Headspace Question?

[BtoVin83]

If push comes to shove make a shim to go between the barrel and the action. I did for a Ruger on a 270 barrel given to me.

 

[cross69]

The most reliable measurement is with the go gauge (you are sure it is not a no-go gauge?). Snap caps are made smallish so that they fit any 8x57 out there. But to get an idea, add layers of tape to the base of a snap cap until you start feeling it get tight to chamber. That will give you some idea of the chambers headspace. Compare that to your go gauge headspace and to SAAMI specs.

It is very strange that you can not close the bolt on a go gauge. The chamber and bolt might need a good cleaning. I would want to fully understand why the go gauge does not pass even if you can resize brass to fit a short chamber.

Thanks, I double checked and it is the go gauge. I will reclean everything again and then test the go gauge. If still no luck. I will start adding the tape to the snap cap as you suggested.

 

[cross69]

What is the dimension stamped on your gauge? A Forster 8x57 go gauge 1.874". No go gauge is 1.880".

Tom

Yes, I am using a Forster. A photo is attached

 

[Toolmaker51]

Place the gauge in the bolt head first, instead of relying on the extractor to snap over the rim on the gauge. Snapping over the rim of a gauge is sometimes harder than over a cartridge.

All the responses are correct, but this adds a significant detail. Brass is nearly self-lubricating; hardened, unpolished tool steel is not. Any tool marks on front of extractor multiply this, especially that both are formed radially and near identical size. Though small, they can engage almost like gears, it just takes one. It is not common, but does occur.

 

[epanzella]

Your reloading dies will tell the tale. Full length resize (sizing die screwed down until it touches the shell holder and cams over) a new case and then chamber it. If the bolt closes you're good to go. If it doesn't your chamber is not cut deep enough. With a bolt action you can use a finsh chamber reamer by hand to lengthen the chamber without taking the barrel off. Just do a smidge at a time until the bolt closes on the go gauge. Of course you can take the cheap way out and sand a thou or two (or three) off your shell holder which will push the shoulder back and equivalent amount but if the chamber is actually too short you won't be able to use factory ammo.

 

[cross69]

The most reliable measurement is with the go gauge (you are sure it is not a no-go gauge?). Snap caps are made smallish so that they fit any 8x57 out there. But to get an idea, add layers of tape to the base of a snap cap until you start feeling it get tight to chamber. That will give you some idea of the chambers headspace. Compare that to your go gauge headspace and to SAAMI specs.

It is very strange that you can not close the bolt on a go gauge. The chamber and bolt might need a good cleaning. I would want to fully understand why the go gauge does not pass even if you can resize brass to fit a short chamber.

I took your suggestion. I removed the extractor and cleaned the bolt and chamber.

The I added the tape to the base of the snap cap. With two pieces of tape the blot closed snugly. With three pieces of tape the bolt didn't close. I marked the datum of .392 on the snap cap and then measured from the bottom of the case with the tape. If my eye sight and measurements are correct, I came up with 1.869 compared to the 1.874 of the minimum headspace a difference of .005. Do you think this variance will be an issue?

Thank you for your help. I really appreciate it.

 

[Tozguy]

As mentioned previously a short chamber would not be an issue for handloaded ammo. Adjustments can be made in your reloading equipment to resize your brass to fit that chamber. 0.005'' is not much so chances are it is just a die height adjustment in the press.
Keep a close eye on case length as it will grow when resizing. Trim case length to .010'' less than chamber length if necessary.

The only issue might be with factory ammo. But even then I would expect factory ammo to be somewhat shorter than a minimum SAAMI chamber so who knows.

May I ask what you are using to measure headspace on the snap cap?

 

[cross69]

I am using dial calipers to measure. The reloading dies and brass should arrive in the mail in a few days so I will move on to that next.

Thanks.

 

[cross69]

Thanks to everyone for sharing their feedback on my question. It has been very helpful.

 

[pontiac428]

@cross69 I would recommend buying a Hornady/Stony Point headspace measuring tool and a bullet comparator. Those two tools (used together) will do more for the accuracy of your loads than anything else I can think of. It gives you a repeatable method of measuring that you can control.