K&M Priming Tool with Gauge Thoughts

[260AckImp]

Hello Everyone

Just wondering how people who use/own the KM priming tool with the gauge like using it?

Do you really need to measure every single primer pocket and primer before seating? Or could you do a 5 or 10 piece sample size and set the depth up accordingly and then use the gauge to set how many thousandths of primer crush you want?

Thanks for your time

 

[DngBat7]

The 21st century click adjustable is the way to go. Effortlessly exact every time. No measuring or gauges needed

http://www.xxicsi.com/super-precision-click-head-br-priming-tool.html

 

[Chaotik]

I have the K&M priming tool and try to use it whenever possible, which is limited by hand and finger discomfort in an old guy with arthritis. If using the K&M is too painful then I resort to the 21st Century tool, which is much easier on my joints.

 

[Chiquita]

I had one. Didn't use it. I prefer the 21st precision.

 

[RegionRat]

Much of how things (primer seating) turn out is dependent on the quality of the brass you have in the first place.

For example, decades ago you could find that surplus brass had some variance due to rims damaged by automatics or sloppy dimensions that were due to their tooling being variable. When trying to turn these into match brass you had to be careful to cull the ones where the rims were bent or sort to get the rim thickness the same.

So, when you seat primers you are often "pulling" on the top side of the rim, but then you are often measuring from the base to the bottom of the primer pocket or top of the primer to judge a result.

If the top of the rim is the working datum, then everything is built on that rim thickness tolerance added to the ones for the primer pockets and primers. If and when the rims are known to be stable, then you can work from some averaged values and keep rolling with a fixed setting to within a tolerance much faster than setting each individual depth based on dimensions.

The K&M tool concept is okay, but I found that it wasn't built tight enough to judge the actual dimensions any better than running on RSS (root sum squared) averages. I still have the tool, but it mostly sits unless I am playing around with strange brass. The ram tolerance and the moving interfaces allow the gaging functions to be a little too sloppy at times. It takes some finesse to get a quiet reading. The effort versus the results are a trade off in terms of speed.

If you weren't so far away I would loan you one to try, but that can't happen. YMMV

 

[260AckImp]

Thanks everyone for your comments so far.
It looks like id probably be better served by getting a 21st Century primer seater instead?

 

[RegionRat]

@Fullbore there are many good ones out there that will allow you good control over the installation height.

The 21Cent version has a click per 0.00125", some of the other designs are adjustable without clicks.

The K&M, PMA, etc. are all very good hand tools. I adjust them for a positive stop and beforehand I work out the crush with an Accuracy One primer seating gage to get the settings.

Primer seating depth doesn't always have a big impact for me, but when it does the gage (and high quality brass) makes my life easier.

https://bullettipping.com/products/precision-primer-gauge/

 

[mikecr]

The indicated K&M does account for each rim thickness/primer height/pocket depth at the same time. It's the ONLY primer seater that shows you directly what your primer crush is. None of the rest do this, no matter their cost or merchandising.

And yes, every single primer seated is measured with the K&M. It is not a set & forget device.

 

[260AckImp]

The indicated K&M does account for each rim thickness/primer height/pocket depth at the same time. It's the ONLY primer seater that shows you directly what your primer crush is. None of the rest do this, no matter their cost or merchandising.

And yes, every single primer seated is measured with the K&M. It is not a set & forget device.

Do you own the KM with the gauge?

Whats been your experience with it?

 

[snoopy001]

Hello Everyone

Just wondering how people who use/own the KM priming tool with the gauge like using it?

Do you really need to measure every single primer pocket and primer before seating? Or could you do a 5 or 10 piece sample size and set the depth up accordingly and then use the gauge to set how many thousandths of primer crush you want?

Thanks for your time

Be carefull by K&M.I had to waste the first order due to verry,verry slopy
made. The lever stucks when pushed almost.I wrote an email to K&M complaining the quality since 8 months ago but the don't answered !!
For me such a quality is no go for ever.
Regards N_F

 

[JimSC]

Am I correct in thinking that the K&M allows for slightly different depth primer pockets and slightly different primer heights and gives a consistent crush automatically? That sounds pretty interesting to me

 

[RegionRat]

Am I correct in thinking that the K&M allows for slightly different depth primer pockets and slightly different primer heights and gives a consistent crush automatically? That sounds pretty interesting to me

If you use enough finesse, you can in theory set a primer to a specific crush per case and primer. It isn't automatic per se, but in theory you have the controls.

I personally can do a faster job with a regular tool like their non-gage version, PMA, Sinclair, etc., by just using a batch setting and accepting the statistics of the primers and cases on the averages.

Most primers have anvils that are not "flat" and many cases have some variations on their rims and pocket depths. That means that if you sample the same parts in different places, you get a different target dimension or variance anyway. Some of this is the brass and primers, some of this is the repeatability of the tool.

When you add the tolerances of the loose parts of the K&M gage tool to all of those, you have to take a step back and look at the whole process. In the end, my K&M gage tool is not all that tight or repeatable and to reduce those variables you end up slowing down and are still left with the variations on the anvils.

Don't get me wrong, I still have and like the tool, but I wouldn't be honest if I skipped telling you it isn't perfect... YMMV

 

[JimSC]

thanks, the way the write up describes it I guess I got the wrong impression. That and I was just wondering what the purpose of the dial indicator was for. I can get a good "feel" with the unmodified RCBS bench unit. Like you pointed out , primer thickness varies.

 

[Joe Maisto]

thanks, the way the write up describes it I guess I got the wrong impression. That and I was just wondering what the purpose of the dial indicator was for. I can get a good "feel" with the unmodified RCBS bench unit. Like you pointed out , primer thickness varies.

When Mr. Ken Merkle owned the Co., I have never heard of anyone say any negatives about it...and this... with SR bench rest competition.. However, we all used Lapua brass and cared for our brass exceptionally for what we did including using match primers and a primer pocket cleaning tool as well.

 

[INTJ]

The K&M Primer Gauge is the only tool that seats to an exact crush every time. This is because pocket depth varies, even on uniformed pockets, and primer cup heights vary as well. The K&M accounts for that. The only way to get that level of consistency with the other primer tools is to measure each primer cup height, measure each pocket depth, then do the math on each case.

Now do we need the consistency the K&M provides? It depends. In my 6 BRA 1000 yd BR rifle I reduced ES by 4-5 FPS when I webber to the K&M Gauge. I can't say that it made any difference on the target, but I have shot smaller groups since using it. Part of the issue is I don't use a chronograph when doing final tuning at 1000 yds.

However, when you consider a typical 1000 yd tune probably has a 20 fps variance where the bullets still have the same POI, allowing another 4-5 FPS because of an improvement in loading methods can help.

I also use this tool for my 300 WSM 1000 yd BR rifle, but given its case capacity I doubt it makes any difference. After all, years ago I got very low ES using a Lee Auto Prime and seating by feel.

Seating by feel usually works well.

However, something that has little value is seating unmeasured primers into unmeasured pockets then checking the primer seating depth afterwards. Also, using a primer tool with an adjustable seating depth is meaningless unless you measure pockets and cups.

So the K&M Primer Gauge is without question the most precise way to seat primers to a consistent crush. A quality tool that has a good feel--like the 21st Century is second to the K&M Gauge. Depending on the cartridge and shooting discipline, the added consistently and precision of the K&M Gauge might provide a small advantage. Regardless, a well tuned node overcomes all of that.....

 

[260AckImp]

The K&M Primer Gauge is the only tool that seats to an exact crush every time. This is because pocket depth varies, even on uniformed pockets, and primer cup heights vary as well. The K&M accounts for that. The only way to get that level of consistency with the other primer tools is to measure each primer cup height, measure each pocket depth, then do the math on each case.

Now do we need the consistency the K&M provides? It depends. In my 6 BRA 1000 yd BR rifle I reduced ES by 4-5 FPS when I webber to the K&M Gauge. I can't say that it made any difference on the target, but I have shot smaller groups since using it. Part of the issue is I don't use a chronograph when doing final tuning at 1000 yds.

However, when you consider a typical 1000 yd tune probably has a 20 fps variance where the bullets still have the same POI, allowing another 4-5 FPS because of an improvement in loading methods can help.

I also use this tool for my 300 WSM 1000 yd BR rifle, but given its case capacity I doubt it makes any difference. After all, years ago I got very low ES using a Lee Auto Prime and seating by feel.

Seating by feel usually works well.

However, something that has little value is seating unmeasured primers into unmeasured pockets then checking the primer seating depth afterwards. Also, using a primer tool with an adjustable seating depth is meaningless unless you measure pockets and cups.

So the K&M Primer Gauge is without question the most precise way to seat primers to a consistent crush. A quality tool that has a good feel--like the 21st Century is second to the K&M Gauge. Depending on the cartridge and shooting discipline, the added consistently and precision of the K&M Gauge might provide a small advantage. Regardless, a well tuned node overcomes all of that.....

Thank you for your response, greatly appreciated

 

[mikecr]

I personally can do a faster job with a regular tool like their non-gage version, PMA, Sinclair, etc., by just using a batch setting and accepting the statistics of the primers and cases on the averages.

It isn't about what you can do faster, but what you can actually do correctly -with every single primer seated.

When you add the tolerances of the loose parts of the K&M gage tool to all of those, you have to take a step back and look at the whole process. In the end, my K&M gage tool is not all that tight or repeatable and to reduce those variables you end up slowing down and are still left with the variations on the anvils.

The tool has a GAGE. It's a direct reading of result. It leaves nothing to assumptions or feel.

Without the K&M, to do what it does, you would need to measure for each case and primer; pocket depth, primer height, rim thickness, and validate seated crush meets calculated, through gage measure w/resp to case head -in separate operations. Doesn't matter how fancy your other seater is, this is the way it is, and only the K&M covers all of it.
You should understand and concede this much AS FACT.

Do you own the KM with the gauge?
Whats been your experience with it?

I've been using an indicated K&M for a long time (since the 80s I believe).
It is slow going for a beginner, but you get good with it, and it's not a race anyway.
The tool itself is pretty good (better than cheap), and one of the first things you learn while using it is that you cannot seat primers to consistent crush by feel. I doubt anyone can, because pockets and primers vary in diameter and hardness, and friction. Your seating varies in speed as well, so registering touch point by feel could vary in thousandths. I'll concede that maybe it's possible, but a direct reading solves it for sure.

Someone might argue that a bottomed out primer will go off and that's good as it gets. That so & so just smashes em in there and they have a record with it.
The problem is: they're wrong, and I don't care about so & so's record.
You can damage pellets or strike them with different quality conditions, and see it across a chronograph. The amplitude of this variance depends on as much as anything else, but it can at least matter.

 

[INTJ]

For precision reloading the K&M Gauge is actual faster than seating primers then measuring depth. For non-precision bull primer seating it is way too slow. I usually do better than two primers a minute.

 

[RegionRat]

The tool has a GAGE. It's a direct reading of result. It leaves nothing to assumptions or feel.

mike, There is more to it.

The ram has clearance, the rotating parts have clearance.

Take the same case and the same primer and just gage it a few different times and see what you find. All those moving parts have to line up on their clearance the same way two times in a row to get an identical reading. It is called a GR&R evaluation and the repeatability of the gage is on the same order as a good batch of components.

I don't want to sound like a critic of the K&M tool cause I do like it, but many other folks who have the tool also see what I see. What would you call the repeatability of the tool?

Don't get me wrong, I really like the tool, but I can accomplish the same net effect faster by carefully sampling a batch of primers and cases, then setting up and running. I end up in the same place faster.

 

[INTJ]

mike, There is more to it.

The ram has clearance, the rotating parts have clearance.

Take the same case and the same primer and just gage it a few different times and see what you find. All those moving parts have to line up on their clearance the same way two times in a row to get an identical reading. It is called a GR&R evaluation and the repeatability of the gage is on the same order as a good batch of components.

I don't want to sound like a critic of the K&M tool cause I do like it, but many other folks who have the tool also see what I see. What would you call the repeatability of the tool?

Don't get me wrong, I really like the tool, but I can accomplish the same net effect faster by carefully sampling a batch of primers and cases, then setting up and running. I end up in the same place faster.

None of those clearances matter. It's like the backlash on lathe dials. All the slack is taken up and then the dial indicator is set to zero. While the primer is being seated all the slack is again taken up so you are getting a precise reading.

And we really can't pdo the same thing by sampling, because proper cups vary quite a bit as do pockets, even uniformed pockets.

Now whether the precise primer crush that the K&M Gauge provides makes a difference or not depends on the discipline and the specific cartridge. It will make the most difference with small capacity cases in LR BR.