44 slugs out at .433?

[mattri]

Ruger NM Super Blckhawk from the early 80s in 44 mag.

Slugged the bore and it comes out to .433"

Seems a little loose but haven't shot it much.

Worth trying an off the shelf mould or go straight to a custom from Accurate?

Thoughts?

[megasupermagnum]

There are options for in-stock molds if that is what you want. NOE makes both .432" and .434" molds. The bigger problem is you probably don't have .433" or bigger cylinder throats.

[nicholst55]

There are options for in-stock molds if that is what you want. NOE makes both .432" and .434" molds. The bigger problem is you probably don't have .433" or bigger cylinder throats.

DougGuy should be able to open the chamber throats up to .433".

I'm also curious about the groove measurement. Did you measure your slug with a micrometer, or vernier calipers? I'd think that it's unusual for Ruger to crank out a barrel that large.

[mattri]

Digital micrometer measured multiple times, seemed large to me too.

[rockrat]

Arsenal makes a .432" mould, but mine comes closer to .433" with WW's alloy

[gc45]

I had this issue once so took my $100. digital micrometer to a local machine shop where the owner double checked it against two different higher end Starrett measuring tools; mine was off in comparison plus not very repeatable when measuring the same object.

[Larry Gibson]

"Slugged the bore and it comes out to .433"

I would also question that. A re slug would be done as would certifying the tool doing the measuring was accurate.

[lead4me]

I had this issue once so took my $100. digital micrometer to a local machine shop where the owner double checked it against two different higher end Starrett measuring tools; mine was off in comparison plus not very repeatable when measuring the same object.

A quick down an dirty way to check your mic, is to grab a set of feeler gauges and measure a couple.

[DougGuy]

Something is amiss there. I have NEVER seen or heard of a BH/SBH 44 barrel with those kind of tolerances.

Do you have a .431" J word bullet? Force that through the bore, if it really is .433" you would only have lands engraved in the jacket, as it would not fill the grooves. Push the .431" into the bore and use a white paper held at the forcing cone to shine light into the bore, see if you can see light around the bullet.

You could snail mail the slug I have a good mic that reads in .0001"

Doug

Edit: Some of the 3 screw 44's had a circle on the barrel in the logo, a good number of those have a significant bulge in the barrel at the barrel/frame juncture, a slug pushed down the bore can come completely loose in this bulge, it's about a half inch in length and is a result of torquing the barrel to the frame in the particular fashion Ruger used when those were made, but by the time it got into the frame portion, before the forcing cone, the bore was back to .429" again.

[fredj338]

I’ll bet ots 0.432”. Most molds will cast close to that or larger, depending on alloy & casting temp. Plus you could pc them to get a bit larger.

[oley55]

A quick down an dirty way to check your mic, is to grab a set of feeler gauges and measure a couple.

just an fyi, I once had a no name USA made feeler gauge set that had three gauges that were completely wrong (.002, .003, .004"). Don't recall all the specifics now, but I was stacking gauges for something and the stacked numbers didn't follow the math. If I recall the .003" was actually .006". I had a thread on another forum about it and one guy swore I didn't know how to use a micrometer. I sent him the bad gauges and he acknowledged they were indeed deflective. That gauge set was probably purchased in the late 70s or early 80s and it is unlikely any of us will see something like that again, but...

I still have the set but with those three are cut out. I MIC'ed the whole gauge set and all of the others were spot on.

edit added: a copy n paste from the mentioned discussion and a memory jogger. I found that two back to back were bogus but sent him the next accurate gauge for validation.
https://forum.accurateshooter.com/threads/the-truth-about-feeler-gauges.4002033/
rsmithsr50 said:
so the 3 feelers showed up in the mail today.
measured both English and metric
marked .002 is .0037
marked .003 is .0053
marked .004 is .004
yep some really weird assembly in marking and putting together.
( do you want them back ??)

oley55 responded: Not hardly, schiff-can those damn things!!! In retrospect, I could have titled my original post differently. The whole point was that I was really, REALLY surprised when I discovered the disparity. I would never have had thought it possible, and by follow-up posts/results from others it is still not possible.

[mattri]

https://i.postimg.cc/crQHJ6rP/IMG-20230116-090409209.jpg (https://postimg.cc/crQHJ6rP)