Kimber Montana conversion ... 8400 WSM now chambered in .308 Win

[MCMXI]

Back in 2012 when I was living in Arkansas I stopped by Fort Thompsom near Little Rock one Saturday afternoon and bought a Kimber Montana 8400 WSM chambered in 300 WSM and a Winchester Model 70 Extreme Weather SS chambered in .300 Win Mag. I paid $1,050 for the Kimber and $850 for the Winchester (I notice that the EWs are in the $1,270 price range now!) About six months later I bought another Winchester Model 70 Extreme Weather SS chambered in .308 Win. Ultimately I ended up selling both of the Winchester rifles last year for various reasons but kept the Montana. I've tried to get excited about the 300 WSM but to this day don't see it as being anything special when compared to the .300 Win Mag and so have decided to divest myself of that cartridge. I have a Montana 8400 and an AI chambered in .300 Win Mag so the 300 WSM won't be missed.

Anyway, to cut a long story short I've just completed the swap of the 300 WSM to .308 Win. I had to change the bolt, barrel (now 22" long with a 1:10 twist), extractor and follower and the barrel is the same profile as the WSM barrel. The rifle capacity is now 5+1 which isn't a big deal on a deer or elk hunt but I suppose it could be useful on a pig hunt. It might not make sense to some to build a .308 Win hunting rifle on the 8400 WSM action since the lighter and smaller 84M .308 Win is available in models such as the Classic, Montana, Mountain Ascent, Adirondack and Hunter. The rifle as shown weighs 7lb-13oz but I will be swapping the Zeiss Conquest 3.5-10x44mm RZ800 in the photo for the better suited Zeiss Conquest 3-9x40mm RZ600 that I have in the safe which will take a little weight off. Also, I like Talley stainless steel rings and bases but if I were trying to get the weight down I could use aluminum one-piece rings/bases from Talley. The Winchester Model 70 EW SS in .308 Win weighs 6lb-12oz without a scope, rings, bases or sling so this rifle in the same ballpark and might even be lighter than a comparably equipped EW. I'm a fan of the 8400 action and accompanying Montana style stocks so this is a good fit for me and that's why I put it together. It's easy to shoot too. Last Sunday after I'd finished reamed the chamber (1.632") I wanted to see if it'd shoot some good factory hunting ammunition into acceptable groups. My gf who has never shot the rifle before shot the group on the left (3/4") and then I shot the group on the right (5/8") after making a scope adjustment. The .308 Win is one of my all-time favorite cartridges and now I finally have an awesome hunting rifle chambered for it. I think that this rifle will do great with a Barnes 165gr TTSX handload.

The final piece of this puzzle will be to paint the rifle or have it dipped like my Talkeetna.

http://www.thehighroad.org/showthread.php?t=787097


Kimber Montana 8400 WSM chambered in .308 Win



Federal Trophy Copper 165gr at 100 yards

 

[Llama Bob]

I've thought about that configuration, mostly because I'd like to put the 8400 detachable box magazine bottom metal on it. It seems to negate the weight advantage of the Kimbers a bit though.

 

[MCMXI]

I've thought about that configuration, mostly because I'd like to put the 8400 detachable box magazine bottom metal on it.

The DBM works on the wood and tactical stocks but it's not an option on the Montana/Mountain Ascent/Adirondack stocks. The new Hunter 84M rifle (84L coming late summer) offers a detachable magazine for those that like that feature.

 

[Nature Boy]

I love it.

I'm not tracking on your scope change though. Saving an ounce of weight maybe? Otherwise, do an extra beer curl every evening and keep the extra 1x magnification.

(and note to mods. lock it down on first post that criticizes for not re-barreling to 6.5 CM )

 

[MCMXI]

Nature Boy, thanks very much. The main reason to change the scope is for the RZ600 reticle and weight savings isn't a big concern. I usually hunt with my Talkeetna that weighs 9lb fully loaded and don't have a problem with it. Last year I hunted mule deer with my AI in .308 which is a 17lb rifle fully loaded! The scope currently on the rifle was on the 300 WSM version because the RZ800 reticle is a better choice for magnum cartridges. the RZ600 reticle is near perfect for my .375 H&H and the .308 Win.

 

[Llama Bob]

The DBM works on the wood and tactical stocks but it's not an option on the Montana/Mountain Ascent/Adirondack stocks. The new Hunter 84M rifle (84L coming late summer) offers a detachable magazine for those that like that feature.

Good to know. I don't think the Hunter stock is really what I want. I'm probably going to end up having to custom build on some other action - the ecosystem just isn't there for the Kimbers.

 

[jmr40]

You went around the world to get there, but I like the outcome. Our tastes in rifles is very similar. I own an 84M in 308. It is a very nice rifle, but have come to the conclusion it is just a little too light as an all around rifle. It is now only used occasionally when I'm hunting in some pretty extreme places where I really want to carry the lightest possible rifle.

I ran across a very good deal on a used EW in 308 several years ago and put a McMillan Edge on it. Depending on the scope it comes in anywhere between 7 lbs even up to 7.5 lbs, almost exactly the same as your Kimber if scoped the same. That is light enough for 95% of what I need and it has become my go-to rifle. I suspect this Kimber will be your favorite too.

I've tried to get excited about the 300 WSM but to this day don't see it as being anything special when compared to the .300 Win Mag

A big part of the 300 WSM's lack of popularity is shooters, and rifle manufacturers, not understanding it's niche. It will shoot the same bullets about 200-300 fps faster than 30-06 and 50-100 fps slower than 300 WM. At a glance it makes more sense to just buy the 300 WM. But from a 7.5 lb rifle the 300 WSM has the same recoil as a 9 lb 300 WM and only 2-3 ft lbs more recoil than a 7.5 lb 30-06.

For someone wanting more punch than 30-06 in a lighter rifle without being beat up with recoil it makes a lot of sense. The problem is that Kimber is the only manufacturer that ever made a truly light 300 WSM. All other manufacturers 300 WSM's are the same weight as their 300 WM rifles. Or within a very few oz.

 

[MCMXI]

One other advantage of a .308 Win rifle on the 8400 WSM receiver is that the magazine box is long front to back (3" internal length) so there's no problem seating bullets out to touch the lands while still fitting in and feeding from the magazine. Not a crucial feature but nice to have.

 

[MCMXI]

jmr40, good points. I'm fairly sure that most shooters would do better with this 8400 than with an 84M, particularly as the range to the target increases. The 1:10 twist gives me the option to shoot heavier bullets such as the 180gr TTSX so I'll be looking at those for elk.

 

[Gtscotty]

Looks like a nice compromise, maybe I missed it, but what make barrel did you use? I like the 84 action, but the Montana's are a little lighter than I want, and I don't like blind mags. The new hunter looks like a nice way to get into an 84 action on the cheap, and it's even offered in that caliber that apparently shall not be named in Nature Boy's presence .

Can you tell us what the build ran you?

I'm in the market for something similar, currently looking hard at either an M70 EW or a Kimber Classic Stainless (or maybe the hunter) . After having read jmr40 wax eloquent about his mcmillan'd .308 EW several times, I've kind of got that sort of rig stuck in my head. After around $1070 for an EW, I'd have to wait a while to spend half that again on a mcmillan.

Anyway, congrats on your rifle!

 

[desidog]

Hows is the feeding going from the WSM case to 308?

I was contemplating doing the same thing with a CZ model 3. I have a lefty Winchester M70 in 300WSM, and picked up the CZ because well, it was cheap and a lefty action; but i don't need two rifles in 300WSM, so i've never even put a scope on the CZ... I was thinking i could rebarrel and boltface it to 308, but was told that the 300WSM action feed is too different from a 308win action's feeding set up...

 

[MCMXI]

I have to confess that this is no easy swap due to the difficulty in obtaining the parts, and it's not something I would have considered or even been able to do if my circumstances were different. I posted this since it's an interesting swap rather than to encourage others to do the same thing. The swap didn't cost me anything. I was able to get a Kimber 8400 WSM barrel with a .308 caliber bore (1:10 twist) and have it short chambered using a .308 Win reamer. I was also able to obtain the magazine well (3" internal length), follower, extractor and bolt used in the 8400 Advanced Tactical .308 Rifle ... no easy task unless you buy a tactical rifle for parts.

Hows is the feeding going from the WSM case to 308?

To be honest, I ended up printing my own modified follower and the rifle feeds incredibly well (I'll take a video to show how well it feeds and ejects live rounds). The follower is black ABS plastic and I made a couple of spares in case I need them.

I will readily admit that jmr40's Winchester M70 Extreme Weather SS with a McMillan Edge stock is a much easier and cheaper solution and it would be fun to compare my 8400 WSM conversion to his rifle.

 

[jmr40]

The 10 twist you have is a better option than my EW with a 12 twist. If I could change one thing that would be it. I haven't tried it with heavy bullets, but think it should still be OK with 180's, but probably not anything heavier. But I know it shoots great with 165's and with today's better bullets they should be enough. One advantage of a "custom" like your rifle is that you can get it the way you want it.

After having read jmr40 wax eloquent about his mcmillan'd .308 EW several times, I've kind of got that sort of rig stuck in my head. After around $1070 for an EW, I'd have to wait a while to spend half that again on a mcmillan.

I can completely understand. That is why an out of the box Kimber at around $1200 is really a bargain if you want a lightweight. Even if not perfect, you can't touch anything else in that weight class for under $3000.

It took some time, but I really don't have that much money in my EW. I ended up trading for the rifle used. I made a handsome profit on a Colt 1911 that I traded for the Kimber and only have about $350 in real money in the rifle. I hunted with it as is for about a year before finding the stock used in the classifieds on another gun forum. I then used some Cabelas bucks and a free shipping coupon to buy the scope for about $100.

I have about $800 total in the rifle, stock, and scope.

 

[Gtscotty]

$800 for everything? Wow, I'm sure I won't be able to find any deals that come close to that number full up. What scope are you using btw?

I'm sure the Kimber is the best value in its weight class, but I really don't want something quite that light. I really just want a good sub 7lb (preferably around 6.5lb) SS CRF with a 3 position safety and a decently stiff stock, basically what MCMXI just built, but with a floor plate. I've found that my just under 6lb Tikka Superlite .270 with a relatively heavy Zeiss HD5 is right at my recoil limit for shooting well... Anything much lighter is going to compromise my repeatable accuracy.

I wouldn't think that a 12 twist would be much of a disadvantage on a hunting .308, I can't see myself using such a rifle for anything that a 165gr Accubond couldn't handle.

 

[MCMXI]

I agree that a 1:10 twist isn't needed for a .308 Win hunting rifle. My only realistic option was to get a 300 WSM barrel before the chamber was cut and the twist in those is optimized for the short magnum. I'll be shooting some Barnes 165gr TTSX handloads tomorrow and hope to find an accurate load around 2,700 fps. I was able to lap the bolt lugs prior to finish reaming so I'm expecting good results from this rifle.

 

[mshootnit]

Sounds like that action would be a good basis for a 6mm Remington.