300 WSM Medium Action Build input

[N8Nobull]

I am currently in the process of building a 300 WSM. I have a SS Proof M24 1:10T currently at LRI to get the murder hornet fluting done and a Zermatt/Big Horn Origin Medium length with Hawkins DBM and mag on the way. I know I am a little restricted with how heavy bullet I can run with the 1:10" twist, but I plan on having the barrel at 22" and hoping to be in the 2800fps range. I figure I'll run 190-210gr projectiles, such as the 190 ABLR, 195 ELD-M, 200gr ELD-X, and 205gr Elite Hunters.

Curious on input if I'm on the right track, and what freebore or reamer specs might be recommended for this setup.

This is also the first forum I've signed up to be on, so I'm a rookie to this, but I have built several custom rifles, so I'm not totally ignorant.

Thanks,
Nate

 

[WeiserBucks]

10 twist is fine for 230 grain lead bullets. I've fired thousands of them.

 

[adk hunter]

Welcome from the real Upstate NY!

I made up a dummy round for my intended pill of choice. GS put 2 thous. extra throat and it hammers. Also, shoots factory 200 grain TA's but those really hit both ways...

Mine is a 1/9 22''CF Proof but not too far off your build.

Nothing is walking away from any of those bullets mentioned in the 2800FPS range.

 

[wvbearhunter]

My proof is a 1:10 on a BHO action and it shoots everything from 130 (barnes ttsx) to 200 ELD-X, like laser beams.

 

[dustbag]

Welcome! I have zero experience with the 300WSM but that barrel is gonna be sweet!! Please post a pic when it's all together. Good luck!

 

[Rick Richard]

H4350 with Berger 180 EH or Hammer Hunter 166 is sooooo sweet.

 

[N8Nobull]

H4350 with Berger 180 EH or Hammer Hunter 166 is sooooo sweet.

That's almost exactly what I guy I work with said, except in a 300 Weatherby.

 

[FEENIX]

I am currently in the process of building a 300 WSM. I have a SS Proof M24 1:10T currently at LRI to get the murder hornet fluting done and a Zermatt/Big Horn Origin Medium length with Hawkins DBM and mag on the way. I know I am a little restricted with how heavy bullet I can run with the 1:10" twist, but I plan on having the barrel at 22" and hoping to be in the 2800fps range. I figure I'll run 190-210gr projectiles, such as the 190 ABLR, 195 ELD-M, 200gr ELD-X, and 205gr Elite Hunters.

Curious on input if I'm on the right track, and what freebore or reamer specs might be recommended for this setup.

This is also the first forum I've signed up to be on, so I'm a rookie to this, but I have built several custom rifles, so I'm not totally ignorant.

Thanks,
Nate

Nate,

Welcome to LRH, and enjoy! My .300 WSM propels the 215 Berger at 2850 FPS with RL-17 out of a 24" 1:10" barrel. It will shine even more with a 3" or longer COAL. Good luck!

Ed

 

[Tiny Tim]

Welcome to the forum.

If your gunsmith doesn't have a recommendation on chamber dimensions, call Manson reamers. They can generally tell you what to use (SAAMI vs Custom) for your cartridge/bullet combo.

 

[N8Nobull]

Welcome to the forum.

If your gunsmith doesn't have a recommendation on chamber dimensions, call Manson reamers. They can generally tell you what to use (SAAMI vs Custom) for your cartridge/bullet combo.

Only one of the three smiths I use has a custom reamer for medium length builds, the rest use a SAAMI and throat reamer.

 

[adk hunter]

Also, Keep posting so people can send you a PM.

 

[Wy Will]

If you need a longer mag to seat further out, Unknown Munitions' bottom metal and mag have a 3.260 internal length on their medium mags

 

[JPatzig]

When I built my 300wsm (Hells Canyon Armory), I saw a post from Alex Wheeler -> ".220-.230 fb range is where I go with the 215s", referencing the 215 bergers. I ended up with .228, and pretty happy with it. I run the the 182 tipped hammers at 3100fps in a 20" barrel. They seat really long and leave a lot of case capacity.

 

[N8Nobull]

If you need a longer mag to seat further out, Unknown Munitions' bottom metal and mag have a 3.260 internal length on their medium mags

I've seen their stuff. So for I think I should have plenty of room with the Hawkins.