best priming tool

[Murray Brook]

@JimSC
As I mentioned in my post I don't have all the answers, but if you have a primer pocket with a depth of .131 and your primer is .127 then with a .004 crush I believe they should be .008 below flush. And as mentioned this could change from case to case and more so from one brand of case to another. As you mentioned I am wondering how the K&M tool compensate for different measurements or must you select primers of a constant measure and primer pockets of an exact depth.

 

[BenPerfected]

@JimSC
As I mentioned in my post I don't have all the answers, but if you have a primer pocket with a depth of .131 and your primer is .127 then with a .004 crush I believe they should be .008 below flush. And as mentioned this could change from case to case and more so from one brand of case to another. As you mentioned I am wondering how the K&M tool compensate for different measurements or must you select primers of a constant measure and primer pockets of an exact depth.

It is pretty easy to sort primers by weight...even if there was an easy way to measure primer length, seems like measuring primer length is tripping over another “mouse turd”....in this case maybe a mouse fart
Ben

 

[JimSC]

@JimSC
As I mentioned in my post I don't have all the answers, but if you have a primer pocket with a depth of .131 and your primer is .127 then with a .004 crush I believe they should be .008 below flush. And as mentioned this could change from case to case and more so from one brand of case to another. As you mentioned I am wondering how the K&M tool compensate for different measurements or must you select primers of a constant measure and primer pockets of an exact depth.

but that is not what I I said I had, <snarky comment> You seem a bit confused

. The primer pockets on the Alpha brass were all uniformed and were a consistent .130 in depth. The Winchester LRP's measured .127 to .128 which is how I came up with the .004 recess number.

now lets do the math real slow .130 minus .127=. 003. so a recess of .004 depth = .001 preload..... some of the primers measured .128 becasue of the domed shape so those will have a .002 preload. if you are going to quote me try and do the math correctly

The Lapua .260 brass had the .131 pockets and I used Remington 9.5s and seated to .005 recess

 

[Murray Brook]

@JimSC
First off I am not drinking. Second I did not quoted you, it was you that quoted me.I simply mentioned your post name. Maybe you are the one drinking. I felt you were asking me a question and I tried to respond.There isn't anything wrong with my math. If you have a primer pocket that is .130 deep and your primer measures .127 and you seat to achieve a .004 crush then I believe you would would be .007 below flush.

 

[JimSC]

Nowhere did I mention .004 crush. This is twice you have distorted and misquoted my posts so bye

 

[mikecr]

So how does the K& M K&M automatically compensate for varied primer thickness and pocket depths ?

The KM's indicator is mounted on the piston that presses against the primer cup. The indicator lifts with the piston, so that it's anvil lifts away from a fixed shelf.

In operation you put a case in the shell holder, squeeze the handle to lift the indicated piston fully into that shell's pocket. Then lift the indicator anvil and slip intended primer (for that pocket) between the anvil tip & fixed shelf(while the piston is still fully raised into pocket). Zero the indicator.

Then release the handle pick out the case and primer, put that primer and that case normally into the seater, and re-squeeze the handle. When the indicated piston has reached the sum of the pocket depth + primer height, the indicator will read zero. Travel further for desired crush.
You should feel with a finger swipe across the case head that the primer is below flush.

I complete seater re-travel to verify desired in case of immediate spring back (tied to primer/pocket fit).
Like all matters of ammo sizing, there is relaxing that occurs right away and over time.
The pockets should be tight enough to keep primers from creeping outward, and even off seated contact over time. Loose pockets may not, and over-smashing them into pockets does nothing to prevent this.

 

[Murray Brook]

@mikecr
I checked out the tool on their web site. Seems like a great tool only costly. Do you know of any other one that gives a specific primer depth. I had not thought of primers backing out due to either loose pockets or over smashing. TKS

 

[JimSC]

The KM's indicator is mounted on the piston that presses against the primer cup. The indicator lifts with the piston, so that it's anvil lifts away from a fixed shelf.

In operation you put a case in the shell holder, squeeze the handle to lift the indicated piston fully into that shell's pocket. Then lift the indicator anvil and slip intended primer (for that pocket) between the anvil tip & fixed shelf(while the piston is still fully raised into pocket). Zero the indicator.

Then release the handle pick out the case and primer, put that primer and that case normally into the seater, and re-squeeze the handle. When the indicated piston has reached the sum of the pocket depth + primer height, the indicator will read zero. Travel further for desired crush.
You should feel with a finger swipe across the case head that the primer is below flush.

I complete seater re-travel to verify desired in case of immediate spring back (tied to primer/pocket fit).
Like all matters of ammo sizing, there is relaxing that occurs right away and over time.
The pockets should be tight enough to keep primers from creeping outward, and even off seated contact over time. Loose pockets may not, and over-smashing them into pockets does nothing to prevent this.

now that is worth paying for if I go down this rabbit hole any farther, been measuring pocket depths all evening. A uniformer seems to be the trick with the Holland modded RCBS and even at that primers vary in thickness.

 

[Richard Coody]

Nice group! What caliber and how much for that barrel?
Ben

Nothing special here. 6br savage target action. Shilen select match prefit barrel.

Now brass prep, reloading techniques and load development do make a difference here.

I have been down the rabbit hole. Found what works for me. Question is what is another tenth or half a tenth reduction in group size worth to you. Lots more important things than primer seating depth if that is what you are trying to do.

 

[JimSC]

Nothing special here. 6br savage target action. Shilen select match prefit barrel.

Now brass prep, reloading techniques and load development do make a difference here.

I have been down the rabbit hole. Found what works for me. Question is what is another tenth or half a tenth reduction in group size worth to you. Lots more important things than primer seating depth if that is what you are trying to do.

like most shooters my issue is not getting groups, it is getting them centered on the target developing the load and building the rounds is the easy part. Even my obligatory flyer was in the ten ring on this target. Nothing wrong with the gun or ammo here, just bad mirage calls. For what it is worth these were primed with a RCBS hand primer and 19 of the 20 were within .3 MOA vertical spread, that horizontal sucks though

 

[Richard Coody]

like most shooters my issue is not getting groups, it is getting them centered on the target View attachment 1090696developing the load and building the rounds is the easy part. Even my obligatory flyer was in the ten ring on this target. Nothing wrong with the gun or ammo here, just bad mirage calls. For what it is worth these were primed with a RCBS hand primer and 19 of the 20 were within .3 MOA vertical spread, that horizontal sucks though

That wind will get you.

 

[jds holler]

RCBS press, with automatic primer feed attachment. Seat primers until they won't go further, and quit. If any stand proud, I address them individually. Never had a primer fail, and never thought I wasn't doing enough to improve the situation. jd

 

[Dusty Stevens]

@mikecr
I checked out the tool on their web site. Seems like a great tool only costly. Do you know of any other one that gives a specific primer depth. I had not thought of primers backing out due to either loose pockets or over smashing. TKS

I just auctioned one off on here.

 

[bigstick6017555]

RCBS press, with automatic primer feed attachment. Seat primers until they won't go further, and quit. If any stand proud, I address them individually. Never had a primer fail, and never thought I wasn't doing enough to improve the situation. jd

Same here Amen++++++

 

[Bob L.]

The pockets should be tight enough to keep primers from creeping outward, and even off seated contact over time. Loose pockets may not, and over-smashing them into pockets does nothing to prevent this.

Is there any way to measure primer pocket tightness or is this something that is verified after the fact when the primers have crept outward?

 

[Richard Coody]

Is there any way to measure primer pocket tightness or is this something that is verified after the fact when the primers have crept outward?

Don't need to measure it. If you use a priming.tool that has the right feel you can most.certainly tell when your primer pocket is done.

 

[JimSC]

Is there any way to measure primer pocket tightness or is this something that is verified after the fact when the primers have crept outward?

go no gages, I keep meaning to buy a set of these since my pockets seem to loosen before I have neck issues

https://ballistictools.com/store/swage-gage-small-primer-pocket

 

[bigstick6017555]

Phew, thanks guys, there for a while i thought i was going to have to buy a hydro primer seater

 

[NWnewguy]

Not much mention of it in all of this but having owned just about every primer seater made in the last 15 years, the Primal Rights primer seater is the best out there. It also costs at least twice what every other one costs. Certainly some diminishing returns as far as cost, but it is amazing. If anyone is looking for one, I have one of the RCBS bench mounted deals that I may put up on the BST.

 

[Bob L.]

go no gages, I keep meaning to buy a set of these since my pockets seem to loosen before I have neck issues

https://ballistictools.com/store/swage-gage-small-primer-pocket

I have those. I don’t know if they are adequate to assure primers don’t back out over time. That concept is new to me.