Pins vs gages

[ckaberna]

Are gauge pins better than the starett “small hole gages” ? Or are they somewhat comparable?

 

[tobnpr]

Are gauge pins better

"Better", depends on the application and level of precision measurement needed.
Gage pins (+/-) are accurate to a tenth- you'll never get that from a hole gage.

 

[TylerFromMS]

Looks like a pear of anguish.

 

[jackieschmidt]

As a machinist, I can tell you that the accuracy of small hole gages such as you picture is dependent on the skill of the machinist.
Gage pins graduated in .0001 are pretty much foolproof.

 

[55fairlane]

Also as a machinist, running a jig bore, I used those type gages to get close, then used gage pins for final hole size.
A lot depends on the skill of the guy using said gages,
What are you trying to measure? That may better help us answer your questions

 

[ckaberna]

As a machinist, I can tell you that the accuracy of small hole gages such as you picture is dependent on the skill of the machinist.
Gage pins graduated in .0001 are pretty much foolproof.

I may need to get pins. I am curious how far-off I am though, my throat measurement aligns pretty well with my reamers as well as what I’d expect out the bras. Thank you Jackie!

 

[ckaberna]

I have been using them lately to measure chamber throat diameter.
Edit: on used barrels from unknown smiths

 

[Dusty Stevens]

I have been using them lately to measure chamber throat diameter.

Im not trying to ask a smartass question so dont take it that way, but why does that matter when its in the barrel already? Its measured in tenths, which you wont measure with a hole gage, and theres not much you can do about it nor is it very easy to measure the exact spot it matters. Just look in there and make sure its not cutting bigger than the grooves and cut evenly all around and make sure it actually cut the lands out

 

[ckaberna]

Im not trying to ask a smartass question so dont take it that way, but why does that matter when its in the barrel already? Its measured in tenths, which you wont measure with a hole gage, and theres not much you can do about it nor is it very easy to measure the exact spot it matters. Just look in there and make sure its not cutting bigger than the grooves and cut evenly all around and make sure it actually cut the lands out

Lol, looking back at my post I should have been more descriptive. On these used barrels and rifles I’ve ran across I have found them handy to confirm the throat. They may not get me to the .0001” but at least I can confirm a .262 vs .269 on an unmarked barrel. Gives me a little piece of mind anyway. I was just wondering how these stack up against the pins.

 

[55fairlane]

Lol, looking back at my post I should have been more descriptive. On these used barrels and rifles I’ve ran across I have found them handy to confirm the throat. They may not get me to the .0001” but at least I can confirm a .262 vs .269 on an unmarked barrel. Gives me a little piece of mind anyway. I was just wondering how these stack up against the pins.

What your trying to accomplish I do believe is very doable, if your simply mic'ing throat or muzzle , your gages are fine, plus or minus .0005 (half thou) really doesn't mean much.

 

[rwj]

Pins measure the largest cylinder that will pass thru an opening, hole gauges measure the size of a 180 degree segment. Neither tells you if the opening is round nor it’s runout/position relative to another datum. Use accordingly…

Edit to correct as @jelenko correctly noted!

 

[jelenko]

smallest cylinder that will pass thru an opening

Should that be 'largest cylinder....'?

 

[Dusty Stevens]

Lol, looking back at my post I should have been more descriptive. On these used barrels and rifles I’ve ran across I have found them handy to confirm the throat. They may not get me to the .0001” but at least I can confirm a .262 vs .269 on an unmarked barrel. Gives me a little piece of mind anyway. I was just wondering how these stack up against the pins.

So youre looking for neck diameter rather than throat dia. That gage will work fine for that

 

[gunsandgunsmithing]

Splitting a mighty fine hair and pins are great but you have to understand something very simple. A 1" pin(or any size) does NOT fit into a 1" hole. They are the SAME, no clearance equals no fit. You will feel light resistance at .0002" clearance and it better be perfectly straight.
Again, we're splitting a mighty fine hair there but if if fits, there's clearance

 

[ckaberna]

So youre looking for neck diameter rather than throat dia. That gage will work fine for that

Correct

 

[DaveTooley]

I've used small hole gages to reverse engineer chambers. It takes a delicate touch but I'm confident I can get to (+/-) .0002" on most true holes.

 

[Bronsin]

Splitting a mighty fine hair and pins are great but you have to understand something very simple. A 1" pin(or any size) does NOT fit into a 1" hole. They are the SAME, no clearance equals no fit. You will feel light resistance at .0002" clearance and it better be perfectly straight.
Again, we're splitting a mighty fine hair there but if if fits, there's clearance

Could you PLEASE tell the engineer's that I work for that! Maybe if they heard it from someone else, they would believe it. These guys, and gals, are under the impression that the lines that actually show the part, are in fact clearance.

I personally use the gages to measure hole size, as they tell you exactly what the hole size is. Pins don't do that unless you know just what size pin will fir into what size hole, and as has been said already, it won't fit without some amount of clearance. You can set your micrometer to a certain size and then adjust your gage to have a slight drag on it and still get the same info a pin would give you.

If you really want to open a can of worms, get a set of flat bottom small hole gages and check primer pockets for expansion............

 

[gunsandgunsmithing]

Could you PLEASE tell the engineer's that I work for that! Maybe if they heard it from someone else, they would believe it. These guys, and gals, are under the impression that the lines that actually show the part, are in fact clearance.

I personally use the gages to measure hole size, as they tell you exactly what the hole size is. Pins don't do that unless you know just what size pin will fir into what size hole, and as has been said already, it won't fit without some amount of clearance. You can set your micrometer to a certain size and then adjust your gage to have a slight drag on it and still get the same info a pin would give you.

If you really want to open a can of worms, get a set of flat bottom small hole gages and check primer pockets for expansion............

Like I said, splitting a really fine hair and pins are good for almost all intents and purposes but you are right. SAME means SAME....Not different. The other side is... it also has .0000 interference. That should help a whole lot!
Micro inches are above my pay grade and skill level. Lol!

 

[jackieschmidt]

In my previuos post, I might have gave the impression that I preferred pins.

Well, no. the only thing I use deltronic pins for is to check the bore diameters of barrels. They are graduated in .0001 increments.

for measuring all other small holes, I use either snap gages, (over 5/16) or small hole gages In conjunction with mics.

 

[ckaberna]

In my previuos post, I might have gave the impression that I preferred pins.

Well, no. the only thing I use deltronic pins for is to check the bore diameters of barrels. They are graduated in .0001 increments.

for measuring all other small holes, I use either snap gages, (over 5/16) or small hole gages In conjunction with mics.

Thanks all for the input , I just like to verify neck diameters on barrels and have found this to be an easy way to do it, if accurate enough.
I incorrectly stated throat in my original post.