It was recommended to a friend that he could shoot these loads (300 gr., 1300 fps) in his Ruger Blackhawk 45LC/45ACP convertible. What do you think?

I've shot them. They're fine in a Blackhawk or a Freedom Arms. They're expensive, if you handload you can get basically the same performance with a heavy hardcast bullet and either H110/WW296 or Hodgdon Lil' Gun pretty easily for a lot less money. Take care they don't find their way into a Colt SAA or clone as you will have a very bad day if they do.

Thanks, Adrook. Went to the Buffalo Bore site and the loads were called +P, whatever that means. No specific pressures were indicated. What kind of pressure do you think is necessary to drive a 300 gr. bullet that velocity. I do know in years past people were warned to not try to magnumize the 45 Blackhawks because of thin cylinder walls. Things seem to have changed.

Why don't you aks Tim Sundles who owns Buffalo Bore, that question at his website?

+P means high pressure. I would guess that BB's loads are in the range of 30K CUP. Actually, the warnings against high pressure loads in a .45 Colt due to thin cylinder walls pertain to the SAA and its clones, not the Blackhawk. Here's a good article that John Linebaugh wrote a while back about this very subject

http://www.linebaughcustom.com/Articles/THE45COLTDISSOL...bid/201/Default.aspx

Beware of shooting these in a new vaquero or blackhawk. They are smaller than they used to be, and have thinner cylinder walls. The old vaqueroes and blackhawks can handle them just fine.

I've shot them in an old model vaquero, (4.5" bbl, non-bisley), and it was a hoot!

I mainly got them for my Marlin '94 cowboy for hog huntin' but have not had a chance to shoot a hog yet with it. They made that lightweight marlin kick a bit though...

I've shot the 325gr 45 Colt Buffalo Bore out of my Bisley... While they did possess some awesome power, the accuracy left alot to be desired. After I started handloading, I was able to duplicate this power and add the missing accuracy component. Just my experience, in my gun. YMMV