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Seating primers

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Dec 13, 2007
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When I seat primers with my rcbs hand primer seater, I just squeeze the handle all the way down every time. I have read that people like to get a good "feel" when they prime cases and also they take extra care to make sure every primer is seated the same. So is there a different way I should be seating them? Should I not squeeze the handle all the way down? Thanks for all the help.
 
When I seat primers with my rcbs hand primer seater, I just squeeze the handle all the way down every time. I have read that people like to get a good "feel" when they prime cases and also they take extra care to make sure every primer is seated the same. So is there a different way I should be seating them? Should I not squeeze the handle all the way down? Thanks for all the help.

I think they may be referring to RCBS press when they try and get a good feel while seating primers . I may be wrong .

Good question , I use RCBS hand priming tool and do it the same way you do . I love it I can prime 50 casings in a snap . I still feel the primer and how deep it is , (old habbit I guess)
 
Arrow,

No, the notion of "feel" applies to the hand priming tools and press mounted units as well. What we're normally talking about here is the ability to actually feel the anvil bottom out within the pocket, and the slight amount of pre-load applied to sensitize the compound. Hand tools don't have as much leverage as a press, and makes it that much easier to get that sense of "feel" to know when all is going properly. The mechanical advantage of the press, so needed to overcome the forces required for case sizing, work against it being a good priming tool. The terrific camming power available in these tools simply overwhelms the small force needed to seat a primer, making it almost impossible to tell when the anvil bottoms out, how much load you're putting on it, etc.. Kind of like trying to drive in a thumbtack with a sledge hammer, more is not always better.

Sounds like you're doing fine here, just take the time to get familiar with the force it takes to seat the primer, what it feels like, and how it "stops" at the end of the stroke. You'll do fine.
 
I use the RCBS bench mounted manual hand primer. I can easily feel the primer when it bottoms out but it just like the one hand operated can be "adjusted" to push the primer "X" deep by adding a shim or removing a teenie tiny bit of material from the cam surface.
 
Crush can't be set consistently by feel either.
It can only be done by actually measuring while seating, as done with a K&M.
 
Arrow,

No, the notion of "feel" applies to the hand priming tools and press mounted units as well. What we're normally talking about here is the ability to actually feel the anvil bottom out within the pocket, and the slight amount of pre-load applied to sensitize the compound. Hand tools don't have as much leverage as a press, and makes it that much easier to get that sense of "feel" to know when all is going properly. The mechanical advantage of the press, so needed to overcome the forces required for case sizing, work against it being a good priming tool. The terrific camming power available in these tools simply overwhelms the small force needed to seat a primer, making it almost impossible to tell when the anvil bottoms out, how much load you're putting on it, etc.. Kind of like trying to drive in a thumbtack with a sledge hammer, more is not always better.

Sounds like you're doing fine here, just take the time to get familiar with the force it takes to seat the primer, what it feels like, and how it "stops" at the end of the stroke. You'll do fine.

Kevin,

I use the hand tool to seat my primers and I bottom out the handle on every primer that I seat. Do you use this tool ? If so how do you know you are squeezing it the same amount each time ? Is there an adjustment with this RCBS hand tool ? I can feel it bottom out. Right now I am getting consistent 3 shot groups at 1000 yrds that measure 8 3/4 inches If i wasnt doing it right I feel that I wouldnt get these results. If you know a better way for me to tighten my groups up I am all ears :)
 
I had use one of the first Hornady Handprimes some time ago and thought it would be better to buy the RCBS Universal Hand Prime. Had done about 100 cases and about 10 had a click before seating - indicating misallignment with the case. This could cause the anvil to slip out of the primer hood and influencing the bang. Maybe the unit was still too new, but I have decided to change over to the RCBS Hand Prime that still uses the shell holders. The allignment on this unit was 100/100. The problem with this latest unit is that there is no retaining washer on the priming stem letting the stem to fall out when you turn the unit upside down. One could say that that is not the way to use it, but it is a way to loose the priming stem. Design fault. Only problem with both RCBS units is that it requires a realy hard squeeze, making it not so possible to feel the primer seating.

I am currently back on the Hornady Hand Prime. The squeeze is easy compared to the RCBS units giving a true feeling of the seating process. Alignment 100/100.
 
Right now I am getting consistent 3 shot groups at 1000 yrds that measure 8 3/4 inches If i wasnt doing it right I feel that I wouldnt get these results. If you know a better way for me to tighten my groups up I am all ears :)
This is a shocking response to the rational information Kevin put out(for our benefit).
bigbuck are you so proud of your +3/4moa as to suggest it can't be improved on?
Just what specifically does your implication here mean to anyone, about anything?
What do you actually know about primer seating, other than "I bottom out the handle on every primer that I seat"?
 
BigBuck,

To answer your question, no, I don't use the RCBS tool. I've used the Sinclair for some time now, and before that used one of the Lee hand primers. I haven't used the K&M but it lloks to be a very well designed and built tool. Not really the issue, as the method isn't nearly as important as some of the other considerations that go into this. Trying various brands and types of primers can make a huge difference in LR ammo, and is something that needs to be determined on target. Sorting primers by lot takes up a considerable amount of time for most serious Long Range shooters, as different lots can perform very differently. Makes a difference, and enough that the time is well spent to find a consistent lot. I don't shoot BR, but I do shoot LR prone, and this is something that's critical to us in that venue. I would think it'd be even more so for a BR shooter, given the more solid shooting platform.

Either way, getting primers seated properly isn't a major trick, and so long as it's done correctly, the other factors (such as those I mentioned) will make a much greater difference in the overall load and the accuracy on target.
 
BigBuck,

To answer your question, no, I don't use the RCBS tool. I've used the Sinclair for some time now, and before that used one of the Lee hand primers. I haven't used the K&M but it lloks to be a very well designed and built tool. Not really the issue, as the method isn't nearly as important as some of the other considerations that go into this. Trying various brands and types of primers can make a huge difference in LR ammo, and is something that needs to be determined on target. Sorting primers by lot takes up a considerable amount of time for most serious Long Range shooters, as different lots can perform very differently. Makes a difference, and enough that the time is well spent to find a consistent lot. I don't shoot BR, but I do shoot LR prone, and this is something that's critical to us in that venue. I would think it'd be even more so for a BR shooter, given the more solid shooting platform.

Either way, getting primers seated properly isn't a major trick, and so long as it's done correctly, the other factors (such as those I mentioned) will make a much greater difference in the overall load and the accuracy on target.

I actually owned a Sinclair for awhile, but it didn't like my old hands very well. I sold it to a buddy and bought the standard K&M. The Sinclair has the best feel of any I've used, but the K&M is right there on it's door step. I have an RCBS and a Lee as well laying around gathering dust. I can feel the primer bottoming out just fine with the K&M, can't get there with the Lee or RCBS. Now K&M sells one with a dial indicator that actually measure the primer hight, and allows to to seat it off that measurment. I may opt to go this way in the future.
gary
 
The function of the indicated K&M is to set every primer at a desired crush, and there is nothing else that does this.
It is first zero'd simultaneously to THE primer and THE pocket it's going into. These are variances with all primers, rims, and uncut pockets.
Then you seat with that primer & case normally, except to indicated crush(rec. 2thou).
Repeat for each primer/case.

This is a good path to consistent primer ignition.
But another big part is consistent & correct STRIKING itself.
So it's very important to ensure pockets cut to a standard depth, so that primers at a given crush have a chance of being struck the same.

With this and for this, you move onto measuring and testing/setting action timing, or you can trial & error with various brand/type primers until grouping improves.
Over the decades many BR competitors have discovered that there is more to primer ignition than merely setting them off (anyone can do that).
 
Well, I have an RCBS and I've seated thousands of primers with no issue whatsoever. Feel is a tenuious thing that varies from end user to end user. I know when my primer is seated but then you may not because you 'feel' differently than I do.

I always 'feel' the top of the cup in relationship to the case head with my finger as a matter of safety. Don't want any high primers.

I like to sit in my lazyperson chair and prime while the missus watches Storage Wars or some mundane program.....

I think you guys are reading a bit more into the procedure than whats necessary IMO. IOW, don't complicate something thats not complex.
 
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