Home Forums Hunting & Shooting Winchester Collectors M70 338 EDGE

Gentlemen,
I want to build an EDGE on a stainless classic action. I want it to be a repeater. I'm probably going to use 250 grain bullets, either 250 Sierra Game King or 250 Nosler Accubond. There are some of you that know a ton more than I do about this action so I have questions.
Is it possible using a factory magazine?
Are all the long actions the same? I know it was available in a 300 RUM and I thought about starting with one of those if I can find one, but I have other long action magnums already that I may cannibalize. If I found a 300 RUM I wouldn't want to tear it apart unless I had to.

Give me your thoughts.
Thanks

Find a RUM action.

I converted a STW action for my 375 RUM and it was a PIA!

I don't know if the Winchester RUM specific mag box is still available and I had a bad experience with a Wyatts box years ago and have avoided them ever since. I think you will need the "windowed" box to get more than two down in the magazine.

And the Overall Length question is another issue.

What made it a PIA? I guess my main question is what is different from a RUM action than other long magnum actions?

You are going to be sinking those long 250's way down deep into the case, unless you have some metalwork completed to get a longer mag in there.

The RUM are wider at the rails, so you'll have less machining starting with a RUM based 70.

I have a 300 RUM now in a 70 Super Grade and hate how limiting it is with even 180's.

How long is the mag box in your RUM? I assume it's all original, correct? The long action magnums that I have measure approx 3.4". Is the RUM longer?

The RUM will take a skosh over 3.6”

RUM box is the same length as any other H&H/STW/300Weatherby box. Like beretzs said, about 3.6". It is also of the wider design and has "windows" or "notches" at the top that helps with the feeding and getting three down in the box. Factory RUMs use a RUM specific follower also. I don't think either the box or follower is available from Winchester/Baco or whoever.

RUM actions have different feed rails machined with a notch or kickout on the left side. The feed ramp may or may not be different. Winchesters quality control was so sloppy it's sometimes hard to tell what was intentional and what was just an oversight.

There’s one currently for sale; I can pm you a link if you haven’t seen it.

Thank you! This is good information. I didn't know that 1, the RUM had specific features and 2, some of the long actions were different than other long actions. I have a 7 STW but I didn't measure that mag box. I appreciate the info.

From the research I did on this, building a 338 Edge it's recommended to have a 3.8 or longer magazine box in order to take advantage of the cartridge capacity. With custom machining this is definitely feasible if you start with a RUM action as recommended. Far simpler to go the Remington style action route unfortunately. I compromised and went with a 330 dakota which is essentially a shortened edge, very similar to 33 Nosler.