Ruger Blackhawk slugged at .3585". Have some questions

[Boy9216]

First post on here and a total newb when it comes to casting but I'm learning. I slugged my Ruger Blackhawk .357mag and it came out to .3585". Based on what I'm reading does this mean I should go with a .359" sizing die?

The other problem is I can't seem to find sizing dies in .359". I was hoping to get Lee resizing dies so I could use my regular press but I can't find them in .359". Is my only option to buy a Lyman or RCBS sizing press which has .359" dies available?

Thanks

[telebasher]

what does your cylinder throats measure ?

[Outpost75]

More important is to measure the cylinder throats and make your bullets fit them. Remove the cylinder, drop some SOFT lead bullets into the chambers from the rear, tap them through and measure with a micrometer. A .3585 cylinder throat diameter for a .357 Blackhawk sounds pretty normal, and if your barrel groove diameter is the same or a bit smaller there is no issue.

Soft bullets will slug up on firing so 1/2 thousandth miss-match is no problem. If it bothers you, it doesn't take much effort to polish a Lee push-through sizer a half thou' using 320 grit wet or dry paper wrapped around an arbor, well oiled and spun in a drill press.

If your cylinder throats are more than a half-thou smaller than barrel groove diameter, you may want to get them reamed, but I would try shooting it first with soft bullets, no harder than 12-13 BHN and see how it does. Hard bullets aren't needed.

You might also measure your bullets and if they cast within a half-thousandth of the desired diameter shoot them as-is without sizing and stop worrying.

[jcren]

Check out NOE expanded. Kinda like Lee but the sizing rings interchange in one die body.

[Boy9216]

Thanks for the fast responses everyone. I literally started casting this week so the help is appreciated.

i just slugged the cylinders and they are measuring at .359"

Also, I had a few cast bullets from my mold and I measured them to be around .359 - .360

hope this give you guys some more information.

[243winxb]

Tumble lube as cast bullets with Lee Alox . Try the .358" sizer. It can be opened up if you get leading.

[CPL Lou]

Welcome to the wonderful world of casting !
I believe we talked at the range today, if so, glad to see you made it here !

CPL Lou

[runfiverun]

in the old day's we would just buy the LEE 358 die.
try some boolits through it and see what they come out at.
if they come out at 358 then we would take a wood dowel and cut a slit in the end of it with a hacksaw.
then wrap some wet/dry sandpaper around it something like 800 grit would work fine.
then we would twist a strip of the sand paper around the dowel until it just fit in the die.
we'd oil the paper and slip the lap into the die and hold the stick with one hand and roll the die up and down our leg a few times with the other.
then we would run a boolit through it and measure the results of our efforts.
we would keep doing that until we got to the point we wanted and then do a little polishing with a bore mop and some flitz or some barkeepers friend and some toothpaste.

[Boy9216]

Hey Lou! I tried searching your name but was search Corporal instead of CPL. glad I found you, or you found me

[CPL Lou]

These folks have a vast wealth of experience, and the best part is they don't mind sharing it !

CPL Lou

[DougGuy]

It sounds like you are measuring with calipers which really are only good enough for a wag as to what the actual size really is. In this world, tenths are important so you would need to invest in a decent mic that reads in tenths, takes the guess work out of it. Forgive me if you are measuring with a mic, but the dimensions you posted don't sound like a stock cylinder at all, they sound like a cylinder that someone has already worked on.

Don't size larger than the throats, ammo may not chamber and once fired the boolit will be sized down by the throat anyway if the throat is smaller than the boolit so all this really does is raise pressures.

In a perfect world, a revolver's dimensions read a little like a funnel. Larger diameters at the breech face, getting progressively smaller as it goes to the muzzle. Boolits should be .001" to .002" larger than groove diameter of the bore (so there is some meat to be forced into the rifling which makes a good seal). Cylinder throats should be .0005" to .001" over boolit diameter so they don't swage the boolit smaller when fired.

Let's say you have a .357" groove diameter, and .3575" or larger throats, if you slug the bore and push the slug out, you should be able to slip the slug into all of the cylinder throats from the front and they should all be even. IN a *perfect* world. If it slides in easily, no biggie, what you don't want is for the slug not to go into the cylinder because that would mean the throats are smaller than groove diameter. This arrangement although improper and undesirable is often the case with factory fitted revolvers.

With factory jacketed ammo this isn't a problem because the factory ammo is often made to bore size or sometimes less, so that it shoots in any firearm chambered for the caliber.

Cast boolits generally are made larger than groove diameter, and you more often than not will need to have the cylinder throats reamed and honed to accept the size boolit you want to use. In your case, for a .357" you would likely want to size to .358" and throats should be .3585." If you get a .358" sizing die and size a few boolits, try them and see if they will slide into the cylinder throats from the front. If not, the cylinder throats need worked over. I can easily remedy that situation.

Just for example, here is a pic of the mic I use and it is used in a cheapo stand to hold it so my hands are free. You can see the measurement across the shoulder of the 9mm boolit is .3585" and this is .0005" larger than what the customer needs for his loads to properly chamber in his barrel. A mic that is accurate and measures in .0001" increments is really the standard form of measurement for this kind of work. Calipers SOMETIMES can get you into more trouble than they are worth and are at best, a close guess.

http://i1202.photobucket.com/albums/bb374/DougGuy/Cylinder%20Services/Dummies/20160624_200138%20Custom%203_zps2bcxoqg6.jpg (http://s1202.photobucket.com/user/DougGuy/media/Cylinder%20Services/Dummies/20160624_200138%20Custom%203_zps2bcxoqg6.jpg.html)


I think I paid about $35 for the mic and maybe $11 for the stand from fleabay.

[Wayne Smith]

And on this subject, when DougGuy talks we all listen. Pay attention, nugget.

[44man]

And on this subject, when DougGuy talks we all listen. Pay attention, nugget.
For sure and I question the groove size the OP got. A hard slug that expanded or poor measuring tools. Time for more work.

[MrWolf]

Good post DougGuy.

[Boy9216]

Thanks Doug guy. I'll get a micro and I'm sure my measurements will start shaping up.

[DrDucati]

Lee will make you a custom 359 sizer if you ask them to; check the web site.

[telebasher]

His explanation out to be made a sticky if it is not already. Ready for a instant refresher. It don't get much clearer than that !

[Boy9216]

I second the sticky mention, telebasher. I looked around this site and did some reading on most of the stickies but this really explained it to me well.

I have a micrometer on order and I'll slug cylinders and barrel again and try to get a more accurate readout. I also have a .358 sizing die and based what runfiverun said, if I need something closer to .3585 or .359 I can use some 800 grit sandpaper with dowel rod and widen it out a bit if need be. I'm feeling confident now in my plan.

Im already starting to like this place from the get go.

[DougGuy]

Read up on the slugging thread(s) too. I use egg sinkers from the fishing section in Walmart, you want pure lead because it won't have any springback in it when it gets compressed. I find the hole in the middle gives it a little room to squish. Dead soft lead, clean barrel, lightly oiled. Can't use boolit alloy for slugging as the springback in the alloy will make it larger than the actual groove of the barrel when you drive it through.

If your mic has a friction thimble on the end of it, these allow a limited amount of energy to be applied at the anvil and the good mics are real consistent in how much pressure they exert. Whem mic'ing soft lead, it is really really easy for the mic to put a tiny flat spot on each side of the lead specimen you are measuring, you will want to align the slug in the mic and sneak up on it one time, because each time you read the slug the flat spot gets a little bigger and the measurement will get smaller. You just have to work with it, you will figure it out pretty quick.
_____________________________________

Here is how I like to check a barrel. I take the cylinder out, get the barrel clean and dry, put on my clip on magnifiers, get a white piece of paper and put it at the breech face, hold the paper up to a bright light and look down the bore. If you are suspecting there might be some thread choke, in the area where the barrel meets the front of the frame, thread choke distorts the reflection you see, it will be a hazy ring about 3/4" from the forcing cone, and that ring will coincide with the barrel/front of frame juncture. It's easy to see when you know what to look for. If you see no detectable distortion in the reflection in the rifling, there is no choke.

Another thing I look for is how deep the roll marked "lawyer warning" on the side of the barrel is. This warning is impressed SO DEEP sometimes, that you can look into the barrel and see a series of raised ridges in the rifling behind each one of the words in the roll mark. One of the things Ruger did when they made the medium framed guns, is lightly impress this roll mark, and they put it on the bottom of the barrel. I commend them for doing this, and you can see it makes a big difference!

Take a plastic or brass cleaning jag and patch it tightly into the bore with paper towels or cotton patches, and push it down the bore. If your barrel has those ridges in it, you can feel those as the jag passes over each one. When it gets to the juncture of the barrel to the frame, and it gets hard to push the rest of the way, that's thread choke you are feeling. If it is just a little extra effort to push it through, the choke is mild and may not cause a detectable problem, and may be firelapped out if it is a blued gun. Same with the rollmark ridges, they can be firelapped out of a blued gun fairly easy. Ruger stainless steel is VERY difficult to firelap, it takes approximately 6x the effort as a blued steel barrel.

If on the other hand your tightly patched jag stops and you dang near have to destroy the cleaning rod to beat it through the rest of the way, you have a very severe choke that is incurable by firelapping without totally destroying the integrity of the rifling in the non-choked portion of the barrel, this gun would need the barrel pulled and shaved and re-installed and re-indexed by a gunsmith, OR sent back to Ruger and hope and pray it won't group for them when they test fire it and they will replace the barrel. Or the barrel can be Taylor throated which will relieve the choke and save the barrel.

None of these methods will tell you how much choke in thousandths a barrel has, but that figure is only a mathematical reference point and is not important. What is important is how smoothly the jag travels down the barrel, this is the EXACT SAME resistance the boolit will see, and the smoother that jag goes through the barrel, the smoother the boolit will too, and the better the gun will shoot.
________________________________________

A note about some of the old model Ruger 44s, and some 44s and 45s with the circle marked barrels. I have noticed that many of these guns have a bulge in the barrel just in front of the frame, and if you tight patch a cleaning jag as the above paragraph describes, and swab the bore with it, it is quite common for the jag to become totally loose in the barrel at this bulge. Easily .003" or more difference in the bulge and the rest of the barrel. Just the way they were made back then..

[MT Gianni]

If you have just started casting and will be involved in multiple calibers, I believe NOE's sizing die with it's replaceable inserts is the least expensive way to go.

[Boy9216]

Hey everyone.... A few updates.

re slugged the barrel with the lead egg weights from WAL mart. Used a micrometer to measure the groove diameter which came out to .3584" (these are really awesome tools). I was able to just barely slide the boolit into the each cylinder by hand from the front, like DougGuy said, but it was a really tight fit. Took a few taps to get the last bit all the way in

Should I resize them to around .3594"? Which would be .0001" over my groove diameter?

Another question, what if when the boolits come out of my mold they are smaller than .3594"?

[Outpost75]

Remove cylinder.

Tap soft lead slugs through cylinder throats and measure with your micrometer and size your bllets to THAT size or 0.0005" less.

[243winxb]

Size to .358" + .. Add linotype to increase as cast bullet diameter. The antimony does it.

[nagantguy]

Welcome to the op, this thread is great reading, really first rate!!! And good, so very good to have a new member who will listen and try the answers to his questions!!!!!-!!!!!!! Thanks dougguy, been meaning to send you a pm on some cylinder work this will spur me on!!! Guys thanks for this, a good bunch working to help out a stranger, smells.like the America I remember!

[CPL Lou]

Glad to hear you're making progress !
If you want to get together and iron put any fine details, hit me up in PM.

CPL Lou

[44man]

Don't size larger then the throats, does no good at all.
Best to have Doug fix the cylinder.

[OS OK]

"Grrreat thread...so concise and clearly stated!"

[725]

FWIW, a member here, buckshot, will make custom sizing dies if they are not available commercially. His work is impeccable.

[nagantguy]

I can vouch for buckshots work, and his patience at answering questions and walking a guy through when he just isn't sure what help wants/needs, helped me to get a very tight throated vintage 30-30 singing again with one of his nose sizing dies.

[runfiverun]

Buckshot has retired from that work.

I'm seeing your gonna need a 359 boolit.
the worst thing that can happen here is your gonna send your cylinder out to have it opened slightly or to have the cylinders throats evened out.

now as far as your mold not making over 358.
your gonna have to make a choice in mold makers and designs.
I.M.E.
if you buy a noe they tend to pour large [358 runs 360], if you order an accurate you can specify the diameter.
if you order a lyman you'll learn how to lap, the rcbs should make just shy of 359.
all from the same alloy.

[44man]

Maybe so but need .3595" throats for them. Molds another matter. Custom is in order.
A Lee die is easy to make .359" in a few minutes.

[dubber123]

When slugging the bore, did you notice any tightness as you got close to the forcing cone? If you did, it means the bulk of the bore is larger than your final measurement. The thread constriction squeezed your slug smaller, and that is what you measured. If it slid through smoothly, you are in business and got a good barrel. Luckily. ;)

[243winxb]

Has the gun been test fired with cast? If not, buy some and shoot.

[Boy9216]

Slugged the cylinders and they're all coming out to .3585" which is what I guess I'll have to size to per the commenters above.

Is that normal to have the cylinder and groove diameter the same in a revolver?

I'm excited to finally start sizing and luging some boolits. It feels like this process is taking forever but I'm sure it will be worth it to have the right info.

[DougGuy]

Size to .358" with .3585" throats.

Something that has ran common through this thread is that for whatever reason OP seems to be consistently getting measurements a little on the plus side for a stock revolver.

I am not there to concur the measurements or see *how* he is reading his instruments, but I would gladly look the cylinder over and measure it with the same pin gages that I have used on hundreds of cylinders, just on the happenstance that those throats might not be as big as the OP says they are. In other words, if it is a stock Ruger cylinder that hasn't ever been worked on, I seriously doubt that a .3585" pin gage will go through the throats. It would be a first.

Not criticizing the OP at all, I am just saying that something don't sound quite right, and I have seen several hundred Ruger cylinders come through my shop in the last couple of years and none of the .35 caliber cylinders would swallow a .3585" pin gage stock from the factory, so if he wants to send the cylinder and get a second opinion on it, it may take a LOT of the "gray area" out of the figures being reported for this revolver, and he would have some very accurate measurements and if needed, have the cylinder throats all sized within .0002" of one another, and if they are NOT .3585" they certainly will be by the time the cylinder gets sent back..

[Boy9216]

Maybe the revolver was worked on before. It's pretty old. I'm just concerned about what is it now. I'm not interested in sending it somewhere to have it worked on. When I measured all the cylinders I was getting all the measurements within .0003 so it seems fairly consistent.

Even if it was, is .3585" bad or undesirable? I appreciate the info, but I just get a feeling now like you're trying to sell me something here.

[DougGuy]

No sales pitch, just an offer of a second opinion. Even though I regularly do cylinder throats and barrel throating work.

.3585" is actually exactly what you want them to be. This is correct for boolits sized .358" I occasionally get a request to size to .359" or .360" from shooters that have a companion levergun and want to use the same ammo in both the levergun and their revolver, but the levergun won't group with anything less than .359" or .360" boolits.

[SSGOldfart]

Check out NOE expanded. Kinda like Lee but the sizing rings interchange in one die body.
Good advice NOE even has your sizing die on sale now

[dubber123]

Throats the same as the bore can work very well. I usually like them bigger than the bore, but sometimes it just isn't possible. I have a F/A .357 model 353, not a cheap gun at all, and the throats were WELL smaller than the very oversized, (and oval) bore. Doug opened the throats up to .359" for me, which just about matches the barrel. It will shoot under an inch at 50 yards, so all is well in my opinion. :)

[44man]

I would size .358" myself. I have run into the Freedom barrels .357 with .3595" one way and .358" the other. Throats were all a perfect .357". Took 3 barrel replacements but still never shot good. Final barrel was .357", round but throats should have been .3575", .3585" better.
Before I knew Doug or I would have had him fix it.
Friend sold the gun at a HUGE loss after spending hundreds.

[mozeppa]

doug....what do you do to help the barrels with choke issues?

or raised lawyer-ese spots in the barrel.

[DougGuy]

As I described with the cleaning jag, if the choke is moderate you can firelap it out, if it is over about .001" on a stainless gun you send it back to Ruger and *HOPE* they find something wrong with it when it doesn't group with factory ammo so they can re barrel it. For the lawyer ridges firelapping will get them out.

A blued gun will firelap out a fairly severe choke. Not so with stainless. Their stainless is tough tough tough to firelap, very slow process and can easily ruin the good rifling that will get lapped as collateral damage.

There is one thing that is possible to do with firelapping and nearly impossible to do otherwise, and that is conform a barrel into a tapered bore. As your lapping boolits travel through the barrel they lap less and less so they do all their work at the tightest spots, since there is resistance, and then the lapping boolit is actually smaller as it travels in the barrel.

If a guy wanted to spend some time to develop a plan where he could control what part of the barrel gets lapped first, he could by changing hardness of the lapping boolit and changing grades of abrasive, have a barrel that got lapped less and less from the forcing cone to the muzzle, and you would have a bore that is constantly decreasing in dimensions, constantly squeezing the boolit into a tighter seal, which IMO would be quite an improvement in shooting cast boolits. You could have amazing 100yd accuracy from a run of the mill Ruger with a barrel like this. Wouldn't need much, we are only talking maybe .0005" to a max of .001" difference from one end to the other.

[Outpost75]

When Ruger repairs a thread choke they seldom rebarrel it, instead they hammer a carbide round-hole broach through the barrel to shave the tops of the lands so that the bore diameter feels uniform, but the depth of groove is still choked. The tool used is similar to a range rod, but the carbide plug, of length about 6 times bore diameter, is ground to minimum bore diameter with its end surface ground so that the edges are razor sharp. The bore is slobbered with Brownell's Do-Drill and the plug, attached to a drive rod, aligned and centered with bushings, is then smacked through with a lead hammer.

One pop and done. Good finish too!

[dubber123]

I would size .358" myself. I have run into the Freedom barrels .357 with .3595" one way and .358" the other. Throats were all a perfect .357". Took 3 barrel replacements but still never shot good. Final barrel was .357", round but throats should have been .3575", .3585" better.
Before I knew Doug or I would have had him fix it.
Friend sold the gun at a HUGE loss after spending hundreds.

I left the oval barrel in place, (I bet LOTS of barrels aren't round), and spent $30 with Doug and walked away happy. Shouldn't have to on a $2,000 revolver, but quickest and best fix for me.