Why 7STW over 7RUM?

[MudRunner2005]

I have heard 1,500+ can be expected for the STW's. But then again, there's always lemons, and there's always unexplained oddities. Someone else might start dropping off at 1,000 rds, and someone else might get 2,000+ out of theirs. Every barrel will be different, there's no magic number of when it's gonna start opening up your groups.

I'm interested to see how the 7RUM performs compared to the 7STW. The more I think about it, I might have to get that 7RUM just to play around with...And like I said, if I hate it, I can always rebarrel to another STW, or build a lightweight 700 .257 Wby Mag for stalk-hunting deer. That Accumark gets kinda heavy after a while... LOL

 

[bigngreen]

I know guys who've smoked out a 7STW barrel in under a 1000 rounds. Barrel life is extremely difficult to put a number to especially with factory barrels and throats. I have a feeling if you use a custom throat in the 7RUM that you'd see much better life than the long and loose throat that the factory chambers have.

 

[Lefty7mmstw]

I know guys who've smoked out a 7STW barrel in under a 1000 rounds. Barrel life is extremely difficult to put a number to especially with factory barrels and throats. I have a feeling if you use a custom throat in the 7RUM that you'd see much better life than the long and loose throat that the factory chambers have.

I have a feeling that you are right on the 7rum possibly having better bbl. life with a shorter throat. You will run into the same issues as some of the roy rounds though, in the fact that factory loads and book loading data may cause over-pressure situations at times with non standard throats. I also think the already small velocity gap may disappear to the point that the 7rum is basically just a less efficient version of the 7stw.
All this talking about the 7rum and I haven't had one in a few years now. The caliber's calling my name pretty loud lately. A 27-28" 10" twist 7rum throated to 3.8" would smoke a 140 ab pretty well for mule deer way out there. I'll built the 7rum as a right hand heavy bbl and leave my 7stw as a left hand carry rifle. Now where's the cash fairy so I can get this done by hunting season???

 

[gunaddict]

I just had a 7ultramag built recently. Remington blue printed action, 29 inch Benchmark light palma barrel, 9 twist . Shooting 180 VLDH with a stiff load of 50BMG. Just shot it at 500yds and shot a 2 1/4 inch group. I am working with my gunsmith to keep track how many rds I will get out of it. He is going to borescope it in a couple of weeks to check for throat eroision. I will have right at 100rds down the pipe.

 

[80 grains]

Does throat erosion occur even with mild to moderate loads? And this raises another question...does COL play a part in erosion too?

 

[BountyHunter]

In either one, spend the $100 to have barrel melonited. It will be well worth the money and barrel life.