"Best" primer seating tool?

Good afternoon,

What I mean by "tweaking" is potentially adjusting how much pressure you are applying when seating your primers. As I said, the primer needs to be flush with the base of the case, not below it.

A simple test, seat your primer and place the case on your load bench. Give the bench a little push or hit it with your hand. Did the case wobble? If so, your primer is not seated flush. Run your finger across the base. Feel any bump? If so, back into the press, carefully seat a bit further. (you are wearing safety glasses of course....). You can also use your caliper to test, running the base of the case against the lower arm. You'll feel the primer catch if it isn't fully seated.

In two plus years of loading I have never set off a primer, don't want to. I have read of those who have accomplished this feat, so be careful in your work.

I hope this helps.

Good luck. Be safe.
 
"YES" I do like my RCBS hand priming tool!!

I have no idea how many years I've used my RCBS hand priming tool, like my other RCBS tools I still have it and it still works and may outlast me!! William
 
Same as 243winxb RCBS Ram Priming unit, I uniform my primer pockets & using the ram primer all the primers seat perfectly.
 
Prof Young said:
I would think that ideally it seats all the way to the bottom of the primer pocket.
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Deeper than that. If you look at a primer, it has a brass (often nickel plated) or hard copper cup, and inside the mouth of the cup is a metal piece called the anvil, which looks like an inverted tripod or bipod, depending on the primer design. Between the bottom of the cup and the inverted tip of the anvil is the priming mix pellet, usually with a paper or plastic or foil cover (this cover is called the foil regardless of what it is made of). It often also has a lacquer water resistant seal applied over all that.

The idea is that when the firing pin strikes the primer, it squashes the pellet smartly between the inside bottom of the cup and the tip of the anvil. The "smartness" of the blow is determined by the kinetic energy behind the firing pin. Each primer has a rating for that energy that is based on priming an empty case, placing it upside down in a holder with a floating firing pin laying nose down on top of the primer, then dropping a weight on it. The kinetic energy of a dropped weight is proportional to the height it is dropped from, as long as it doesn't get going so fast that air resistance becomes significant. So the test just rates primer sensitivity in terms of the height the weight is dropped from. Below is an example of military primer sensitivity specs.

MilitaryPrimerSensitivitySpecs_zps24ae7517.gif


The problem with the above is you have to be careful to ensure nothing can mitigate the energy transfer from the firing pin to the primer. If your primer is only seated part way into the primer pocket, then a portion of the energy in the firing pin is absorbed by first knocking the anvil loose, then finishing seating the primer cup. That extra work leaves less energy to ignite the primer, and is a common cause of misfires for that reason. Another, smaller factor is the foil acts like a small cushioning pad. Still another is that some primers may have thicker pellets than others, and a thick pellet can theoretically cushion the firing pin strike, too. These last two factors can be handled by "setting the bridge" of priming mix between the cup and anvil, or "reconsolidating" (as in squeezing together) the primer parts.

Here's how that works: Notice that an unfired primer's anvil has its two or three little feet protruding slightly beyond the mouth of the primer cup. This serves two purposes. One is that because the anvil is narrower than the cup—actually able to press down inside it–having the feet protrude means that they touch the floor of the primer pocket before the mouth of the primer cup can run into whatever radius the corner at the outer edges of the floor may have. That eliminates one possible source of shock absorption at firing pin impact. The other is it compresses the foil and squeezes the primer pellet to a more uniform thickness. Alan Jones points out there was a time when priming mix was brittle, but no more. You will not make it crumble doing this.

Getting the above correct makes the primer optimally sensitive. It also causes the ignition to be more uniform in speed than with a primer merely touching the bottom of the pocket. This is important for maximum rifle accuracy at long range. It allows you to get velocity SD down below the 10 fps range, where that can be hard or impossible to do at rifle velocities (10 fps is a pretty small percentage of a typical high power rifle velocity) without careful primer seating.

There are different ways to go about getting consistent primer seating. First, you can do what manufacturers do, and that is seat primers to a fixed depth that produces the right result on average. Remington and Winchester have reconsolidation ranges for compressing the anvil into the cup of 0.002" to 0.006". Their case primer pockets have ±0.001" depth tolerance, which eats up half that range. The rest allows for primer differences. In the end, you wind up about 0.004" below flush with the head of the case as the target value.

The Dillon 1050 press seats primers that way on the handle down-stroke in one of its eight stations. It is a good way for a manufacturer to work because he knows his own brass. For the Dillon it will work best for long range rifle ammo only when you use brass with the same rim thickness, as rim thickness variation alters the seating depth produced by the Dillon mechanism. It is fully adjustable, but you want to have all your cases the same rim thickness for any given adjustment.

A method that works with any rim thickness is built into the Forster Co-ax press. This seats the primer with a ram that has a shoulder on it that stops against the case head. The center portion that drives the primer protrudes beyond that shoulder to follow the primer up into the primer pocket, setting it at the correct depth. It is a one-at-a-time tool, though. I have one of these, and rather than handle primers individually, I have primed rifle cases on a Lee tool while watching TV, then run them through the Co-ax press to set final primer seating depth. It seems to take less time that way, and I find this is a good slamfire countermeasure with ammo destined for floating firing pin self-loaders.

Yet another method of accomplishing the above that is also immune to rim thickness variation is achieved with the Sinclair priming tool. It can be set up with shims to produce any exact final depth you might seek. It is also a one-at-a-time operation, but it lets you finish in front of the TV.

As a practical matter, these days primer pellet thickness is pretty uniform, so that pellet thickness variation in the final bridge thickness is not the issue it originally was. Being relieved of that concern gives you another option, and one I find works very well, but is very slow going. This is to use the K&M Primer Gauge tool. This tool has you place the case in it as if you were going to primer it, but with no primer, and then put the primer anvil-down on a little pedestal so that a dial indicator touches the bottom of the cup. You then close it until the primer ram finds the bottom of the primer pocket, and rotate the scale to line the indicator needle up with zero. This zeros the primer pocket depth against the exact height of the individual primer. You then open it, remove the case, place the exact same primer you just zeroed against into the end of the sleeve around the retracted seating ram, put the case back and press the handle again. This time the ram is priming the case, but because the dial indicator now touches the pedestal, when the dial reads zero the primer's anvil feet are just exactly at the bottom of the pocket. No relying on feel to tell you this. You then press the ram further, watching the dial indicator until you have reached the desired number of thousandths of bridge set. That would be 0.004" with Remington and Olin products. 0.002" with Federal small rifle and 0.003" with Federal large rifle primers (these numbers are recommended by Federal), or 0.003" for military primers (per NOIH numbers of 0.002-0.004" consolidation).

And then there's the Armstrong method. Just seat firmly by feel as consistently as you can.

”There is some debate about how deeply primers should be seated. I don’t pretend to have all the answers about this, but 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 deviations of less than 10 feet per second, even with magnum cartridges and long-bodied standards on the ’06 case, and I haven’t been able to accomplish that seating primers to lesser depths.”

Dan Hackett
Precision Shooting Reloading Guide, Precision Shooting Inc., Pub. (R.I.P.), Manchester, CT, 1995, p. 271.
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Prof, I had a similar problem a few years ago. Result was high primers and a lot FTFs. I found the culprit, the connecting rod between the handle and the piston. The end of the rod (the large rounded end) had worn down so much that at its full extension it still wasn't long enough to properly seat the primer. As a temporary fix I found a very small washer (the same diameter as the piston) and epoxied it to the bottom which basically made the piston a little longer. Still works but I did find another connecting rod to be safe. In hind sight, I may not have oiled that rod as often as I should have. Take a look at it, I'll bet it isn't as round as it should be. Best bet is to go to ebay and buy a new tool, there are always some for sell. Start your own collection of spare parts.
 
F. Guffey wrote: I have two RCBS automatic hand primers, and I have enough spare parts to build another. Long story. There is not enough room between the top and bottom of the primer/flip tray for a primer to flip. I remove the tray when loading primers and the RCBS has more leverage than the Lee.
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there is more than enough room for the primers to tip on their side or over when the lid on the tray gradually climbs up. When I use mine I have to use a spring type paper clip to ensure the lid remains down. Unfortunately the spring clip must be located right next to or over the shoot into the tool and makes a comfortable tool uncomfortable. Something about a spring clip cutting into my knuckle I guess.
 
there is more than enough room for the primers to tip on their side or over when the lid on the tray gradually climbs up.
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I agree. I was having a bad problem with flipping primers and found that the lid was not staying tight and lifting slightly. I eventually had to resort to using rubber bands to keep the lid tight. I finally called RCBS and they sent me one of the newer "square" trays that's used on the universal hand primer. The lid on those trays "snaps" shut and so far seem to be staying secure.
 
Are there primer seating tools that have a longer stroke than the Lee
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OP take a close look at how the primer arm seats the primer,it pushes it in
until it bottoms out. It can go no further than that and no other method can push it any deeper. If you are looking for even more leverage then you could consider their ram prime,there you push the primer in on the down stroke.
 
Uncle Nick and Mark Glazer

Uncle Nick:
Thanks for the great info. An education in primers . . . so of a primer on primers . . . sorry I couldn't help myself.

Mark
When I use my Lee hand primer the post that seats the primer is at the end of its stroke when I am done. In other words it will not extend any further. This factor is what makes me think I may need a different/better priming tool.

Live well, be safe
Prof Young
 
Call or email Lee Precision and they will send you what replacement parts you need. The tool should seat all primers below flush.
Idaho Gaiters
 
there is more than enough room for the primers to tip on their side or over when the lid on the tray gradually climbs up. When I use mine I have to use a spring type paper clip to ensure the lid remains down. Unfortunately the spring clip must be located right next to or over the shoot into the tool and makes a comfortable tool uncomfortable. Something about a spring clip cutting into my knuckle I guess.
__________________
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There is no shortage of 'C' clamps around here, if primers were going to flip in my tray I have to do something to cause that. Chatter when seating primers can cause primers to move, again, there is not enough room between the (my) lid and tray to flip primers on my trays when seating squeaky/chattering primers.

If there was and the tray is a flip tray flipping primers back with the smooth side down would be a matter of moving the primers across the flip tray.
 
Looking at the tool without the shell holder in place, with the handle upright, the seating rod is even with the plastic housing piece that protects and guides the primer into place. If your tool looks the same then the tool is fine.

Question: do you have issue with the primer pocket not being clean? Any build-up preventing the primer from being fully seated?
 
I realize this is an older post but if anyone is still having an issue with primer depth, this may help.
I had a similar issue with my RCBS hand priming tool not seating deeply enough for my taste. It was seating the primers flush instead of slightly below flush as I prefer. Since it only happened when priming .338 Win Mag brass and no other calibers, I discovered the problem was with my shell holder. Apparently there are some dimensional differences between some of the older RCBS shell holders and the newer ones. Maybe the one I had was out of tolerance or at the high end of the tolerance range.
In any case, I discovered the older shell holder was spacing the brass just a little too far away for the seating rod to effectively seat the primers. I tried a newer RCBS shell holder which allowed the brass to sit a bit lower (closer to the seating rod) and my problem was solved.
 
So much can be said re. this one phase of handloading.

I used the old style Lee Auto Prime for 30 years. Had two of them, one set up for large primers and one for small.

Also had an RCBS because when I was silly enough to load .32 ACP, I discovered lots of variations of case rim and some wouldn't work in the Lee shell holder. Which I have found is a short-coming of some of the Lee proprietary shell holders.

Because of my difficulties with the .32 ACP, I bought an RCBS Hand Priming Tool, their #90200, which may not be what they sell now. It did a fair job of work if you were careful and didn't allow the tray to fall out. My biggest complaint about it, the shell holders are difficult to change. As someone before me said in this thread, you nearly have to take it all apart to make the change. Not convenient.

So, for the most part I was content to use the old Lee tools with the round trays. Then one of them broke and it was an ugly surprise to find that the old style was no longer available. It had been replaced by the new model with the square trays and the lawyer-proof (nothing really is, though) two stage lift to prevent chain detonation. I sent away for one of these a few years ago and it's never worked correctly and has been the source of much frustration.

It was such a pain in the prat to use that I set it aside for a couple of years. Then I figured, might as well get used to it and make it work. After exchanging several emails with an engineer at Lee, it still doesn't do what it's supposed to and does a few things that it shouldn't. I did get the action greased up well enough that the handle no longer sticks on every press.

After doing everything the way I'm supposed to with the tool, it still has issues that drive me nuts. It just hates small primers. It's that two-stage lift device that causes problems. It will flip a primer so it comes up on its side or back; it will jump a primer on top of another in the lift entrance and this nudges the cover off. I've had several spillages of primers which waste lots of time. I don't think I'm done with the Lee engineer yet; who knows, I might have a dud that won't work in any case and the thing may be making a trip back to Wisconsin.

One other thing I don't like about it is the stroke gives nothing to spare like the old version (with the round trays) did. After handloading for decades, you get a feel for when the primer has been properly set. More about that below. The old Lee tool had a little extra stroke left and you could feel when the primer was home in the bottom of the pocket. The new one has nothing extra on the stroke; if the shell holder is a loose fit (as some Lee holders are), then you may not get a primer seated quite deep enough. This is a problem with .223 Rem because the Lee proprietary shell holder is a #4, originally for a .32 S&W and anybody who has compared the two rim designs knows they ain't the same. A .223 case in a Lee #4 shell holder lifts up a few thou. before it stops and the primer starts to go home. The Lee engineer sent me the latest version of their #4 and this is still true.

Back to the RCBS Hand Priming Tool. The actual rod that pushes the primer into the pocket is just that, a simple steel rod. If you have problems getting the depth right in a given case, you can adapt your own rod to whatever length is appropriate. At least it has that going for it.

So why do some primers seat at different depths that others? Variations in depth of pocket, variations in case rim, even variations however slight in different brands of primers. The main thing is that the primer be seated fully. It may be flush or it may be recessed slightly. YOU DON'T WANT HIGH PRIMERS IN ANY CASE, this is an invitation to accidental discharge.

One more thing I have for priming is a discontinued RCBS bench-mount model, very effective, has good feel, will give complete seating with no problem but it's a load one at a time.

In the decades that I've been priming cases, I've never had one go off. That includes decapping live primers from cases, never had one go off.
 
Bottom Gun, All of my RCBS shell holders have a deck height, the deck height of my RCBS shell holders is .125", even the ones that go back to the 50s. Since the 50s RCBS has changed shell holder designs meaning I have 3 different designs. The first two designs are will not fit the RCBS Auto hand Primer with the round flip tray.

So, for the most part I was content to use the old Lee tools with the round trays. Then one of them broke and it was an ugly surprise to find that the old style was no longer available. It had been replaced by the new model with the square trays and the lawyer-proof (nothing really is, though) two stage lift to prevent chain detonation. I sent away for one of these a few years ago and it's never worked correctly and has been the source of much frustration.
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Setting off a primer: Never once did R. Lee mentioning double clutching the Lee Auto Primer.

F. Guffey
 
Both the Lee and the RCBS will seat just below flush as will the Dillon 550 press. You may find certain brands of primers and cases that make primer seating easier. It ain't rocket science.
 
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