I took my Mark X out of the stock and noticed a small cut on the bottom of the reciever on the ejection port side (see red circle in pic).



The cut is about 1/16" wide and goes clear through the bottom of the rear locking lug recess but doesn't go through the feed rails in the front.

This made me pause as I'd purchased this rifle for conversion to something like a 9.3x64 or a 416 Taylor. So I have three questions for any of the experienced smiths that care to chime in.

1) Is this normal for a Mark X?
2) Is this safe as is for a .270 Win?
3) Is this safe for a conversion to something larger?

Any help is appreciated.

1: its normal
3: interarms did...

it is the slot cut for a bolt blocking safety, which some of the original markX/interarms used

i have NO IDEA why it was continued, but it is what it is

I have two Mark Xs here and I too would like to know what that cut is for. Both of mine have nonfactory triggers and I suspect that whatever that cut is it probably has something to do with a trigger that has a safety of some sort attached to it.

I would say that if it bothers you and you are using a trigger that doesn't need that hole just have it welded up. People have cut military mausers in half, added a length, and rewelded them back up to use for magnum actions.
If I understand correctly from some of the illustrious Riflemakers on this forum, it is the front locking lugs and their recesses that take most of the punishment on a bolt action, and that the rear one doesn't really do much. I know people who have built 458s on Mark X actions and had no problems with them.

quote:

Originally posted by jeffeosso:
1: its normal
3: interarms did...

it is the slot cut for a bolt blocking safety, which some of the original markX/interarms used

i have NO IDEA why it was continued, but it is what it is

That's my impression too and it has nothing to do with receiver strength.....Receiver strength issues would normally be in the bolt seat area and this is far away from that.

As the others have said. The original MKX safety lever would block the bolt from opening. They later removed that function. I asked my distributor years ago why it was still there. He said he was told that it wasn't worth the effort or expense to alter the action design. True or not I have no idea. I have or have owned over 30 MKXs and they all have the slot. If my memory is working at all the Daly's have it as well.(I'll check in the morning)

Thank you to everyone who replied. Glad to know it's nothing to be concerned about, so I guess I shall plug along with my project and I'm certain I will return with more equally "intelligent" questions. =)

Oh well, like one of my proffessors used to say, "There are stupid questions, but you'll never know if it's one 'til it's been asked and answered."

Here is a pic of the trigger. this one is actually on my old Herter's J9 but it's the same Zastava action as the old interarms MK X.

Notice it's a very simple design on a modified military style trigger. The flat metal piece slides into the recess where the rear lug turns. When it is pushed forward it blocks the rear lug (straight down when action is closed) from rotating.

Weagle