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Worth working on? Sporterized m98 mauser w/ bad chamber.

Discussion in 'Gunsmithing and Repairs' started by Ed Ames, Sep 22, 2014.

  1. Ed Ames

    Ed Ames Well-Known Member

    I'm in a bit of a safe clean out mood and would appreciate thoughts and opinions on this...

    I was given a commercially sporterized m98 in 30-06. It has an ok Monte Carlo (not cut down military) stock. I think it was made from a Nazi rifle after WWII by Golden State Arms or similar (that was their business model from after WWII until the 1960s).

    It has the absolute worst chamber ever. As in it can't be shot because the reamer they used was chipped enough to cut rings in the chamber. The brass case forms into those rings and lock when the gun is fired. It takes a blithwapper to open the bolt with a fired case in the chamber.

    I also have an in-the-white/rough chambered 7mm Rem Mag barrel I got a long time ago for reasons I have since forgotten. I don't really have a use for a 7mm mag Mauser and I am only assuming the cartridges will feed etc.

    My question: is there anything worthwhile that can be made from those bits for a justifiable price? They are basically taking up space on the off chance I will get laid off and be able to use some of that sweet (fantasy) severance money to take some of the short form gunsmithing classes/use it as project material. However, after 20 years of holding on to that dream it just doesn't look like it is going to happen.

    So what would you do if that was in the back of your safe?
  2. BBBBill

    BBBBill Well-Known Member

    Mausers are 1.10" x 12 TPI with a shank length of anywhere from .620" to .700" depending on the particular variant. Remingtons are 1.062" x 16 TPI with a .855" shank. The shank would have to be removed, with the shoulder cut back to create a new shank for threading. Depending on the specific chamber dimensions of the original chambering and the desired final chamber, you might or might not be able to clean it up with a reamer. We used to fit .30-06 03 Springfield barrels to Mausers that way ending up with a .308. The barrel contour from the shoulder forward also plays a part. If the barrel tapers too quickly the new shoulder will be too far forward with respect to the taper for good appearance. All of that to say that, basically, you need to map the barrel to make an accurate assessment its usefulness.
  3. Ed Ames

    Ed Ames Well-Known Member

    Oops, sloppy wording on my part. I should say...I have an unfinished/in the white large ring Mauser barrel that has been short chambered for 7mm rem mag. As far as I know it will thread in and can then be finish reamed for headspace but I don't have the tools to hold the receiver properly and remove the old barrel without twisting something that wasn't meant to twist.
  4. Willie Sutton

    Willie Sutton Well-Known Member

    Why don't you consider running a reamer into it for one of the "improved" cases? Where's the damage located?


  5. fguffey

    fguffey Well-Known Member

    I would suggest you determine how deep the gouges are in the chamber, two options, the 30 Gibbs and the 30/06 Ackley improved.

    There is the 308 Norma Mag if the bore is good, feeding will become a problem without additional work.

    F. Guffey
  6. 4v50 Gary

    4v50 Gary Moderator Staff Member

    The barrel is salvageable and I'd have the chamber reamed for another .30 caliber.

    If it must be 30-06, then a new shank will have to be cut. The length lost from the barrel length will correspond to the area of the chamber that can be salvaged by reaming deeper.

    ETA: The barrel can be bored out, a new 30 caliber liner inserted and a new chamber reamed.
  7. Kp321

    Kp321 Well-Known Member

    If you have access to a lathe or someone who owns one, remove the barrel and set it back one thread (1/12" or .0825") and rechamber. The 30-06 has enough taper to clean up pretty deep damage with one thread setback.
  8. Ed Ames

    Ed Ames Well-Known Member

    Reaming the chamber makes a lot of sense. I hadn't thought of that because I'm generally wildcat-ignorant.

    I think my first step is to get some cerrosafe, melt and pour, and hope I can get it out of the chamber. That way I'll know exactly what I am dealing with.

    Any advice for getting cerrosafe out of a rough chamber other than wooden dowel and mallet at 30 minutes?
  9. LAGS

    LAGS Well-Known Member

    If you rebarrel the rifle with the 7mm Mag barrel, you will have to have the Bolt Face modified to fit the Magnum case head.
    You are going about things the correct way.
    Cast the chamber and see where the damage is.
    Have the barrel pulled, and then one thread cut off the shank to set the barrel back.
    Then it can be Hand reamed to proper headspacing.
    Even if you had the barrel vise and the action wrench, you still need access to a Lathe.
    But you can have the barrel pulled and replaced with any low cost short chambered aftermarket barrel , but that will end up costing as much if not more then to have the barrel set back one turn and re headspaced.
    IMO, it is worth messing with.
    For what you have in the rifle, it is well worth investing some time and money to get it shooting again.
  10. LAGS

    LAGS Well-Known Member

    When I do a chamber cast,
    I use a 1/4" aluminum rod about 3' long.
    I use it to push a patch over the end of the rod the same as if you were using the rod as a cleaning Jag.
    Push the rod and patch on the end all the way in untill it is just at the throat of the chamber just ahead of the freebore.
    Then tape the rod to the muzzle so it doesnt fall out or move.
    Leave the rod in the bore when you do your casting.
    The Patch should be snug in the bore anyway, but tape it just to be sure.
    Now when you cast your chamber you only have ONE thickness of patch that will effect the force when you try to drive out the cooled cerosafe.
    many people stuff a Ball of cleaning patch in the end of the chamber, and it creates a cushion when you try to drive out a stuck casting.
    That is called " Over Ragging "

    The aluminum rod also transfers more energy when pounding out the slug with a Mallet, and is less likely to fracture like a wood dowel will.

    Don't worry,
    If the casting Refuses to come out, the cerosafe can be melted in the chamber with a heat gun or propane torch by warming the chamber and pouring it back out.
    Been there , Done That
    Last edited: Sep 29, 2014
  11. Maj Dad

    Maj Dad Well-Known Member

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