|
|
03-11-2017, 08:57 PM
|
Member
|
|
|
Join Date: Sep 2003
Location: SC
Posts: 298
Likes: 499
Liked 154 Times in 77 Posts
|
|
Plug Gauges
I want to buy hard cast bullets for my 629-6 and I want to measure the cylinder throats first. Other than an unsatisfactory attempt to slug the barrel of my .357 revolver, I have not done this kind of measurement before. I have plug gauges for .427,.428, .429, .430 and .431 in my shopping cart for MSC. They are all "plus" pins.
Does this sound like enough different pins to cover the possibilities?
Should I get the "minus" pins as well?
|
03-11-2017, 09:14 PM
|
Vendor
|
|
|
Join Date: Jan 2010
Location: Kansas City area
Posts: 6,190
Likes: 54,459
Liked 13,612 Times in 4,290 Posts
|
|
That should cover anything that is not wildly out of spec. Just the + ones will be fine if you want to measure in .001 increments. If you want to measure in (approximately) .0005 increments, get the - ones too.
|
The Following User Likes This Post:
|
|
03-11-2017, 09:16 PM
|
Member
|
|
|
Join Date: Aug 2003
Location: Occupied California
Posts: 2,793
Likes: 1,526
Liked 5,591 Times in 1,613 Posts
|
|
The set of plug gauges that I use are Minus .0003". That means that a .430" marked gauge actually measures .4297". In other words you want minus gauges because you couldn't stick a .430" gauge in a .430" hole. Being minus by .0003" is close enough for measuring cylinder throats. If you can slide a .430" gauge in a throat but not a .431" gauge, the actual throat is somewhere between to .4297 and .4306" and you can use .430 diameter bullets.
|
The Following 3 Users Like Post:
|
|
03-11-2017, 10:18 PM
|
Member
|
|
|
Join Date: May 2010
Location: The Steel City
Posts: 2,158
Likes: 6,830
Liked 4,405 Times in 1,409 Posts
|
|
I would add .432 and .433 as I have used both in measuring S&W cylinder throats.
|
The Following 2 Users Like Post:
|
|
03-11-2017, 10:46 PM
|
SWCA Member
|
|
|
Join Date: Jul 2005
Location: Indiana
Posts: 11,953
Likes: 10,141
Liked 10,127 Times in 4,799 Posts
|
|
Buy 0.427 through 0.433, minus tolerance. Buy the least expensive grade they have, which will be more than sufficient for what you are doing. Handling and using lab-grade pin gauges is beyond the capabilities and interests of most gun hobbyists. No sense in paying the extra money for them. Remember, with pins you are just doing a "go" check of the entire feature based on the Taylor Principle of gauging, not measuring, which is a different thing - necessarily a lot more complicated, and requiring more expensive tools.
The older 44 Magnums, Model 29s, and Model 629s sometimes have exit bores that are even a bit bigger than 0.433 by a few tenths, but it's not really important because I have yet to see one with chamber dimensions that allow >0.433" bullets with US commercial brass. Most older 44s won't allow bullets much bigger than 0.432 or 0.4325. I've never seen a newer gun smaller than 0.428.
|
The Following 2 Users Like Post:
|
|
03-12-2017, 03:20 AM
|
|
Member
|
|
|
Join Date: Dec 2012
Location: N.E. OKLA.
Posts: 6,484
Likes: 5,882
Liked 9,332 Times in 3,497 Posts
|
|
I agree with M29since14. My S&W 44's range from .428" to .432" throats.
Just go with the "minus" (they're .0002" under marked size) plugs; they're cheaper if I recall correctly too. The pin gages also help you spot out-of round throats too (I got one of those I need to ream.).
A few years ago I was going to order just a "few" pin gages, like you, but finally decided to buy a (discount) whole set & I was GLAD I DID !!
I've used it so many times on my various guns it's was well worth the extra money. Great to check the barrel's bore for uniformity too, among others.
They make a great backdrop too.
.
.
__________________
Waiting for the break of day
Last edited by BLUEDOT37; 03-12-2017 at 11:26 PM.
Reason: .
|
The Following User Likes This Post:
|
|
03-12-2017, 05:53 AM
|
SWCA Member Absent Comrade
|
|
|
Join Date: Nov 2002
Location: SLC, Utah
Posts: 5,060
Likes: 739
Liked 3,275 Times in 1,282 Posts
|
|
Where are you buying your plug gauge sets? Cost?
|
03-12-2017, 09:54 AM
|
Vendor
|
|
|
Join Date: Jan 2010
Location: Kansas City area
Posts: 6,190
Likes: 54,459
Liked 13,612 Times in 4,290 Posts
|
|
|
The Following User Likes This Post:
|
|
03-12-2017, 10:26 AM
|
|
US Veteran
|
|
|
Join Date: Oct 2013
Location: Central Montana
Posts: 13,715
Likes: 12,858
Liked 39,479 Times in 10,047 Posts
|
|
An unsized soft lead slug or round ball drove through a disassembled cylinder is easy to measure. Set cylinder on hardwood block and use a flat face brass punch. Just like slugging a barrel and no rifling to worry about on cylinder.
|
The Following 3 Users Like Post:
|
|
03-12-2017, 06:03 PM
|
Member
|
|
|
Join Date: Sep 2003
Location: SC
Posts: 298
Likes: 499
Liked 154 Times in 77 Posts
|
|
Thanks much for the great info guys.
|
|
Posting Rules
|
|
|
|
|