500 S&W cylinder throating with a brake hone?

[RobsTV]

Is it possible or fine to use a 1/2" automotive brake wheel cylinder hone to open up the 500 S&W cylinder to .5015? Cylinder holes are currently .498. A quick check of the stones used in the 2 stone/arm brake hones are advertised as #220 to 240 medium grit stones.

If so, any tips would be greatly appreciated.

Normal reamer rental places do not seem to have the proper reamer in that size.

EDIT: Scratch the plan. Friend that works at moldmaking shop will hook me up after the first of the year, using proper tools and machines.

[kir_kenix]

Sounds like you found and alternative that will suit your needs better then a brake hone. Probably going to be happier with the results of the right tools.

Did want to add that I have successfully used brake hones of various sizes to open up shotgun's with fixed chokes in the past...but would probably past on cylinder throats myself.

Bet you can't wait for your buddy to fix you up so you can go out and shoot some BIG chunks 'o lead down range!

[RobsTV]

Yep, can't wait. Need to correct the size to assist with solving poor accuracy using 440gr cast lead. Hopefully that will be the final step needed.

Friend said he needs to look at what he has, but probably a .501 reamer and a brass adjustable lapping tool in the need range. If just using a .501 reamer, will that be enough or do I need to go to .5015? They are a large shop with a dozen or so toolmakers, always eager to assist in my weird projects.

[Iron Mike Golf]

Have you slugged your barrel?

[RobsTV]

Have you slugged your barrel?

Hopefully someone mentioning opening up throats has slugged their barrel first!

But you made me double check my notes and while I thought it slugged at .501, it actually slugged at .500 to maybe .5005. So I guess cylinder throat of .501 will be fine.

Shooting gas checked 440, sized to .501, heat treated to 22+ BHN, Carnauba Red, seated shallow crimp groove, chrono at 1490fps. Zero leading. Just need a little better accuracy. Tried several loads with this being the best so far. Will start over after opening up cylinder throats a little.

[MtGun44]

Or you could try a cold chisel.

Sorry for the sarcasm but this is NOT the place for jackleg solutions. This is
EXTREMELY precise work if you are planning on not ruining a nice pistol. If you
aren't real comfortable working to tolerances of 0.001" or better, and don't
have the experience and tools (mic with .0001" reading NOT caliper) you
will be much better off sending it to a compentent gunsmith ----

AFTER you do enough precision measurement to know what you really
have and why you would change the throats.

Maybe you are a tool and die maker and know all about this with years
of experience, but it isn't coming across and a brake hone would be a
tool really likely to mess up your throats and funnel them out at one
end or the other.

Let's back up an do some good diagnositics and see if opening up the
throats is something likely to help.

1 - How does the gun shoot? Are you a really excellent pistol shot, or
have you had a really excellent shot benchrest the gun and see what
it can do?

2-Have you slugged the barrel for groove diam and checked for a
tight spot at the frame?

3 - Have you measured the throats with pin gages?

Bill

[RobsTV]

Or you could try a cold chisel.

Sorry for the sarcasm but this is NOT the place for jackleg solutions. This is
EXTREMELY precise work if you are planning on not ruining a nice pistol. If you
aren't real comfortable working to tolerances of 0.001" or better, and don't
have the experience and tools (mic with .0001" reading NOT caliper) you
will be much better off sending it to a compentent gunsmith ----

AFTER you do enough precision measurement to know what you really
have and why you would change the throats.

Maybe you are a tool and die maker and know all about this with years
of experience, but it isn't coming across and a brake hone would be a
tool really likely to mess up your throats and funnel them out at one
end or the other.

Let's back up an do some good diagnositics and see if opening up the
throats is something likely to help.

1 - How does the gun shoot? Are you a really excellent pistol shot, or
have you had a really excellent shot benchrest the gun and see what
it can do?

2-Have you slugged the barrel for groove diam and checked for a
tight spot at the frame?

3 - Have you measured the throats with pin gages?

Bill

As mentioned above, this will be done by professionals with many years experience and the proper equipment, not me and a hone, although searches show that is a method many people do use.

1. Gun inaccurate. Tester excellent shot..
2. Yes slugged again, no check for frame tight spot.

3. No to pin gages. But it does fail the jacketed .500 push threw test, and requires hammer and dowel to beat a jacketed .500 through the cylinder. And this simple test is what steers toward the need to enlarge cylinder throats. Might need to do other things as well, but the inability to push jacketed through cylinder shows the cylinder throats are too tight to properly shoot lead.

When the work is to be done after the new year, all will of course be remeasured by the toolmakers prior to doing anything.

[runfiverun]

i read the header earlier today and all i heard in my head was a loud long NOOOooooooo!
you do need to open the throats a bit.
but i think a hone at home is the last thing i would try.

[MtGun44]

BBL tight at the frame is extremely common. Really need to see if
this is an issue.

Try driving a soft lead slug through the throats from the back to front
of a dismounted cylinder to protect the crane from damage.

Drive a soft slug into the barrel to about the middle of the bbl threads,
then back out - requires a short rod and offset transfer bar (I use
wood) and is tricky, clamp bbl in vise properly protected, of course.
Drive a soft slug down about 3-4 inches into the bbl from the muzzle,
the work it back out the front - takes a series of short rods dropped
down the bbl from back, and tapped back out.

What are you measuring with? If calipers, you need to get a 0.0001"
reading micrometer for this kind of work, calipers just will not cut it,
+/- 0.001 accuracy, makes zero difference how well you think you
can read it, the instrument is rated by the maker as +/- .001 or worse
for some. Enco tools usually has Fowler mics for $35 or less and they
are good ones.

This will get things started. A reamer or lap is the preferred way to
open up throats if it is needed. Ream undersized and polish out
the last .0005 or so with snug split dowel and 400 grit wet or dry
sandpaper. Lap will work well, is slow and leaves a good surface.

You say "inaccurate" - need better definition, group sizes at distance
rested on sandbags by expert shot. Info about groups would help,
like 4 into a good group and one flier or whatever, just scattered
around. What ammo? Factory or handloads?

Bill

[cbrick]

Or you could try a cold chisel.

Sorry for the sarcasm but this is NOT the place for jackleg solutions. This is
EXTREMELY precise work if you are planning on not ruining a nice pistol. Bill

Now Bill, a break hone would not ruin the pistol.

The cylinder would certainly be toast but the rest of it should be fine. :coffeecom

No wonder I get a sick feeling in my stomach when buying a used gun.

Rick

[Mal Paso]

After you figure what size you need, call Dave Manson - Manson Reamers.

You need a square, true, hole.

Recent S&W Throats are cut for J-words.