Headspace gage for the .338 Lapua Magnum?

[mdslammer]

Hi Guys,

I'm looking for a head space gauge for my .338 Lapua Magnum. I have the calipers and the bullet comparator but I need the bushing.
I went to Midway and the online tech said this would work:
Hornady Cartridge Headspace Gage Bushing 420 Diameter

Fits: 284 Winchester, 7mm Remington Magnum, 300 Winchester Magnum, 8mm Remington Magnum, 338 Winchester Magnum, 375 H&H Magnum

Will this work for my .338 Lapua Magnum? If not, can your recommend a gauge that will please?

Thanks guys.

MDslammer

 

[mdslammer]

Was able to get through to Hornady and they said that the E420 will work for anyone out there wondering.

Hornady Cartridge Headspace Gage Bushing 420 Diameter

 

[HobbyShooter]

Months later, I know, but Thanks! I was trying to find the right size today for a 338LM. Good to know the 420 I have for my 7mm RM will work for both.

 

[pcmacd]

You can get the CIP chamber print here:

- CIP - Homologation

Unfortunately, CIP does not directly call out headspace the way SAAMI does. I did some trig working back from the turbulence point (the vertex of the triangle formed by the converging 39 deg 59'48" angle.) This angle works out to 39.997 degrees.

The diameter of this Hornady tool is 0.420", so its radius is 0.210". With a slight of hand (using the tangent function) we can determine that the distance from this vertex to the point 0.420" in diameter on the cone is -0.577". Add this to datum S (the vertex; 2.909" ) and we get a length from the head to the 0.420" cone diameter as 2.332" to use with the Hornady 0.420 gauge.

I also have a JGS chamber print (#4637 revised 4/12/2013 which references the CIP drawing of 2/5/15 - go figure) that specifies a datum on the cone at 0.4540" diameter @ 2.2833" from the head. This is the only place I have seen this information directly documented, for what it's worth.

 

[Powermac]

this is a old thread but if anyone is looking for a good 338 Lapua headspace gauge, Giraud tool company makes a good headspace gage/ comparator for 30 bucks.

The digital one from Innovative technologies is my favorite though.

 

[AIdog]

+1 for the digital headspace gauge it works great and with all cartridges

 

[High Binder]

Months later, I know, but Thanks! I was trying to find the right size today for a 338LM. Good to know the 420 I have for my 7mm RM will work for both.

I use the 420 and have no problems..

 

[pcmacd]

That CIP link has moved!

You can get the CIP chamber print here:

- CIP - Homologation

Unfortunately, CIP does not directly call out headspace the way SAAMI does. I did some trig working back from the turbulence point (the vertex of the triangle formed by the converging 39 deg 59'48" angle.) This angle works out to 39.997 degrees.

The diameter of this Hornady tool is 0.420", so its radius is 0.210". With a slight of hand (using the tangent function) we can determine that the distance from this vertex to the point 0.420" in diameter on the cone is -0.577". Add this to datum S (the vertex; 2.909" ) and we get a length from the head to the 0.420" cone diameter as 2.332" to use with the Hornady 0.420 gauge.

I also have a JGS chamber print (#4637 revised 4/12/2013 which references the CIP drawing of 2/5/15 - go figure) that specifies a datum on the cone at 0.4540" diameter @ 2.2833" from the head. This is the only place I have seen this information directly documented, for what it's worth.

CIP - Homologation