Go gauge for shouldered prefit?

Is a go (no-go) gauge necessary for a shouldered prefit?

  • Fuhgeddaboudit. Screw it on and go shoot.

    Votes: 7 9.6%
  • Use a piece of virgin brass and some tape to calculate headspace.

    Votes: 7 9.6%
  • Use a go gauge and some tape for no-go.

    Votes: 22 30.1%
  • Confirm with both a no-go and a go gauge.

    Votes: 37 50.7%

  • Total voters
    73

entoptics

Well-Known Member
Joined
Jan 16, 2018
Messages
860
Curious what the hive mind thinks about checking headspace when installing a shouldered prefit?

I've rebarreled Savage actions with barrel nuts 5 or 6 times, and always use a go gauge to set the headspace, then applied a piece of painters tape to the go gauge to function as a no-go, and have had 100% success achieving a consistent minimum headspace.

I now have a Pure Precision Summit Ti and a Preferred Barrel Blanks shouldered prefit on the way, and wondered if it's really necessary to shell out another $50 bucks on a go-gauge for installation.

I'm debating just using a piece of virgin ADG brass, and applying tape layers until it "no-gos" to determine how much brass growth I'll get on first firing. If it's sub 0.010" I figure I'm good to go with the brass I have. It would be nice to know where I sit in "SAAMI space", but the odds of ever feeding the rifle factory ammo or someone else's reloads is pretty minimal.

Since it's a shouldered prefit, I can't adjust the headspace like I could on a barrel nut rifle anyway, so I figure what's the point of messing with go/no. Determine if it's safe to fire the brass I have, and run with it.

What say the peanut gallery?

P.S. If anyone has a 7mm PRC go gauge handy, and the Hornady Comparator with the #13-41 (or #11-37) insert, could you measure the base to shoulder dimension and report it here? That would be very helpful as a reference, so I'd have a better idea where my virgin brass is currently sitting...
 
if my math is correct the datum should be 408, so does it fall in the same line with the 6.5prc (420) or 400 with 270wsm/6.8west? Then again, I might've forgotten how to figure datum?
 
I think the short version to figure it out is diameter at shoulder divide by 2 then add half the neck od to it?
 
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Here’s another way to look at the subject. Let’s say you wanted a gunsmith to build your rifle. Would you expect the smith to use gauges, or just fudge it and hand you the rifle?

Let’s say you built this rifle and it wasn’t to your liking and you wanted to sell it. On the ad you fully disclose you didn’t use gauges when building the rifle. How many people do you think you’d turn away from the sale?
 
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