Reamer freebore?

[BitOfShush]

What a great site, been lurking a bit trying to soak up info but cannot seem to find any regarding the most useful reamer freebore dimensions for the 300 Whisper.

A 1:8 twist seems mandatory to go above 220gr bullets, though some seem to shoot OK from a 1:10.

The reamer company advised they can machine me a reamer to suit any bullet, but there's the problem!

Supersonic:
I'd like to shoot 125gr Ballistic Tips, 100gr Speer Plinkers or 110gr Speer HP

Subsonic:
200-220gr cast lead bullets
220gr HPBT or
240gr Sierra Match Kings

They advised:

"The standard 300-221 freebore is .160"

240 grain Sierra Match King should have .190" freebore, 1°-30.

125 grain Nosler should have .025" freebore

If you want a reamer that will do both, you can order the reamer with .025 freebore and order a uni throater to throat the chamber out for the 240 grain"

So should I just order the standard reamer, or go for the extended throat version?

Will accuracy suffer greatly by shooting 125gr BT's in such a long freebore?

I guess excess pressures will never be a problem :smile:

Hope someone can help, my head is fairly spinning with options :confused:

Cheers

BoS

[pug]

It depends on who you have to satisfy. If you tell a bench rest shooter it is throated for a 240 but he is loading 125s he is not going to be happy :). You just have to pick one and live with the rest. Pressures do go up shooting the heavies in a short throat if you can get them to chamber. Also if you get a uni throater you will have to have them grind a custom rear bushing because the standard 30 caliber one will not work with the 300/221. The only ones that I know who have gone with the short throat planned to only shoot light supersonics. Most go with the standard and live with it by seating just a hair deeper and slightly reducing loads for the heavy bullets. Have fun.