Mold for 35 cal rebore

[Bob_in_pa]

I was wondering if anyone can provide some advice for a mold for a Mauser 98 rebored to 35 Whelen by JES Rifle Reboring (www.35caliber.com). It’s a friends rifle and we just can’t get the thing to shoot lead. He’s tried commercially available cast bullets in .358 and .359 and gets severe leading and 2 foot groups with key-holes at 50 yds. .360 cast was just as bad. It shoots those copper colored bullets pretty good (1” at 50 with no real load development).

Tried slugging the bore but it’s 5 groove and measuring is a problem. The 35caliber.com site lists 349 Bore-359 groove for 35 cal. but we can’t confirm. The concern is buying a custom mold and having it not shoot any better. We’re thinking .362 “should” work but don’t want to wind up with an expensive paper weight. Going with a .363 mold and sizing to .361 then .362 etc. is another option.

It seems like JES is very popular. I’ve read a lot of good things about them on this site, but nothing specific about the best dia. for their 35 cal barrels. I would think someone’s been through this before and would really appreciate some insight based on that experience.

Thanks,
Bob

[Beerd]

Welcome to the board Bob!

No answer here but it may help if you could tell us the twist rate that JES used.
..

[Outpost75]

A 16" twist will adequately stabilize a 260-grain flatbased bullet which is not over an inch long.

[bhn22]

Perhaps the bore needs to be lapped. Perhaps your bullets are too small. Perhaps your lube isn't up to the task. There are a lot of potential variables.