I was talking about a 450 WSM for a 700 Rem short action on the 450WSM thread. I was parusing COTW and saw that 10.57 Lazzeroni cartridge. I went to their website and they show 2450+ with a 400gr in a short action and a 26" barrel. This thing has a base dia. of .577 so is very close to a 416 Rigby with a 2.05" case length.

I never trust factory velocity tables so I'd like to know what kind of velocity real world loads are developing. Who here loads for it and what kind of barrel length vs. velocity are you getting.

I have a local gunsmith that is willing to do the action work and barreling for a reasonable price.

-Catter

Wildcatter...the Maverick is based on the Lazzeroni Patriot case (.308) which provides .300 WinMag velocities and then some. I have a 9.53 Lazzeroni Hellcat which is the Patriot necked up to .375 and I can readily reach 2550+ fps with the 300gr Nosler in a 23" barrel. If you do the math you should be able to reach 2400 fps with the 400gr bullet in a 24" to 26" barrel. The only two 'smiths I know that do a lot of Lazzeroni cartridges are Prarie Gun Works (Canada) and Mark Bansner in Pennsylvania..both of whom are excellent 'smiths. I would be a little leary of opening the Rem 700 bolt as far as needed for the 0.577" case head as excessive bolt-thrust could become a problem. You can buy the action that Lazzeroni uses from McMillan..it's the MCRT...not inexpensive but for a dangerous game rifle I would want absolute reliability. Good luck on your project...the Lazzeroni line of short magnums is great.