Properly seating primers

[magnum338]

Thanks Armoredman for your response. It's good to hear that what I said may have answered a question from someone.

I've picked up discarded brass on the range and wondered how the unusual marking came about. Thanks for posting the pictures. They explain it.

Actually, I'm not much for handguns (OK everyone, in unison now, Booooo). Of course I have several but they're not my first love.

I've seen excess force distort primers badly but it evidently doesn't matter in a handgun. Has anyone had a primer let go in the tool? It scared the tar out of me when it happened many years ago when I was getting started. Is the situation different in handguns?

Whenever I load for my M1, or any of my rifles, I'm very careful not to allow the primers to protrude at all. I can imagine what would happen in a slam-fire with a high primer. Therefore, I cut the crimp out of mil cases and seat my WLR's to the pocket bottom. Remingtons will not seat that way in most cases. By feeling the primer bottom out I know the anvil is seated against the web, and press it no further.

 

[GLOOB]

I've seen excess force distort primers badly but it evidently doesn't matter in a handgun.

I guess my post was too long to make good reading.

Yes, excess force DOES matter in some handguns. Squashing the primer can make it too deep for a gun with a short firing pin protrusion. It's also possible for the priming compound to crack, rendering it unlikely to fire. It all depends how strong you are, I guess. I've a friend that has used my press and couldn't even get CCI 400 SRP's flush in luger cases. I, OTOH, have to be careful not to crush the cups.

 

[LiveLife]

This is specific to pistol primers (LP/SP).

Many people continue to post on various forums that they are still having ignition issues with Wolf primers. I initially thought this was attributed to the harder nickel plated Wolf primer cup from a lot sold last year. I have been curious about this issue and here's my updated opinion based on my use of Wolf/Tula (nickel and bronze color) and PMC (lighter brass color) primers.

For primer to ignite, the firing/striker pin must indent the cup deep enough to pressurize the priming compound against the anvil, which sets the anvil feet against the bottom of the primer pocket.

Wolf and Tula primer cup sizes are a bit wider than domestic (Winchester/CCI) and Brazillian (Magtech) primers I use and take significantly more "Ooomph" effort to seat them on my Lee Auto Prime and Lee XR hand primers. Because of the effort required, I now hand prime Wolf/Tula primers only the XR (XR has much heavier/stronger handle than Auto Prime - for press priming, I push until they are seated). The larger sized primer cups will prevent the primers from being seated to the proper depth (.004" below flush) and not allow the anvil on the bottom of the primer cup to "set" against the priming compound.

With most domestic primers that are not seated deep enough, the first primer hit will usually seat the primer deeper in the pocket, setting the anvil against the priming compound and the subsequent primer hit will ignite the compound. With Wolf/Tula primers seated high (at or above flush), first primer hit may not seat the primer cup any deeper and subsequent primer hits may/will not ignite the priming compound. Combine the larger cup size with especially tight primer pocket cases like Sellier & Bellot (S&B), you have a situation where proper seating of primers becomes a problem. The first primer hit won't ignite and subsequent hits won't seat the primer any deeper and no "bang".


Solutions?

1. If you experience primer ignition problem (especially no "bang" on subsequent primer strikes), check the head stamp to see if it is S&B. If it is, then you want to separate out S&B cases for Wolf/Tula primer use. I have started to separate out S&B pistol cases from my plinking brass bucket and add to my match brass bucket as I do not have ignition issues with S&B cases and Winchester primers.

2. If you are having ignition issue with non S&B cases, make sure you are seating them below flush (.004") and see if ignition problem continues.

3. If you are getting light primer cup indents (see post #17) with striker fired pistols, check the bottom of striker pin tube channel for any hard fouling buildup that will prevent full striker pin travel and scrape/chip out this hard buildup with 15-20 minute soak in Hoppe's #9 solvent (plug striker pin hole on breach face). Usually, striker pin spring replacement has not been necessary if the light primer cup indent was due to the fouling buildup.

4. Hammer/striker/firing pin spring replacement is the last option if all above do not address the primer failure to ignite issue (I guess you could always go with softer cup primers like PMC ).


I hope this helped.

 

[33rowdy]

So why is this tool a sin or a bad idea to use?

http://media.midwayusa.com/productimages/medium/764/764406.jpg

 

[gamestalker]

I use an RCBS priming die that allows me to set it to a certain depth and not have to worry about too much or not enough. I started using that die when I started reloading more than 30 years ago and have never had one single mis-fire. I can't say the same for factory ammunition, by any means. And the factory that has failed to fire over the years, which by the way is quite a few times, has been because of the primer being seated to shallow. So my rule of thumb is simply, make sure the primer is below the head by .001" or so. "Or so" is the common sense part of priming. If it is the slightest degree below the case head it will go bang. I use CCI primers and have forever, and they seem to have a sweet spot that is easy to feel when your at that point.

 

[oldreloader]

So why is this tool a sin or a bad idea to use?

http://media.midwayusa.com/productimages/medium/764/764406.jpg

It's not. I use one on every case I reload because I want to and because it removes one more inconsistancy.

 

[Cop Bob]

So why is this tool a sin or a bad idea to use?

http://media.midwayusa.com/productimages/medium/764/764406.jpg

It ain't... I just don't use it on every round I load... Pistol stuff... no way, I go through way too much of it... it's all done on progressives, and there just isn't a station for that... if there was, I would be using it...

It is a right handy and good tool... 1/2 twist of the wrist and your done...

For pistol ammo that I run for duty/self defense, yup, I go the extra step, those I often do in fairly small lots, on a single stage...

Rifle ammo, especially target and long range, ream and debur primer pockets, clean pockets, then load.. all on single stages, and taking the time to be finicky..

.223, nope, too much of it, and all run on progressives... only special attention that new to me, once fired military gets is decapping on single stage, trip through the primer swage, then dumped in with the once fired for loading on the Dillon. On the third trip through, trim to length, repeat... Often factory loads for duty, or self defense.. nothing against reloads for social endeavors, I prefer them, but only if they are mine.. I have no control over the care and quality control of others...

 

[LiveLife]

I want to clarify my post.

For most of non-S&B brass, Wolf/Tula primers work well (other than extra effort needed to seat the slightly larger cups). If the reloaded cases have loose primer pockets for smaller domestic primers, larger Wolf/Tula primers will extend the usable life of these cases before they need to be tossed/recycled.

My post speaks to tight primer pocket cases like S&B and some once-fired cases that cause failure to ignite. If you are loading rounds for match and/or SD/HD shooting where your rounds must go bang, this is an issue.

 

[Shmackey]

Primers probably receive more overthinking than any other aspect of reloading. Well, maybe they're second to case cleaning.

Here's the complete, detailed list of how to seat a primer:

1. Push primer into case as far as it can go.

 

[LiveLife]

With softer cup primers like PMC, you can seat the primer too deep and crush the primer with anvil puncturing the priming compound. If I wanted to, I can seat primers in the Lee hand priming tool to .006-.010"+ and certainly can push the primer in the press til "crush" depth. I usually hand prime match loads until I feel the initial resistance of primer seating and next look for the anvil setting on the bottom of priming compound (second slight resistance). It is difficult to feel this second resistance while press priming.

This is what TheRiflemansJournal posted on their benchrest website on properly seating primers:

In my own testing, I have found that the best method is to clean the primer pocket (I don't uniform them) then, seat the primer until you feel it just touch, then apply a bit more pressure (not a lot) until you feel a second level of resistance just starting.

If you examine some new primers you'll see that the legs of the anvil stick out past the bottom of the cup. When the legs hit the bottom of the primer pocket you feel that first resistance. As you continue to apply pressure you bring the cup over the legs and then the second level of resistance begins as the center of the anvil begins to compress the pellet. Stop!

This is what Co-Ax website says about crushing primers:

Illus. 1: IMPROPERLY SEATED - This primer is improperly seated, preventing the cups of the primers from resting solidly on the bottom of the primer. Some primer cups measure .120” in height, and if seated with crowns more than .004” below the case head, the anvil would be forced through the crown, rendering the primer useless.

Illus. 2: IMPROPERLY SEATED - This primer is improperly seated too high. A high primer is erratic in performance. It is also dangerous and could explode in the chamber of a rifle when the breech block closes on it before it is locked.

Illus. 3: PROPERLY SEATED - This primer is properly seated, exactly as it would be with our Co-Ax® Reloading Press. The crown is .004” below the surface of the case head; the anvils are on the bottom of the primer well; and the primer mix is properly stressed by the anvil for sensitivity. It is also much safer than either of the two seated primers shown above.