hand priming tool ?

[old roper]

This is one of the priming tool I own

http://www.sinclairintl.com/.aspx/pi...r-Priming-Tool


I have the K&M and it's a good one but somewhat limited compared to the Sinclair. Sinclair locks the case head and they furnish shim to adjust seating depth based on rim thickness. The Lee and K&M and others don't lock the rim so you get different feel seating the primer as you use more pressure since primer has to hold rim against the shell holder then you seat the primer.

Does it really make a difference which tool is best not really. I use the Sinclair on all my tight neck rifles

[Unclenick]

Funny how impressions differ. I have the Sinclair and like the K&M better.

Since I load for gas guns I run into cases with extractor dinged rim irregularities, so a single shim can't be counted on to provide uniform primer bridge thickness with them. This is also true right after swaging military primer pockets, which raises the brass around the primer pocket perimeter as much as a couple of thousandths, making primer pocket floors a less regular depth from the highest part of the rim. That flattens back out on firing, so the shim has to thinner for the next round of loading them. The bridge setting based on the dial indicator is certainly slower to use than the shim, so if all you are concerned with is getting the primer a fixed distance below flush with the head, say for slamfire considerations, the Sinclair may well be more satisfactory. But the gauge, which adapts to each case so that variations in pocket depth are compensated for, the dial indicator provides greater certainty the bridges are set the same.

The Sinclair tool has to be tightened down on each case while the K&M's spring-loaded primer guide sleeve also satisfies Audette's concern on getting primer insertion as perpendicular as the rim allows to the case head. That makes it quicker to pop cases in and out of the K&M. In either tool, though, perpendicularity of the primer insertion is guaranteed only insofar as the flatness and perpendicularity of the head and rim from the primer pocket axis allow.

[old roper]

Nick, you might want to read this

http://riflemansjournal.blogspot.com...e-and-pre.html

[Unclenick]

Old Roper,

The article in that link you provided explains the general principles, but some of its details are incorrect. It says of the K&M tool, "of course, the system depends on all primer pockets being uniformed for depth." That statement leads me to believe the author doesn't understand what the tool is doing when used as directed. I'll describe it and put in a link to the instructions, so you can see for yourself.

The K&M tool with gauge, when used as directed, zeros to each individual primer pocket's depth by running the priming ram up into the primer pocket with no primer to locate where the bottom (floor) of the pocket is. You then place your primer anvil-down on a small pedestal and rotate the platform to put the primer under the gauge. This deflects the gauge pointer which is now indicating the height of the primer referenced to the location of the primer pocket floor. You then rotate the dial graduations so zero lines up with the pointer. At that point the zero line is where the gauge will read when you insert that particular primer far enough that its feet kiss the floor of that particular case's primer pocket, whatever that depth may be.

You next release the handle, remove the case from the shell holder and the primer from the platform. You flip the primer over and set it onto the primer ram inside the guide sleeve, reinsert the case over top of it and press the handle to seat the primer. You push it past that dialed-in zero by 0.002" for small primers and by 0.003" for large primers. That sets the thickness of the primer pellet bridging the distance between the bottom of the primer cup and the center of the anvil. In this way, to keep the the bridge compression consistent, the K&M gauge pairs the height of the individual primer with the depth of the individual case primer pocket. That is the one thing the Sinclair tool gives you no way to do other than by feel.

The way I often use the K&M is a little different. For long range match loads I uniform primer pockets, then sort primers by height with a gauge I made for the task. Then I can simply seat all primers the same height to the same gauge value without placing an empty case in and finding zero each time. That seems to work pretty well. Primeres are usually pretty consistent within a box, and the odd error is sorted out.

In the Precision Shooting Reloading Guide, Dick Wright says he contacted the Federal Cartridge Company about proper primer seating technique, and they replied that consistency was paramount and they suggested 0.002" past touchdown for small primers and 0.003" past touchdown for large primers, same as K&M's instructions recommend (and Federal is likely where they got them). So why they wouldn't tell Audette, as your linked article describes, but would tell Dick Wright, I don't know. Maybe they'd done further research on an answer by the time Wright asked, or maybe he just got the right person and Audette didn't.

Wright says:

…the only way to seat a primer in the above manner is to use a K&M Primer Gauge which is the only tool especially made for this task… My wife and I have both used a Primer Gauge for some time.

He goes on to say that that he became lazy and convinced himself he could tell the feel not only of touchdown, but of 0.002" crush. He also says he now has a bridge he will sell to anybody else who's convinced themselves to believe they can do this.

Mrs. Wright continues to use the primer gauge and continues to beat the writer in most matches.

The Sinclair tool is heftier and feels nicer in your hand. Kept greased, it is very smooth in operation and has more of a "quality" feel about it. It does not do what the K&M Primer/Gauge tool does, but if you are going to go by feel, it is probably what you want. That is what it is designed for. If you set the shims per the instructions, you have 0.010" protrusion of the ram from the primer guide sleeve at full handle press, and you would normally need only half that to complete the job.

You can, however, also set the Sinclair up to do what large commercial and military manufacturers and the Forster Co-ax press's built-in priming tool do, and that is seat to a fixed distance below flush with the case head. You juggle the choice of shims with setting the threaded connecting rod that drives the ram until you get a fixed 0.005" protrusion from the primer guide sleeve. Then you just seat all your primers all the way to the end of the handle stroke. It also is a way to guarantee the primer is a minimum depth below flush for military self-loaders whose floating firing pins increase risk of slamfiring if primers are not adequately below flush, and especially if they are actually high. So the Sinclair tool, though designed for benchrest shooters, makes a good choice for that application when so adjusted.

The web between the bottom of the primer pocket and the inside of a case tends to bulge slightly into the primer pocket with each load cycle, gradually making the primer pocket more shallow. The K&M tool, used as directed, will simply adjust the primer bridge to compensate for that, letting the primer seating level below flush get gradually shallower along with it. That's not desirable with floating firing pin guns. Some folks address this problem by letting their primer pocket depth uniforming cutter double as their primer pocket cleaner, so the depth is reset every load cycle, making the practice of seating to a fixed depth below flush more consistent in terms of bridge set as well.

The article also suggests you can overcompress a primer. This can be topic of hot debate. Alan Jones said that early priming mixes used by Speer were brittle and you could ruin them that way, but that modern priming pellets are not brittle and are far more difficult to damage. Dan Hackett, authoring a different chapter of the Precision Shooting Reloading Guide says:

…I have experimented with seating primers to different depths and seeing what happens on the chronograph and target paper, and so far I've obtained my best results seating them hard, pushing them in past the point where the anvil can be felt hitting the bottom of the pocket. Doing this, I can almost always get velocity standard deviation of less than 10 feet per second, even with magnum cartridges and long bodied standards based on the '06 case, and I haven't been able to accomplish that seating primers to lesser depths.

How hard is Hackett's "hard"? He uses the Sinclair tool, but says he ground the primer sleeve to give him more extra ram protrusion. He must not buy that an indented cup is necessarily a bad thing.

[old roper]

Nick, This is my last post on this subject but here is something Audette wrote.

Audette gave us the following standard for a priming tool: “I think a little ingenuity in design could result in a primer seater where the part which holds the primer in alignment with the pocket, and through which the primer punch advances, could be moveable, so it would come hard against the case head as the punch is advanced. This automatically squares up the case. The punch is made so the amount of protrusion beyond the primer holder is adjustable and forward movement of the punch is limited by the holder, which comes up hard against the head of the case, as the tool is actuated. The distance could be set with feeler gauges. Or, there could be a series of thin washer-type shims to be inserted in the tool to give the compression desired for the primer height being used.” (Precision Shooting; Primers Chapter 6, Creighton Audette, March 1995 p. 24, at p. 26).


I'm sure since your the expert you can post the following article that were written listed below

Creighton Audette chose primers as the subject of his final work for publication. (See: Precision Shooting; Primers, Chapter 1 through Chapter 6, Creighton Audette, October 1994 p. 48; November 1994 p. 38; December 1994 p. 77; January 1995 p. 19; February 1995 p. 46 obit. p. 8; March 1995 p. 24).

[Unclenick]

Old Roper,

You've raised a point I don't know the answer to, and I'm going have to call Federal or CCI or maybe write Alan Jones to see if I can get it resolved.

Before I get to that, I'll just say that while I have Audette's PS articles, I can't post copyrighted materials without the copyright holder's permission any more than any other board member can. That would open the board up to law suits. I could call Dave Brennan's to see if he can give permission. Sometimes the copyright is the author's rather than the publisher's, which in this case would mean it belongs to Audette's estate, since copyrights no longer expire automatically. I ran into this problem trying to get permission to post an article from the NRA's out-of-print book, Handloading. NRA member services offered to try to get me permission, but said that if NRA Books didn't hold the copyright, it could take months and they might not ever be able to find the person who has to give that permission if the author is no longer alive. That was over a year ago, and they haven't tracked anyone down yet.

Back to the topic at hand, first I'll see if I can sort out where our difference is. It leads to what I don't know the answer to. Here's the tricky point: Audette both identifies a necessary control principle and proposes a design approach to achieve that control, but those are two distinct things. He says the primer is, in effect, more analog than digital, so controlling compression of the priming mix is important to do consistently. He then proposes a design approach he believes will result in that control. The Sinclair tool does, indeed, match Audette's proposed design approach. However, I infer from Dick Wright that, armed with the specific compression information that Audette didn't have, he finds the K&M meets Auddette's identified control criteria more completely than Audette's own proposed design does.

But now I'm questioning the certainty of Wright's position (and the one I've held) because of what I don't know the answer to. It is the case that the K&M tool compensates for primer pocket depth while the Sinclair does not, but that can be handled in the Sinclair by uniforming primer pocket depths, which I assume that Audette assumed would be done. However, the K&M also compensates for the height of the individual primer. What I don't know is, what is the dominant source of that primer height tolerance? If it is due to difference in the thickness of the primer pellet, then the Audette-type Sinclair design can force the bridge to the same thickness each time and the K&M approach will merely thin that thickness by a fixed number of thousandths. That would give the Sinclair tool the edge, provided you uniform the depths of the primer pockets for it and you set the ram to stop a uniform seating depth below flush with the head. But if the pellets are the same thickness within a fraction of a thousandth and the difference is due to the anvil tolerances, then the K&M will better control the final thickness of the bridge because the error in the anvil is corrected for.

So, I have to see if I can find out what the dominant source of primer height tolerance difference is.

And all this begs several other questions. Dan Hackett seems to have found, by proving the value of simply seating hard, that there is some threshold of compression beyond which the analog nature of primer compression is at a limit and fine differences no longer matter so much. It would be kind of nice if that's true, from the standpoint of easy setup and less picky priming. Another is if the Federal 0.002" and 0.003" compression numbers, given that Federal seems to be the only major maker using the hydroxide form lead styphnate, really apply to other primers equally? That might also be complicated by using the CCI #34 and #41 primers which use a different anvil shape to control sensitivity. I've adhered to those 0.002" and 0.003" numbers blindly, thus far, and now think I may be staring at another pile of experiments that have to be conducted.

The bottom line is always going to be the same: you have to test what you are doing in your guns and see what works best. What seems more in doubt to me than before is being able to declare what approach is uniformly best. There may be no one-size-fits-all answer here.

[jimkim]

I like my old Lee Auto Primes. They seat primers and you don't need a PhD or JD to use them.

[rclark]

I've been using my RCBS hand primer for years.... Works great.... and you don't need a PhD to use it either . Errr.... you do need to know to squeeze properly though. Ever milk a cow? . Just kidding !!

[jimkim]

Ever milk a cow? . Just kidding !!

I know you're kidding, but oddly enough, yes...yes I have. Well that's two that avg people can use.

[marklyftogt]

Lee ergo prime. It is awesome.