Modifying McRees LA stock to accept the 338 Lapua AI CIS Extended mags? (3.850)

I guess it isn't a HUGE difference between the standard AI 338 LM mag - 3.650 COAL / 3.725 OD and the AI CIP Extended 338 LM mag at 3.750 COAL / 3.850 OD, but the longer I can seat the bullets the better is what I am thinking. Even the extended mag is painfully TOO SHORT for all of my 300 grain bullet handloads. As of yesterday, McRees does not offer a G5 or G7 chassis that is machined to accept the longer mag boxes, only their XL chassis fit those.

The Savage LRH 338 Lapua that I own has the CIP length bottom metal and magazines, so clearly there is plenty of room back from the front action screw to cut some metal off the McCrees. The McRees is going on this barreled action so I would prefer to keep the mag size identical and at CIP length. It doesn't look to be too complicated other than I don't own a mill......so would have to pay someone to do it or spend several hours with a flat file (yuk!)

Have any of you modified your McRees stock so it will accept the 3.850 / CIP Extended magazines? If yes, please post a picture or two and tell how you got there. Not having one in hand makes it difficult to tell if it can be done without too much trouble. If the spacing is anything like my Savage LRH, if the McRees magwell is cut where the rear surface of the well is pretty much flush with the back edge of the opening on the action, then I can't see why it wouldn't work by removing 0.125 from the stock up front of the magwell.

Thanks

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Well, I found the answer. It won't work without removing 0.125" of metal on the REAR area of the magwell which would mean moving the mag retaining latch back also. The front of the magwell is already flush with the opening in the action. The rear area is more complex than the front of the magwell so would best be done on a milling machine.

Though it is possible, it would also require drilling a new hole for the mag latch retaining pin -- not possible without filling in the original one first which would not be simple. Dang it - I guess I am stuck with the shorter mags on the McRees.