CPS just beat the Sinclair primer seater?

[Bronsin]

I’d like to view the instagram attachment with out the instagram. The PMA case checker or a Larry Willis headspace comparator is on my bucket list

Rimlock for CPS

 

[orkan]

If you’re going for the ultimate solution, I would expect it to index off the shoulder and not the rim or base of the case at all. The shoulder defines the position of the case in the chamber and the distance to the firing pin tip.

I did a prototype about 3 years ago that indexed off the shoulder. It was stupid of me, because when you seat primers with a lot of interference, it sets the shoulder back. Not to mention, there are at least 4-5 different shoulder angles to account for on each case diameter... which would require a shooter to buy a dozen or more "inserts" as each case would require a different setup. Then there's the compound stacking tolerance as we move up the case. Then there's the infinite variability in reamer designs, and how those reamers actually physically end up being cut. Just because the print says its a 40° shoulder, doesn't mean its the "same" 40° shoulder exactly along its length, or that the radius in the neck/shoulder junction is the same, or that any tool made for interfacing with it will be the same.

There is always movement when we're dealing with the brass, and specifically shoulders and necks. Anyone that has ever run the sizing die to chamber spec issue to ground knows this. When you have the right equipment, measuring variance in case dimensions between fired and resized cases reveals massive irregularities in the reamer/die industry's capability of solving this problem to absolute satisfaction.

Then there's the fact that primer seating force changes firing to firing, which will put a varying force on the shoulder/body and the neck/shoulder and shoulder/body junctions... presenting an ever moving target, making it impossible to calibrate your body to the right cadence of movement to deliver the best results. I've done prototypes with robotics, but due to the explosive nature of primers, it is just not viable for the home handloader.

Go and look at how many short action custom funnel/headspace comparator inserts there are to accommodate everything. ... and none of those are actually getting pressure applied to them.

I have the equipment here to measure the slightest variance in brass movement. With it I can detect an angle change or movement in a radius down to about 5 microns with absolute reliability.

Bottom line; the rim/base is the only part of the case designed to have these forces applied. Even those can have easily measured rim deflection when primers are seated on traditional shell holders. There is simply too much force being applied for the hardest, thickest part of the case to handle. The thinnest parts of the case certainly can not handle it. Other designs which do not address the deficiencies of the shell holder itself, will never solve the problem completely.

I did another prototype that involved a pin through the top of the case that indexed off the inside above the flash hole. Another stupid idea fraught with expected and unexpected problems with brass movement and accuracy issues.

The Rimlock has improved my numbers significantly enough to make the slower speed of use worthwhile when I'm really going for absolutes. Removing uncertainty from my testing when shooting is important to me. So if I can prime 100 cases and have more of them be closer to perfect than fewer, I like that, especially when testing. It certainly keeps the rim of my cases in better shape across many firings than a traditional shell holder. Headspace variance due to rim deflection is VERY real... and so are the other problems it creates. I still use a regular shell holder for prairie dog ammo.

Then again, maybe I've got it all wrong. I guess I wouldn't know it if I was. I've had a lot of stupid ideas. I abandon stupid ideas, even if I think people would buy them. If you'd like a priming tool that indexes off the shoulder, maybe you're right... Maybe others want one too. You should build one and try to sell it. I wish you success.

Thanks to the customer who called and referenced this thread and called to ask me the question. I will not be discussing it here further.

Happy new year.

 

[Evan]

I did a prototype about 3 years ago that indexed off the shoulder. It was stupid of me, because when you seat primers with a lot of interference, it sets the shoulder back. Not to mention, there are at least 4-5 different shoulder angles to account for on each case diameter... which would require a shooter to buy a dozen or more "inserts" as each case would require a different setup. Then there's the compound stacking tolerance as we move up the case. Then there's the infinite variability in reamer designs, and how those reamers actually physically end up being cut. Just because the print says its a 40° shoulder, doesn't mean its the "same" 40° shoulder exactly along its length, or that the radius in the neck/shoulder junction is the same, or that any tool made for interfacing with it will be the same.

There is always movement when we're dealing with the brass, and specifically shoulders and necks. Anyone that has ever run the sizing die to chamber spec issue to ground knows this. When you have the right equipment, measuring variance in case dimensions between fired and resized cases reveals massive irregularities in the reamer/die industry's capability of solving this problem to absolute satisfaction.

Then there's the fact that primer seating force changes firing to firing, which will put a varying force on the shoulder/body and the neck/shoulder and shoulder/body junctions... presenting an ever moving target, making it impossible to calibrate your body to the right cadence of movement to deliver the best results. I've done prototypes with robotics, but due to the explosive nature of primers, it is just not viable for the home handloader.

Go and look at how many short action custom funnel/headspace comparator inserts there are to accommodate everything. ... and none of those are actually getting pressure applied to them.

I have the equipment here to measure the slightest variance in brass movement. With it I can detect an angle change or movement in a radius down to about 5 microns with absolute reliability.

Bottom line; the rim/base is the only part of the case designed to have these forces applied. Even those can have easily measured rim deflection when primers are seated on traditional shell holders. There is simply too much force being applied for the hardest, thickest part of the case to handle. The thinnest parts of the case certainly can not handle it. Other designs which do not address the deficiencies of the shell holder itself, will never solve the problem completely.

I did another prototype that involved a pin through the top of the case that indexed off the inside above the flash hole. Another stupid idea fraught with expected and unexpected problems with brass movement and accuracy issues.

The Rimlock has improved my numbers significantly enough to make the slower speed of use worthwhile when I'm really going for absolutes. Removing uncertainty from my testing when shooting is important to me. So if I can prime 100 cases and have more of them be closer to perfect than fewer, I like that, especially when testing. It certainly keeps the rim of my cases in better shape across many firings than a traditional shell holder. Headspace variance due to rim deflection is VERY real... and so are the other problems it creates. I still use a regular shell holder for prairie dog ammo.

Then again, maybe I've got it all wrong. I guess I wouldn't know it if I was. I've had a lot of stupid ideas. I abandon stupid ideas, even if I think people would buy them. If you'd like a priming tool that indexes off the shoulder, maybe you're right... Maybe others want one too. You should build one and try to sell it. I wish you success.

Thanks to the customer who called and referenced this thread and called to ask me the question. I will not be discussing it here further.

Happy new year.

I know a lot of people have picked fights with you in the past and I’m not trying to disparage your product; the one I had the opportunity to handle was a very finely made machine and CNC machining in the US isn’t cheap. I appreciate you sharing some of your prototyping experience. Bumping the shoulder accidentally was a concern I had with my concept too, particularly for some of the new ultra-tight pockets I have encountered with some brands of brass. There are no easy ways forward.

 

[6BRA]

I did a prototype about 3 years ago that indexed off the shoulder. It was stupid of me, because when you seat primers with a lot of interference, it sets the shoulder back. Not to mention, there are at least 4-5 different shoulder angles to account for on each case diameter... which would require a shooter to buy a dozen or more "inserts" as each case would require a different setup. Then there's the compound stacking tolerance as we move up the case. Then there's the infinite variability in reamer designs, and how those reamers actually physically end up being cut. Just because the print says its a 40° shoulder, doesn't mean its the "same" 40° shoulder exactly along its length, or that the radius in the neck/shoulder junction is the same, or that any tool made for interfacing with it will be the same.

There is always movement when we're dealing with the brass, and specifically shoulders and necks. Anyone that has ever run the sizing die to chamber spec issue to ground knows this. When you have the right equipment, measuring variance in case dimensions between fired and resized cases reveals massive irregularities in the reamer/die industry's capability of solving this problem to absolute satisfaction.

Then there's the fact that primer seating force changes firing to firing, which will put a varying force on the shoulder/body and the neck/shoulder and shoulder/body junctions... presenting an ever moving target, making it impossible to calibrate your body to the right cadence of movement to deliver the best results. I've done prototypes with robotics, but due to the explosive nature of primers, it is just not viable for the home handloader.

Go and look at how many short action custom funnel/headspace comparator inserts there are to accommodate everything. ... and none of those are actually getting pressure applied to them.

I have the equipment here to measure the slightest variance in brass movement. With it I can detect an angle change or movement in a radius down to about 5 microns with absolute reliability.

Bottom line; the rim/base is the only part of the case designed to have these forces applied. Even those can have easily measured rim deflection when primers are seated on traditional shell holders. There is simply too much force being applied for the hardest, thickest part of the case to handle. The thinnest parts of the case certainly can not handle it. Other designs which do not address the deficiencies of the shell holder itself, will never solve the problem completely.

I did another prototype that involved a pin through the top of the case that indexed off the inside above the flash hole. Another stupid idea fraught with expected and unexpected problems with brass movement and accuracy issues.

The Rimlock has improved my numbers significantly enough to make the slower speed of use worthwhile when I'm really going for absolutes. Removing uncertainty from my testing when shooting is important to me. So if I can prime 100 cases and have more of them be closer to perfect than fewer, I like that, especially when testing. It certainly keeps the rim of my cases in better shape across many firings than a traditional shell holder. Headspace variance due to rim deflection is VERY real... and so are the other problems it creates. I still use a regular shell holder for prairie dog ammo.

Then again, maybe I've got it all wrong. I guess I wouldn't know it if I was. I've had a lot of stupid ideas. I abandon stupid ideas, even if I think people would buy them. If you'd like a priming tool that indexes off the shoulder, maybe you're right... Maybe others want one too. You should build one and try to sell it. I wish you success.

Thanks to the customer who called and referenced this thread and called to ask me the question. I will not be discussing it here further.

Happy new year.

Great explanations of why I spent the $210.00.
Thanks. Please post a video to YouTube! Thanks
Happy New Year!
Mike

 

[DngBat7]

I did a prototype about 3 years ago that indexed off the shoulder. It was stupid of me, because when you seat primers with a lot of interference, it sets the shoulder back. Not to mention, there are at least 4-5 different shoulder angles to account for on each case diameter... which would require a shooter to buy a dozen or more "inserts" as each case would require a different setup. Then there's the compound stacking tolerance as we move up the case. Then there's the infinite variability in reamer designs, and how those reamers actually physically end up being cut. Just because the print says its a 40° shoulder, doesn't mean its the "same" 40° shoulder exactly along its length, or that the radius in the neck/shoulder junction is the same, or that any tool made for interfacing with it will be the same.

There is always movement when we're dealing with the brass, and specifically shoulders and necks. Anyone that has ever run the sizing die to chamber spec issue to ground knows this. When you have the right equipment, measuring variance in case dimensions between fired and resized cases reveals massive irregularities in the reamer/die industry's capability of solving this problem to absolute satisfaction.

Then there's the fact that primer seating force changes firing to firing, which will put a varying force on the shoulder/body and the neck/shoulder and shoulder/body junctions... presenting an ever moving target, making it impossible to calibrate your body to the right cadence of movement to deliver the best results. I've done prototypes with robotics, but due to the explosive nature of primers, it is just not viable for the home handloader.

Go and look at how many short action custom funnel/headspace comparator inserts there are to accommodate everything. ... and none of those are actually getting pressure applied to them.

I have the equipment here to measure the slightest variance in brass movement. With it I can detect an angle change or movement in a radius down to about 5 microns with absolute reliability.

Bottom line; the rim/base is the only part of the case designed to have these forces applied. Even those can have easily measured rim deflection when primers are seated on traditional shell holders. There is simply too much force being applied for the hardest, thickest part of the case to handle. The thinnest parts of the case certainly can not handle it. Other designs which do not address the deficiencies of the shell holder itself, will never solve the problem completely.

I did another prototype that involved a pin through the top of the case that indexed off the inside above the flash hole. Another stupid idea fraught with expected and unexpected problems with brass movement and accuracy issues.

The Rimlock has improved my numbers significantly enough to make the slower speed of use worthwhile when I'm really going for absolutes. Removing uncertainty from my testing when shooting is important to me. So if I can prime 100 cases and have more of them be closer to perfect than fewer, I like that, especially when testing. It certainly keeps the rim of my cases in better shape across many firings than a traditional shell holder. Headspace variance due to rim deflection is VERY real... and so are the other problems it creates. I still use a regular shell holder for prairie dog ammo.

Then again, maybe I've got it all wrong. I guess I wouldn't know it if I was. I've had a lot of stupid ideas. I abandon stupid ideas, even if I think people would buy them. If you'd like a priming tool that indexes off the shoulder, maybe you're right... Maybe others want one too. You should build one and try to sell it. I wish you success.

Thanks to the customer who called and referenced this thread and called to ask me the question. I will not be discussing it here further.

Happy new year.

Please do a video somewhere posted on public domain, YouTube etc…. I do not have any social media.

 

[6BRA]

 

[PhilC]

Sinclair meets, more likely exceeds, all my needs.

 

[tharger]

Does any of this have anything to do with the target