Slugged my Redhawk

[Revolver]

Barrel seems small at .427
I only slugged one cylinder .433

I measured some known size stuff and my calipers are spot on. I lubed a lead ball and tapped it through the barrel with a wooden pencil. In one end and out the other.

The barrel seems small?

[RobS]

A bit small but then you could have a constriction some where in there. Was it harder to push it through once the slug ball made it to the frame where the barrel screws in???

Also I've see quite a few Rugers that are tighter toward the muzzle end which isn't too big of a deal since the bullet exits the muzzle after it is squeezed down. However a constriction at the barrel threads is a whole other story and a PITA.

[40Super]

Being a machinist for 2 decades and with some of the highest quality calipers,I still won't take the numbers from them as "accurate" .

[ShooterAZ]

Agreed...I learned early on that a micrometer is the best tool for boolits. Calipers are OK for measuring OAL etc, but for accurate diameter measurement, a micrometer is a must.

[GRUMPA]

In my mind the only thing worse than checking diameters with calipers is checking diameters with digital calipers. And if your getting the groove diameter that small I would say there's something just not right.

[Revolver]

Not only are they digital but they are the cheap harbor freight digital. I did however compare to some factory made boolits sized to .430 and they measured exactly .430 which is why I think they are reading accurately.

[462]

Yes, but are assuming that the factory boolits are, indeed, .430". What if they are only .429"?

I'm not a machinist, but when it comes to measuring a boolit, I'll trust my micrometer over a caliper, and I have both dial and digital calipers.

[40Super]

If your doing it correctly, the way your comparing is ok as a "close" comparison. I would double/tripple check on several different makes of bullets to make sure your close(+/-.001?), and do several slugs. Then your can know that your measuring decent. I wouldn't go by the numbers other than a comparison.

I would also try to push a slug in the muzzle about an inch or two and then back out, plus shove some all the way through and then compare. That may tell you if you have one of the famous Ruger thread crush barrels.

If you don't have access to a mic you can mail me or someone else here and be glad to give you some good numbers.

As far as digital calipers(the better ones) not being able to be as accurate as the vernier or dials, well I do know better than that ol' wives tale.

[Revolver]

Ah well. I guess I will just keep shooting it. I've been shooting .429 sized boolits through it with minimal leading and good accuracy. I'll have to slug my Dan Wesson now, I was hoping I wouldn't have to keep two different sets of 44 ammo.

[runfiverun]

just shoot some in your D/W that will tell you more than anything else.
i have just used .430 in all 4 of the 44 D/W's i have had,never bothered to measure.

[mdi]

Keeping different ammo for different, but same caliber guns isn't a big deal. All my ammo boxes get a stick-on lable with load info and it's easy to glance at the lable and see what's in the box. I also have a lable maker so I have .44 magnum boxes labeled; Puma, 629, and Contender. I can shoot the "629" loads in my Super Blackhawk, Dan Wesson, and Contender 'cause they are loaded light for my S&W 629. But my Puma loads are only used in my Rossi Puma 'cause the bullets are .433". But if I shoot my "Contender" loads in my Super Blackhawk or Puma I'll sometimes get leading (429"-430" bullets).

.427" sounds small (I won't jump on you about your choice of measuring tools), more like a 44-40. I would concentrate more on the cylinder throats and get good measurements there. Size the bullets the same size as your cylinder throats and I'm sure the bullets will be larger than groove diameter, and shoot with little or no leading.

[leadman]

Could it be that your slug did not quite fill out the rifling? A wooden pencil is not usually strong enough for slugging.

As far as the calipers go mine measure exactly the same as my Starrett anf Lufkin mics.

It is all relative anyway as you are using the same instrument for measuring the barrel slug and the cylinder slug. Then again on your sized and lubed boolit. If the caliper is off it is off the same for all measurements more than likely.

It is not so much the exact measurement as the fact the boolit should match or be slightly larger than the cylinder throats, then the boolit should also be the same or slightly larger than when it exits the cylinder throat when entering the barrel. The boolit should not be sized down by any thread constriction at the barrel/frame joint.
One could get by without a measuring device just by using the same slug to check fit.

[troy_mclure]

i had bad leading in my super blackhawk with .429, i bumped it up to .430 and i get no leading at all.

[MrMagoo157]

Ok, this is my first post so forgive any mistakes made....but I happened upon this thread, which I have some experience with. I slugged my Super Redhawk years ago (micrometer used) and found the cylinder throats and grooves to be oversized @ 0.431". A PA boolit company told me these pistols generally run oversize and I found it to be true, so he sized a large batch of boolits for me @ 0.432" and I have never had a single problem with leading up to 1400+ fps. It would seem unusual for a Ruger to have a smaller barrel than standard but anything is possible.

[40Super]

Most of the issues with them is that where the barrel is threaded into the frame, the barrel on some gets crushed down a few thou. The barrel may measure .001 oversize, but for a 1/2-3/4 inch length under that threaded section, it could be .003 to .005 UNDER sized. So a bullet shot will be squeezd undersize to go through that area, then for the rest of the barrel its way too small and terrible leading is the result. Some were good, some were real bad, newer ones maybe don't have that issue at all. I believe there are some other makes that have certain models that are that way also.

When slugging all these pistols I would push a couple slugs in the barrel, some in from the muzzle down an inch and back out, another in from the cylinder end and carefully feel to see if it gets tighter under the threaded area and then goes easy the rest of the way out.

[JIMinPHX]

Being a machinist for 2 decades and with some of the highest quality calipers,I still won't take the numbers from them as "accurate" .

I hear you, but since he is taking side by side measurements of 2 similar diameter slugs that are being compared for relative size, I think that a set of calipers are OK here. Unless they have been bashed around pretty badly, even the cheap ones shouldn't have a big difference in error over a few thousandths difference in size.

[JIMinPHX]

Most of the issues with them is that where the barrel is threaded into the frame, the barrel on some gets crushed down a few thou. The barrel may measure .001 oversize, but for a 1/2-3/4 inch length under that threaded section, it could be .003 to .005 UNDER sized. So a bullet shot will be squeezd undersize to go through that area, then for the rest of the barrel its way too small and terrible leading is the result. Some were good, some were real bad, newer ones maybe don't have that issue at all. I believe there are some other makes that have certain models that are that way also.

When slugging all these pistols I would push a couple slugs in the barrel, some in from the muzzle down an inch and back out, another in from the cylinder end and carefully feel to see if it gets tighter under the threaded area and then goes easy the rest of the way out.

I've seen this more on the newer S&W revolvers with the hybrid barrels than I have on the Rugers, but any barrel with a snug fitting thread can experience this issue. I was surprised to feel how tight the bore got when I used a .001" press-fit ring to mount a front sight on a gun. The sight base ring was only about .02" thick, so I didn't expect it to make the .3" thick barrel constrict very much. I got a rude little surprise when I went to clean that gun. The cleaning patch felt a definite tight spot at the muzzle that had not been there previously. It takes a lot less than I thought to pinch down a barrel enough to give you trouble.