Anyone around Edmonton that could look at some brass for me?
- Thread starter Revolution
- Start date
mattyboylewis
Regular
- Location
- Oliver, BC
BrotherRockeye
CGN Ultra frequent flyer
- Location
- Rural Saskatchewan
or code the link so it's easy to c/p into your browser...
Code:
http://www.youtube.com/watch?v=orJdUR_X67MWhat signs are you seeing? I normally look at three things.
1. Primer edge profile - Primers have a bit of a bevel at the outside diameter. The higher the pressure the more this bevel rises up against the bolt face. i.e. the primer becomes more square edged instead of beveled. In extreme case the primer can blow out. Here is a progressive photo:
2. Primer firing pin profile - Although this can be affected by excessive firing pin clearance, you are looking for how flat the primer is next to the firing pin dent. Normally pressure is getting up there if the dents shows a crater or raised rim. You can generally feel this with your finger nail.
3. If your bolt has an extractor pin, and pressure is too high brass will flow back into the extractor pin recess. You will at first see a slight impression, and in bad cases the brass flows back and gets sheared off when you rotate the bolt.
There is a method of measuring case web head to estimate pressure, but I have not had great success with it. Perhaps not enough effort on my part.
Also can you post a photo of your brass?
1. Primer edge profile - Primers have a bit of a bevel at the outside diameter. The higher the pressure the more this bevel rises up against the bolt face. i.e. the primer becomes more square edged instead of beveled. In extreme case the primer can blow out. Here is a progressive photo:
2. Primer firing pin profile - Although this can be affected by excessive firing pin clearance, you are looking for how flat the primer is next to the firing pin dent. Normally pressure is getting up there if the dents shows a crater or raised rim. You can generally feel this with your finger nail.
3. If your bolt has an extractor pin, and pressure is too high brass will flow back into the extractor pin recess. You will at first see a slight impression, and in bad cases the brass flows back and gets sheared off when you rotate the bolt.
There is a method of measuring case web head to estimate pressure, but I have not had great success with it. Perhaps not enough effort on my part.
Also can you post a photo of your brass?
