300 WSM Chambering

[Lpart]

I am starting a new build of a 300 WSM on a trued Rem 700 LA. I would like to think that with the LA magazine and the ability to seat the bullets out further to maintain/increase powder capacity I can effectively get higher velocities with the longer and heavier bullets. Any suggestions on how much additional leade over SAAMI specks would be beneficial?

 

[dkhunt14]

I run a .210 freebore for a 210VLD in my 1000 yard BR guns. It lets the pressure ring even with the neck shoulder junction. You could go a little more. The 230 needs around .270 or so. Matt

 

[Lpart]

I have set up a dummy round with the 175 gr Barnes Long Range TTSX. Easily fits my LA magazine and COL is 3.153". Too long is rifle is throated properly? Base of bullet comes to base of neck.

 

[brentc]

Go with the SAAMI for the most versatility. It's tried and true. You won't gain much with a custom leade in the 300 WSM. MY SAAMI chamber leaves a 210 berger right at 3.000" touching the lands. A 230 OTM is 3.010.

 

[dkhunt14]

If you go with the 230 Berger and move the freebore out to .280 you can reach 3000 FPS with 7828 SSC. If you shoot the 215 and go with .210 freebore you can get 2950 with 4831 SC. Without moving the freebore out you can't get the velocity because the bullet eats up powder capacity. Matt

 

[AZShooter]

There has been no mention of barrel length which IMO has more influence in velocity than throat length.


I am as guilty as others in lengthening throats and magazines. Sometimes it will require some gunsmithing to get back the smooth feeding.

I always grin when I think of my friend's 300 WSM with its 2.8" magazine length restrictions. For grins seated the 230 target match hybrid to fit and feed. The bullet is obscenely deep into the case. We joke that it is sitting on the flash hole. Using RL-17 got 2720 from his 22" browning A-bolt! It worked so well he used it to take a cow elk last fall. A very spectacular kill at 300 yd was the result.

 

[Steve lippitt]

If you go with the 230 Berger and move the freebore out to .280 you can reach 3000 FPS with 7828 SSC. If you shoot the 215 and go with .210 freebore you can get 2950 with 4831 SC. Without moving the freebore out you can't get the velocity because the bullet eats up powder capacity. Matt

 

[Steve lippitt]

What speed would you get out of a 26 inch barrel

 

[Rick Richard]

Did you ACTUALLY experience these speeds or they estimated? Seems very high for the weight of the projectiles with WSM. Just curious because my experience thus far is not near that.

 

[brentc]

Did you ACTUALLY experience these speeds or they estimated? Seems very high for the weight of the projectiles with WSM. Just curious because my experience thus far is not near that.

The best I've seen is 2950 fps with a long throat and a 215 berger loaded stout with RL26. I'd be surprised to see anyone actually achieving 3000 with a 230 with decent precision in hunting weight rifle.

 

[Rick Richard]

The best I've seen is 2950 fps with a long throat and a 215 berger loaded stout with RL26. I'd be surprised to see anyone actually achieving 3000 with a 230 with decent precision in hunting weight rifle.

That speed and projectile weight is more in the 300 RUM performance range. My 300 WSM with 180 grain projectile will only average around 2975 fps with H4350.

 

[bigngreen]

Matt is the king of the 300 WSM in accuracy shooting circles, there is no doubt he runs what he says, how he says, no doubt the reamer is perfected for his purpose.

In shorter barreled suppressed hunting rifles were seeing 215's running mid 2900's when throated out and ran from a med action.

 

[nksmfamjp]

Nice choice of caliber. I think when I think lr hunting and 300 WSM, I think 200 or 212 ELDX; Accubond long range 200?, Berger 210 vid hunting...I wouldn't waste time below 190 gr.

I would pick your bullet of choice and seat the bullet so only the boat tail is inside the case. Then send that to your gunsmith.

Don't forget to match twist! No reason to run a 212 eldx in a 1:10 barrel.

Also, I pick barrel length by what I can accept in the field regarding balance....that limits me to about 26", but I would add a brake on 26".

Surely others have more experience than I do...

 

[Rick Richard]

Nice choice of caliber. I think when I think lr hunting and 300 WSM, I think 200 or 212 ELDX; Accubond long range 200?, Berger 210 vid hunting...I wouldn't waste time below 190 gr.

I would pick your bullet of choice and seat the bullet so only the boat tail is inside the case. Then send that to your gunsmith.

Don't forget to match twist! No reason to run a 212 eldx in a 1:10 barrel.

Also, I pick barrel length by what I can accept in the field regarding balance....that limits me to about 26", but I would add a brake on 26".

Surely others have more experience than I do...

Sounds fine and dandy, however I doubt seriously you can seat the larger projectile as you indicated and have it fit the magazine in a short action...single feed yes, but not otherwise.

If I am incorrect in my thinking through my experience and using an extended Mag length (3.10 inches), please school me.