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Posted: 2/21/2013 8:15:00 AM EDT
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I know there are several methods for checking primer pockets. I wanted to see what method people use and how they may have confirmed their method is accurate. I'm especially interested in perhaps just gageing them.
I've noticed that sometimes when i seat a primer on my LNL AP i hit the rare round that it makes me stop it goes in so easy that i think the primer must not have fed, then i check...sure enough seated primer. so i pull it, bang it on the bench a few times...doesnt fall out so i go ok...mark it with my marker so i know to recheck it at firing to see if there is a cause for this. funny thing this is once fired LC. i've only found like 2 out of thousands i've processed. |
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Don't forget that there is another piece to this puzzle, the primer itself. They are not as uniform as we might believe. I just miked three Federal large pistol primers (all I had in the sleeve). They came out at .2101, .2109, and .2105. That is a lot of spread for a press fit.
I use a bench top rimer press that has a good feel to it. I notice some variation in feel when priming. My .308 cases were all once fired with no primer crimp. It is a good idea to mark the suspect cases but don't be surprised if the feel is different the next time you prime them. |
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Quoted:
You have a oversize primer pocket, it might have been a hot load, or maybe over zealous use of a reamer or swager, whatever the case the cartridge case is toast, its time to put it in the recycle bin. once fired brass with mil crimp and i swagered, but no more than any of the other rounds. Still open question...how do you guys test for these? anyone use calipers to test for this and if so what are your go/no-go marks? |
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For measuring IDs, the ID feature on calipers can give deceptive results. IF there is any flat at all on the blades, the small dia. curvature of the hole will touch the edges of the blades only.
I have a surplus set of precision ground pins found on e-bay for checking small hole dia.'s like primer pockets. 
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Quoted:
For measuring IDs, the ID feature on calipers can give deceptive results. IF there is any flat at all on the blades, the small dia. curvature of the hole will touch the edges of the blades only. I have a surplus set of precision ground pins found on e-bay for checking small hole dia.'s like primer pockets. http://i255.photobucket.com/albums/hh133/counterclockwisester/measurement_over_pins.jpg that is pretty cool.. how much $ did that run you if you dint mind me asking? |
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The only method I've found that's 100% to see if a primer pocket needs to be swaged is to use the small swager bit from the RCBS Primer Pocket Swaging Combo as a primer pocket gage. If the primer pocket isn't crimped, the bit will fit all the way in:  If the primer pocket is crimped, the bit won't fit all the way in: 
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Quoted:
The only method I've found that's 100% to see if a primer pocket needs to be swaged is to use the small swager bit from the RCBS Primer Pocket Swaging Combo as a primer pocket gage. If the primer pocket isn't crimped, the bit will fit all the way in: http://i749.photobucket.com/albums/xx135/AssaultRifler/reload/Part3/TutorialPart3_08.jpg If the primer pocket is crimped, the bit won't fit all the way in: http://i749.photobucket.com/albums/xx135/AssaultRifler/reload/Part3/TutorialPart3_09.jpg that's a good point there, but brings to light another question. Seeing i have that same tool, when i do the crimp, should i be setting it to push them all the way down to that same point that your pictures show? Basicly to the end of the taper. |
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Quoted: Quoted: that's a good point there, but brings to light another question. Seeing i have that same tool, when i do the crimp, should i be setting it to push them all the way down to that same point that your pictures show? Basicly to the end of the taper. Instructions are here, I won't second guess RCBS http://www.rcbs.com/downloads/instructions/PrimingToolsAndAccessories.pdf I actually don't use this tool anymore since I have the Dillon swager, but I do use the swager bits as primer pocket gages |
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Quoted:
For measuring IDs, the ID feature on calipers can give deceptive results. IF there is any flat at all on the blades, the small dia. curvature of the hole will touch the edges of the blades only. I have a surplus set of precision ground pins found on e-bay for checking small hole dia.'s like primer pockets. http://i255.photobucket.com/albums/hh133/counterclockwisester/measurement_over_pins.jpg Nice. Very nice. |
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Quoted:
Quoted:
For measuring IDs, the ID feature on calipers can give deceptive results. IF there is any flat at all on the blades, the small dia. curvature of the hole will touch the edges of the blades only. I have a surplus set of precision ground pins found on e-bay for checking small hole dia.'s like primer pockets. http://i255.photobucket.com/albums/hh133/counterclockwisester/measurement_over_pins.jpg that is pretty cool.. how much $ did that run you if you dint mind me asking? I cannot remember. I got the idea from one of the gun-writers magazine articles who ordered a similar set to measure revolver cylinder bores. Ebay has (had) some good tooling deals from time to time. |
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Quoted:
Quoted:
Quoted:
For measuring IDs, the ID feature on calipers can give deceptive results. IF there is any flat at all on the blades, the small dia. curvature of the hole will touch the edges of the blades only. I have a surplus set of precision ground pins found on e-bay for checking small hole dia.'s like primer pockets. http://i255.photobucket.com/albums/hh133/counterclockwisester/measurement_over_pins.jpg that is pretty cool.. how much $ did that run you if you dint mind me asking? I cannot remember. I got the idea from one of the gun-writers magazine articles who ordered a similar set to measure revolver cylinder bores. Ebay has (had) some good tooling deals from time to time. Probably Hamilton Bowen. |
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