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Testing Firing Pin Protrusion

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11 January 2008, 03:15
preventec47
Testing Firing Pin Protrusion
I'd like to know where I can buy a precision
caliper type device for measuring the protusion
of firing pins. Also what is the device called
and if options exist, what are the approximate
prices ? I'm assuming there would be some
kind of simply dial guage that you could place
over the front of the bolt face when the firing
pin is relaxed.
Thanks
11 January 2008, 06:01
triggerguard1
You can use a "depth mic"....

do a search through MSC or J&L and you'll find plenty.

the dial gauge style is not as accurate as the micrometer type.

you'll be looking at about $150.00 i believe, but it has been many moons since I was shopping for one.


Williams Machine Works

11 January 2008, 06:13
zimbabwe
You can always use the butt end of your vernier calipers. Works exactly like a depth mike with out the thimble. Exactly how ACCURATE do you have to be.


SCI Life Member
NRA Patron Life Member
DRSS
11 January 2008, 07:10
Duane Wiebe
For centerfire rifles, .055-.065 is acceptable standard. For years, I have used a piece of 1018, about 3" long 1/8" x 1/2" One end is "GO" and other is NO-GO" All done in the mill in about 1 minute...check the measurements with a depth mike to be sure
11 January 2008, 08:05
Westpac
preventec47, here is a device Brownells sells for recording the amount of protrusion. I use a caliper, or, a depth mike. Depending on what's handy at the time.

http://www.brownells.com/aspx/NS/store/ProductDetail.as...20PROTRUSION%20GAUGE


_______________________________________________________________________________
This is my rifle, there are many like it but this one is mine. My rifle is my best friend, it is my life.
11 January 2008, 13:11
preventec47
These answers have given me the idea that a set
of feeler guages much like sold for autos could
be made with little notches cut out with different depths so that the tips of the little metal pieces could be dragged over the protruding firing pin and it it touched then
you know it pin was sticking out at least
a certain distance.
Then keep using a larger depth gauge until the pin no longer touched and you would know the range within the pin protuded. probably start with .040 and move up in .005 increments to .075
I assume that was what was describe above
by the go and no-go gauge.
I like that idea also as for that concept
only two would be needed. My problem is a Mauser that doesnt fire mil-surp ammo reliability when two of my other rifles always
fire 100 percent. It is obviously the firing
pin as headspace is fine and a stronger spring
didnt affect the problem.
11 January 2008, 13:38
preventec47
After looking at the device sold by Brownells
and MidwayUSA, we could very simple make a cheap
simple device by finding a small barrel nut
( which is like stacking 4 or 5 nuts together
in length) and a hex head screw that was of
the same thread size. We could place the
barrel nut over the firing pin and turn the
screw until contact was made and then we
could use micrometer to measure the difference
in length. OK where to buy small barrel nuts?
11 January 2008, 14:41
mete
It's not that big a deal . You need about 1/16" [1.5mm] you can almost eyeball it or use a proper piece of shim stock next to the pin.Also consider tip shape.My old "gunsmithing " by Dunlap has a ggod section on firing pins.
11 January 2008, 18:56
preventec47
How can you say FAILURE TO FIRE is "no big deal" ?
11 January 2008, 19:08
Rusty Marlin
reventec47, mete means that measuring the protrusion is not that big a deal. You are thinking way too much on this.
Buy one of these http://www.use-enco.com/CGI/INSRIT?PARTPG=INSRAR2&PMAKA=610-5077&PMPXNO=947742 and go forth and measure the protrusion.

If the Enco brand $12 unit is too cheap, buy the $150 starret.


Rusty's Action Works
Montross VA.
Action work for Cowboy Shooters &
Manufacturer of Stylized Rigby rifle sights. http://i61.photobucket.com/alb.../th_isofrontleft.jpg
11 January 2008, 19:18
rem721
quote:
Originally posted by preventec47:
How can you say FAILURE TO FIRE is "no big deal" ?


It's not, unless of course it's unintentional. Big Grin
11 January 2008, 19:34
mete
Yes , I meant measuring firing pin protrusion is no big deal.Failure to fire ?? Then there are lots of things to check. Failure to seat primers all the way.Bad primers.Dirt in firing pin hole . Burrs on firing pin and firing pin hole [found both in one gun !] Hammer spring problems ,etc, etc.
12 January 2008, 07:41
tsturm
quote:
Originally posted by preventec47:
How can you say FAILURE TO FIRE is "no big deal" ?


You ever used a set of dial calipers?? Wink