Re: Which 7mm???
I too have been looking at all the 7 mm options. Recently I bought two new 26" Rem takeoffs and had one chambered for the 7 RUM and the other for the 7 STW. Every component was indentical. Moly coated 168 Berger VLDs, RL-25, Fed 215 primer and virgin Rem brass. The 7 RUM beat the 7 STW by approx 50 fps with max loads. I concluded that the 7 RUM needs a longer barrel.
I liked the 7STW so much that it stayed in that platform. The 168 VLD has a .160" jump to the rifling and fits the model 700's factory mag box and feeds perfectly. It also didn't require any alterations to the magazine feed rails like the RUM would have.
To top this off, as I mentioned in an earlier thread, I had a friend give me a like new 20 yr old Interarms Mark X in 375 H and H. I already have a 375 Taylor so decided to rebarrel this rifle. The McMillan stock barrel channel is quite large. So...I ordered a 30" SS #7 profile Lilja 3 groove 1 in 7 twist barrel to shoot the 180 VLD! I then pondered long and hard as to which 7 magnum sized case to use.
My friend Dan was struggling with a 7 STW CM barrel that went south with only 470 rnds through it. He had a long talk with Dave Kiff of Pacific Tool and Gauge. Dave told him the 7 STW was one of his favorite cartridges. Dave said he went through many barrels before he realized if you keep the bullet into the rifling instead of a jump it will last much longer. He said Dan could get around 1500 rounds of barrel life if he followed that approach. Dan ordered a reamer from Dave and also ordered a wyatts extended length box mag for his model 70.
Based on this information and the difficulty in extended the length of the mauser style mag box, I opted to go with a 7 Rem Mag. I sent in a dummy to Dave with a lengthened OAL which will allow full engagement of the rifling with the 180 VLD and plenty of room to chase the rifling as it wears.
I also have a lightweight (7 1/2 lb) Ruger M77 tang safety in 284 win. It has an extended mag box of 3". When barrel number 4 wears out I will have Dave make be a custom reamer for it too.
As for fluting the barrel go for it! I have two #5 fluted liljas that are 27" and 28". The fluting looks good and does lighten it a bit. As for length, 26" would be great for a walkaround hunting rifle in either 7 mag or 7 STW. Lilja's standard finish length is 27" so I'd go with it as is. If I were to want a 7 RUM it would have to be at least 28" or longer or IMO not worth the extra blast, recoil and powder comsumption.
I hope you have a great time with the entire process.