Building a new Mtn rifle! whats your take

[longrange7mm]

I am going to build a new mtn rifle and I want some input, (gotta be a .284 already have the barrel) I am thinking of the following .280 ackley improved, .280 RCBS, or a 7mm JRS. I dont want another belted cartridge so dont recommend the 7mm rem to me lol "I have one" Do you guys have any experience with any of these I have shot the 280 ackley and like it but have not shot the other 2. Any other recomendations or advice would be appreciated. I plan on building this one within the next couple months. I just need to decide on a round and get the reamer.

The Barrel I have is a Benchmark Contour 5 fluted
It will be going on a Rem 700 action
Jewell trigger
and the stock I already have for it is a Greybull Precision

[high country]

What twist and contour? I am assuming 5 is number of flutes. Gonna do a wyatts box? A quick twist 280ai is on my build list.

What is your target weight

[jdb]

7mm08?

[whacker1]

7mm ultra?

[Jamieb]

I only have experience with the 280AI, never shot the RCBS or JRS.
The 280 AI is almost the balistic twin of the 7rem mag and the route I'd go if I was builing a .284

I've looked at the Greybull stocks on line, They look good but I've never held one in my hand and am too poor right now to buy one just for R&D so I'm all ears if you've got anything to tell about it. Have you shot a rifle wearing that stock?

[longrange7mm]

What twist and contour? I am assuming 5 is number of flutes. Gonna do a wyatts box? A quick twist 280ai is on my build list.

What is your target weight

Target weight is < 9 lbs with scope, twist rate is 1:9, contour 5 with 5 flutes. Yes, I have a Wyatts box on my 338 RUM too they're nice. I am leaning torwards the 280 AI.

I origanlly bought this barrel to build a lighter 7RUM  whacker1

[longrange7mm]

Jamieb- they are awesome I shot my deer with a a 7mm RUM that was on one this year at its a great stock! they fit really good.

[Jamieb]

Jamieb- they are awesome I shot my deer with a a 7mm RUM that was on one this year at its a great stock! they fit really good.

How stiff are they in the forearm? One of my biggest complaints of a lot stocks is the flex in the forearm, especially when I'm shooting prone over a backpack.
Howed that stock do as far as absorbing recoil on that big 7mm? Compared to a McMillan?

[high country]

I have a 5.5 contour finished at 27" in a Mc swirley mine weighs 11# ......better cut them deep.

[haugenna]

Take a look at lone wolf stocks.  If you want a true mountain rifle, start getting in that 7lb range. 

[gadwall]

Take a look at lone wolf stocks.  If you want a true mountain rifle, start getting in that 7lb range. 

His meaning of "Mtn Rifle" doesn't have much to do with weight.  When he gets done, his will shoot from mountain to mountain

[jackelope]

9# is not a mountain rifle...is it?

[Jamieb]

9# is not a mountain rifle...is it?

Not by my standards but if it's going to be packed in the mountains, then it could be considered by some as a mountain rifle.
My mountain rifle is a hair under 7# loaded, my longrange rifles start at 9# and go up

[spookgus]

Since you already have a go fast .284 bore in the 7mag, I would go as light as possible with a short action and skeletonized action in .284 Win or 7mm-08AI. Light guns can shoot well. I had a 300WM built that weighs 5.5lbs without scope and is guarantied to shoots under 1/2 inch at 100. Yes, it is ported and yes, the gun shoots better than me. I have other rifles I shoot more often but if I am on a hunt where the hunt lasts as long as I can live off what I can carry the 5.5lb 300WM goes.

[Jamieb]

The barrel he has is a #5 so light isn't going to happen

[spookgus]

#5 doesn't sound like a traditional mountain rifle, so since money is being spent turn the barrel to #1 if you want your mountain rifle to be light weight. In my opinion the mountain rifle is an ultralight one shot hammer.

[thinkingman]

What twist and contour? I am assuming 5 is number of flutes. Gonna do a wyatts box? A quick twist 280ai is on my build list.

What is your target weight

Target weight is < 9 lbs with scope, twist rate is 1:9, contour 5 with 5 flutes. Yes, I have a Wyatts box on my 338 RUM too they're nice. I am leaning torwards the 280 AI.

I origanlly bought this barrel to build a lighter 7RUM  whacker1

9lbs is not what I'd call a Mtn rifle.
My Tikka 7-08 is under 8lbs with scope.

[longrange7mm]

I want a 9 lbs gun I could care less for the 7 lbs guns they shoot fine if you want a 400 yd rifle. I have seen it with every light rifle I have ever tried to data for any distance.

I have packed 12 -18 lbs guns for a long time and it hasnt really bothered me , so yes a 9# rifle would be a good mtn rifle for me and what I want out of the rifle.

High country- what stock do you have? my 338RUM  is a contour #5 27.5" not fluted and is 10.1 - 12.2 after scope and rings

This is what I come up with for weight

Action Rem 700 - 2.6 lbs (including bolt, guard screws, trigger guard magazine liner, trigger assembly, recoil lugs, follower and spring)
Barrel #5 @ 26" - 4.25 after flute and reaming 3.2
Stock Greybull Precision - 2.6 lbs

8.4 lbs before scope
after scope and rings im right at 10. still going to be lighter than any of my other rifles that I hunt with.

talley rings and bases- 4.6oz
Scope is not out yet but will be approx. 1.1 lbs

I looked at the 7mm 08 it would be a fun target gun but just not the ballistics I personally look for in a rifle 

[bobcat]

I'd go 7mm Rem Ultra Mag.   

[thinkingman]

284/378, for sure.

[MtnMuley]

9 lbs would be great for a mtn rifle imo.  When you are used to packing a 13 1/2 lb rifle everywhere you go, losing 4 1/2 lbs would be heaven.  If I could find a gun that could be consistantly inside 8" at 1000yds, I'd pack it, but until then, 13 1/2 it is.  Try a 7RUM LR7.

[addicted]

http://hunting-washington.com/smf/index.php?topic=40940.0

huntwa's take on it a year or so ago. 8 pages of goodness. lol

[longrange7mm]

http://hunting-washington.com/smf/index.php?topic=40940.0

huntwa's take on it a year or so ago. 8 pages of goodness. lol

Kool thread great ideas on there, if i was starting from scratch, however i was looking for input on a caliber, action, and stock I already have just wanted ideas as to what particular .284 cartridge I am going to build my next rifle off of.

I would love to build a lighter 7RUM but would have to get a different action or break down a different gun to do so   The ballistics of a 7RUM are amazing you can get 1100 yds on one revolution with a 180 gr VLD.

Maybe momma will buy me a new action for my birthday  Just sayn!! 

[addicted]

well neither. i would go short action. lol. 

[whacker1]

The ballistics of a 7RUM are amazing you can get 1100 yds on one revolution with a 180 gr VLD.

Is that for real? 

I shoot a .300 RUM, and I can honestly say that I had never thought about how many revolutions the bullet made in its flight....I am currently shooting the 168 VLD.

[MtnMuley]

whacker, he's talking one revolution on the turret.  Trust me even he doesn't know the mathematical formula for that!

[high country]

That would be a 1:39600 twist. I doubt it would stabilize a 180.

[longrange7mm]

That would be a 1:39600 twist.

might as well be a smooth bore and shoot a ball  

yes i am talking about turret sry for not saying one revolution of my turret  

[longrange7mm]

Whacker check out the Greenhill formula.

[Jamieb]

Most 300 RUM's have a 1 in 10 twist, 3960 turnes in 1100 yards

[addicted]

Most 300 RUM's have a 1 in 10 twist, 3960 turnes in 1100 yards

assuming the spin doesnt slow down in conjuncion with the speed ofthe bullet.

[Jamieb]

I have no way of testing this myself but I've read that the spinning is a constant that don't change. The bullet is going to spin 1 time in 10" , it takes less time to cover that 10" at the muzzle then 1100yards but as the bullet slows so does the rotation so it's still turning once in 10" until its slows enough to unstablize witch for most bullets is around the subsonic barrier.

[longrange7mm]

Right Jamieb   :tup  if your shooting at 3300 fps  It will change if you shoot a faster/slower bullet or different twist rate of course

3300fps x (12/10) x 60 = RPM                             2970 x (12/10) x 60                 3450 x (12/10) x 60             

3300 x 1.2 x 60 = 237600 RPM at the muzzle         2970x 1.2 x 60 = 213840           3450 x 1.2 x 60 = 248400

237600/60 = 3960 rps at the muzzle                    213840/60 = 3564 rps                   248400/60 = 4140 rps

your bullet will loose velocity much faster than spin rate but will decrease slightly down range

as for how to calculate how many revolutions the bullet will loose down range Im not sure how to figure that out I would love to know if anyone knows

[whacker1]

Thank you for the clarification - not sure why I didn't pick up on the turret.  Must not have been my day. 

[longrange7mm]

Plans changed  just sold my 338 RUM to an outfitter in AK. I guess I will have to start hittn Pawn shops and gun shows looking for another action so I can build a Lighter 7mm RUM. 

[snowranger]

How about 6.5-284    high BC and excellent energy down range.

[addicted]

338 federal.  lots of bullet choices.

[280ackley]

Go with the the .280 Ackley.