300WSM action size

[spaniel]

Is it a safe bet that all 300 WSM drop-in barrels require an action for the large barrel shank?

[KRP]

No.

[rinodods]

You can easily order a small shank in a WSM. I'm guessing most barrels anyone had on hand would be large shank though. I'm headed that route soon myself. Taking a 300wm to a WSM. Though after getting the WM out on steel today at 660yrds I'm second guessing that move. lol

[spaniel]

I've been hearing that the large shank was introduced after some cracked barrel nuts running WSMs in small shank actions. This concerns me. Thoughts?

[rinodods]

Not sure why that would be the case. The SAAMI specs show 300WM rated at 64,000 PSI and the 300WSM at 65,000 PSI. Not much difference there. Wouldn't think it would cause any issues in a small shank. Got any references on those barrel nut issues?

[efm77]

I've only heard of the large shank nuts cracking sometimes since they're thinner. One thing you have to think about though is that although their pressures are similar, the WSM cas has a larger diameter than the win mag so the chamber walls will be thinner and possibly not as strong. I haven't heard of any problems with them though.

[spaniel]

Not sure why that would be the case. The SAAMI specs show 300WM rated at 64,000 PSI and the 300WSM at 65,000 PSI. Not much difference there. Wouldn't think it would cause any issues in a small shank. Got any references on those barrel nut issues?


I found it on several sites yesterday talking about why they started manufacturing WSMs on the small shank but quickly switched to the large shank. I mean, Savage had to have a reason for wanting to go to the larger shank size, it certainly does not make life easier for them I would think. I do know that the creator of the 358 BFG (an Indiana deer-legal WSM derivative) will not supply Savage drop-in barrels in small shank for this very reason.

[sinman]

If there was a problem with a small shank wsm savage would of recalled them. I have a small shank rum action and there isn't anything wrong with that either. And as a side note I offer the 358 IDC in small shank barrels.

[efm77]

+1 on what Sinman said. If it were dangerous Savage would have recalled them. Many WSM's and RUMS out there on small shank barrels and never heard of one blowing up. It's a preference thing. I myself prefer the large shank barrels but don't think that the small shank barrels are dangerous for those cartridges. Savage probably did it to add a larger safety margin or to keep the chamber wall from being too thin in one place if they were to bore the chamber slightly off center (thicker chamber walls), but the small shanks must be safe enough or there would have been a recall and you would hear stories of bulged barrels etc. There are a couple aftermarket barrel makers that won't make ultra mags or WSM's on small shank barrels but most will. Last I heard ER Shaw wouldn't do it, they will only make them with large shanks.

[geargrinder]

I've only heard of the large shank nuts cracking sometimes since they're thinner. One thing you have to think about though is that although their pressures are similar, the WSM cas has a larger diameter than the win mag so the chamber walls will be thinner and possibly not as strong. I haven't heard of any problems with them though.


+1

The only nuts that I've heard of splitting were large shank nuts.

[rinodods]

Can't see the WSM vs WM cartridge size being the issue either. Look at the numbers. Case width of .5319 for the WM and .535 for the WSM. A difference of only .0031. I'd think the old WM would be pushing the edge of safety as well then. Not much more work for savage to provide two shank sizes and if everyone is buying aftermarket barrels you might just trick a few into thinking they need to buy a new action to support that change to another caliber. ;D It's kind of like all the changes in screw spacing on the actions. Did it really need to change?

[efm77]

That's the rim diameter. The case diameter of the WSM/RUM is .555. Measure it above the extraction groove, it's a noticeable difference between it and a belted magnum. On a standard shank barrel with a WSM or RUM chamber you have chamber walls only about .25" in thickness. IE, standard shank diameter is 1.055, width of WSM case above the extraction groove is .555. 1.055-.055=.5 .5/2=.25. My theory is that Savage just wanted to make it a little thicker to make it a little stronger. The large shank is 1/8th of an inch thicker which gives you 1/16th of an inch more steel in the thickness of the chamber wall. A small amount but if tempered right probably adds a lot of strength. I guess the easiest way to find out is to call Savage and ask them.

[rinodods]

That's the rim diameter. The case diameter of the WSM/RUM is .555. Measure it above the extraction groove, it's a noticeable difference between it and a belted magnum. On a standard shank barrel with a WSM or RUM chamber you have chamber walls only about .25" in thickness. IE, standard shank diameter is 1.055, width of WSM case above the extraction groove is .555. 1.055-.055=.5 .5/2=.25. My theory is that Savage just wanted to make it a little thicker to make it a little stronger. The large shank is 1/8th of an inch thicker which gives you 1/16th of an inch more steel in the thickness of the chamber wall. A small amount but if tempered right probably adds a lot of strength. I guess the easiest way to find out is to call Savage and ask them.


Very right. I was looking at the wrong measurements.