I have an FN built Winchester 70 short action Featherweight that i'd like to turn into a 6.5-284 Norma.

I can get to 3.1" max by removing the spacer in the mag & i have a stockpile of Barnes 120gn TTSX's to use in it. Has anyone got any ideas about suitable reamer specs to make this work? I've been told this one will work, any thoughts?

You're just as well off getting a short or no throat reamer and a separate throating reamer. Seat the longest bullet you want to shoot at max length and use that as a gage when throating the barrel after the chambering process is complete. Then you will know for certain where the bullet will touch the lands. Just my opinion.

I have a .284 with a .175 throat length shooting 175 grain Sierras. The overall length is 3.165 which is a bit too long for your mag even with the spacer removed. The overall length is, of course, directly related to the length of the ogive of the bullet. My guess is that the .175 length of throat on this reamer is a bit long. Press one of the 120's into a case with the straight section at around .175 throat length and check the OAL.

quote:

You're just as well off getting a short or no throat reamer and a separate throating reamer. Seat the longest bullet you want to shoot at max length and use that as a gage when throating the barrel after the chambering process is complete. Then you will know for certain where the bullet will touch the lands. Just my opinion

I do that with most of my wildcats. Makes it simple to match the chamber to the rifle and load.