Which Hand Priming Tool

[Joe Salt]

rkittine I have a 21st century, but if this is going to be your first priming tool start with the K&M. Your teacher at the PA 1000 yard club kicked all our butts at the World Open. I've been pondering trying the K&M but God only knows I have too many priming tools already.

Joe Salt

 

[Matt in Virginia]

Sinclair. Easily adjustable and quality is excellent.

fwiw,
I've been using a Sinclair Tool for about 15 years. I have zero experience with either the 21st Century or the K&M. I was looking very hard at the 21st Century a short while back just to give it a try. The .00125" click adjustability looked very interesting. It also looks a little more ergonomic. That said I have found the Sinclair tool to have superb feel when seating the primer and I really tried to avoid too much of a "crush" fit. Shows my ignorance as to what is ideal. I went for a firm seating in the primer pocket. I came very close to buying a second Sinclair tool when they were on sale last month and some of the new one piece shell holders. Just to have one small primer ram and the other large. Actually found the new one piece shell holders are made by another company for $15 a piece, intended for a different purpose, as opposed to Sinclair's $20 per price. I've also never really taken the time to shim the tool every time to perfectly time the opening of the shell holder to the ram. I just unscrew the case holder until the case goes in, turn it until solid contact, and seat the primer. I've never felt a press or reloading company hand tool with anywhere near the same amount of feel. That said I have never used the Lee the Sinclair was based on. That said I'm very much interested in both the K&M and the new 21st Century. We are really fortunate to live in a time where EXCELLENT PLUS Tooling is widely available at reasonable prices...

Regards, Matt.

 

[Matt in Virginia]

I don't know how familiar you are with the K&M operation. I'll try to dummy down a description(to the best of my IQ).
-Picture any standard primer seater operation
-Add a platform protrusion connected to the inner seater plunger, and an external/stationary dial indicator that measures off this platform.
-If you put a case in it's shell holder and fully raise the plunger, the case is lifted against it's rim as the plunger bottoms in the primer pocket.
-You could zero the dial indicator to that position of plunger(bottomed), but you really want the zero to include the specific primer height.
-So you place a primer between the fully raised plunger platform and the dial indicator spindle -and then you zero the indicator.
-Now your zero includes and removes rim variance(as mentioned earlier), pocket depth variance, and primer height variance, all at once.
-Then you seat THAT primer into THAT case with THAT pocket, to zero value, and continue to target crush value.
-Do this for each and every priming, so that preload is actually the same for every one, regardless of stacked variances.

It probably sounds complicated & slow, but you get good at it fast, and then it no more than triples priming time(which is little).
While nothing eye candy about the K&M priming tool itself, it's actually a really good & robust tool. It's old school, with some of that schooling behind it's design. I feel like K&M's innovations deserve our support -over copy companies, that no more than spice up & divvy into other people's markets.

Mike, This is why I am asking about these two tools only as they seem to be able to accurately control crush. CCI recommends 4 thou "Crush" on their 450 Small Rifle Primers as per the instructor at the Williamsport Bench Rest School. I am just trying to be a good pupil and do my homework!

Bob

rkittine I have a 21st century, but if this is going to be your first priming tool start with the K&M. Your teacher at the PA 1000 yard club kicked all our butts at the World Open. I've been pondering trying the K&M but God only knows I have too many priming tools already.

Joe Salt

Gentlemen,
Fascinating... Very much a learning opportunity for me. I follow on the crush value and on Bob's excellent explanation of how the K&M tool makes that doable for each and every case. This leads me to the following:

1. The Sinclair tool may be giving me excellent feel, however, I have no reference on "crush" or any clue with that tool to duplicate it...

2. Joe, you have the 21st century tool, however, you are not recommending that as a first hand priming tool. This is not mine, however, I am getting ready to load the CCI 450 in the 6.5x47L hence this seems very relevant. Coming from 15 years with the Sinclair is there ANY reason not to go with the K&M? How can .004" past contact be "dialed" into the 21st Century Tool? Very much interested in both of your takes...

Very much appreciate everyone's input here. Completely new area of specialization... Thank you ahead of time.

Regards, Matt.

 

[rkittine]

Thanks again guys. Since the only one I have is an old RCBS hand priming tool, I want something better. Joe, thanks for the explanation. I remember him going through all those steps. I think I will go ahead any purchase the K&M / Gauge unit.

Bob

 

[rkittine]

My primary rifle is also a 6.5x47L and although the new 21st Century uses clicks of 1.25 thous, the old ones were 2.5, so my uneducated thought was that the 21st Century would let me do 3 clicks, 3.75 for the 4 thou "Crush".

I now get how repeated able, albeit time consuming, the K&M is.

Next question, which Arbor Press?

Bob

 

[XBBR Shooter]

Some things to think about...

If you "uniform" the primer pockets, you are cutting the bottom of the primer pocket with a tool that indexes and uses as a reference, the cartridge face... that place where all the little writing is.

But ALL of the "precision" priming tools use the inside back wall of the extractor grove as the indexing reference.

Now, problem #1... there is no precision standard for this wall - the cartridge companies put the groove there so you can get the damn cases out of the gun after you have fired them.

SAAMI groove specifications for a standard (0.473) case head.

Note, the groove can vary from 0.039" to 0.049"... and it does, even in the box or bag of brass. This is NOT one of the manufacturer's important measurements... like head space, which is held to a much higher tollerence of XXX.XXX -0.007" (whoops).


So if you are buying a priming tool and want to have "precision", you are looking at tools in the $125 to $600 (YIKES) range... but none of them can actually hold those tolerances.
If you have a tool with a real cool micrometer on it, and a dial indicator on it... you still have a tool that uses it's basic reference index point, a groove that varies by 10 times the precision that is either advertised or implied.

Problem #2... you cannot pre-sensitize the primer. The priming pellet is primarily made of Sodium Azide, which detonates at 17,000 feet per second. If you do the math, that means from the time the first crystal cracks, until the whole primer is consumed, takes ~ 0.00000003.7 of a second (3.7/100,000,000 of a second). There is NOTHING you can do that will change this.

From the time that the first reloading tool company did some research and discovered that the more dials and micrometer thingies you put on a tool, the more you can charge for it, we now have "micrometer and dial" priming tools available to us.

But a very strong case can be made that manual priming (seat "n" crush) tools are more accurate then these magic wonders that eat our money faster than an Ex wife to be, on the way to the lawyer's office.

 

[R.Morehouse]

Nice Post......

 

[Joe Salt]

2. Joe, you have the 21st century tool, however, you are not recommending that as a first hand priming tool.

Matt sorry it sounded like I didn't like the 21st century priming tool, I love it! it seams to do everything I want. I guess if you really want to make yourself NUTS, measure the depth of the primer pocket, measure the primer, seat it, then measure how deep its in. after about 20 of them, you will be ready for the funny farm.
I just seat by feel, and occasionally check the depth with the back end of the caliper just to be sure I'm close. mine are at 6 thou. deep. But not all the time!

Joe Salt

 

[dickn52]

I seat to make the primer flush with the case mouth.

 

[dogdude]

21st century for me, bought 2, one for large, one for small primers.

 

[Brians356]

This is totally what we're not suppose to be doing in primer seating(mashing the hell out of em).
... you flat out cannot feel what measurements would show, and 'crush' does not mean smashed into pockets with all you got, nor deftly touching.. Crush is a seating preload, typically ~2-5thou past bottom touching. It is properly sensitizing primers for the striking.

I'm not going to disagree with your position on how to best seat a primer for accuracy. But I do need to clarify what I meant by feeling the "final crush":

With the old Lee Auto Prime, and uniformed pockets, I can easily feel the primer bottoming out in the pocket, and that initial seating takes relatively little force on the tool's lever. But, even with the tool's cam design, it takes some force to then add a tiny bit of crush, yet in that position on the tool's cam, a lot of movement of the lever results in very little additional seating (crush) of the primer cup. I'm never trying to "crush the hell out of it" or to bottom the cup against the anvil. But just getting a few thou of crush still takes some effort. It's my estimation that using the Lee tool as I described does pre-load the primer ~2-5 thou past bottom touching. I just have no way to measure that, so I will concede the method I describe is less repeatable and controlled than what certain more sophisticated seaters can undoubtedly produce.
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