338 LMI, 300gr Berger OTM freebore

[stymie12000]

I'm working on a reamer print for 338LMI. I plan on using the Berger 300gr OTM bullet. This will be single feed only.

What are your thoughts on freebore for this setup? I want to keep the bearing surface clear of the Donut. My calculations are telling me .265-.275"

 

[moondog]

I have my own short throated Reamer and a throating Reamer. I would strongly advise you to get the Dies first and have the Reamer made off those die dimensions. JGS will set you up. I run a 300 grain OTM +.010 and have the bullet seated at the neck/shoulder junction. There are more variations of that caliber than you think.
Getting the appropriate dies is the key.
Maybe Mr. Wheeler can chime in with a combo. My Dies are Warner.

 

[stymie12000]

I have my own short throated Reamer and a throating Reamer. I would strongly advise you to get the Dies first and have the Reamer made off those die dimensions. JGS will set you up. I run a 300 grain OTM +.010 and have the bullet seated at the neck/shoulder junction. There are more variations of that caliber than you think.
Getting the appropriate dies is the key.
Maybe Mr. Wheeler can chime in with a combo. My Dies are Warner.

I will be ordering a sizing reamer based off of the finish reamer from jgs and will make my own sizing die.

 

[SKWERLZ]

I'm working on a reamer print for 338LMI. I plan on using the Berger 300gr OTM bullet. This will be single feed only.

What are your thoughts on freebore for this setup? I want to keep the bearing surface clear of the Donut. My calculations are telling me .265-.275"

That freebore sounds about right
Similar to the regular 338 Norma freebore that positions a 300 OTM nicely in the neck.

Hopefully Mr wheeler will chime in.

 

[Bubba Boomstick]

Alex Wheeler is the expert on this subject. I am following.

 

[MagnumW]

I would call redding. They make two versions of a 40 degree die. Ask them what they recommend for the 300 Berger and where to get the matching reamer. Or just order a 338 Terminator and Die from Defensive Edge - thats the smart button.

 

[Alex Wheeler]

On the shorter side but it will work.

 

[284winner]

I have my own short throated Reamer and a throating Reamer. I would strongly advise you to get the Dies first and have the Reamer made off those die dimensions. JGS will set you up. I run a 300 grain OTM +.010 and have the bullet seated at the neck/shoulder junction. There are more variations of that caliber than you think.
Getting the appropriate dies is the key.
Maybe Mr. Wheeler can chime in with a combo. My Dies are Warner.

My 338 LMI (40°) FL bushing die is a Whidden click die. My seater die was modified by my gunsmith for the improved cartridge and is a Forster micro adjust model. My freebore is .282 +/-. It's cut for the OTMs. I shoot the 285s and 300 ATips also. Wish I'd have built the rifle as a single feed platform but it's mag fed. The OAL is over 4.0" so pretty much a waste of money. My recent CFW 338 LM is built to run the 230-270 ELDX bullets and will feed from mags. It's a hunting rifle exclusively vs the other being a range gun mostly.

 

[DaveTooley]

Min .275" with a .3392" FB diameter

 

[stymie12000]

Thanks everyone for the response. I will be finalizing the print here soon.

 

[MagnumW]

I went the route you did the first time and the second time I just had Defensive Edge chamber their 338 ai (terminator) and include their dies. Simple and works better than what I could come up with. 3000 fps out of a 27” barrel. 300 bergers.