I was cleaning up some stuff today and took a close look at a Winchester M70 (post-64) Classic Sporter that I have in 7mm STW. I noticed that it is a CRF action. That got me thinking.

When I check the dimensions of the 7mm STW, the case length is 2.850 and the end of the case is .532. When I check the dimensions of the .458 Lott, the case length is 2.800 and the end of the case is .532. One cartridge is belted of course and the other is not.

My question, it would seem to me that converting this action to a Lott should be pretty darn simple. The bottom metal should be fine, the action should not have to be trimmed, the bolt face is already opened up, already drilled and tapped, three position safety installed, etc. Is this as simple as getting a .458 Lott barrel and having the barrel mounted and headspaced (and having sights installed of course) or am I missing something significant? I like the Winchester action and having one in a .458 Lott would be nice.

Your are correct. Except for making sure it feeds correctly, it is just a re-barrel job. The STW is built on what Winchester called the "Express" action. I had one in 416 that I re-barreled to 470 Capstick. It took a bit of work to get it to feed correctly. Mostly, modification to the follower and removing some metal from the inside/top of the magazine box (not the rails) in the area of the cartridge shoulder to accomodate the larger diameter case. In original condition, the cartridges would pop out of the magazine unexpectedly when operating the bolt. Also, some work on the feed ramp for the larger diameter bullet.

Both the Lott and the STW are based on the H&H BELTED case.

Your rifle would readily convert into a 416 Rem Mag. Advice is worth what it costs, yadda, yadda, yadda, but, I believe you would be much happier in the end with the 416 Rem Mag than the 458 Lott.

LD

LD,

I have a Winchester M70 in .416 Rem Mag already (the Safari Classic or whatever it is called version). That is the rifle that I was referring to when I said that I really like the action. They seem smoother that most of the other comparably priced bolt actions.

I was mistaken about the 7mmSTW being unbelted, the rear of the cases on the 7mmSTW and the .458 Lott are identical. The OAL of the Lott is slightly shorter which should help on feeding. I am convinced that stepping this up to a .458 Lott should be as close to a piece of cake as is possible.

Do any of the good quality barrel makers make prechambered, threaded barrels for the M70?

Mike most of the barrel makers make a chambered barrel for the lott, I used Pacnor for my 470 Capstick on a similar conversion. If you want to use factory parts (stock, barrrel bands, sights, etc) get the number 5 contour and it will be the same as your 416, so you can use all the same parts. As to the cartridge the stw is a belted mag on the 375 h&h case as is the 458 lott so it make a relativly simple conversion. Good luck

I have rebarreled several STW's to .450 Ackley also.

Don't you have one or two Lotts already (or in the works)? Or is is just 458 Win Mags?

You have been on quite the rifle spree the last year or so!

i think he's suffering from chapuis withdrawal....... and tip needs to work on my .416, so he doesn't need another project.... at least untill june....

Turn it into a 404 Jeffery. Damn the torpedoes, full speed ahead!

I must confess, the .404 Jeffery thought did cross my mind.