Convert Win M70 458 WM to 458 Lott

nksmfamjp

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Can you recommend a gunsmith to convert a Win 70 safari 458 wm to 458 Lott...rechamber, confirm/smooth feeding, possibly add recoil reducer?

I’d prefer OH, but I’m willing to ship.
 
I used Gary Junk in Fairbanks AK. He did a great job on the conversion, cutting the barrel down to 22”, installing banded front sight and sling swivel, etc. Gary is semi retired but I think he still keeps Arctic Gunworks contact info alive.
 
Wild West Guns in Anchorage, AK did 1 of my conversions for me. Did an excellent job and haven't had any issues whatsoever in numerous hunts with it.
 
Dennis Olson in MT did my M70 conversion to make a 404 Jeffery and did a great job at a reasonable cost.

500 1st Street
Plains, MT 59859
Phone: (406) 826-3790
 
If you get this done, let us know how much it costs and how well it works. I have a Model 70 458 as well.
 
For those that are expert at reloading there is another option... swap out your short magazine, follower,ejector and bolt stop for ones from 375 H&H. You can then handload to 3.6" length. In 2009, I published an article about this in Magnum Magazine in South Africa. I used the Pressure Trace system to measure pressures and Johan Loubser from Western helped with powder selection since he had been a ballistics expert at Somchem. I used a Winchester M70 in 458, a CZ 500 in 458, a Ruger No. 1 in 458 and for reference of both the "458 XL" and Lott .. a Ruger Magnum rifle in 458 Lott.

Attached are parts of the article from 12/2009 and a pic of the Cape I shot with the CZ550 with the 458XL cartridge.
Magnum Magazine 2009_1.jpg
Magnum Magazine 2009_2.jpg
P8080113.JPG
 
I have had several suggestions to do this, but why not just go to the larger standard round with known load data.
 
Load data is essentially the same. Using H335 and Fed215 primers... 82 grains in the XL yielded 2248 fps and the Lott 2291. The extra neck tension probably being the reason. There is one good point to rechambering a 458 into Lott. During the workup, the Ruger Lott could not use all of the bullets out to length as with the Trophy Bonded Bearclaw. The 458 could. The conversion to 458 Lott still required that same parts swap out. The XL has a niche though. In some countries, rechambering means re-registering with all the hassle and risks. I am attaching the published loads developed with the usual points that this is with this rifle and all handloading must be judicious. Follow the rules.
Loads.jpg
 
One thing I did notice is that a Lott reamer won’t completely recut a WM chamber.

The WM has a super long 29 min lead while the Lott has a short throat and 2 deg lead....interesting

How well does shooting WM in a Lott work? I wonder for deer hunting in Ohio...
 
and those leade angles make a big difference to pressures.
going from 1/2 degree to 2 degrees can make a safe load blow primers, even with a longer throat.
don't ask me how I know this.
bruce.
 
Yea, but this is kind of opposite, right? Like a normal 458 Lott goes from throat diameter to bore at a steeper 2deg angle. On a conversation, it will go 2deg to the remaining 29 min throat....should lower pressure slightly and guide bullet to bore more accurately!
 

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