|
Forum Rules | Firearms Safety | Firearms Photos | Links | Library | Lost Password | Email Changes |
Register | FAQ | Calendar | Today's Posts | Search |
|
Thread Tools | Search this Thread |
December 12, 2017, 12:26 AM | #1 |
Senior Member
Join Date: December 29, 2016
Location: NY Area
Posts: 310
|
Barrel / cylinder clerarance
I checked my clearance between barrel cone and the cylinder.
Use two pieces of 20lb paper that measure .01 or 1/128. Does that seem normal?
__________________
NRA Life Member NRA CSRO NRA Pistol Instructor NYS CCL Instructor |
December 12, 2017, 07:29 AM | #2 |
Senior Member
Join Date: March 5, 2009
Location: NY
Posts: 317
|
.01 = 1/100
this was a test right??? I seem to remember about .005" or .008" on one of my firearms. That was a long time ago. Last edited by tango1niner; December 12, 2017 at 07:38 AM. |
December 12, 2017, 08:07 AM | #3 |
Senior Member
Join Date: December 29, 2016
Location: NY Area
Posts: 310
|
Test, no question yes,
Was my method so strange?
__________________
NRA Life Member NRA CSRO NRA Pistol Instructor NYS CCL Instructor |
December 12, 2017, 09:37 AM | #4 |
Senior Member
Join Date: August 5, 2013
Posts: 116
|
if both pieces of paper measured at .001 and that was as much as you could fit in there, seems a bit tight for my taste. do you get any binding when the cylinder rotates? do you have access to some feeler gauges? to take a more accurate reading? i mean .001 is a bit tight but if it rotating freely and all i wouldn't worry to much. normally you would have anywhere from .004 - .008 from factory. repairs are normally required when you are in the .010 and above then that would be unsafe and may cause spiting.
__________________
"No free man shall ever be debarred the use of arms." - Thomas Jefferson, Virginia Constitution, Draft 1, 1776 https://www.youtube.com/channel/UC1b...RUE9AMVlI88MrQ |
December 12, 2017, 10:02 AM | #5 |
Senior Member
Join Date: December 29, 2016
Location: NY Area
Posts: 310
|
I think my measurement technique may be off, I can "see" a space between the barrel and the cylinder. And the two pieces of paper can fir their.
Just don't remember that much space. Recently a gunsmith "shimmed" the cylinder because it had movement. Though I needed a barrell, but is shoots ok now. Just wondering. Have to look through my garage, used to have gauges, must be there somewhere... Thanks
__________________
NRA Life Member NRA CSRO NRA Pistol Instructor NYS CCL Instructor |
December 12, 2017, 12:46 PM | #6 |
Staff
Join Date: November 2, 1998
Location: Colorado
Posts: 21,841
|
We generally use feeler gauges. .001 seems rather tight. Target gun?
__________________
Vigilantibus et non dormientibus jura subveniunt. Molon Labe! |
December 12, 2017, 01:40 PM | #7 |
Senior Member
Join Date: December 29, 2016
Location: NY Area
Posts: 310
|
Found my feeler gauges, but the smallest is .012 /.3mm.
It fits if I close the cylinder, but it;s snug, so it;s less than .012 and I can see a little light between. SO maybe it's ok?
__________________
NRA Life Member NRA CSRO NRA Pistol Instructor NYS CCL Instructor |
December 12, 2017, 01:56 PM | #8 |
Senior Member
Join Date: March 5, 2009
Location: NY
Posts: 317
|
Hey guys, I don't see anywhere where Jeryray said .001" or one thousandth.
He said " .01" which is .010" or 10 thousandths. Jeryray, your method is not bad if you have an accurate way to measure the paper thickness, of course feeler gages are better. What had me scratching my head was the 1/128". Don't know how you arrived at that... New math??? Last edited by tango1niner; December 12, 2017 at 02:54 PM. |
December 12, 2017, 04:17 PM | #9 |
Senior Member
Join Date: February 28, 2008
Location: Michigan
Posts: 2,620
|
What gun are you measuring?
Usually the max. for cylinder gap is .008 and .003 in min. Shimming a cylinder usually is to cure excessive headspace. for barrel/cylinder gap the barrel is set back one thread and the face of the forcing cone is machined to set that gap. |
December 12, 2017, 07:44 PM | #10 |
Staff
Join Date: November 2, 1998
Location: Colorado
Posts: 21,841
|
Opps. You're right tango1niner.
__________________
Vigilantibus et non dormientibus jura subveniunt. Molon Labe! |
December 12, 2017, 07:48 PM | #11 |
Senior Member
Join Date: June 25, 2006
Location: The Keystone State
Posts: 1,970
|
gap
Pick up an automotive metal feeler gauge
__________________
"Peace is that brief glorious moment in history when everybody stands around reloading". --Thomas Jefferson |
December 13, 2017, 02:41 AM | #12 |
Senior Member
Join Date: February 13, 2006
Location: Washington state
Posts: 15,248
|
Barrel-cylinder gap should be between .006" and .012". Any tighter and the cylinder will bind when firing due to heat. Any wider and you have a spitting nightmare. So you are about .010"-.012" from the sound of it. Shoot it.
__________________
Never try to educate someone who resists knowledge at all costs. But what do I know? Summit Arms Services |
December 13, 2017, 07:15 AM | #13 |
Senior Member
Join Date: December 29, 2016
Location: NY Area
Posts: 310
|
Thanks to all.
__________________
NRA Life Member NRA CSRO NRA Pistol Instructor NYS CCL Instructor |
December 13, 2017, 07:37 AM | #14 | |
Senior Member
Join Date: December 17, 2005
Location: Swamp dweller
Posts: 6,187
|
Quote:
__________________
NRA Life Member, NRA Chief Range Safety Officer, NRA Certified Pistol Instructor,, USPSA & Steel Challange NROI Range Officer, ICORE Range Officer, ,MAG 40 Graduate As you are, I once was, As I am, You will be. |
|
December 13, 2017, 07:45 AM | #15 |
Senior Member
Join Date: December 29, 2016
Location: NY Area
Posts: 310
|
That 1/128 came form a conversion built in to the caliper.
__________________
NRA Life Member NRA CSRO NRA Pistol Instructor NYS CCL Instructor |
December 13, 2017, 08:31 AM | #16 |
Senior Member
Join Date: January 24, 2016
Posts: 323
|
Jeryray, if you already had a smith shim the cylinder, you should be fine. It sounds like you are close to max spec.
Measuring tenths (.0001) or even thousandths (.001) is part art and part science. Skill will affect the recorded measurement. Gauges can compress, parts can spread, and temperature can also play in. With feeler gauges, you want a very slight drag. Just touching. No clearance and no interference. This will give you the best number. Closing the cylinder can mask an interference, which you correctly determined makes it tighter than .012. You can find a nice set for less than 20 dollars that will go down to .002 or .0025 and up to .030. Very useful if you tinker. If you have say .009 or .010, and aren't spitting lead, I say shoot it, and keep an eye out. If that gap increases, or you see lead, investigate further. Merry Christmas Rich |
December 13, 2017, 12:02 PM | #17 |
Senior Member
Join Date: March 5, 2009
Location: NY
Posts: 317
|
Jeryray, That caliper is going to get you in trouble down the road.
|
December 13, 2017, 06:31 PM | #18 |
Staff
Join Date: March 4, 2005
Location: Ohio
Posts: 21,063
|
SAAMI test barrels with vents to simulate barrel/cylinder gap use 0.008", but you see a bigger range than that. I had 0.002" on a S&W I got in a trade, and it had some cylinder face scoring, so it is correct that if you fire fast enough to heat up such a gun, you will find that number is too small and can allow dragging. 0.006" is, IIRC, the thickness of the feeler gauge Dan Wesson provided for setting the gap in their change-barrel revolvers.
If your feeler gauge is snug at 0.012", it is probably a little over. You are probably in the 0.011-0.012" range.
__________________
Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle |
December 13, 2017, 11:37 PM | #19 |
Senior Member
Join Date: December 29, 2016
Location: NY Area
Posts: 310
|
OK, new feeler gauges on the way.
Exact measurement soon.
__________________
NRA Life Member NRA CSRO NRA Pistol Instructor NYS CCL Instructor |
December 14, 2017, 04:45 PM | #20 |
Senior Member
Join Date: December 29, 2016
Location: NY Area
Posts: 310
|
Received 2 sets of gauges today.
Measurement is between .006 and .007. Does that look good?
__________________
NRA Life Member NRA CSRO NRA Pistol Instructor NYS CCL Instructor |
December 14, 2017, 10:38 PM | #21 |
Senior Member
Join Date: December 19, 2016
Location: Atlanta, Georgia area
Posts: 455
|
.006"-.007" is fine for a typical revolver. (S&W, Colt, Ruger Taurus)
Some will not accept anything over .004". They have a hard time finding examples that meet their expectations. Notice that the feeler gauge blades are oiled ? Keep that gauge in a dry place with no chance for condensation. These are RAW steel and will happily turn themselves into a brown lump. |
December 15, 2017, 10:12 PM | #22 |
Senior Member
Join Date: December 29, 2016
Location: NY Area
Posts: 310
|
Thanks, will do
__________________
NRA Life Member NRA CSRO NRA Pistol Instructor NYS CCL Instructor |
|
|