best priming tool

[JMayo]

Don't know HOW MANY primers I''ve seated with my Lee Auto Prime, large and small. All I know is if you have one, hoard it and keep extra parts on hand. My guess is? Probably seated 10,000 + with no issues. Sure wish Lee made a replacement that is as good as the old standby.

I wore my lee out 5 yrs of 2k a month.....
This rcbs is easier on my hands but a bitch if not held a correct angle.

 

[mikecr]

Please elaborate
I have been doing it sucessfully over 40 years.

Pretty sure you haven't.
This is the first thing you learn with use of an indicated K&M.
You can't feel the crush point (a tiny resistance) amidst other seating friction/forces. Then you can't see 2-4thou crush without an indication of it.

This is dynamic (springy) like shoulder bumping, and has to be measured to know it's actually right.

 

[deanq]

You can't feel the crush point (a tiny resistance) amidst other seating friction/forces. Then you can't see 2-4thou crush without an indication of it.

For those of us that aren't professional primer seaters, What are the indications of 2-4 thou crush? Thanks

 

[JimSC]

primer depth seating from the AMU and how to measure

Primer Seating Depth — Why Uniformity is Important

 

[mikecr]

For those of us that aren't professional primer seaters, What are the indications of 2-4 thou crush? Thanks

The indication is as measured.
The indicated K&M operation begins with simultaneous zeroing of a primer about to be seated AND it's intended primer pocket. This, adjusting for variances in both primer heights and pocket depths. It's tarring the scale. Then when seating the primer, it's indicator displaying zero means the primer is at touching pocket bottom. This, regardless of force amount. Go further 2thou crush for Feds, 4thou for CCIs (my recommendation).

With this, each primer is preloaded/sensitized to a known good standard.
If you desire those primers to always be below the casehead (they should be), uniform the pockets beforehand, with a preset Sinclair uniforming reamer.
At these standards you can then test & adjust your firing pin striking (with given trigger sear position) for tightest grouping.

Simply setting primers below casehead means nothing about their relationship to pockets. And neither does smashing them with great excess force or travel. As far as these seaming good enough, I've tested and found that primer striking can be screwed up to the point of doubling group size, and every single one still fired. This was with a 223, and was of course not the achievement to settle on..

That many 6PPC shooters are so sure they can tell anything here without measure, (by feel) isn't based on their primer measure (because most don't do this), it's their group measure giving them confidence. Then again, they're running underbores at competitive pressures way beyond viable for hunting cartridges. They're so deep in diminished returns from powder load, that any firing of that powder is good enough to reach result. Primers will still fire, and pressure peak will still be way up at 70-85Kpsi for them. And a normal variance in that, their variance, is unlikely to show on paper -up close.

 

[Richard Coody]

The indication is as measured.
The indicated K&M operation begins with simultaneous zeroing of a primer about to be seated AND it's intended primer pocket. This, adjusting for variances in both primer heights and pocket depths. It's tarring the scale. Then when seating the primer, it's indicator displaying zero means the primer is at touching pocket bottom. This, regardless of force amount. Go further 2thou crush for Feds, 4thou for CCIs (my recommendation).

With this, each primer is preloaded/sensitized to a known good standard.
If you desire those primers to always be below the casehead (they should be), uniform the pockets beforehand, with a preset Sinclair uniforming reamer.
At these standards you can then test & adjust your firing pin striking (with given trigger sear position) for tightest grouping.

Simply setting primers below casehead means nothing about their relationship to pockets. And neither does smashing them with great excess force or travel. As far as these seaming good enough, I've tested and found that primer striking can be screwed up to the point of doubling group size, and every single one still fired. This was with a 223, and was of course not the achievement to settle on..

That many 6PPC shooters are so sure they can tell anything here without measure, (by feel) isn't based on their primer measure (because most don't do this), it's their group measure giving them confidence. Then again, they're running underbores at competitive pressures way beyond viable for hunting cartridges. They're so deep in diminished returns from powder load, that any firing of that powder is good enough to reach result. Primers will still fire, and pressure peak will still be way up at 70-85Kpsi for them. And a normal variance in that, their variance, is unlikely to show on paper -up close.

Opinions vary

 

[kcjim]

The 21st Century priming tool is great. I used the Sinclair tool for a couple of years loading for competitions and sold it after I tried the 21st Century tool. It is simple, precise, and fast. It’s a quality tool.

 

[BenPerfected]

The 21st Century priming tool is great. I used the Sinclair tool for a couple of years loading for competitions and sold it after I tried the 21st Century tool. It is simple, precise, and fast. It’s a quality tool.

As the primer setting tools are/can be precise, how often to you tune up the depth of primer pocket? When does the primer pocket depth variance show on paper?....at what distance?
Ben

 

[JimSC]

As the primer setting tools are/can be precise, how often to you tune up the depth of primer pocket? When does the primer pocket depth variance show on paper?....at what distance?
Ben

I am curious about that myself. Having just seated my primers precisely myself for the first time I am. Looking forward to my next trip to the range with chrono. I have been getting single digit SD's with my primers seated normally so I am not sure how having them all seated at .004 under flush is supposed to help anything. I got into the habit of uniforming primer pockets at brass purchase long ago. Any benchrest people care to chime in and educate me ?

 

[mikecr]

4thou 'under flush' means precisely nothing..
Running a pocket reamer in does not mean the pockets are the same depth, unless you took a full cut on every one. Even with this, a .004" relationship means nothing unless the primers were verified same height.
Then, you could measure & calculate meaning.
Or,, simply handle it with an indicated K&M seater.

Any change means revisiting load development. Shooting better or worse without this is just an abstract, holding no meaning at all.

 

[JimSC]

4thou 'under flush' means precisely nothing..
Running a pocket reamer in does not mean the pockets are the same depth, unless you took a full cut on every one. Even with this, a .004" relationship means nothing unless the primers were verified same height.
Then, you could measure & calculate meaning.
Or,, simply handle it with an indicated K&M seater.

Any change means revisiting load development. Shooting better or worse without this is just an abstract, holding no meaning at all.

ok so now I have to ask why would seating with a Sinclair instead of a RCBS with the Holland adapter do away with the need to measure individual primer thickness or individually measuring each primer cup ? Does the Sinclair automatically compensate for primer pocket depth and inconsistencies in the primer thickness somehow?

On the ones i just loaded. The primer pockets on the Alpha brass were all uniformed and were a consistent .130 in depth. The Winchester LRP's measured .127 to .128 which is how I came up with the .004 recess number. Ammo loaded the prior week without the Holland adapter had the primer anywhere between .005 and .006 with 2 of 20 measured at .010 below flush. Other rounds loaded with this same method and charge had chronoed with a SD of 4 and ES of 7 for 5 shots but when stretched out to 15 shots I had a couple of outliers that pushed the ES up to 23. I am hoping to eliminate those outliers. Measurements were taken with a Starrett 25-141 with the conical tip off so I would get consistent readings on the primers.

 

[bigstick6017555]

4thou 'under flush' means precisely nothing..
Running a pocket reamer in does not mean the pockets are the same depth, unless you took a full cut on every one. Even with this, a .004" relationship means nothing unless the primers were verified same height.
Then, you could measure & calculate meaning.
Or,, simply handle it with an indicated K&M seater.

Any change means revisiting load development. Shooting better or worse without this is just an abstract, holding no meaning at all.

Is it to say then that now i would have to measure every primer cup for consistency of size if we are talking thousandths of seating depth.

 

[HTSmith]

Is it to say then that now i would have to measure every primer cup for consistency of size if we are talking thousandths of seating depth.

Kinda sounds that way to me. I'm thinking we are deep down that rabbit hole.

 

[JimSC]

Is it to say then that now i would have to measure every primer cup for consistency of size if we are talking thousandths of seating depth.

Makes you wonder how you can even get the holes on the paper doesn't it? The consistently seated primer theory does make sense in the terms of lock time and ignition time but I still fail to see how loading the primers one at a time has to do with that unless you are measuring each individual primer and cup as you seat them. That is still a bridge a bit too far in my opinion. We are discussing a time of appx 20 milli seconds here according to this book

https://www.amazon.com/dp/1500891010/?tag=accuratescom-20

 

[Murray Brook]

Although I've been hand loading for over 35 yrs it is just recently that I've gotten into the finer points of primer seating. I purchased some 6br Laupa cases and found the seated primer depth to be somewhat deep. This led me into primer measurement as well as primer pocket depth. The primer pockets on the Laupa brass were between .123 and .126. The primer measured between .118-.119 for the Fed 205m and CCI 400 and .116-.117 for the Rem primers. With this difference in the pockets and primers I most certainly agree with @mikecr that the .004 measurement below flush is useless. Some of my primers to be seated correctly in my Laupa cases would require a measurement of .010 or more, allowing for crush to be properly seated. I'm not sure what the answer is for priming unless all individual pockets and primers are measured then seated..

 

[JimSC]

Although I've been hand loading for over 35 yrs it is just recently that I've gotten into the finer points of primer seating. I purchased some 6br Laupa cases and found the seated primer depth to be somewhat deep. This led me into primer measurement as well as primer pocket depth. The primer pockets on the Laupa brass were between .123 and .126. The primer measured between .118-.119 for the Fed 205m and CCI 400 and .116-.117 for the Rem primers. With this difference in the pockets and primers I most certainly agree with @mikecr that the .004 measurement below flush is useless. Some of my primers to be seated correctly in my Laupa cases would require a measurement of .010 or more, allowing for crush to be properly seated. I'm not sure what the answer is for priming unless all individual pockets and primers are measured then seated..

in post 51 I gave the measurements that I took on pockets on th eAlpha brass and Win LRP's but I will quote them below and ask you what depth would you set the seating depth at to get .001 to .002 preload ?

oh and a late edit, the measurements I just took for Rem 9 1/2's and Lapua brass were slightly different than the Alpha brass and Win primers so anytime you change brass or primers you need to keep it in mind they may be slightly different. Also noted the Lapua brass was .001 deeper than the uniformed Alpha brass so the uniformer would not hit bottom. All fifteen I measured were a consistent .131 however

On the ones i just loaded. The primer pockets on the Alpha brass were all uniformed and were a consistent .130 in depth. The Winchester LRP's measured .127 to .128 which is how I came up with the .004 recess number.

 

[mikecr]

ok so now I have to ask why would seating with a Sinclair instead of a RCBS with the Holland adapter do away with the need to measure individual primer thickness or individually measuring each primer cup ? Does the Sinclair automatically compensate for primer pocket depth and inconsistencies in the primer thickness somehow?

No, the Sinclair does not compensate for or do away with any of this.
I never mentioned the Sinclair, but did mention the K&M a bunch of times in this.

 

[JimSC]

No, the Sinclair does not compensate for or do away with any of this.
I never mentioned the Sinclair, but did mention the K&M a bunch of times in this.

So how does the K& M K&M automatically compensate for varied primer thickness and pocket depths ? I am finding this primer depth thing interesting. Measuring all my primer brands and seeing if there are lot differences and keeping a small spreadsheet for when primer testing a load. That's about as far into the weeds as I will get, I figure if I load them to AMU specs then all should be good

 

[Richard Coody]

Well i am pretty satisfied with my primer seating method

 

[BenPerfected]

Good internet chat....and another thing for me to stop worrying about nothing. I’m going to have start worrying about something else.
Ben