Can custom bottom metal be had for a Winchester M70 Classic Stainless action to hold three down (or more?) in the box of an improved .338 Lapua Mag?

This wildcat is .500-caliber and has the shoulder blown out wider than the greatly tapered .338 Lapua Magnum.
It has .570" diameter at the shoulder which is in the same place (base to shoulder distance) as the standard .338 Lapua Magnum,
the latter having only .544" shoulder diameter.

The current 300 RUM windowed box has been windowed some more and will get three down in the box but it is too tight for the bolt to close, on the .500/.338LM wildcat.
That third round will CRF off the top of the box when the bolt is closed.
As long as I keep the North Fork .500-calber FP and CP COL down to 3.450" it feeds those two from the box.
The current rails do retain those two cartridges well, no porpoising.
It will fit and feed 3 of the heavily tapered standard .338 Lapua Magnum cartridges as long as COL is kept to 3.600" length.

Rubber-band three cartridges and make a box to fit them for the M70 Classic action, same as Mauser cosine rules:

The inside width of the box then would be about 1.095" (1.100"?) at the rear (base) and 1.070" at 2.162" (2.170"?) forward of the base,
and inside length of box anywhere from 3.550 " to 3.600" max allowing for a thicker/reinforced front wall of box compared to the sheetmetal box currently on the M70 classic, which is about 3.625" long inside.
So, the opening in the bottom of the action needs to be opened up to fit this new box?
And a new stock too?

I would prefer a McMillan synthetic stock, or HS Precision or Bell & Carlson with full aluminum bedding block,
assuming any of these could be made to fit.

The action is not opened up, it is the .375 H&H length.
Three-down should be possible in the standard M70 stock if it can be modified to fit the new box (HS Precision or Bell & Carlson, both with full aluminum bedding blocks, or McMillan without aluminum bedding block), I think, but if 4-down is possible with a drop-belly and a new stock (McMillan makes an M70 stock for drop box?), that would be great too.

Thanks in advance for your consideration, or any input, to all you amateur and professional gunsmiths.







Or do I just Leave it a 3-shooter in a tupperware stock?
Needs custom dies in the meantime.
One trip to the range at a time.

Haven't seriously measured anything, but would you still have action rails left if the inside of the box measured 1.1??

I'm thinking you might have to settle for an "improper" stack and make the box deeper.

Some serious room can be added by making the box slightly trapezoid (this is how we designed our XRM box for an extra round).

I think you have the same scenario 500 Jeff shooters are up against...proper stack equals a box wider than the action.

We have a prototype 4+1 500 Jeff or 98's, but means a really deep Rigby style flooplate(Starting out with 1" stock) AND doing the trapezoid trick

Hi Duane,
I knew you could do it if anyone could.
I'll get started by ordering one of your XRM boxes and one of your followers.
I have other applications for that one, even if it is not perfect here.
I will do some measuring of the bottom of the action too, and get back to you.
Thanks!

Best,
Rip "Ron In Person" Berry

Ron,

I think D'Arcy Echols’ Legend stock (McMillan stock manufactured to Echol’s specifications) is designed to handle a slightly trapezoid shaped box similar to what Duane discussed; you might want to check as the stock is also designed strictly for the M70 Winchester action.

Jim,
Thanks for that headsup, in case I need a trapezoid.
I'll get the bugs worked out eventually.
Maybe I won't have to go the trapezoidal route.
The trapezoidal box I assume is wider at the bottom than the top.
I like the McMillan stock. They make the Legend for Echols, eh?
I won't need any "Edge" technology, standard weight will do for this .500/.338LM aka "49-bore."

Duane,
Thanks for your prompt return call today to take my order.
Got me thinking over on the big bore forum:

I have ordered Duane Wiebe's XRM box (and his machined stainless steel follower) that is a drop-in fit for the Winchester M70 Classic Stainless 300/375 H&H length.
XRM stands for "Xtra Round Magazine."
Gets 4 down in .375 H&H with the original stock and floorplate.
It has got to be a little wider than the original, same height and lengtIh.
The old Pre-64 H&H M70 box was wider than the current one, Mauser cosine perfect for 4 H&H cartridges in the box.
They should have never changed it.
The RUM action simply windows the Connecticut Classic box.
Maybe it will be big enough for me to get 3-down in .500/.338LM.
It certainly should be if I have Rusty window one of those boxes like he re-windowed the original RUM box.
Will see how the feeding is then.
Other mods included a Williams extractor shaped just right for the Rigby rim of the .338LM, and rail and ramp carressing.
We live in exciting times,
if it is this simple to get an M70 working for a .500/.338LM 4-shooter,
that will be very exciting.
If it works, Duane makes a one-piece bottom metal unit for XRM,
as well as a deeper unit of the usual M70 width,
for a drop belly stock.
The box alone is only $47.
The one-piece units are $420.

A hybrid of the XRM width and the extra depth might be the cat's meow for me.
Might fit in the McMillan drop belly stock.
Accurate Innovations might be able to make a drop belly stock with bedding chassis,
bamboo laminate?

Might be an improvement for a RUM-based cartridge, steel follower instead of aluminum, no windows required, and use the original type RUM follower spring with no "loop."
Might be an easy way to convert any long action M70 to .375 RUM, 500 MDM, or 404 Jeffery.
Will report on how it works for RUMs and 404 Jeffery, and .338 Lapua cats.

It will be nice to not have to do all the Lapua cats on CZ 550 Magnum or Dakota 76 actions.
M70s are sexy: Pre-64, Classic, and Myrtle Beachers from SC.

Don't everybody rush to buy these up. Duane only has about 30 in stock. There is a blocked one for 30-06 and short magnums.

www.customgunandrifle.com

Duane,
If you have the XRM boxes and are still just backlogged on the followers, please just send the XRM boxes.
I have followers, just thought it would be nice to try your followers, whenever you get around to it.

However, I have a serious hobby-need for your XRM boxes.

Another call to Duane last Monday:
He said he could mail the 2 XRM boxes he had in stock, and send the followers later.
I will get Rusty McGee to fit the Sunny Hill drop floor plate to my 49-10, with a McMillan "Winchester Safari" stock designed to fit the Sunny Hill.
This will work with the windowed RUM box that came with the M70.
Will be interesting to see if the XRM box can also be used with the Sunny Hill,
or modified somehow to work.
Either way, I am sure to get a 3-down box with the "49-bore/.500-caliber/.338 Lapua magnum Improved of 2010."
It feeds two from the RUM box and standard floor plate.
Going for 3 down and one in the chamber.

Thanks, Mr. Wiebe.
I got the XRM boxes, no bill included in the box, so I assume you found the CC number I gave to you in May?
Send the followers when you can.
I will call again to be sure we are square.

Ron "In Person" Berry