6mmBR Reamer Specs

[Phil3]

I am building a 6mmBR rifle and would like some advice on reamers. This is just a fun gun using a factory action and a custom barrel for shots out to 300 yards, but would of course would like it chambered to fit my needs.

The gunsmith I am considering offers two reamers. One is PTG having a .272 neck with .040" free bore. The other is ECT (subsidiary of PTG) with a .272 neck and .113 free bore. I am figuring that I will be using 68 - 80 grain bullets and the PTG reamer might have too little free bore and the ECT too much. I will be using Lapua brass and am OK with turning necks. I am new at this, so any experience and wisdom is welcome.

Thank you.

Phil

 

[DCRYDER]

I'd do the .040" FB. Most 6 ppc's have between .030" and. 060" so you should be good to go. A throating reamer could be used to make it just right.

 

[fdshuster]

Phil3: When I was using the older, thicker gold cardboard box Lapua 6BR brass, my 6BR reamers were the then standard .272" no turn chamber necks. Have since sent the reamers back to PTG and had them reground to .269" for the new blue box Lapua brass. Loaded round diameters are .2665" to .267", so still a good no-turn choice.

The .272" would work, just a little larger than I would choose.

If you're going to limit distance to 300 yards, and with the short, lightweight bullets only, then any freebore from zero to around .050" ( I would not go any longer than that) would also be fine.

Consider buying your own reamer (?) cut to your exact specs? If you then have no further need for it, it can be sold for close to what you paid for it, and your chamber was cut with a new, virgin reamer. The advantages of a floating pilot reamer are someting else to consider. The only kind I buy, and the vast majority that PTG sells.

 

[jonbearman]

The bluebox reamer I have is.2704.Do you turn your brass for a cleanup?

 

[Phil]

Phil.

Call me,i`m off work today.

You need to buy a reamer.


Phil

 

[fdshuster]

jon: Nope ! Use them as is out of the box, unless I find a below standard lot that has more then .0005" to .001" variation. Then the lightest possible cleanup cut.

 

[lpreddick]

i bought my own, the .2704 neck and .040 freebore. my 14 twist shots up to 70 gr bullets and if i did it over, i'd consider less freebore. .040 is ok with 68 gr bullets since they seat about half down the neck when loaded .020 into the lands. the 60-64 gr are about 1/4 into the neck. i don't turn necks and i was concered as to whether the clearance was safe...i really like the tight neck. LT 32 powder works great as does n133 and benchmark. tried 8208 XBR yesterday and it might become "the powder". my most enjoyable gun to shoot.