Which reamer should I use???

[fieldratsniper]

chris from pac-nor sent me all their 6br reamer prints,i think i asked to many questions) and i just want some help since im not too familiar with reamer specs.

i want to use lapua brass without turning the necks, and i want to try 87gr. vmax and 105 amax,maybe some other brands in that range too).

I'm planning on trying out the 3 groove or maybe the the polygonal barrels,8 twist).

ive got it narrowed down to two reamers. both chambers look like they will fit lapua brass, but the BR Rem,#1125)has a slightly longer throat,.0158" right?). id like to use the lapua chamber,#3447) but i dont know if the throat is long enough for the 105gr bullets.

any input is greatly appreciated. anything else im missing?
Jeremy

 

[WayneShaw]

The PTG reamer print has no leade, and a throater must be used. The JGS print has way too long of a leade.

Ask them if they will thoat the chamber about .030 to .040 in length. Otherwise find someone who can.

 

[wnroscoe]

"Zero" free bore isn’t always a bad thing, the lead still has some taper to it and the lighter bullets may work better with it. Some of the PPC shooters are using a "Zero" free bore in their chambers for the 00 Barts. My 6mmBR, 6 Dasher and 6XC Reamers all have .104" free bore and are set up for the 105/107/108's. The 6BR has a .269" Nk, all others are .272". It's going to be hard to pick one free bore for all bullet weights, especially from the 87 to 105 grain weight range. .060" may be the best compromise you could make.

Pac Nor should be able to cut the throat by hand for your chamber when using their "Zero" free bore reamer, that’s probably why they have it.

 

[fieldratsniper]

can someone explain "freebore" to me. im not sure what it is.

The rifle in this article seems to have the chamber that i'd like to have Click Here

it's mentioned to have a .073" freebore.

so, they would use the lapua reamer and then use another reamer to cut the neck?

thanks for the help,
Jeremy

 

[WayneShaw]

Simply put, the "freebore or leade" is a section ahead of the chamber which is cut to allow longer bullets to be seated farther out of the case. Some reamers are made with the freebore made in. Some don't have any freebore. Zero freebore will be fine for short range light bullets, however, when you get into the long VLD types, you need some room for the long bullet.

While wnroscoe suggested a .104" long freebore, and the article refers to .073", either one will work. I suggested .030" to .040", so it can work with most any bullet. The 6BR has a fairly long neck which allows seating most any of the 107's or lighter without the bullet entering the case section with a .040" freebore. Plus, as the throat erodes from firing, you have room to chase the lands.

I would think Pac Nor can throat the chamber as you ask.

 

[fieldratsniper]

okay, i just wanted to make sure i understood what i was talking about.

i understand what you guys are saying about cutting the chamber and then going back in and cutting for the desired freebore.

on the reamer print it shows that the throat is .2004" farther forward than the lead. im trying to understand the difference between the lead length and the throat length. i thought that the distance between the case mouth and the lands was the throat length. but if the freebore is set by the lead length, i must be mistaken.

Thanks for the help guys. you've already answered my question on what i need to do about my reamer and freebore choice, im just trying learn from you guys.

Jeremy