Bullet measurin

[Pete Wass]

I decided not to hijack Al's thread with what I am about to say here.

Last Saturday I had a conversation with a gent who has one of Bob Green's bullet measuring devices. He explained to me how the device was constructed. From his discription there is a rod that has the same size vee shaped hole as a bullet seater stem has. This stem is somehow interactive with a dial indicator. The base of the tool has the shape of the throat of a chambered barrel machined into it. One pushes a bullet into the device, pushing the stem simulator to the indicator which reads any differences in the bullets one checks. This is THE dimension one wants to be ale to check and to know because this is how a bullet will be seated into a case.

From what he told me, he finds about the same variability I find using the Tubb device I use. Some bullet lots are very consistent while others are very inconsistent. I find it intersting that two dis-simular devices seem to provide the same kind of imformation. It would be interesting to check the two devices against each other to see if they find the same readings.

 

[hulk]

?

I believe your Tubbs tool measures bearing surface. Bob Green"s tool measures something very different.

Bob's tool is extremely well made and precise. The tool has a stem, like a bullet seater. The dial indicator will push the stem past the bottom of the tool. Placing the tool on a flat surface allows you to zero the indicator. Push your bullet into the tapered hole until it stops. With this dimension and proper sorting of bullets, you can assure that OAL is very consistent. Naturally, your bullet seating die and tool to measure OAL must be equally well made and precise. Call Bob, he knows tis stuff much better than I do.

 

[Pete Wass]

Thanks

I believe your Tubbs tool measures bearing surface. Bob Green"s tool measures something very different.

Bob's tool is extremely well made and precise. The tool has a stem, like a bullet seater. The dial indicator will push the stem past the bottom of the tool. Placing the tool on a flat surface allows you to zero the indicator. Push your bullet into the tapered hole until it stops. With this dimension and proper sorting of bullets, you can assure that OAL is very consistent. Naturally, your bullet seating die and tool to measure OAL must be equally well made and precise. Call Bob, he knows tis stuff much better than I do.

After talking to the gentleman I spoke with, I had a pretty good grip on the tool and what it did. I find it interesting that bullets sorted by bearing surface length show the same seating depth variability that bullets measured in Bob's device do. It's as if the ogive of the bullets are stretched thus pushing the part that touches the lands down or allowing it to go up the ogive.

Based on my experience, I think both devices do the same thing but in a different way, as you point out. I haven't found the need to use anything other than the bearing surface comparitor yet.