300WSM in a MINI G?

[Jgun]

I know that you do the 35 Whelen for the Mini G, and that it requires that you send your barrels for reboring. I've seen 300 WSM conversions done on the M14's. I was wondering if it would be practical to do a 300WSM conversion in a MiniG? As far as I know the conversion on the 14s requires that the bolt be counterbored, and the barrel chambered for the 300WSM cartridge, is it possible that they would feed from the enblocs? I'm guessing that you'd be giving up performance from the 16" barrel, and that the 35 would still be more powerful, but, if it could be done wihout the barrel rebore it might be easier to accomplish, no?

[timshufflin]

I would imagine it might be possible, most anything is. I know nothing of the 300wsm, not even the most simple spec. I just don't have the motivation to learn about the round because I don't have demand for it.

Even the 35 Whelen has little to no demand and that's a very simple rifle to do. Until my phone rings over and over and over with people clamoring for the mauser, 300wsm, 338, 35 Remington, only then would I even bother to learn if they could work.

Sorry I don't know more but I'm just ignorant about the 300wsm.

[Jgun]

I thought that I had read somewhere (maybe here) that You had chambered them for other calibers besides .308 and 35 Whelen, thought I'd ask. I think the biggest question would be if they would feed from the enblocs, the rim is .075" bigger than the .30 06.

[Shug]

Because I didn't have much better to do this evening, I took a look at the cartridge ODs for 30-06 and 300WSM, and the barrel OD for a USGI-profile Garand barrel. The barrel OD is 1.100 at the chamber opening, if I'm reading the drawings correctly. The nominal OD at the web of a 30-06 is .470, and for 300WSM is 0.555. Assuming a perfect fit in the chamber, that means a 0.315 chamber wall thickness for 30-06, and a Garand barrel reamed out for 300WSM would have a 0.272 chamber wall. Based on my Lyman manual, max pressures for WSM rounds seem to be ~5000PSI higher than 30-06. So a WSM-chambered Garand would have a chamber wall only 86% as thick as stock, with 8% higher pressures. I wouldn't want to be the guinea pig for that experiment without someone doing a thorough engineering analysis first.

And there's the question of what the extra gas volume and pressure at the muzzle would do to the oprod. I'm thinking it wouldn't be pretty.

[Jgun]

Thats very interesting. Sounds like you've considered things that I hadn't take into account. What actually got me thinking about the concept in the first place was reading here that it took a long time to have a M1 barrel rerifled to .35 cal for the Whelen conversion. I started to thank about what other .30 cal cartridges would actually fit the M1 action. Then I came across this http://www.gunbroker.com/Auction/ViewItem.aspx?Item=387907527 Now, just because someone else has actually done something, doesn't mean that it's a good idea, or even safe, but I figured that if it could be done with a cast Springfield receiver, the forged USGI M1 receiver should be able to handle it. I think I read somewhere that the M1 receiver is actually stronger than the M14s were. After reading your post I measured the barrel on my M14 type and found that it was the same as the M1. looks like both are 1" 10 threaded at the receiver end. Although the heavy barrels are much larger in front of the receiver threads, the GI M1 barrel measures 1.1" in front of the receiver, but you could gain greater wall thickness in the chamber area in front of the receiver if you went with a heavy contour barrel. as far as the muzzle end of the barrel, I was originally thinking that the rebarreling of the GI barrel, for the Whelen, left you with a very thin barrel wall thickness at the muzzle end of the GI barrel. The original GI barrels are .590" behind the splines and .5" at the muzzle, which leaves (unless I'm mistaken) a wall thickness of .075" at the muzzle for a Whelen. Now the .100" thickness of the .30 cal barrel isn't a lot, but it's 25% more than the Whelen's. I had assumed that, just like the standard Mini G, any overgas problems would be solved with the Schuster adjustable gas plug. After reading your very well thought out post, I now am thinking, other than the enbloc question that I raised, the question of how much more pressure the 300WSM creates over the 35 Whelen, may actually be the bigger issue. I guess it would take someone motivated (and brave) enough to try it out.