[7.62MM Firearms]

This will cover the Receiver Bridge, Overall Height, and Barrel Band.

The measurement of the bridge is taken from the front of the receiver to the rear side of the bridge at the highest point. The spec range for this measurement is 3.935 – 3.925.

The overall height is taken from the front of the receiver to the highest point on the heel. The spec range for this measurement is 7.920 – 7.900

The barrel band is measured from the top/front of the receiver to the rear of the band. The spec range for this measurement is .701 - .698

It is important to note that SPEC’s are SPEC’s. There is no one better place to take a measurement other than the highest or lowest point.

The equipment that is used for this is calibrated Mitutoyo Height Master, Mitutoyo Heightmatic 600, and 2 digital Mitutoyo slide calipers on a Starrett Granite Surface Plate. This is the best equipment for this task, Not Gauge Blocks.

It will be needed to post a few reply's to get pictures loaded.

I hope this shows the right way to measure receivers.

 

[7.62MM Firearms]

More pictures

Pictures of the receivers.

 

[7.62MM Firearms]

more pictures

Pictures

 

[7.62MM Firearms]

Results

The pictures show the detail that is required along with the proper equipment that is needed to measure the receivers correctly.

Here are the results:

 

[7.62MM Firearms]

Pictures

Pictures

 

[7.62bthp]

What? No plastic calipers?DI5

Nice post 7.62mm. Thanks!

 

[MemphisMachinists]

Nice Pics. Not sure what you have against guage blocks. Doesn't matter as long as you get it right and it looks like you're trying. I bet you have learned a lot over the past couple of years getting to this point.

 

[toppkatt]

Hey, I think one of those is my receiver!

 

[gb2814]

Thank you for a fine product. It's proven to be quite a shooter...

 

[ExMR2]

The pictures show the detail that is required along with the proper equipment that is needed to measure the receivers correctly.

And if I'm reading the pic of the results correcly, it just goes to show why when you really need to know what you've got measuring something, never trust calipers if it needs to be really close.

Looks to me like two seperate checks measured both ways and there's .0005" difference on one and .0195 difference on the other. If I had to bet my next paycheck, my money's on the height gauge.

Calipers are good so long as you realize they have their limitations. It all depends on how accurate you need to be. Not to mention you have to develop a certain feel for using them.