Shoulder Measuring Tool On the Cheap

[Smokerroller]

I have been wanting to measure the shoulders on my 308 cases to tune in the amount of shoulder bump back while full length resizing. I thought a solution today while lamenting not having a shoulder gage. I took a 40 S&W case and inverted it, putting the mouth of the 40 S&W on the shoulder of my 308 case. It fits about half way down the shoulder. It is not as solid as I'm sure a real gage would be but I get a consistent measurement which consistent on all my fired cases from the same 308 chamber. Of course I will only use this one 40 smith case and not interchange with any others. What do you think? I think it gets me what I need to know and gives me the ability to bump back my cases 3 thousandths. Do the real shoulder gauges measure differently?

 

[308sako]

I use a 40 for 308's and a .32 ACP for .223's... works very well keep them in the die box, always the same

 

[427Cobra]

Yep I discovered the 40 trick after buying the Stoney Point tool(Hornady now), just make sure to decap it.

 

[SWThomas]

I spent the $15 and got the Sinclair gauge and body.

 

[RyeDaddy]

I used a 10mm case for a while for 308 based cases. Worked great till somebody gave me a gift card for MidwayUSA and I bought the Hornady setup to finish out an order. No difference in consistency of measurement, the Hornady gauge uses a .400 hole to measure datum on 308's and similar, so you're all set.

 

[ShtrRdy]

I use a decapped 10mm case to measure a 300 Win Mag shoulder. I think the main thing you have to be careful with is pressing on the case since the mouth can spread and cause inconsistent readings.