Difference in Heaspace gauges?

[ronniet]

Looking for some headspace gauges for 250 Savage and 22 Savage HP , what are the difference in CIP and SAAMI gauges?
Ron

[samari46]

Always use the go and no go from the same manufacturer. While all are supposed to use the same datum line on all cartridges not all of them do. Anytime I order a set of headspace guages it's from one manufacturer. Frank

[nicholst55]

CIP is the European equivalent of SAAMI, but their 'standard' specs do vary slightly. For practical purposes, there is probably no real difference. For an American cartridge, I would order gages to SAAMI specs, however.

[John Taylor]

I had a Forster gauge once that was not correct. It's always a good idea to check the chamber with a factory loaded round and test fire if possible. I now buy all my gauges from PTG direct. If I have a problem with something they make I can call and get it corrected.

[Nobade]

I had a Forster gauge once that was not correct. It's always a good idea to check the chamber with a factory loaded round and test fire if possible. I now buy all my gauges from PTG direct. If I have a problem with something they make I can call and get it corrected.My Forster go gauge for 22-250 has been causing me problems recently. I just measured it against a new Manson go and it's .004" shorter. No wonder I got some complaints. Time to get a new set for that cartridge.

[243winxb]

Links below. Does CIP use a datum? I dont see it?

[McFred]

They way I interpret the CIP drawing is the Junction Cone dimension "S" is the CIP flavor of headspace. If your 250 Savage reamer is 53˚ included angle on the shoulder then the theoretical intersection of the shoulder angle should be 48.95mm to the bolt face. If the reamer's angle is wrong or you run the reamer deeper/shorter then that "S" number changes. In theory if you have a "Go" gauge then the only thing you need to worry about is being able to just close the bolt on that gauge and you'll be golden.

SAAMI headspace dimensions give you a length to a specific diameter on the shoulder of the round. If you took that intersection's shoulder diameter to "zero" (where the shoulder angles would intersect) then it'd be the same measurement as the CIP dimension.

Saami appears to give you .010" of "Go" headspace fudge factor. So there's the minimum chamber headspace spec, and the maximum headspace spec that factory ammo should all fall within.


Ronniet, use whichever headspace gauge you like and make it such that it will close on that "Go" gauge but not with the "Go" gauge with a piece of thin scotch-tape stuck to the bottom of the gauge. Here's what I use: It's a "Go" gauge that has a .001" piece of steel shim stock cut to fit behind it. Works pretty well. I can easily hit the Gauge's headspace dimension within the thickness of that steel shim.

https://i.postimg.cc/mkf2WhxL/headspace.jpg

[243winxb]

S- Trim length?

L1, L2, L3= Minimum chamber, or headspace??