Bullet Comparators, how big are the holes?

[270guy]

Hi All,
first project rifle completed and barrel broken in. Need to do some serious load development, and was wondering, how big the holes are in Bullet comparators? I have always just used the seat and chamber method, where you blacken the bullet, and increase the seating depth until there are no signs of the projectile touching the lands. On either the Hornady or nut styles, are the holes the sizes that are stated by the manufactures or slightly smaller? Also are they straight holes? Have some time and access to a small mill and lathe, thought I might have a go a making some in .223, .264, .277.

I know they are cheap, but so am I . And not so cheap here in NZ, or after adding USD$16.00 to have a set posted here. I can't be that hard to make something that works for me.
cheers

 

[expiper]

Hey 270 ....im pretty cheap tooo.....just use a bushing of an appropriate size out of a neck size die!!! ...use one a cal or so small and it will hit the bullets on the ojive in a measurable spot.....I still just measure a bullet...if im jammen em I go in aprox .007-.010" so the lil a bullet vvaries doesnt seem to hurt ...same if im jumpin em .040 or .080...whats a thou or 2???!!!You hear folks say .."im jumpin em .005"!!! this is a measurement taken from an arbitrary ,imaginary "touching spot,,the bullets will vary that much....whew....just make shur they all are jammed plenty,,,or all jumpin enuff to get a good runnin start on the lands........Roger

 

[TonyR]

Hey 270 ....im pretty cheap tooo.....just use a bushing of an appropriate size out of a neck size die!!! ...use one a cal or so small and it will hit the bullets on the ojive in a measurable spot.....I still just measure a bullet...if im jammen em I go in aprox .007-.010" so the lil a bullet vvaries doesnt seem to hurt ...same if im jumpin em .040 or .080...whats a thou or 2???!!!You hear folks say .."im jumpin em .005"!!! this is a measurement taken from an arbitrary ,imaginary "touching spot,,the bullets will vary that much....whew....just make shur they all are jammed plenty,,,or all jumpin enuff to get a good runnin start on the lands........Roger

Neat idea, Roger. Those bushings are made to much tighter tolerances than the comparator inserts I've had. I bought 2 inserts for my 7mm bullets and they will measure the same round 0.040 inches different. Not a problem if I keep them seperate but the first time I mixed them up, I thought my throat had evaporated!

 

[Heman]

I did the same thing you are talking about. Stoney Points measure so far up the nose I have no idea what their diameters are and I never pinned them to find out. The Sinclair comporator inserts are 0.002" smaller than caliber so .22 cal is .222", 30 cal is .306". When I made mine I went 0.0008" under caliber any smaller and they might eat bullets.