Primer seating

[/VH]

Me too. Uniforming adjusts depth, no tension. --Jerry

I agree, uniforming adjusts depth from the case head but not not necessarily from the groove side of the rim, which is where my 21st Century seater indexes from. I also have a Sinclair seater which clamps the case rim but I haven't used it for a while and can't remember the particulars of just exactly how it indexes.

 

[Fotheringill]

I have mentioned this on other forums and probably here in another thread. Doing things by feel will never be as accurate as using a ram primer. I have the RCBS, and after trial and error, found the right depth for seating primers. I locked it down and have not had a FTF or blown back spent primer since. IMHO, take the human error out of what you are doing as much as possible.

 

[mikecr]

With an indicated K&M, which actually measures crush(unlike any other), the first thing you learn is that 'feel' is not at all accurate about primer seating. Neither are click adjustments from any set reference. Also, it matters not that all your primers are going bang. I can tell you how to double group size while they all bang away..

Dismiss merchandising and generalizations.

 

[rkittine]

I am new to all this and know very little, but while at the Williamsport 1,000 Yard Shooting School this year, we were told about the importance of "Crush" on primer seating, so I bought the K&M Primer Seater with the micrometer and now measure everything, head, rim etc. and "Crush" 4 thous. as recommended. I hope that it really makes a difference since I am now spending an awful lot of time insuring EXACT crush.

Bob

 

['Freak]

Reading Glen Zediker’s “Handloading for Competition”, it’s said, ~, seat the primer such that the anvil sets each foot flush on the flat of a uniformed pocket floor, slightly tensioning (sensitizing) the anvil legs; but not taking it so far that distress inflicted upon the anvil in turn causes the primer compound to be compromised.

 

[mikecr]

4thou crush is right. And keep in mind that primers themselves are different in height.
You have to zero out the particular pocket to the particular primer being seated. Seat that primer to that pocket to zero + .004".
With this, you can rule out primer seating inconsistencies.

 

[savagedasher]

I want all my primer to be seated the same depth below the head surface . Dead stop priming is a must with me. Larry

 

[Iowa Fox]

I want all my primer to be seated the same depth below the head surface . Dead stop priming is a must with me. Larry

Larry, would you be willing to share a few of your dead stop primer seating secrets with us? I tried it many moons ago but just wasn't pleased with the results I was achieving. Thanks Jon D.

 

[/VH]

With an indicated K&M, which actually measures crush(unlike any other), the first thing you learn is that 'feel' is not at all accurate about primer seating. Neither are click adjustments from any set reference. Also, it matters not that all your primers are going bang. I can tell you how to double group size while they all bang away..

Dismiss merchandising and generalizations.

I am new to all this and know very little, but while at the Williamsport 1,000 Yard Shooting School this year, we were told about the importance of "Crush" on primer seating, so I bought the K&M Primer Seater with the micrometer and now measure everything, head, rim etc. and "Crush" 4 thous. as recommended. I hope that it really makes a difference since I am now spending an awful lot of time insuring EXACT crush.

Bob

4thou crush is right. And keep in mind that primers themselves are different in height.
You have to zero out the particular pocket to the particular primer being seated. Seat that primer to that pocket to zero + .004".
With this, you can rule out primer seating inconsistencies.

mikecr/Bob,

I didn't know the indicated K&M seater existed until I saw your posts. Or, maybe I had seen it quite a while back and just thought it to be too anal, for no better than I shoot...I don't seem to remember things very well recently.

However, after looking at it on K&M's website, reading the instruction sheet and watching a video, it does appear to offer the most consistent method for seating primers with a uniform crush/preload.

So, now that you've got me eyeballing it...would one or both of you mind giving me a ballpark idea of how long it takes you to seat primers with it?

Also, I noticed the instruction sheet called for .002" crush for small primers and .003" for large primers. You and Bob have recommended .004". From prior posts, I'm guessing Bob is loading small primers in 6.5x47L. Do you guys stick with .004" for either size primers?

Thank you.

Brian

 

[rkittine]

Brian,

With my lack of experience, I am not the one to really advise or recommend and only pass on what I have been learning from those that I look up to and respect as the ones in the know. I did confirm with CCI what I was told regarding Crush for 250 Magnum Small Rifle Primers and CCI is the one recommending 4 thou of "Crush". (Yes for my 6.5x47L)

My checkbook started to cry after I returned from the Williamsport BR School as I went out and replaced almost all of my reloading gear, some that I had been using since the 70s. The one reloading instructor at the school was using the Gauge K&M Primer Seater, so when I returned home I looked into one. At the same time I looked at the new model of the 21st Century, which has 1.25 thou. click depths (the older ones at 2.5 thou per click) allowing 3.75 "Crush" with a three click setting, but as someone else pointed out, that would only be consistent if EVERYTHING else, Primer Height, Pocket Depth, Rim Thickness etc. were identical. So I decided on the K&M.

From a timing standpoint, with all the Sinclair Tools I also bought, I was already, chamfering flash holes inside and out, chamfering the pocket, reaming the flash hole for consistency and using the primer pocket uniforming tool. (Also weighing and sorting primers) Mine has a fixed depth so it makes the primer pocket more consistent as long as none are too deep already. So then for timing for the actual seating, it is basically double as it takes the first pass to measure the depth and seat the primer to the bottom of the pocket and then adjust from that depth to get the desired crush. The click tool would for sure be quicker if everything was already uniform.

Since I am a new BR shooter and not all that good, I have no clue if it makes much of a difference other than what others tell me, but I figure it can't hurt and since I am excessive compulsive anyway, I think it helps me mentally.

I did a write up on a Primarily Hunting Forum, on how I now load match rounds and I think a lot of guys there think I have lost my mind.

Sorry I can not be more help. Bob

 

[/VH]

Thanks Bob, that is quite a bit of interesting and helpful information for me.

 

[mikecr]

The 4thou crush will always work,, I see it as a good starting point. 'Best' will be what the gun tells you.
I have logged 2thou for F205 and WSR, 4thou for F210, and 5thou for BR4.
But this is post tweaking results in load development per my primer striking and loads.

It's probably hard to imagine this as a matter to lose sleep about. I don't, because I measure and set em all the same.
And barring serious problems, any bottomed primers will fire.
I doubt it would matter with 6PPC pressure loads, nor for large capacity cartridges(7WSM, +).
But for 223, 6br, 6xc, 6.5wssm capacity loads, I can see primer/striking adjustments just like I can see CBTO and tension adjustments.

Speaking of striking; If you haven't, it's worth while to spend a day testing trigger hangers, firing pin protrusion and spring force for best precision. Get your bolt handle stable through pin release. Make sure the cocking piece is not giving up energy on release. This potentially being inconsistent, depending on bolt turned to position. Makes sure the spring can't bind in the bolt.
Optimization of striking can give you better than you thought from your load. You need at least one thing that is always fixed in this, and a set primer pre-loading provides this.

Ever notice how random primer choice has always been? We trial & error for whatever primer works best in this & that gun -even while they all fire. I don't think it's the primers themselves. I think it's our seating and striking of them, and that it's possible to optimize this for any one primer chosen. Just like it's possible to optimize seating for each chosen bullet.
If you adjust released pin protrusion, group shooting 20thou at a time, in mid-capacity cartridges anyway, you'll see grouping open, close, and reopen along the way.

Primer seating is slower with manual operations the indicated K&M takes you to. Bullet seating is slower where you verify each. Powder charging is slower where you measure each. Good ammo making is not a race.

 

[/VH]

Thanks for sharing your thoughts mikecr. I have had the impression for quite a while that you have spent considerable time studying and testing in great detail and I appreciate all you have put out there, to consider.

I have my powder weighing, neck turning and bullet seating procedures pretty tight but could see that my primer seating was open to improvement. I also believe consistent strike matters but haven't ever done anything as far as changing and testing it.

So, now:

1. What caused this 'flyer'?
2. How much does it bother me?
3. Could all 5 shots have been tighter than the 4 that are together?
4. Etc., etc.???

My shooting ability is the prime suspect but the more I learn, the more I see there is to consider.

I find the level of precision that has been developed with rifles and ammunition to be amazing and I appreciate those who have figured it out and shared their vast knowledge.

Thanks mikecr.