Cylinder throat reaming

[buckndee]

Just got 3 cylinders back from Cylindersmith.com. I can recommand his work as excellent. Good communication, 1 week turn around time, fair pricing.

Worked over a Ruger OM SB 44mag and OM blackhawk 45ACP/45colt cylinders.

Buck.:castmine:

[218bee]

I've got a 45 Colt Blackhawk and was thinking of having this done. How did you decide what dia. to have reamed? I assume based on grove dia of barrel? maybe a few thousandths larger? Approx. what does he charge? Any other tips?? Thanks...

[Ricochet]

I'm watching this with interest. I have a Walker replica that needs its chambers reamed out. Groove diameter's bigger than the chambers by .005".

[MtGun44]

Ricochet,

I would wonder if pure Pb would slug up .005" - but I instantly realized that
you have certainly tried this and apparently it doesn't work. Light charges
or full charges?

Not too hard to do yourself if you have a good drill press. refer to my old post
http://castboolits.gunloads.com/showthread.php?t=12464

Bill

[Ricochet]

Full charges, formerly with FFFg Goex and recently with RS Pyrodex because of its ready availability. There is some slugging up, as I've recovered balls that showed a longer cylindrical band around the equator than I'd expect from shaving in loading. I've never seen a gun that leaded as heavily as this one does with Crisco or several commercial lubes I've tried over balls. The lead pulls off in filaments so the inside of the bore looks like a wire battery terminal cleaning brush! I've discovered recently that pure lanolin over the balls or bullets eliminates most of that, and yesterday I fired 12 shots with the Lee 452-160-RF over a 60 grain charge of Pyrodex RS that left NO leading! I was using my homemade lube mix of various waxes, lanolin and LLA, and had just added more lanolin to it. Still, it seems to me it should shoot better if the boolits started off bigger than (or at least as big as) the groove diameter. I think a .450-.452" chamber diameter would work with .447" groove dimensions, and should be a snug fit on my .45 boolits without shaving much, if any.

I hadn't seen that thread on reaming or lapping in Gunsmithing. Thanks!

I'm an inactive pilot. Used to be very interested in experimental aircraft like your Long-EZ and the RV series. Decided my life circumstances just weren't compatible with keeping current, and I'm out of touch with what's happening in general aviation these days. :(

[MtGun44]

You're welcome on the thread. I'm also (forced) inactive right now. MI in 2005,
no residual damage, but haven't gotten the paperwork sorted out, nuke treadmills
show zip problems. I'll get the med back, just haven't yet.

The filaments of lead sound very strange. Have you tried the felt wonder wads
over the powder? This works like magic for my Pietta 1860 and Colt late prod
1861 Navy, dry and clean gun and can shoot as much as you want. Zero leading
in either gun. Never shot a walker, tho. Also never slugged or measured the
throat on either one, the both shoot great, like 5-6" at 25 yds offhand. Which
suits me considering the hammer play side to side and tiny notch and tiny cone
are not conducive to target accy.

Bill

[Ricochet]

Never tried the wads. Noted the thread about making your own from felt weatherstripping. Thought about getting a 7/16" gasket punch and trying that. 1/2" would probably work with round balls, wrapping up around the base.

The filaments of lead ARE really strange! Never saw that with anything else, but it's been a frequent thing over the years with this Walker (mainly shooting swaged lead balls from Speer and Hornady, but also with cast ones), and I've seen it basically just fill the grooves to invisibility as well.

Target accuracy really isn't a concern, as the thing shoots so high I'm delighted when I guess the holdunder right and send a pop bottle flying. I'm happy when I don't have to scrub huge amounts of lead out, and it looks like my homemade lube on top will prevent that. Lanolin works well, too, but is soft enough to blow most of it off the top of the balls or boolits with the first shot, and leaves some strings of lead on the edges of the lands.

Hope you get your medical back without too much trouble!

[DanWalker]

I'll second the nod for cylindersmith.com
He reamed the throats in my NMBH45 and it now shoots light and medium loads GREAT.

[buckndee]

:Fire:
Hello every one, I think we have a thread. I slugged 12 revolvers for barrel and cylinder specs, got eye strain and a headache reading the micrometer, pace your self.

Check Cylindersmith.com for pricing and reamer sizes (limited reamer sizes). Only .4305/4325 for 44cal and .4525 for 45 cal.

From what I have learned from MtGun44, Ricochet and others on this forum is cylinder throats should be at least equal to or .001-.003 larger than barrel groove diameter. The two guns that needed help grouped well for about 50 shots then leaded up and shot like crap.

The 44mag had .4325 barrel and .4305 cylinder throats. Now .4325/.4325
The 45ACP/45Colt had .4525 barrel and .4506/.4502 cylinder throats. Now .4525/.4525

To answer 218bee questions I slugged the barrel with fishing weight egg slip sinkers of the approximate size ( not all sinkers are created equal, look for soft lead, some brands are harder than WW). Lubed the barrel and slip sinkers with RCBS case sizing lube. Used a lead hammer to drive them into the barrel. Cleaning rod with a brass cleaning patch jag with a pointed tip that fit the hole in the egg sinker to push them through. Next time I will cast pure lead bullets if I need to do this again.

Used minus ground pin gauges for approximate cylinder measurements (close enough for our needs). But used expandible ball gauges and digital micrometer for precise cylinder measurements.

Will post shooting results after this weekend when I take the wife and guns to the range.

[MtGun44]

I would suggest that for most folks the gage pins are more accurate
than gage and mic - OTOH, if you are trained, the gages will be more
accurate at a location, the pin shows the max inscribed circle that will
fit, which might be of more value, but this is uncertain.

I'll wager that your new cyl dimensions will please you much more than
the originals.

Bill

[buckndee]

I agree the pin gauges are easier and accurate enough for fitting bullets to the gun along with a barrel slug measurement.

I expect that both guns will shoot as well, hopefully better than before the cylinder reaming. At least the severe barrel leading should go away as the bullets will not be .002 plus under size.

Measuring 12 guns was educational. Now I have a better understanding of what bullet size is potently going to shoot best in these guns. Moulds and sizing dies can now be better matched or culled out. Looks like I only need .357/.359 bullets, .4325 and .4525.

All 12 guns now have barrels that slug the same as the cylinder throats to .005 over. Now to get busy casting, loading, shooting and testing loads. Good shooting weather is finely hear, time to play.

Buck.

[218bee]

Pin guages??? Ball gauges??? I got a Starett dial caliper ain't that ok for govt work

[MtGun44]

It is difficult to locate the widest point and to keep from tilting the
calipers in the cylinder. All errors will cause a reading of smaller than
the actual diameter. Not saying it can't be done, just that it is difficult
to get a consistent and accurate value.

For $60 from Enco you get a set of 'minus' pin gages which will easily
tell you to the nearest 0.001" what the cyl throat diam is. Very easy to
get right, very hard to get wrong, very quick. NOT the only way, but
"a" good way to measure any hole diam, such as muzzle bore diam,
or similar hole measurements, esp with something strange like an odd
number of lands and grooves.

IMHO, measuring more accurately than .001" is fine, but not necessary
to figure out how to get your revolver sorted out. I won't buy a
revolver any more without measuring the throats, if possible (mail order
prevents this, for instance) and will reject any that have the throats
substantially (like +.003" or more) oversized to the bore, since accuracy
is unlikely and cylinder replacement is the only fix and is expensive. I just
let it pass. Undersized is fine, easy to fix and you can make it exactly what
pleases you.

Bill

[alamogunr]

I would suggest that for most folks the gage pins are more accurate
than gage and mic - OTOH, if you are trained, the gages will be more
accurate at a location, the pin shows the max inscribed circle that will
fit, which might be of more value, but this is uncertain.

I'll wager that your new cyl dimensions will please you much more than
the originals.

Bill

+1. I got a set of minus gages on evilbay that had 5 pins missing. Those missing pins cut the bids considerably. Took a chance that they were ones that I wouldn't need. Turned out that they were ones that I would never have a use for, at least not for measuring cylinder throats.

[buckndee]

There are several new minus pin gauge sets listed and a used set currently for $1.25 missing a few odd pins on the evil auction site.

I do not go to the gun shows or gun shops without them any more.

[Ricochet]

...will reject any that have the throats
substantially (like +.003" or more) oversized to the bore, since accuracy
is unlikely and cylinder replacement is the only fix and is expensive.
That causes accuracy problems in revolvers, with boolits sized to the throats?

[floodgate]

Has anyone here come up with a quick, easy and CLEAN way to get that crumbly waxed paper and sticky preservative grease off 250 pin gauges?

floodgate

[alamogunr]

Has anyone here come up with a quick, easy and CLEAN way to get that crumbly waxed paper and sticky preservative grease off 250 pin gauges?

floodgate

No! I used Ed's Red.

John

[buckndee]

Has anyone here come up with a quick, easy and CLEAN way to get that crumbly waxed paper and sticky preservative grease off 250 pin gauges?

floodgate

NO/yes.

Scraped the waxy paper with thumb nail. Then Brake Kleen, wipe with paper towel. Only did the ones I needed to measure cylinders with, other pins are going to stay mint new.

[MtGun44]

Ricochet,

.003+ may be overly restrictive, but as you get bigger the boolit can tilt in the
throat and start off crooked, then slam into the forcing cone to be forever wobbling
that angle to the bore.
I have read (never seen personally) of some .45 cal pistols with .458 throats
and .452 bores that just would not shoot even remotely well. Only fix is a
new cyl.
It is difficult to decide on "the limit", but I personally have decided there is no
point in buying a $400-900 "lottery ticket" on more than .003" over bore diam.
Of course, when checking in the store, you can't slug usually, so must assume
normal bore diam, not guarenteed.

Bill

[nicholst55]

Has anyone here come up with a quick, easy and CLEAN way to get that crumbly waxed paper and sticky preservative grease off 250 pin gauges?

floodgate


Quick, easy and clean? No; I toss them into a bread pan and pour mineral spirits over them and let them soak for a few minutes. The wax paper falls right off, and the grease wipes right off, too.

[218bee]

So with the pin guages you insert a guage into throut or cylinder and when one fits and next size doesn't you know size?? Is that correct?? Why are they called minus??

[Ricochet]

Ricochet,

.003+ may be overly restrictive, but as you get bigger the boolit can tilt in the
throat and start off crooked, then slam into the forcing cone to be forever wobbling
that angle to the bore.
OK, that I understand. Chamber's bigger than the bullet, so there's alignment and concentricity problems. I was thinking of a situation where the chamber's bigger than the groove diameter of the bore, but filled by a bullet of the same diameter that can't tip. Has to swage down in the forcing cone. That's done a good bit with cast boolits in rifles, where it often gives good accuracy. I couldn't see a reason why that wouldn't work in a revolver, that's why I was asking.

[floodgate]

218bee:

For the "el cheapo" sets we are talking about, the "minus" sets are guaranteed to be within between 0.0002" undersize (that's one-fifth of a thousandth) and the full marked size - and NOT oversize. That provides 0.0001" clearance on average and insures they will go into an opening of the marked size; this is the most useful setup for our purposes. They also make "plus" sets (0.000" - 0.0002" oversize), but they would be less useful to us.

floodgate

[MtGun44]

Richochet,

Sorry about the delay, finally back where I can get on the net, at least via cell
phone. You are exactly right. If you have too large a throat, you can make it work
with big enough boolits, the only limit is what will chamber and what you can
find a mold for. You just need to have a reasonably good fit to the throat to get
the boolit started straight. Forcing cones are far larger than the boolit, so modest
oversizes like we are talking about are no problem.


floodgate,
that's a good clear explanation of the reason for the minus set of pin gages.

Bill

[Ricochet]

Thanks!