go - nogo primer pocket pressure gauges

ricka0

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Altho Case Head expansion (CHE) has been considered the best approach to measure excessive pressure - The physicist/statistician Denton Branwell has demonstrated that CHE cannot be used to measure over pressure. ( Even with my exceptional Mitutoyo .0001 blade Mike )

On my RUM brass, the primer pocket radius grows about 3x as much as the Case Head - so primer pocket radius is a more sensitive indicator. (it's probably also more uniform)

Suppose I take my preped (uniform the primer radius) brass and have a machinist make me some <font color="brown">go, go with force /ubbthreads/images/graemlins/cool.gif , no-go gauges </font> to slip into the primer pocket. I would have a fast way to measure primer pocket expansion.

I would like to use this approach in conjunction with the RSI rsi pressure trace system. (also using factory ammo as a reality check).

When I get a Allen uber Mag, I won't have the luxury of factory ammo.
comments, suggestions, idea please.
 
i don't really see why that wouldn't work, but you would have to give the machinist the exact diminsions you are willing to have for your go, no-go. I would recommend you find a very seasoned machinist for the task as well. you are talking about tolerances close to +/- .0001 on a manual lathe.
 
Well, you better make up your mind on your favorite brand of primer because they are not the same. No-go, on one, can be a perfect fit on another.

Good hunting. LB
 
What about using a scale to measure bolt stiffness? I could measure primer diameter, CHE and bolt stiffness and see how well they agree with my RSI pressure traces.
 
If you want to measure the pocket diameter, and changes there in, get a few "Plug Gauges" (the class X ones are NIST tracable), there available in increments of .0001 (tolerance of -0.00000/+.00004 for go type, -.00004/+0.00000 for No-Go types). Or you can get a set of 13 (-.0012 to +.0012) from nominal (select a nominal that is between your "go" and "no-go" numbers. A 13pc set will cost you $100, singles run about $15ea, from McMaster-Carr.
 
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