mark 5 action

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by sodwyer, Oct 7, 2010.

  1. sodwyer

    sodwyer Active Member

    Sep 23, 2010
    Hey guys is there anybody out there useing the weatherby mark 5 action as a platform fo a custom build?
  2. B23

    B23 Well-Known Member

    Oct 30, 2008
    I'm not a gunsmith but I am an owner of some Weatherby's with their MkV action and I'm not sure if this is exactly the information you're looking for but I'll pass on what I've learned and you can go from there.

    Right wrong or indifferent, Weatherby's MkV action is NOT going to be the first choice for a build platform of more gunsmiths than not. In fact, you will probably find a few smiths that won't build on them at all. Now that doesn't mean they are a bad action, just that some don't like to play with them for one reason or the other.

    One of the biggest concerns I hear from the gunsmiths I've talked to was they struggle to feel confident all 9 lugs, even after lapping, are/were contacting the same. Other than that, I believe they can be trued pretty much the same as any other action.

    IMHO, if you are serious about building on a MkV you should look for a gunsmith that LIKES to build off of this platform. JE Custom and Kevin Cram are two that come to mind and not only are they great supporters of this Forum but I have personally talked to both and both these guys were excellent to deal with.

    There are quite a few guys on this forum that have built semi customs around the MkV action with great results.

    Autorotate is on this site and he has a couple semi customs built on MkV's. Look him up and he can probably give you much more information than I. He wears a white lab coat and reloads in a vacuum sealed environmentally controlled lab and, wellll, I think he's a little OCDish too but shhhhh, don't tell him because he still thinks he's normal. :D

    None the less he is great to chat with about his MkV builds.

  3. Autorotate

    Autorotate Well-Known Member

    Apr 2, 2007
    B23....why don't you go uniform some meplats, and double check your weight sorted primers....your scale could've been off when you did that last time......and leave me alone.....sheez. There are some crazy OCD people on this site. He is right though about one thing....about me being perfectly normal:)

    30-338 Lapua, you can get the whole story here

    338 LMAI, built by Joe Starnes

    338 Excalibur, built from a very knowledgeable and skilled LRH gunsmith.

    The guy I would talk to is "Broz".....he's cranking cold bore hits out of his MKV where most commercial range finders run out of steam, and has bagged many critters at distance with his rig.

    Another is "Long Time Long Ranger"......

    B23 is right...if you already have a donor action....use this thread to find you a 'smith for it. Don't force that action on your smith.
  4. Long Time Long Ranger

    Long Time Long Ranger Well-Known Member

    Mar 12, 2002
    The MK 5 wby action is the best action available for a rifle build if your are considering a large magnum build. If you can find one this is your best option. Just carry it to a top gunsmith that knows wby actions. One tip is if the smith starts knocking the wby action move on because that shows he has a bit to learn and I wouldn't have him touch my rifle.
  5. bgouin

    bgouin Active Member

    Feb 13, 2006
    I semi customized my Mark V rifle. The darn thing was very inconsistant. Sometimes the groups were acceptable and sometimes they were just terrible. This is a 340 WM and I like the caliber. I put on a McMillan sporter type stock and had the local gunsmith bed the action. No improvement, but my gunsmith had a bore scope in the shop and, after inspection, we found out that the barrel was the culprit. It then had the the action trued and the bolt squared. My gunsmith elected to skip trying to lap the lugs indicating the futility of such a venture. I am in the process of breaking in the barrel and hope to be able to use it for (semi) long range shooting. I am using a Leupold M-4 scope with a Holland ART reticle.

    One problem with the Mark V action is the lack of after market stuff. Also the action is not as easy to accurize as other actions. The action can be modified for cartridges as long as the 378 Weatherby if you use Weatherby parts and modify the bolt stop. This would allow you to modify the bold face and chamber for a 338 Lapua, 338 Norma, or any case based on the 378 Weatherby. If I were to do it over again on a Mark V action, I would probably use a heavier, longer barrel and a McMillan A-5 stock, keep the bolt face stock, add a longer magazine, lengthen the bolt travel, and chamber for 338 Edge. If you are not interested in taking shots longer than 500-700 yards, or if you do not want to lug a 12-15 pound in the field choose whatever caliber that you had in mind and stick with a thinner 26" barrel.

    Good Luck
  6. Broz

    Broz Well-Known Member

    Feb 3, 2007
    Joe Starnes built my 338 Lapua on a Mark V action as Autorotate indicated. The mark V will easily accomodate larger cases that some actions will not. I don't think you will find a better factory action if a fat case is in the plan.

    Joe Starnes built my Lapua. He is very well versed in ELR and does it on a regular basis. Actually my Lapua was a build he was going to do for his own personal rifle and he offered the parts to me and thn did the build for me. I have no regrets.

    Dave Young of Youngs Gun Smithing in Tracy MT. is another Wby fan. He builds some aweome 34" 338-378's in a V-block floated action the send big bullets at some steller speeds. Again on the Mark V actions.

    I have not had any problem finding good smiths to build on one and I would have no problem doing another.

  7. ffwd

    ffwd Active Member

    Sep 23, 2008
    I built my custom on a Mark V. It is in the pictures section. It did take quite awhile to get the lugs all lapped, but I'm quite happy with the result.
  8. Willys46

    Willys46 Well-Known Member

    Oct 4, 2006
    I have one as well but can not find any my pictures.

    Like other have said, yes they can be built on and if the gunsmith starts talking bad, just move on. Would it be my first choice, NO.

    If you have a action already, then building off it is fine. The 60 degree bolt, the smoothness can not be beat. But if your looking to find a action to build on, then just by a custom action. MKV are usually expensive to buy and for the price you can get a nice custom.

    Mine is on its third barrel in 18 years. I purchased it for myself when i was 14. It has sentimental value now and has never shot better (.33 moa).
  9. RDM416

    RDM416 Well-Known Member

    Jan 31, 2005
    I also have a semi custom built on a WBY action with excellent results. Mine is a 338Kahn built from a 338/378. The rifle shoots great and with almost 800 rounds through it, it still will shoot 1/4 moa.

    Kirby Allen built mine several years ago..... not sure if he still does that kind of work or not but it would not hurt to ask.

    I agree with Willys46 though, if you already have the action fine, but if not then just a little more money will get you a custom action and a lot more smith who are willing to build on it.
  10. sodwyer

    sodwyer Active Member

    Sep 23, 2010
    My mark 5 is a 300 win mag and I would like to remove the magazine block off to take advantage of this actions true length. it looks like the bolt stop grove will need to be extended not shure how much? Is there anything else to consider?