300 WSM - Defiance XM - Freebore

[Graycliff]

Hello All,

New member here. I’ve been into precision shooting and reloading for about 15 years. All my experience has been with a GAP built 260 Rem, I’ve achieved some great accuracy and harvested some nice animals over the years.

Last fall I commissioned GA to build me a 6.5 PRC on a Defiance XM action, with the goal of shooting at longer ranges and possibly some future elk/mule deer hunts.

A luck would have it, I was drawn as a non-resident for a once in a lifetime Maine moose tag. Although I know the PRC is capable of responsibly harvesting a moose, I decided I wanted a bit more.

I’m having a 300 WSM barrel spun up, and I’m having a difficult time finding reference info for setting up a proper chamber for 300 WSM on a XM length action.

I don’t want to limit myself on COAL when I have the extra length of the XM action to play with

For the hunt I’ll be using a Swift 180gr. Scirocco, which I have been told by Bill Hober, likes a jump of anywhere from .030-.070

For target work I was thinking of a Berger in the 180-200ish weight class. Possibly the 200.20x

The barrel will be a 10 twist 22” carbon Bartlein carbon blank

I’m in the process of sourcing .30 cal components now

if anyone would be willing to help shed some light on this for me, I would greatly appreciate it.

Thank you

 

[B Nettesheim]

My wsm .030 off with the 208 Berger measures 3.262 oal with a.220 fb

 

[Edd]

After you get your components, assemble some dummy rounds to the OAL you want for your magazine. Then measure your dummy rounds and make your decision based on those measurements. Anything else is just a guess.

I suspect the difference in the shape of those two bullets is going to make it tough for you to find a freebore length that satisfies your desires for both bullets.

 

[Graycliff]

Thank you, I appreciate that. Now onto finding 200gr Berger’s..

 

[Laguna Freak]

Hello All,

New member here. I’ve been into precision shooting and reloading for about 15 years. All my experience has been with a GAP built 260 Rem, I’ve achieved some great accuracy and harvested some nice animals over the years.

Last fall I commissioned GA to build me a 6.5 PRC on a Defiance XM action, with the goal of shooting at longer ranges and possibly some future elk/mule deer hunts.

A luck would have it, I was drawn as a non-resident for a once in a lifetime Maine moose tag. Although I know the PRC is capable of responsibly harvesting a moose, I decided I wanted a bit more.

I’m having a 300 WSM barrel spun up, and I’m having a difficult time finding reference info for setting up a proper chamber for 300 WSM on a XM length action.

I don’t want to limit myself on COAL when I have the extra length of the XM action to play with

For the hunt I’ll be using a Swift 180gr. Scirocco, which I have been told by Bill Hober, likes a jump of anywhere from .030-.070

For target work I was thinking of a Berger in the 180-200ish weight class. Possibly the 200.20x

The barrel will be a 10 twist 22” carbon Bartlein carbon blank

I’m in the process of sourcing .30 cal components now

if anyone would be willing to help shed some light on this for me, I would greatly appreciate it.

Thank you

You will likely find a 180 Scirocco II accuracy node with a very long freebore. IMO you will be fine for both bullets if you plan for the berger’s freebore. I’m still playing with the 180 Scirocco after switching to RL23 in my saami 300 WSM but the African Plains hunters consistently say long jump and push the Scirocco II fast.

 

[Graycliff]

You will likely find a 180 Scirocco II accuracy node with a very long freebore. IMO you will be fine for both bullets if you plan for the berger’s freebore. I’m still playing with the 180 Scirocco after switching to RL23 in my saami 300 WSM but the African Plains hunters consistently say long jump and push the Scirocco II fast.

That’s what I keep hearing about the Scirocco, as well. Thank you, I’m going to give that plan a try.

 

[dkhunt14]

I believe you will find better target performance with a 210 VLD or a 215 Berger. That's what all the 1000 yard BR guys are using. They have set alot of records with these two bullets. They plain down just shoot. The 210 will need around a .230 freebore or a little more and the 215 will need more.

I have shot the 210 VLD for 13 years in a WSM and never saw a reason to switch bullets. That bullet and H4350 seems to really shoot. With that combo a 215 primer is not needed. Matt

 

[B23]

Not that they're any easier to find than the Berger 215's but the Berger 200.20X is becoming very popular especially in the mid size cases like the WSM. I think I read the 200.20X is basically a lighter version of their 215.

 

[Graycliff]

I believe you will find better target performance with a 210 VLD or a 215 Berger. That's what all the 1000 yard BR guys are using. They have set alot of records with these two bullets. They plain down just shoot. The 210 will need around a .230 freebore or a little more and the 215 will need more.

I have shot the 210 VLD for 13 years in a WSM and never saw a reason to switch bullets. That bullet and H4350 seems to really shoot. With that combo a 215 primer is not needed. Matt

Thanks Matt. After reading this I did some digging, looks like this will work out well. It helps that I have some H4350 and 210m’s on hand.. a few less components to source and overpay for