I know this has been hashed over many times BUT, I have a Herters J-9 (older Zastava) action barreled in 458 WINMAG that I am thinking of converting to 458 Lott. My question is; can you practically extend the magazine box fore and aft to accomodate the Lott and if so, how much in either direction? I realize that you don't want to remove very much from the foreward end of the magazine mortise. From what I have seen and measured, I could come back nearly .250" at the rear and about .060" at the front. Does this seem practicle?

I also realize that I could get a Sunny Hill or Blackburn box to do the job but, I'm too cheap so, I want to alter my existing box (it does have a hinged floorplate).

Anyone's comments would be appreciated.

Not sure what your starting point is. My MKX start at 3.4 my FNs a little shorter.

When Zastava converts to a 375H&H they thin the rear about in half and then extend in the front. Yes it does remove a good amount of the feed ramp. Never heard of an issue on a 375H&H.

You can pick up space both front and rear. How much I have no first hand experience. If you pick it up to the rear then you will need to alter the bolt stop and ejector as well. Bottom of the action to fit the new rear location. Maybe the rear of the port if you have an ejection issue.

can be done, and I would take the .300 it needs from both ends and make the mag wider while I was at it.

you can make up a box, just like if it was an enfield, and weld it on... heck, send it to mississippian!!

jim wisener published an excellent article on the 416 rigby and 505 gibbs on enfields.. and his principals of mag geometery are stated directly and clearly, easy enough to follow

jeffe

quote:

Originally posted by ramrod340:
When Zastava converts to a 375H&H the thin the rear about in half and then extend in the front. Yes it does remove a good amount of the feed ramp. Never heard of an issue on a 375H&H.

Paul,

The 375 Mark X box I've got here is opened entirely in the front. It will drop into the bottom of any Mark X receiver.

quote:

The 375 Mark X box I've got here is opened entirely in the front

Sorry if I wasn't clear. I agree the outside lines of the box are extended to the front. In the 2 that I have when you look at the rear wall it has been thinned on the inside.

A normal MKX rear wall I just measured is .114" my 375s are .055". So they picked .059" by removing material from the inner rear wall of the box. Outside rear dimensions are still the same.

If that doesn't make since I could post a pic later.

FIreball,
yep, your 375 bottometal will bolt up.. and there will be a .300 or so overhang on the ramp, as the markX .375 is opened mostly forward

Jeffe - Does Jim post that information on magazine geometry on his website? (I guess I could go look).

quote:

Originally posted by ramrod340:
[A normal MKX rear wall I just measured is .114" my 375s are .055". So they picked .059" by removing material from the inner rear wall of the box. Outside rear dimensions are still the same.

You're right - didn't notice the difference in wall thickness.

Jeff - you're absolutely right as well. That's how I'm planning to make my Lott on the .458 action.