7mm Rem Mag and freebore

[Slim13]

I’m getting ready to put a new tube on my 7mm rem mag and I have a question for the brain trust here. Currently I’m setup with it chambered at minimum SAAMI spec. I shoot the Berger 168 VLD’s just fine out of it but want to move up to the 180’s to help cheat the wind a little bit more. When I get this new barrel chambered, do I need to ask for more freebore to be able to properly seat the 180’s a little farther out? For what it’s worth, using a 168VLD I’m 2.709 (CBTO) to the lands (or 3.416 COAL) in my current chambering. Action is a Remington 700 if that makes any difference. Maybe I’m over thinking this, but it sounds like seating the 180’s a little farther out will give me an incremental increase in case capacity.
Thanks in advance.

 

[AckleymanII]

split the neck on a case. Seat the bullet to the magic depth that turns your crank. Load a dummy round, send that dummy round to the gunsmith for him to throat the new barrel to.

Many, good gunsmiths on this site can do this for you, they will hit the number within .010.

You will probably want to send your action and have a Wyatt's mag box installed also that will give you another .125 of OAL.

Good luck!

 

[Slim13]

split the neck on a case. Seat the bullet to the magic depth that turns your crank. Load a dummy round, send that dummy round to the gunsmith for him to throat the new barrel to.

Many, good gunsmiths on this site can do this for you, they will hit the number within .010.

You will probably want to send your action and have a Wyatt's mag box installed also that will give you another .125 of OAL.

Good luck!

Thanks for the response, but here’s the rub: I don’t know what length is going to turn my crank. Hahaha.

Maybe my question should be “What COAL is optimal for a 180 VLD and fill feed from an internal magazine (Wyatt’s or stock)?”

 

[Zero333]

If I remember correctly, 3.550"ish is optimal COAL with the 180 Hybs in the 7mm RemMag. Not 100% sure what the freebore equals out to. 0.170" comes to mind.

3.680" is about MAX COAL for R700 LA boxes.

 

[idahoorion]

Slim, my 7mmRM has a freebore of .188 (or it did several hundred rounds ago), that is optimized for the 168 vld's or SMK. .220 or longer is usually the starting point for 175/180's and longer still for the 195's. with a short reamer, just take a bullet and seat and try to get the junction of the bearing surface and boattail close to the neck/shoulder junction of the case and you'll be close. Then see how that fits in your magazine and you'll know what you need to do. the .188 does work with the 175/180 class bullets and my barrel prefers them.

Idahoorion

 

[Slim13]

Thanks for all the answers. Seated bullets are on the way to the smith.