New Savage Belted Mag Closes on No-Go Gauge???

Discussion in 'Gunsmithing' started by KY Gun Geek, Dec 16, 2008.

  1. KY Gun Geek

    KY Gun Geek Well-Known Member

    Dec 3, 2008

    On a learning curve with belted magnums - I've got a 116 in 338WM new from Savage. It has one of the new squishy recoil pads on it, so I think it was made this year. It was bought as new from a shop that I've done business with, and they had to special order it (it is a lefty), all the stuff was wrapped up in the box, it doesn't appear as though it has been monkeyed with.

    Anyway, I checked the headspace with a set of Forster gauges and found that the bolt will close on the no-go. In a non belted cartridge, I would be a little concerned about this (never happened before). There is some drag on the no-go making, in my experience with non-belteds, the actual headspace just a little more than the gauge. The gauge is marked .223, (the go gauge is marked .220), so the headspace is probably .224 or .225.

    I did some research and found headspace figures of .220" Min, .227 Max.

    If the headspace is actually .224 or .225, that would seem to be OK, per above.

    I know belteds are famous for stretching the heck out of brass. This seems to imply setting headspace closely is less of a problem in belteds - the engineering trade off was made to stretch brass but get a wider tolerance for headspace. We have to make up for it in reload techniques. My plan is to neck size, and bump the shoulder when chambering gets tight.

    The reason I checked the headspace is because I am going to take the barrel off to have a brake installed. The brake requires a top-dead-center mark so it can be properly indexed. If I'm going to change the headspace, I want to do it before I mark TDC (duh). I normally set headspace to be as tight as possible (just close on the go gauge), should I do that here?

    Seems like this would likely help the brass stretch situation - if I move headspace down by 2 or 3 thou, that would shorten the chamber by the same amount - meaning less stretch. I do not want to move the headspace out of the spec range to manage brass. If I sell the rifle, I do not want to do it with an out of spec chamber. I guess the concern would be that a factory round (or one FL sized by my die) would still chamber.

    Any comments? Is this thing safe? Is a call to Savage in order?

    Thanks in advance...
  2. Ballistic64

    Ballistic64 Well-Known Member

    Dec 21, 2004
    I think thats the exact reason Savage sets the headspace a little loose.The dimensional variance of the belt from different brass manufactures.

  3. PEI Rob

    PEI Rob Well-Known Member

    Dec 21, 2004
    If your smith has Grizzly rods, or similar piloted rods, you do not need to remove the barrel. I normally install the brake after installing the barrel and wouldn't bother to remove this barrel. Anyhow, if you make index scribes under the stock line, place another scribe on the action .085" after the indexed scribe. This equates to 1/16 of a turn on a 1.35"action, which equates to just over .003" on 20tpi threads. Placing the barrel in this position leaves you the ability to time the new brake a little either way by adjusting the barrel and still be within headspace spec assuming the smith gets the brake very close to his mark. Factory barrel markings will likely be ok but a little uneven. Does your 'smith want you to mark the TDC of your barrel tip so he can index the brake?? If you worried about the number of reloads you get on your brass, you could try resizing so it headspaces off the shoulder not the belt. On a hunting rifle, I wouldn't want too tight a round.
    Last edited: Dec 29, 2008