Primer seating

Use what knowledge is best for you.

Lefty223 said:

Finally bought the Frankford Arsenal priming tool from Cabelas and love it! Comes complete in a set with all most common shellholders included. There is a depth adjustment on it too, which is a nice feature. So far I like it as much as the older generation Lee tools, which were de bomb, as far as I'm concerned.

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This is the other one I am looking at. I have heard the same about some of the rcbs tools taking a lot of pressure but the couple I have used weren't too bad.

Anybody else use the frankford arsenal perfect seat? I am thinking it is what I will buy, If I can find it in stock. If it isn't what I need I will get the k&m.

Have you ever wondered why a load likes one primer over another? Why trying different primers to 'see which is best' seems such an abstract?
Ask 'what primers work best for 6BR', and you'll get every brand of small rifle primer, but your testing will only show one or two that are clearly better -for you. That is, IF you tested.

Well I don't know why. I'll declare that.
But I have discovered that LOCAL primer striking plays a big role in it.
If you have some really nice grouping going for you, and you alter firing pin protrusion, FP fall, FP weight, FP spring, trigger sear location & lock time, head space, primer seating/position, or any primer changes, that grouping can be affected from marginal(better or worse) to an extreme worse.
With any issue here, you might never reach best from your system, and all the while every primer can fire just fine.. BANG with every trigger pull..
You could be happy with your development leading to a 1/2moa shooter, while oblivious to a gremlin limiting your efforts to just that.

There is testing you can do, things you can watch for, and it helps in this to hold consistent headspace, and lock primer seating and location into known standards -as actually measured (every round). That's at least a couple easy items to scratch off the list. It helps to set primer pocket depths to a standard, and it helps to preload primers correctly to these depths, again, as actually measured. Controlling head spacing through measure is a given anyone reloading should know.
The indicated K&M is the only seating system I'm aware of that simultaneously sets primers of varying heights, to pockets of varying depths, to the desired preload(crush), which should begin at manufacture's recommended (2-4thou crush). It does it fast & easy, and it's a pretty good seater overall.

I used to go with the lee hand held years ago but had problems with it not fully seating primers on Rem Rum brass. For Cheytac size brass I use the Sinclair hand held which is an adjustable high quality seater but slow which is fine, loading high quality is not a fast process. For every thing else I use the Forster co-ax press. It's delivers a .004" crush but may vary depending on pocket depth. The important thing is with any brass brand it has been able to put a crush after the primer is seated. I have my hands all over primers while seating and have never noticed any ill affects from handling. You would really have to press hard to indent your finger into the primer material and transfer oils from your skin. I started off using latex gloves to seat primers but I have since quit using them. Then again it might have some small measurable affect if your looking to achieve benchrest accuracy idk. I have not noticed any while loading ammo for tactical matches or hunting but I also have not tested this directly.

I run the RCBS Universal hand priming tool, works on everything from 17Rem to 416Rigby. The only cartridges I have that don't fit are my 505Gibbs/500NE.
I get very uniform depth with this tool, my old one that uses shell holders would vary with whatever shell holder I was using. I was not pleased with this.
If you prime while watching tv, as I do, this tool is very easy to use and foolproof.
Just don't get hamfisted with it, I watched a buddy use his for the first time and he 'thought' that the handle HAD TO TOUCH THE FRAME to get a fully seated primer. The force he used from BOTH HANDS to close it must have been HUGE, yet the primer didn't detonate.
I enlightened him that you can 'feel' the primer bottom out when there was a spring to the handle and you can get very consistent seating depth this way.

Cheers.

I am supposed to be able to feel the primer bottom out? Y'all cut that out I a'int play either.

Mike Dunaway said:

I am supposed to be able to feel the primer bottom out?

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Most folks gage their success by misfires or lack of. This is a very low standard.
People who measure primer seating learn right off the bat that you cannot accurately set primers by feel.
Primers are different from each other, like pockets are different from case to case.
It isn't just depths, but diameters, and hardness, and friction.

I think that its a bit of an old wives tale about rubber gloving your primers and contamination paranoia etc. I have loaded cases of primers by plucking them with my forefingers and sticking into my hand primers and never missed a lick. I have only had one dud out of many thousands of large rifle recently and who knows why. Maybe that was the 1:10,000 from not using match br. Not saying I am going to prime with drippin oily hands but I usually have residual imperial wax on em and just wipe my hands off on a rag and get to work.

For hunting loads I will wash my hands and dry them just to be on the safe side tho. I see pics and videos of people wearing rubber gloves and just cringe thinking how uncomfortable that would be. And not to mention unnecessary unless, I guess, if you are loading for some national championship.

I only use a hand primer - newest fav is the 21C - as its the fastest way for me to prime and truly feel the insertion pressure. The depth is already preset for crush. Last night I primed 100 casings and out of that I felt 3 soft ones out of the batch. I deprimed them and measured the pocket and they were 1-2 tho over normal. Those casings were all 4x fired. Thats another reason I like to hand prime is to be able to feel the primer insert and give me a heads up on any loose pockets so I can toss them in my annealing test case bin.

I agree on the paranoia associated with the contamination of primers by handling them with bare hands. I wash my hands with soap and water just prior to priming cases, and then handle primers with clean bare fingers with my K&M hand priming tool. I also only handle the primers with my left hand fingers, and am cognizant to not touch or handle oily objects with the left hand fingers until priming is completed.

However, I don't believe in Bigfoot, or the abominable snowman either. So to each his/her own.

Schnyd112 said:

This is the other one I am looking at. I have heard the same about some of the rcbs tools taking a lot of pressure but the couple I have used weren't too bad.

Anybody else use the frankford arsenal perfect seat? I am thinking it is what I will buy, If I can find it in stock. If it isn't what I need I will get the k&m.

Click to expand...

I have the Frankford, had several other brands mentioned, except the K&M. The Frankford is the best I have ever used.

if you only single stage then use your press. But, I have been using the lee auto prime and love it. Enough said

Mikecr said:

Most folks gage their success by misfires or lack of. This is a very low standard.
People who measure primer seating learn right off the bat that you cannot accurately set primers by feel.
Primers are different from each other, like pockets are different from case to case.
It isn't just depths, but diameters, and hardness, and friction.

Click to expand...

Mike, you are correct, but you CAN see and FEEL when a primer stops moving and the cup/anvil 'spring' letting you know that any further seating will be moving the cup and distorting it. On press priming often results in flattening the cup excessively, which MAY cause misfires, although I am yet to experience one in 30 years of handloading.
After seating many thousands of primers on my hand tool and measuring them for the .004"-.005" below flush, even with different brands, you do get a feel of when the primer cup and anvil are at the same height as each other.
If you seat a primer so that it is so flattened that the radius is affected, then you have crushed the anvil into the priming compound.
A primer only needs to have the anvil against the pocket floor and the cup sitting flush with it, no pre-tension or stress is required, this is a long believed myth. I still have boxes of factory ammo with ROUND TOPPED primers, which is where the term "watch for FLATTENED primers" came about, modern primers are already FLAT on top with radiussed edges. I'm not sure of the decade when this changed, but it WAS significant for handloading as primer appearance really was no longer a good indication of excessive pressure.
Primers are packaged with the anvil proud of the cup for a reason, to avoid a mishap during handling etc after manufacture.
If you READ what the manufacturer states about THEIR primers and how much seating below fluch is required, you will see that it changes by brand as to the amount is required to get the anvil and cup seated flush WITHOUT crushing the cup/priming pellet. Cup thickness is the largest factor with this, obviously.
Cup hardness is often sighted as more or less between brands, this may be true, untested by me, but most believe a nickel plated cup is harder than a non plated cup. Winchester primers are often called soft and undersized, perhaps they are, but I have measured them with .0001" accurate micrometers and they are within 2-3 tenths of plated cups. I truly believe it is FRICTION that is felt between plated and non plated cups that makes a difference, not necessarily hardness.
I know that ALL brands of primers feel HARD to seat in new Norma brass.

Cheers.

Measurement shows what really is.
In all the cosmos, you won't ever better measurement -with another approach.
And the indicated K&M is the only priming tool that actually measures primer seating.

Check me. Pretty sure this still holds true.

Mikecr said:

Measurement shows what really is.
In all the cosmos, you won't ever better measurement -with another approach.
And the indicated K&M is the only priming tool that actually measures primer seating.

Check me. Pretty sure this still holds true.

Click to expand...

Check out the 21C primer seater.