Here's a photo of mine, along with a 500 yard group.
This rifle runs about 8lbs. as you see it.
Manners Super Light stock
Stiller Predator action
Satern #4 taper fluted barrel, 26"
Talley rings and bases
Nightforce 2.5-10 scope
Built by Allen Precision
Mine happens to be chambered in 270 WSM, just .007" short of a 7 Rem mag.
I am a real fan of the 7 mag. , and with the action you are using I would chamber in the .280 improved.
For the weight you want, I think the 5 taper is going to be too heavy. Properly built you should get good accuracy with the 4.
Remember though, we are talking light weight rifles here, not purpose built 10 lb long range rifles. While mine gets great accuracy, it will not shoot with my 13.5 lb long range gun.
Look hard at weights of components if you are shooting for 7-8 pounds. I weigh pretty much everything, most of my hunts use my back for all transportation Live in ak and try to fly in when I can
Anyway, 7-8 pounds is already heavier than most of the shelf "sporter" rifles. Scopes and ready to go. Even at 8 you are talking a 6.5 factory gun. 7... You are talking a pencil barrel. Not the 5 fluted you mention
Again, weigh your components. Throwing out 7-8 pounds is harder to accomplish than you think.
Think most have a light weight sporter in mind and end up with a 9 ish pound gun.
What I have so far is a Stiller Long action Tac 300 with a 308 bolt face.
I used a TAC 300 to build my 280. Got a smokin deal on a couple of Shilen barrels, so I have a #3 sporter 24" long, no flutes. McMillan stock, Jewel trigger. You can see it in my 2012 CO mule deer thread. I also had a 270 built at same time, both identical other than barrels. The 270 has a Krieger.
If you go with a carbon fiber barrel you can still have a stiff bull barrel and not a lot of extre weight,I have a 300 rum with a 26 inch carbon barrel,a brake,fluted bolt,lightened bolt handel,aluminum bolt shroud,bell&carlson alaskan stock and a 20 moa rail it weights 6.6 lbs, with lightweight tally ring/base combos and the right scope you could have it,I would go 280AI also
My rum shoots 230g Bergers at 3100 fps 1/2 moa dont be afraid of the carbon barrels good luck with your build
An ABS barrel wouldn't be a bad idea, you get the contour & strength w/o the weight, if used, i'd probably keep it in the 24" area. I would probably avoid the detachable mag unless you can find an H-S Precision. I don't know about everywhere else, but here, you are restricted on how many rounds you can have in the rifle. Plus, they add more weight. The reason I suggested the H-S is the light weight, flush fit design & restricted mag capacity.
If only going to 800 on the lighter stuff, you could probably get away with using the 2.5-10, althought I would personally prefer the 3.5-15. Have Cam Murphy whip you up a Titanum base & ring package, that should cut some weight w/o using aluminum alloy, which I feel is just too weak to be trusted on a hard core hunting rifle.
If your Stiller's bolt is fluted anything like the LoneStars, maybe Boltfluter or Chad DIxon can deepen the flutes for your. I just held a lightweight 280AI that Chad had hollowed out the bolt handle too. Looked awesome & shed some oz's.
The stock is going to be the make it or break it area. Do you remember the LoneWolf Carbon Fiber Stocks? For some reason I think they went under... maybe it was someone else. Do your homework here, I would ditch any bedding blocks etc & opt for Pillars & a good bedding job, shed some more weight.
Hope this helps some.
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