I know i ask a lot of questions but what can i say, This stuff intrests me very much. Anyway i acquired a Sinclair priming tool and i want to make sure it is seating my primers correctly. I uniform my pockets on my ppc and BR cases with a tool i bought from Sinclair. From my measurements i am crushing my primers right at .0055 when i seat them with the tool i have. I came to this measurement by first measuring the primers before seating them on my Micrometer. Surprisingly they were all pretty uniform. I then set them with the tool and immediately decapped them catching the spent primer and measuring it again with the same micrometer. The primers were all .0055 shorter than factory thickness. I havent given any of this much thought until i read an article in one of the big bench-rest publications i have. ( i dont remember the name as i have several) I read this article some time ago and i dont remember what i read really. I am not concerned that i am doing this wrong, as the results are very satisfactory, but the curious side of me has me wondering if i do in fact have my tool set correctly. I asked this question on 6mm BR but i trust you folks here more-so so i thought i would see what you fellas have to say. I'm pretty sure i can adjust the tool, if needed. Again this kinds of things fill my mind with wonder, so i thought we could discuss what some of your fellas general priming techniques are a bit. Thanks Lee
Primer crush or jam??
- Thread starter skeetlee
- Start date
Boyd Allen
Active member
I have my Sinclair priming too set so that the handle does not bottom on the tool body when seating a primer. I seat by feel. If your results are fairly uniform, and it goes bang every time, you are probably OK. I like mine bottomed and slightly compressed.
jackie schmidt
New member
Skeet
I agree with Boyd, most shooters seat their primers with a feel for when the primers just seat at the bottom of the primer pocket. That means that the tool is adjusted so that it does not break over center as you seat the primer.
I seat the primer, then spin the case about 180 degrees and gently touch it again, just to insure it is square. I do this more out of habit than anything else.......jackie
I agree with Boyd, most shooters seat their primers with a feel for when the primers just seat at the bottom of the primer pocket. That means that the tool is adjusted so that it does not break over center as you seat the primer.
I seat the primer, then spin the case about 180 degrees and gently touch it again, just to insure it is square. I do this more out of habit than anything else.......jackie
Just read your post and thought I would let you know what I do.
I experimented quit a bit with this issue and feel I have it figured out to my satisfaction.
I am relatively new to the game and am very analytical & experimental as it sounds you are.
After much research and discussions, with some very good shooters, decided the best way to seat the primers was to compress the anvil about ½ into the primer cap.
I did this by using FEDERAL 205M Primers and:
1.) Measure from the top of the primer cap to the bottom of the anvil (.120±)
2.) Measure from the top of the primer cap to the bottom of the primer cap (.113±).
There is a .007± of exposed anvil below the cap.
3.) Now measure the depth of the cut primer pocket (I cut mine with a Sinclair PPC Primer Pocket
Cutter) yielding (.123±)
4.) When seating the primer and the TOP of the primer cap is .003± below the head
of the case, the anvil is just touching the bottom of the primer pocket.
5.) Because we want to compress the anvil ½ into the primer cap we need to seat it
.0035± deeper into the primer pocket.
6.) This would mean to compress ½ of the anvil into the primer cap, the primer would
have to be .0065-007± below the case head.
7.) If you are using the Sinclair Priming Tool you can use the shims provided to adjust the
throw of the seating stem to give you precisely what you need. This way, the primer
will be seated properly when the handle of the tool touch the body.
8.) Rotate the case 180° and operate the handle one more time as Jackie recommended
for square seating.
It may be my wishful thinking, but I felt I was shooting better using this method. I was in doubt until I took some chronograph readings and found this method of seating primers yielded must more consistent results, i.e.: SD & very low variances in velocities.
I couldn't figure out how to attach the crude drawing I made for you. If you want it or have any other questions please feel free to contact me @ (570) 443-9694
Shinny
I experimented quit a bit with this issue and feel I have it figured out to my satisfaction.
I am relatively new to the game and am very analytical & experimental as it sounds you are.
After much research and discussions, with some very good shooters, decided the best way to seat the primers was to compress the anvil about ½ into the primer cap.
I did this by using FEDERAL 205M Primers and:
1.) Measure from the top of the primer cap to the bottom of the anvil (.120±)
2.) Measure from the top of the primer cap to the bottom of the primer cap (.113±).
There is a .007± of exposed anvil below the cap.
3.) Now measure the depth of the cut primer pocket (I cut mine with a Sinclair PPC Primer Pocket
Cutter) yielding (.123±)
4.) When seating the primer and the TOP of the primer cap is .003± below the head
of the case, the anvil is just touching the bottom of the primer pocket.
5.) Because we want to compress the anvil ½ into the primer cap we need to seat it
.0035± deeper into the primer pocket.
6.) This would mean to compress ½ of the anvil into the primer cap, the primer would
have to be .0065-007± below the case head.
7.) If you are using the Sinclair Priming Tool you can use the shims provided to adjust the
throw of the seating stem to give you precisely what you need. This way, the primer
will be seated properly when the handle of the tool touch the body.
8.) Rotate the case 180° and operate the handle one more time as Jackie recommended
for square seating.
It may be my wishful thinking, but I felt I was shooting better using this method. I was in doubt until I took some chronograph readings and found this method of seating primers yielded must more consistent results, i.e.: SD & very low variances in velocities.
I couldn't figure out how to attach the crude drawing I made for you. If you want it or have any other questions please feel free to contact me @ (570) 443-9694
Shinny
Something to consider
Shinny,
In my experience, crush seating primers can lead to duds and hangfires in rainy, 99% humidity, saturated environment conditions.You can test this by reloading in your shower for a 16 hour period,or you can wait for "mother nature" to make a believer out of you ,or you can just take my word for it. "Ha !, death to the infidel".
On the subject of squarely seated primers; Does it really matter, if the firing pin hits the thing in the middle ?
Joel
Shinny,
In my experience, crush seating primers can lead to duds and hangfires in rainy, 99% humidity, saturated environment conditions.You can test this by reloading in your shower for a 16 hour period,or you can wait for "mother nature" to make a believer out of you ,or you can just take my word for it. "Ha !, death to the infidel".
On the subject of squarely seated primers; Does it really matter, if the firing pin hits the thing in the middle ?
Joel
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Q
Quoddy
Guest
I'm a reloading newbie, but I set up my K & M tool by standing the primed shell on my very flat surfaced loading bench. When it didn't rock at all, I added about a 1/8 turn adjustment. When measure with my caliper, my primers are set between .0005 and .001 inches from flush. Works for me. BTW... I'm using Norma brass and BR4 primers.
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