Ultra mag magazine boxes


Well-Known Member
Sep 30, 2008
What is the difference in the Wyatt's extended mag box and a factory ultra mag length replacement from Remington? Does the receiver have to be modified with a Remington ultra mag length box from a standard long action like the Wyatt's box? I like $7 versus $30...
The Remington Ultra mag box is the same length as a standard mag box, it just has cutouts in the sides to allow the fatter ultramag cases to stagger and feed properly within the constraints of the action to floorplate depth.
The wyatts is .100 longer, you have to machine or grind the back of the action where the extra screw hole is in front of the trigger to make it fit, as told to me yesterday by Jim See. I am going to order another mag box from remington and cut the 2 and weld them together longer.
Thank you Sambo, that was the info I was looking for.

Thank you Sdeering, I knew the extended length was different from the Wyatt's diagrams, I just couldn't get any information on the Remington boxes.
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