"Adjustable" go no-go guage

[n4ue]

Hi. Today I spent several hours rechambering one of my 223 Axis rifles into a 22-204. Cutting the new chamber was kinda easy using a PTG 223 AI reamer. I got it exactly where I wanted it. However when trying to set the bbl into the receiver, I had some issues.
I do not have the go no-go guages. I have several sets for 223, 223 AI, etc. I know better than trying to use just new brass..... I tried, paper, labels, etc. Unfortunately, after a bolt closure or two, it was useless.
So, I had a thought (always dangerous at my age)......... What about using a set screw from inside the case? I have a large number of setscrews and a 10-32 'cup point' screw looked perfect.

I took a 22-204 case and drilled a #21 hole through the primer pocket. Made sure the case bottom was flat and burr free. Then I tapped said hole with a 10-32 tap, being careful not to fully form the hole, so the set screw had some friction and would be 'tight'.
It worked perfectly! I used a regular 22-204 case as a 'go' and the adjustable case as a 'no-go'.

There are a couple of caveats here (ain't there always?)

1. I have a lathe for the drilling and tapping operation.
2. I have several good depth guages B&S, Starrett, etc.
3. The set screw MUST be a 'cup point' since it has to straddle the firing pin hole.

Wadda think????

ron

[stangfish]

I might be missing the point. My thoughts on gauges where that they defined a dimension by acceptance or rejection. How does something adjustable define anything but what the user wants.

At one time, long ago, I made thread and taper ring and plug gauges. They were all inspected by an independent source and certified to meet standards. So one day I walk by a machinist who was cutting internal threads(I think it was a class 3 4.5" 8tpi if my mind serves me well). He was filing on the male thread gauge. I asked him what he was doing and he said that he had fed in enough and the gauge should fit. I looked at his insert and it was broken off. Head in hands I walked away.


Since you are probably a hand loader and 223 AI is not an off the shelf cartridge it probably doesn't mean anything to be exact. But what is it you are trying to do that keeps you from setting the headspace from a sized piece of 223 AI brass?

[n4ue]

Stangfish. you missed the first part of my post. I have 4 Axis rifles in 223. One is stock, one is a 221 Fireball I built, one is a 223 AI I built and this one is a 22-204. It uses the 204 Ruger case opened up to 224 and I used a 223 AI reamer to build it. I set the 'go' using a 22-204 brass. However, when I tried to set the bbl depth to the 'no go' (+.008"), the printer paper, etc method didn't work. The paper would crush due to the bolt camming. So, I modified the case as described above.
After I submitted the first post, I should have described it as being like a "high primer". With good depth guages and 32 tpi, it is easy to adjust.
Now, the bolt will close with only the slightest resistance on the 'go' case, but will not close on the 'modified' case.
I measured several of my go no-go sets to establish the correct no-go length so I should have no case stretch. It has worked great on both the 223 AI and the .221 Fireball. BTW. the 221 is a Ball to shoot! A LOT more fun than my XP-100.

Next build is a McGowan SS 24" bbl chambered in 6.5 TCU which will be fun considering I have a ton of loaded ammo, dies, bullets, etc. Leftover from my IHMSA days........Still have the 14" T/C......

ron

[sharpshooter]

Once set on a go gauge, or sized brass, you don't really need a no go gauge. Place a small length of red plasti-gage in the bolt face and close on the go gauge or the sized brass. The width of the smashed plasti-gage will tell you exactly how much clearance you have. If you do it correctly, you will have .002" difference.

[missed]

Thanks Fred, I never thought of using plastic gauge for that. I've just been using a piece of feeler gauge.