUM which started life as a 338 Win Mag. The WinMag bbl was replaced w/a REM new take off sporter barrel - 26". It has a Holland QD brake installed along with a Limbsaver recoil pad on the other end.

    I Tubbs'd the "new" barrel as part of the break in process.

    My first input would be about your statement: "as soon as my shoulder heals up". My rifle weighs in at 10# all up and I'm attempting to shoot the barrel out to get a halfway decent excuse to upgrade to a bigger cartridge.:rolleyes: I shoot it prone all afternoon and have no recovery time. What kind of brake are you using??

    Next, I can't get anywhere near the velocities you are getting. An inch+ advantage that your barrel has doesn't provide "that" much more velocity.

    Considering the excessive copper fouling even after the Tubb's process is something to be considered.

    What if the extra velocity, if it is really extra, and excessive copper fouling would it be silly consider a loose bore? What that means I have no idea but it may also make a little sense that it doesn't like boat tails. It's my under standing that flat base bullets and RBBTs seal at the base a bit better at the base upon firing.

    If all else fails one last thing to try, which is a bit selfish on my part as you are posting some good stuff.

    Have a go with US-869 and 300gr SMKs. Hodgon's says 101 grains is max but I'd look it up first. I got nothing to shoot in my 338 RUM until I got to this combination. Now she's 1/4 MOA @ 200. 2730 +/- 1 fps @ 40* F.

    PS: with a Lilja which are tight bores, your pressures will go up and velocity will go down but most certainly the accuracy will be there if all else is in order.
     
    Last edited: Jan 7, 2008
  11. J E Custom

    J E Custom Well-Known Member

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    Vertical stringing is normaly caused by inconsistant trigger pull.

    Horizontal stringing is caused by barrel/action to stock fit (poor
    bedding ,barrel touching stock on one side, loose bedding screws,
    or no metal to metal contact between action screws and recever.

    As far as the fouling I have had a few barrels that had to be lapped
    to save them.

    Now I biuld only on select match stainless barrels and have eliminated
    this problem and the cost is very little more considering extended
    throat life and they are already laped and contoured.

    I would try lapping and if this does not improve the accurace then
    replace it with a premium stainless barrel and you wont be sorry.

    Just my opinion
    J E CUSTOM
     
  12. D.Camilleri

    D.Camilleri Well-Known Member

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    These are all good ideas and will be followed up on, but I still have a question about about the throat length of a blue printed 338 RUM. I am thinking about having the smith that built this gun make a chamber casting and check the dimensions. When he built it, mine was the first barrel to be done with a new reamer. Maybe the reamer wasn't cut properly. Just talked to a friend with a factory barreled 338 RUM and he can get his bullets within .030 of the lands. I can't get within .090 of the lands and my throat isn't erroded. My factory barrel shot every bullet well before the problems started, this barrel has never shot any bullet well with the exception of the 250 gr partions.

    One other thing I am considering is to increase the bedding area in front of the lug, due to the fact that the chamber taper ends at a rather sharp point and changes to barrel contour and in my opinion, if the barrel was going to whip, it would start right at this transition.

    I just picked up a lead sled yesterday, so I can quit abusing my body with this shoulder abuser.
     
  13. D.Camilleri

    D.Camilleri Well-Known Member

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    I measured the chamber yesterday with several different bullets. I think I am zeroing in on a problem. Nosler partitions are much closer to the lands than Nosler Accubonds, but I had no idea the difference would be .400. There is no way I could ever get an accubond close to the lands without single shotting it, which isn't an option in grizzly country. The partions are showing some promise, so I will start playing with the oal to see if I can shrink the group. I also just bought a lead sled so I can take me out of the equation.

    I also measured the 250 grain sierra game king and it is within .018 of the 250 grain partition, but with the same powder charge it shot a pattern not a group.

    Why doesn't this barrel like boat tails? I am strongly thinking it is time for a different barrel, maybe a Mike Rock. Any thoughts?
     
  14. Chawlston

    Chawlston Guest

    You have more than one issue:

    --barrel turned after final lapping

    --gunsmith who did the above probably did the rest of the gun

    --the chamer is throated way too far (seen this before)


    My recommendation is to get a "new" set of eyes on the project so that something else does not go un-noticed

    BTW, we are getting <.375" @ 100 yards and right at 1.2" @ 400 yards with factory Remington guns shooting factory ammo. Factory guns with reloaded ammo will yield significantly less than the above.

    Finally, a good mirage shade can always be a good asset when shooting loads to determine recipe loading data. When I forget to put mine on, it is very easy to see it in the grouping at 100 and 400 yards.

    Chawslton