6.5x47 reamer question

[twotwothree]

Hello,
I have my first rifle built recently using a 6.5x47 reamer from JGS. The reamer has the number 2124 on it. I have found a reamer print and am trying to work out if the lands position would be listed as one of the measurements on it. The diagram lists the lead as 2.0378 and the throat as 2.2975. At the bottom of the diagram there is a comment that says throat datum .262 x 2.087 from bolt face. Any help explain these measurements would be appreciated. My second question is, is a reamer like this suitable for shooting 130-140 projectiles. Sory if this sounds a bit silly but its all new to me. Thanks

 

[Preacher]

Send a reamer print photo, and someone will help you out..

 

[Pablo]

Why don't you load a dummy round with both bullets and find the lands by adjusting seating depth. The bullet with approximately one caliber of bullet diameter in the neck would probably be the one you want but you really have to shoot it with both to find out. In my experience the 130 is a really good bullet for this cartridge.

 

[twotwothree]

 

[twotwothree]

Thanks for your replies. I have loaded dummy rounds but im not sure it is really accurate. Also the bullet is a long way in the case.

 

[ridgeway]

That will work fine for the 130's

 

[Dusty Stevens]

Look for alex wheelers video on finding your lands. You dont have a way to transfer that print measurement to your tools.

 

[Jarhead6870]

I have a barrel chambered with this reamer and while I personally would prefer a little less freebore, the .163 cut with this reamer works well for me shooting Berger 130 or 140 Hybrids.

Ideally, I would prefer a freebore in the .140 to .150 range to primarily shoot the 130s and then switch, if necessary, to 140s as the throat eroded. If shooting the 120 class of bullets, a freebore in the low .120s seems to work well.

Enjoy your 6.5x47, it’s a great round...

 

[SRM]

Take out the firing pin assembly to find the lands. Modify a case or three for ejector clearance. Nice easy feel . Works better to take ejector out .

 

[kendog]

Hello,
I have my first rifle built recently using a 6.5x47 reamer from JGS. The reamer has the number 2124 on it. I have found a reamer print and am trying to work out if the lands position would be listed as one of the measurements on it. The diagram lists the lead as 2.0378 and the throat as 2.2975. At the bottom of the diagram there is a comment that says throat datum .262 x 2.087 from bolt face. Any help explain these measurements would be appreciated. My second question is, is a reamer like this suitable for shooting 130-140 projectiles. Sory if this sounds a bit silly but its all new to me. Thanks

The throat datum dimension on the print is the point where the ogive of any given bullet will touch the lands on a new chamber. Of course it moves forward as round count increases. Set a micrometer to .262" (.002" under groove diameter) and use the carbide anvils to scribe a circumferential line around the bullet. I color the area with a sharpie to make the line more visible. Seat the bullet with that line at 2.087 from the case head and the bullet is just touching the lands in the angled throat. This works for all calibers, the rule of thumb is to set the mike at .002" under groove diameter you are working with.

To find the throat datum in any given chamber, make a collet necked case by splitting the neck in two or three places and breech seat a bullet marked as above, then carefully extract it and measure it. You can get scary close with your eyeball and a 6" caliper. Knowing this dimension will allow you to accurately track throat wear in any given chamber and adjust seating depth accordingly, or know how much to jump or jamb.

I'd like to claim I thought all this up myself, but I got the info from Carey at JGS many years ago!

 

[AckleymanII]

Be sure to check your actual case length against the case length on the print.

 

[twotwothree]

Thanks everyone, been very helpful