A couple of months ago, I rechambered a 35 Whelen to 350 Rigby Mag. It originally was a Vickers sporter in .318 WR that someone had rebored to 35Whelen, probably due to the scarcity of .330 bullets. After test firing, it showed nice results using the express sights at 50 yards with a load of 4350 and a 225 grain Sierra, two 3 shot groups around 1.25", not bad with my old eyes! Since it shows promise, I went ahead and started the action/magazine modifications to make this 375 length cartridge feed and function through a standard M-98. I have done this job several times before, but this time, I used Duane Wiebe's booklet as a reference. The pictures and explanations were quite helpful and helped keep me out of trouble as it had been several years since I have done one. The front of the magazine had originally been extended by Vickers, but was still a bit shy, so I put it in my mill and thinned it as much as was practical. The back of the mag was already thinned and the bolt stop had been trimmed back, all I had to do was shorten the feed ramp to match the mag. After altering the feed rails and touching up the ramp, it fed slick as snot and by following the instructions, the rim was slipping under the extractor just as the bullet started to enter the chamber maintaining true controlled feed. I get a kick out of the fact that Mr. Wiebe uses a Dremel with carbide burrs to alter and shape the feed rails, most folks make fun of using the Dremel, usually referencing "Bubba", but in the hands of someone like Duane, it is a viable tool to do the job. I had recently added a cordless Dremel to the collection and it sure was easier to control. After stoning and polishing and a bit of touch-up bluing, the old girl is ready for a trip to the range.I still need to relieve the rear of the front ring for loaded cartridge clearance, but that is for another day, it ejects loaded rounds just fine, but when loading the mag, you have to be sure and slide the round to the rear to clear the front ring. All in all it is fully fuctional as is, I just need to decide the contour to use on the rear ring mod. Anyone thinking about making these mods would do well to get Duanes' booklet, it is $24.95 well spent and has many great tips, like radiusing the bottom of the extractor to allow the rim to feed up under easier. It was a productive weekend!

Pictures?

I'm not much of a photographer and the pictures would have to be tight and the lighting right, to show any details of the mods made. Way above my pay grade. sorry!
If the rain will stop, I am loaded up for a trip to the range.

Where can one get a copy of Duanne's booklet?

As far as loading for the 350, mine shot well with the 250 gr hornady rn with both Varget and H4350. As I recall my top load with Varget was 66 gr, and the top load with H-4350 was 72 gr. Accuracy was best with the Varget load and both were chronoing 2700 fps +/- I'd expect the 225 sierra to accept a few more grains of powder.

Used a 225 sierra out of my 350 rem mag to take a cow moose last week. Not much of a test with a high lung shot ~150 yds. that didn't hit any ribs and just barely nicked the bottom of a vertebrae. It did drop at the shot though so a perfect no tracking meat shot.

quote:

Originally posted by Paul H:
Where can one get a copy of Duanne's booklet?

As far as loading for the 350, mine shot well with the 250 gr hornady rn with both Varget and H4350. As I recall my top load with Varget was 66 gr, and the top load with H-4350 was 72 gr. Accuracy was best with the Varget load and both were chronoing 2700 fps +/- I'd expect the 225 sierra to accept a few more grains of powder.

Used a 225 sierra out of my 350 rem mag to take a cow moose last week. Not much of a test with a high lung shot ~150 yds. that didn't hit any ribs and just barely nicked the bottom of a vertebrae. It did drop at the shot though so a perfect no tracking meat shot.

Here’s Duane’s booklet:


http://www.customgunandrifle.c...r-conversion-booklet

Earlier this week, despite the monsoon like weather we have been having, I went to the range for a little 100 yd. work. Using brass that I had made out of .375 H&H brass, from the bench I managed to shoot a couple of sub 2" groups with the irons. This rifle comes in at 6 lbs. and with a steel buttplate and 250 grain loads, after about 14 rounds, I gave it a rest! I sure wish it had a scope, but I cannot bring myself to drill and tap it. It is a sweet and light little rifle and would be a hammer in the woods. It likes the 225 grain Sierra bullets and they are easier on the shoulder although from a standing position, none of the loads are bad. I thought, at one point, that I was going to have to get an AR out of the truck to use against the mosquitos! With two weeks of rain, they have flourished and we have some real Texas sized ones at the range. All in all, this little project has turned out nicely and I am getting more profficient at turning the belt off, deepening the extractor groove, and re-cutting the extractor clearance bevel on the 375 cases with the lathe. The first 6 took me about two hours and after I got a feel for it, I could turn out about 20 per hour. I loaded the mag (3 down) with mixed RN and SP's and ran them hard and they fed and ejected great. I have yet to relieve the back of the front ring and will, but it ejects loaded rounds with gusto! This has really been a fun project !