I'd look for another #4 bbl, condition of bore unimportant.
Then send it off and have it rebored.
I have a LeeSpeed that was already rebored to 35 on the 303 case when I bought it. Beautiful work but I don't know who did it.
I had JES Reboreing do the same to a Martini Sporter built by Watson Bros, that had a bad 303 bore.
I think there's enough mat'l to go to .375 in the #4 bbl. if you want a bigger bore.
JES charges $250 includes return shipping of bbl. last I knew.
I noticed his website shows .359 as groove dia for 35cal but mine is .358. Might be a typo.
Turnaround was a couple of weeks.
http://www.35caliber.com/index.html>
>
444Marlin may be another option for a rebarrel. Seems someone used to sell a replacement bbl for the conversion (Numrich?) so maybe there's one floating around. Some mag conversion work would be needed though to a single stack style IIRC.
If you were to use a No1 action, you could rebbl with a LongLee bbl for a slightly heavier and longer (cut to length) barrel. Threads are the same, extractor slot sometimes needs a bit of touching up. They index the same.
Not that L/Lee bbls are found lying about in quantity, but a poor boor specimen could perhaps be located and sent for rebore.
I don't know if a L/Lee bbl will fit the #4 action thread.
Too modern for me!
Good luck on your project...
