Factory barrel headspace dimensions?

[Nortonics]

Curious question: Is there a listing somewhere that I can find the factory headspace dimensions that are milled into my Savage 12BVSS Win .243 barrel? Perhaps a diagram such as this:

Does Savage or other manufacturers make this information available to the general public?

 

[kaferhaus]

All factory rifles are chambered to SAMMI tolerances. If what you're wanting to do is find out how much headspace you actually have, that's pretty easy to do.

Remove the ejector from the bolt, buy some brass shim stock from ACE hardware,.001 or .002) cut a few pieces so that they'll fit into the bolt recess. Take a full length resized case, put a couple shims on the bolt face and see if the bolt will close.. whatever thickness shims allow you to just close the bolt will be your headspace.

Headspace problems are easily remedied on Savages anyway... you can just loosen the barrel, insert a full length sized case into the chamber, snug the barrel down onto the case and then tighten the nut...

 

[Rustystud]

Nortonics/Tom:

Very nice drawing. For What it is Worth My Forster go gauge,1.60) and my Forester no-go gauge,1.634) are SAAMI spec.
Rustystud

 

[BoydAllen]

Savage uses a so called "swing gage" to headspace their barrels. It is .002 under SAAMI min. to allow for initial thread "settling",my word) when they are proof fired. Their barrel nut allows the tightest tolerances for setting headspace. A friend once bought a fancy Remington fluted stainless barreled .223 varmint rifle. The bolt would close on a no-go gage. This is not to say that I don't like Remingtons, just that I don't think that they hold the same tolerances on headspace. I have never seen this problem on a Savage.

While I am on the subject of factory goof ups, I once saw a new Winchester model 70 come out of the box with a smooth bore. It was a .30 caliber,I forget which) and the bolt face showed brass from proof firing. Now that is quality control!

 

[robbor]

Im very skeptical of savage setting of headspace. I got a 300 rum factory rifle and first thing I did was to fire a primed piece of brass in it. On all three pieces of brass i fired the primers backed way out of the primer pocket. So either my new federal brass was way under sized or my savages headspace is way to loose. I never measured it but its got to be .010" if not more. Im planning on getting a wrench and a go gauge and resetting the headspace some time in the future. I dont think the manufactures get enough Sh@t for poor quality control. The magazine did not function properly either with snap caps or loaded shells. I hate having to pay and take the time to send new items back and worry about damage in shipment and removing scopes, then resighting in.
How many firearms are out of spec and the owners never notice.

 

[kaferhaus]

Im very skeptical of savage setting of headspace. I got a 300 rum factory rifle and first thing I did was to fire a primed piece of brass in it. On all three pieces of brass i fired the primers backed way out of the primer pocket. So either my new federal brass was way under sized or my savages headspace is way to loose. I never measured it but its got to be .010" if not more. Im planning on getting a wrench and a go gauge and resetting the headspace some time in the future. I dont think the manufactures get enough Sh@t for poor quality control. The magazine did not function properly either with snap caps or loaded shells. I hate having to pay and take the time to send new items back and worry about damage in shipment and removing scopes, then resighting in.
How many firearms are out of spec and the owners never notice.

A primer backing out under the conditions you describe is to be expected.

Doesn't mean a thing as far as headspace is concerned. Check it with the shim method described above.

When Savage installs a barrel, they screw it onto a guage.. tightening the nut usually increases the headspace a couple thousandths. Right within spec.

 

[brickeyee]

"...fire a primed piece of brass in it."

Primers nearly always back out under these conditions.
Maximum brass dimensions are always smaller than minimum chamber dimensions.
A new piece of brass has a size that will always be less than the actual chamber headspace.

 

[BoydAllen]

Kaferhaus,
If you are going to investigate a measurement, you might want to invest in the proper tool(s).

 

[shortgrass]

Kaferhaus,
If you are going to investigate a measurement, you might want to invest in the proper tool(s).

A+ The only proper way to check headspace is with gages, a "GO" and a "NO-GO". Using once fired in the chamber or full length sized will tell you very little if nothing for setting headspace. If it did, gunsmiths would use that method. Consider the PSI your dealing with. Play it safe, use gages.

 

[DCRYDER]

Rusty, are you saying that the saami specs allows up to .034" fudge factor in headspacing?

 

[Rustystud]

SAAMI specs allow for .0035" difference between a Go and No Go gauge.

All american Firearms and Ammunition manufactures follow SAAMI spec.

Our european brothers us the CIP standard basically the same but in metric.

SAAMI = Small Arms and Ammunition Manufactures Institute

If a comercial firearms or ammunition manufacture carries liability insurance they follow SAAMI specs.

SAAMI requires the use of steel Go and No Go Gauges in setting headspace.

Nat Lambeth

 

[jonbearman]

I think Nate he asked because you listed your headspace gages like this , 1.6 and 1.634.I think you fat fingered while typing thats all.

 

[Larryh128]

I agree , firing a primed only case will back out a primer about every time. Probably absolutely nothing wrong. But it doesn't hurt to check.