300 Win Mag shooters, what would you have done different on your builds?

[BallisticSam]

Found a really nice Old Rem. 700 mag action at the local shop got a good deal on it. it will be the start of a 300 win mag build. I know what I want for the completed rifle as in stock, bolt knob style, etc...
What I would like to know is what barrel length and contour did you go with and then wish you would have got. I will be running suppressed. It will be mostly used from a know location for hunting, as in I won't be walking around with it much. I do plan on running bullets as light at 150 and up to 220. I hand load so I'll be all over the place trying different pills down the tube. Your thoughts will be appreciated.

 

[...]

right now im running a 26" Reminton varmint contour.....and im actually pretty happy with it.....

when i rebarrel it, im likely going with a 22-24" MTU contour and have it threaded.1/9 twist if i can

im running an XLR chassis and already machined up a solid steel buffer tube to add weight.......if i can add more weight with a barrel im gonna do it.

 

[Mtleadfarmer]

I put together three rifles using these Remage style barrels from Mcrees Precision, a 6.5 creedmoor and two win mags. I can't say enough about them, his accuracy claims are no BS. http://shop.mcreesprecision.net/McRees-Precision-Barrel-Kit-300winmag-300wm-BKIT.htm

 

[NukeMMC]

I shot a couple Navy Match McMillan 300wm rifles and they were quite good. Their McMillan prone stock was a PITA to set up for me, but the rifles shot quite well. Later, I had AJ Brown, thru High Caliber, build me a 26.5" Lilja 1:10" 4-groove with the A191 chamber and the MK13 Mod 5 contour and the Crane/Clements lug. I wanted to hot-rod my ammo for long range. 190s going 3100fps and 208s going 2925fps was the result. My muzzle was contoured for my Ops Inc 3rd Model suppressor that I ran for every shot except the first 10 break-in rounds. I used a McMillan A5 with the adjustable buttplate, which worked well for me. I shot a match with that rifle and the ROs breathed a heavy sigh of relief when they saw the can on it. The Sako TRG42 ahead of me had a brake and their teeth were still loose.

Now I am having RW Snyder build me a similar rifle but with a T4a, Bartlein 1:10 with a Hvy Palma profile, still contoured for the 3rd Model, and 26" OAL but also fluted. This time I will run a match chamber since I will be loading all the ammo for this rifle. I sent him a 40x trigger to install, but any of the Walker triggers, properly tuned to about 2-2.5# are great for shooting anything short of 1000yd NRA matches.

 

[FatBoy]

I had a 700/300 built (mk13 mod0 predecessor - no McCann rail) and a mk13 mod7. If in was going to change anything it would be the throat in the a191 chamber of the 700/300. I did throat the mod7 out so 230 OTMs are .015" off in an AX mag. The mk13s are heavy rifles but 74gr of powder under a 210-230vr bullet thumps you, even with a can. I won't hunt with these, too long a d heavy for four legged critters in TN woods. They do shoot exceptional out to 1250y.

if I wasn't building a clone, I'd go 30" 9 or 9.5 twist cut rifled in something like a medium varmint. I'd have a reamer made that's .007" long on the shoulder of new Win brass and co-headspace. The throat set up so I could seat .020" short in the blind mag and jump a 230 .015". this would allow me to use most of the case capacity and blind mag load. With a 30" tube and long throat, 2875 - 2900fps with a 230 is possible, which is supersonic to a mile+.

 

[brianf]

thats a good pile of info between those posts. i happen to love the WM but its at the beginning of "larger, longer, heavier" gets you better results.
anything longer than 26" barrel is a real pain in the ass in the woods.
so the can will make you crazy if you have to walk any distance, unless you really know where the first shot goes after you put it on.
as you already know hunting is a one shot (we all hope right lol) deal so getting the can to settle and then shoot groups or steel isnt a option.
and trying to keep it on the lighter side of 15 while wanting to shoot 220gr takes real practice and focus for reputability.
that being said 26" will get you 14-1500 really well (at 1200 its not even sweating).
i wouldnt go less than 180gr unless its you one really nice rifle. your wasting the barrel and not getting much out of it drop wise in close.
and you can push the 150's fast enough that bullets start getting screwy and not performing on game properly.
off the bat i would get some H1000 powder winchester, lapua or my favorite for 300WM RWS brass, load it with 200-215 bullets (amax have really good ballistics and believe it or not the sierra 200 SMK does pretty well and is about the easiest bullet to load for.on the planet)

 

[BallisticSam]

Thank you very much guys. I'm thinking for the barrel a fluted M24 Bartlein finished at 26" left hand twist threaded for my can and the chamber cut to run 208 ELD's and just see how well the lighter stuff works in it. I'll be loading with Federal brass then maybe some Nosler brass to start with, then IMR Enduron 7977 and H1000, w/208 ELD's. I'm hoping to have Short Action Customs do the work.

 

[BangBangBlatBlat]

I think mine turned out perfect. I used a TRG S action, KRG chassis, and Lilja Mk.13 barrel.

It's very heavy but it soaks up recoil. Shooting 215 Hybrids at 2975fps in Norma brass.

 

[BallisticSam]

I think mine turned out perfect. I used a TRG S action, KRG chassis, and Lilja Mk.13 barrel.

It's very heavy but it soaks up recoil. Shooting 215 Hybrids at 2975fps in Norma brass.

Thats awesome! If I don't end up with the McMillan A-5/Manners of same design, KRG will be the go to chassis.

 

[.30kal]

Thank you very much guys. I'm thinking for the barrel a fluted M24 Bartlein finished at 26" left hand twist threaded for my can and the chamber cut to run 208 ELD's and just see how well the lighter stuff works in it. I'll be loading with Federal brass then maybe some Nosler brass to start with, then IMR Enduron 7977 and H1000, w/208 ELD's. I'm hoping to have Short Action Customs do the work.

I'm doing something similar. 1-10 27" M24 Bartlein, Chamber for 215 Hybrids and also try 208 ELDs, Manners PRS2 stock and Calvin 2 stage. Just waiting for my Mausenfield LA, then sending it off to LRI for barreling. I'm hoping it comes in soon as my friend is trying to talk me into 7mm.

 

[shields shtr]

I have a 24" proof on mine, only thing I would have done different (which I am now) is get a different brake. I went with the thunderbeast brake since I am going to eventually run suppressed, but it is not very effective at all. Muzzle is all over the place. Trying the area 419 stuff out. I am also contemplating going with a little lighter bullet, maybe a 190 or 200 grain. Shooting 215 bergers now, which you don't really see huge advantages ballistically until you get waaay out there. Most of my shooting is done under a thousand yards, Then again my gun shoots the 215s so well, I might just stick with it.

 

[CMP70306]

I'm doing something similar. 1-10 27" M24 Bartlein, Chamber for 215 Hybrids and also try 208 ELDs, Manners PRS2 stock and Calvin 2 stage. Just waiting for my Mausenfield LA, then sending it off to LRI for barreling. I'm hoping it comes in soon as my friend is trying to talk me into 7mm.

So that will make 3 people I know of with a .300 WM Mausingfield, myself included. Mine sports a 30" Pac-nor heavy Palma prefit, Manner T4AF with mini chassis , jewel trigger and a Vortex Gen 2 Razor. Took a year to get all the parts but like 20 min to assemble. I started with the 215 Berger at 2985 but found better accuracy with the 212gr ELD-X at 2975, running it suppressed with a SilencerCo Hybrid gets me to 3010.

The other day I started to do some testing on the 225gr ELD-M which show promise, I could get 2920 suppressed out of it.

As for what I would have done differently, I should have went with a 9 twist as I pretty much only shoot heavy bullets except for a breif tryst with some 115gr Controlled Chaos bullets at 3600fps.

I plan on hunting with it this year because I can though at 20lbs hiking it up the ridge to my stand might be a bit overkill since a long shot is 150yds.

 

[BallisticSam]

Damn Guys! That's some awesome information and thank you so much. CMP70306, Shields Shtr, your rifles look awesome!! Very inspirational.

 

[Mormegil87]

I had one in a Manners T4A before selling it. This time around I'm going to do a Mk13 Mod7, because why not?

 

[moosemeat]

From my years with a 300 win mag I wished I had a heavier contour than the Remington varmint. Maybe a extra long heavy varmint contour or mtu out around 30". Definitely get adjustable check and length of pull on what ever stock you like. I would run a 1-10 twist. I would probably get a fluted barrel, not for weight but to aid in heat dissipation. Buy top of the line bases and rings. Maybe open it up for 8-40 screws. My last 300 broke a Leupold ring(I must have let it get a touch loose, but I installed with a torque wrench and a dab of loctite).
Main thing I would do if I wanted a hot rod 300 win mag is build a 300 Norma mag.
Remember, barrels are replaceable. I shot one out pushing 190s fast in 1100 rounds. It actually started to open up around 900 but wasn't to bad until it just randomly opened up to a 2 MOA gun in a F class match.
Man now I want another 300 wm.

 

[schmi015]

My rifle started as a Rem 700 5r in 300wm. I sent it to GAP, it has a 27 inch bartlein medium palma barrel and sits in the an AICS 1.0 chassis. I'd stick with bullets of 190 grains and up and go with a 1/10 twist dont go faster than 1/9. There isn't to much i'd do different, it looks like a mk 13 without the aardvark and kac suppressor.

 

[Rob01]

If I built another it would have a 9 twist 28" barrel and be shooting the 225 ELDs. Get the most performance out of it I can while keeping it fairly mobile.