New gun at the range today

[shooting on a shoestring]

Took my new SS NMBH 4&5/8" to the range for its maiden voyage. Overall a good first outing. I was a little surprised to discover one chamber had a burr that made loading an unloading a pain. Removed the burr with the judicious use of a Case Stockman hollow ground SS pocket de-burring tool. Problem solved. I was also a bit alarmed when the first fired cases were all a bit draggy on extraction with lots of tool marks in them from the chambers. About 500 rounds later that symptom had vanished. I guess all the peakies got hammered down into the valleys and the chambers smoothed out.

My Belt Mountain base pin didn't get here in time, but the revolver was not terribly loose with the stock pin. Now that I've verified function, I'll take it apart tomorrow and remove the trigger creep.

I was surprised the little critter leaded with my pet load of 358091, 7.5 gr Herco WWAC'd. My SP101 eats those by the hundreds w/o a bit of leading. Not so the NMBH.

The little SS NMBH did a nice job with the Lee Group Buy 175 Keith SWC over 13.0 gr H110. No leading, 1150 fps, 2 to 3" at 25 yds. My SP101 was making 7" plus groups with that load.

I did see more leading with Lee 140 SWC with 8.5 gr Power Pistol, 1340 fps. Not to surprised.

However I still got leading with .38 cases, 3.5 gr Bullseye Lee 140 SWC, 358156 w/o GC installed, 358091 and Lee TL 158 lubed w/mixture of LLA and JPW.

I slugged the barrel a few days ago and found it to be .357. Today after about 350 rounds, I used a pair of dial caliper and found the muzzle to be .358" (8 groove rifling). My throats are .3583 to .3589". Boolits all are sized .359. Now I'm wondering if I do have a tight spot in the barrel. I can't feel any with a tight patch, but maybe its there.

I think I may shoot it another 500, maybe 2000 rounds before I get to excited about lapping or some such.

But I can shoot that GB 175 SWC just fine and it sure slams my dueling tree with authority!

[leftiye]

Make all the throats the same size. Slug the bore again so you can do the measuring with the same tool you used before. Make the chamber mouths .001" larger than what measurement you get.

[calsite]

I've heard of people applying some polishing compound or rouge to the exterior of their bullets to knock down sharp rifling or a high spot. (Fire lapping). You might give that a try.

[44man]

Buy a bunch of jacketed bullets (HORRORS) and shoot the blazes out of it. Clean the copper out a lot.
I have power lapped but wonder what JB bore paste would do on a cast boolit. Use it for boolit lube for about 20 very low velocity shots. I never tried it but it sure would not hurt anything. Wipe out the chambers after every 6.
Ruger stainless is TOUGH stuff and it takes a lot to smooth it. I know you will not live long enough to wear the bore.
You will only see it get better and better.

[shooting on a shoestring]

Yep, I think both perscriptions are in order, slightly opening or evening out the chamber throats, and shoot some lapping loads of some sort. I really don't want to invest in a pot full of jacketed, and for a stainless barrel it would take a whole damn pot full, so I'm leaning toward some spiked boolits.

I'm thinking a handful of 358089 rolled between some steel flats with valve grinding compound smeared on them. That would probably stick some abrasive into the lead a do a dandy job of lapping a barrel. Going slow would probably be in order. A regimine of about a dozen lapping shots, a good thorough brushing and cleaning, a box or two of regular fodder to check for leading and improvement, another good brushing/cleaning, another dozen lapping shots etc... until improvement.

The chamber throats also might change a little during that, and the tighter ones could be fired more than the looser ones.

I think its worth prepping some lapping boolits and see if it can help.