I have a chance to buy a Cooper in 6x47 Remington. Will this caliber work for HP silhoutte?

Regards,

Jim

Don't do it specially if is the old 6X47 and not based on the 6.5X47 Lapua case. I believe the other one was based on the .222 case neck opened to 6mm.
which was never a very good cartridge I was told by Martin Hull, Sierra's ballistics expert in the 80's and 90's

If it doesn't have a 7 twist bbl, run away from it. You need to push a 107 at 2800+ to take rams.

It is likely that Cooper used a barrel twist for varmint weight bullets which would not stabilize anything over 85 grains and maybe not even that. Although I think the case is based on .222 Remington Magnum brass rather than .222 Remington. It was developed as a benchrest cartridge and had a reputation for driving men to drink trying to keep it shooting. It got retired by the 6 PPC.

I join Tony in suggesting that you stay away from this cartridge for silhouette. There are several cartridges better suited to silhouette. If you ask, you will probably get more than a few opinions about what "the best" choice is.

The Cooper action is sort of an "odd duck" for serious target work...nobody uses it.

Rick