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Primer Seating tools

  • Thread starter Thread starter jp
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jp

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What adjustable primer seating tool is the most precise for seating primers?

I want to experiment with primer seating depth

Thx
 
This is the most precise.


What you want to experiment with is variations in primer crush. This is the only tool I know of that shows you the exact crush of each primer and pocket.

Primer cup heights vary. I routinely see .004" variance in cup height. So seating primers to a certain depth is pointless unless you have measured all your primer cup heights and then sorted them accordingly. That also assumes uniformed pockets.

Knowing this, why do so many BR competitors use the 21st Century or Sinclair Primer seaters? Because there is very little to be gained by tuning with primer crush.

Using a good quality primer tool, seating until you feel the primer bottom out then giving just a tad more gives you 90% of what you need. The 21st Century and Sinclair give you that. Even a CPS, IF you buy the longer handle, has good enough feel to seat with a little crush.

The K&M Primer Gauge allows you to see exactly how much crush you are imparting with a dial indicator.

When I tested the K&M Primer Gauge vs seating primers to a certain depth, I improved ES by 5 FPS in a well tuned LRBR rifle chambered in 6 BRA. That was it--5 FPS in a case that uses 30ish grains of powder, in a full-on BR rifle.

That was meaningful in that rifle, because having a 5 FPS wider velocity node can help keep the gun in tune better during a match.

However, I can think of no other application outside of BR--Long Range or Short Range, where a 5 FPS wider node is useful. Even then, the conditions have to be very good for it to show up on paper.
 
I use 21st century PP uniformer, 21st century priming tool and purchased the CPS recently.
I don't have any score or grouping data to justify my tools. FWIW, I was using Hornady PP uniformer with good results.

With good tools I know I can trust them and I can have some tool bragging rights. :cool:
 
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Buy the RCBS RAM Prime. It has an infinitely adjustable die plus you can also use competition shell holders. Its $33 and easier on your hands than any of the hand priming tools. Just be sure your primer pockets are consistent to start with.
 
Knowing this, why do so many BR competitors use the 21st Century or Sinclair Primer seaters? Because there is very little to be gained by tuning with primer crush.

Even then, the conditions have to be very good for it to show up on paper.

I use my old Sinclair but I tell every primer they're being seated by a CPS. We both feel much better that way....:cool:
 
You don't need to crush anything. Get a Sinclair or 21st Century tool and seat the primer to bottom out. You'll feel it. You needn't uniform the primer pocket; this is largely busy work, but it hurts nothing. Do it if it makes you feel better.
 
Buy the RCBS RAM Prime. It has an infinitely adjustable die plus you can also use competition shell holders. Its $33 and easier on your hands than any of the hand priming tools. Just be sure your primer pockets are consistent to start with.
Yup.. and you can use shims under the die as well to go deeper/shallower. Cheapest option out there (well, the Lee ram prime is a little cheaper) and you can control depth to .001".
 
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You don't need to crush anything. Get a Sinclair or 21st Century tool and seat the primer to bottom out. You'll feel it. You needn't uniform the primer pocket; this is largely busy work, but it hurts nothing. Do it if it makes you feel better.

You should crush it and informed the pockets. And it does indeed make difference in high precision rifles.
 
Many guys say to seat the primers until you feel the primer hit the bottom of the case. Until what hits the bottom of the primer pocket, the primer wall, or the anvil?
 
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You should crush it and informed the pockets. And it does indeed make difference in high precision rifles.
There are always exceptions. Can you go into a little more detail? "High precision" is a bit vague, Are you making reference to any very accurate rifle, a benchrest gun, or something else?
 
Can l brag about my LEE AUTO-PRIME?? Purchased in the late 1900s and still going strong
I love mine. I think they offer good feel, but mine have consistently broken at around the 12-month mark. I keep two so I can cycle the broken one back to Lee for replacement.
 
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