I own a 7mm STW.
I have thought about doing a &mm Ultar instead of a 7m WSM.
The wsm and the 7mm caliber would be or possibly is bordering on an overbore cartridge.
In order to gain the full potential of the 7mm WSm you will need a longer barrel possibly no less than 28 being the bottom line and 30 being a good compromise.
My 7MM stw with the 180 gr Bergers and behind 74.5 grs of H1000 pushes it to 3100.
These Bergers like to be pushed fast almost to the point of disinegration in my rifle.
I have a 34 in Lilja 4 groove barrel.
This could be the reason why they need to be pushed faster in my gun.
One great advantage of the WSM case is no belt and shorter powder column.
One day I will rechamber it to the 7mm Tomahawk (300 Tomahawk necked down) and increase barrel length to 36 inches with a 1:9.5 twist.
I have yet to get to the range for testing of the LRBT 162 gr 7mm bullet, or Sierra's 168 MK or JLK's 168 gr bullet either.
Just my two cents, please all who read lets hear your comments.
Hope all is well with the Tullahoma boys, & glad to hear you're comtemplating coming over to the darkside! (7mm vs. .30) I haven't heard any ACTUAL feedback from 7WSM shooters, although the talk from the 300 WSM shooters is impressive.
Like Dave, the overbore factor is something to consider. I agree on maximum barrel length & s-l-o-w powders. One thing about the Bergers, I talked to Walt Berger at length when I started the 7mm RUM project. He said that the RPMs the RUM would produce at 3,300-3,400 fps with a 1:9" twist might disentigrate the bullets due to the thin J4 jacket. Kreiger tried it with a test barrel & found that to be true - they blew up. That being said, I've heard of NO ONE who has had the problem at the 3,100 fps mark. JLK & Cauterucio are made with thicker & tougher jackets. Whatever you build, try different bullets. I'll send you a few Cauterucio 176s if/when you get something built.
I thought you Tennessee boys were tough - afraid of a teensy weensy little RUM are you?????????? [img]images/icons/tongue.gif[/img]
I read this yesterday, but am more inclinded to be using the heavy match bullets. 2950 to 3000 is all I'm looking for here. How have you liked it so far, and have you used any of the heavier SMK's or VLD's yet?
My barrel will likely be no longer than 30". Actually, 30" is what I plan on. Anything longer and holding it up in a sling for 30 minutes becomes a labor of love,,, and a bit of pain.
I can't go so far as to use the RUM. I'm also hopeing to get about 2K rounds from a tube. If I can't get at or just over 2000, I don't see the point in switching from the 6.5x284. If you got the powder measure workin' bring the RUM down on the 24th... We're shooting 20 at 500, 600 and 1000,,, but that would pretty much be it for the barrel huh [img]images/icons/grin.gif[/img] LOL...
You should by all means be able to obtain your velocity requirements, I doubt H1000 will get you their maybe Rutumbo or H870 or possibly wc872.
RL 19, 22, or 25
H4831, H4831 SC
Since you oviously shoot a lot you should have no problems nailing down what your barrel likes.
Now as far as longer barrels go, if you got it heavy fluted and added 2 inches, say .75 at muzzle tapered to within 4 to 5 inches in front of recoil lug/action face, for rechambering purposes a straight 4 to 5 inch section will allow you to get possibly 2 to 3 more chamberings out of the barrel.
8 flute design, with four being .375 wide by .375 deep, and the other four being .25 wide by .25 deep, the .375 say start it at 2 inches from crown, and 2 inches from straight part of barrel at action end, the .25 flutes 2 inches from ends of .375 flutes.
Should look nice and drop a lot of weight but still give you enough stifness to lesson barrel harmonics.
I personally like Shilen barrels but since they onyl provide 32 in long barrels I only have one gun built with a Shilen barrel.
I think they are excellent quality and are amongst the top three competetors of benchrest comps so you cant go wrong, Lilja and Douglas would be my second and thrid respectfully.
The RUM's barrel is a 30" Kreiger 1:9" twist in a 'heavy Palma taper.' I thought about the fluting option, but went with the HPT configuration. As Dave mentioned, this does have the first 4-5" untapered to allow for re-sets.
Depending on your twist, don't overlook some of the mid-range bullet weights. The BC vs. velocity tradeoff is pretty close, plus you have less recoil from the sling. I shot several Cauterucio 156s & they worked very well - averaging @ 3.25" at 500 with less recoil & a very similar POI. Something to consider.........
Powders will be more generous with a wissum than a RUM. One of the members here, Gary Veit, is a buddy from Indiana who has done some piddling with several. He might pitch in.......
I'll think about the match on 11/24. That sounds fun. I may even try some new loads from that rifle in F-class - it'd sure give a good look at them. Oh, by the way you comedian... throat erosion is actually proving to be pretty reasonable.