primer seating?

large pistol primer .45 ACP ALL the way in OR just past flush with the case head?

All the way in.

Is there a difference? Just past flush sounds like all the way in. I was taught to not flatten the primer with undue force - something about the anvil. If they aren't going in easily or strait I use a pocket reamer to touch them up, especially if using CCI (hard) primers.

My 550 tends to seat just below flush. Not far below, but enough to where it is visible from the side. When I handprime, I shoot for the same.

If seated not all the way in, anvil is not supported and first strike may seat it deeper instead of igniting. Hence the lite strike.

I would seat until full contact with primer pocket for consistent ignition. Coming from long precision rifle many seat primers with .006--.009 crush when seating primers, claiming better ignition and accuracy. I don't know if primer crush would make a difference in pistol calibers at 50 yds. and in.

The manual for my Dillon states .002"-.006" below flush.

Thank you all! as the gentleman said "coming from precision rifle" those guys are still debating primer seating 100 years later, I primed 700 cases this afternoon, now I'm trying to decide if I want to open the 20 pound steel keg of BULLS EYE or the 4 pound steel can of HERCO or the 4 pound steel  can of UNIQUE? Anybody load magnum want to trade for a can of 2400?

Seat all the way!
For years I primed on my Dillon SDB below flush (I thought it was all the way)=99.99% reliable reloads in my wad & ball guns. - -Then I got a 45acp revolver & the same ammo had misfires AT LEAST 1 round in 20.  - I started hand priming for the revolver-mashed 'em in good w/ signs of deformation on many=NO IGNITION PROBLEMS SINCE-revolver or 1911. 2¢ - YMMV

Russ OR wrote:Seat all the way!
For years I primed on my Dillon SDB below flush (I thought it was all the way)=99.99% reliable reloads in my wad & ball guns. - -Then I got a 45acp revolver & the same ammo had misfires AT LEAST 1 round in 20.  - I started hand priming for the revolver-mashed 'em in good w/ signs of deformation on many=NO IGNITION PROBLEMS SINCE-revolver or 1911. 2¢ - YMMV

Greetings,

Interesting result. Thanks for the details.

Question? Do you decap your brass and wet wash it with pins? (i.e. clean primer pockets.)

Curious to learn if "Krud" in the primer pocket could be an influencing factor.

Cheers,

Dave

To fc60- and all.
I de-prime before tumbling. I also wet tumble without pins. The carbon in the pockets is usually gone but if there is some still there, I don't really worry about it. The new primer will crush it and seat.
I have found that a good firm/steady push will seat them just fine. But I'm never in too much of a hurry.

Not a lot mentioned here on the method for seating primers.   In my reloading course I teach to use a hand primer tool as opposed to using the press to seat primers.   The reason is the hand primer gives you the "feel" during primer seating that a press simply does not.   All the way in and just past flush are one and the same.

Don

I've used a Dillon 650 and 550 to seat primers for decades. As long as I seat them as far as they will go, I never have problems with ignition. Hand seating primers for a serious bullseye pistol shooter isn't practical and takes time away from training.

USSR wrote:Not a lot mentioned here on the method for seating primers.   In my reloading course I teach to use a hand primer tool as opposed to using the press to seat primers.   The reason is the hand primer gives you the "feel" during primer seating that a press simply does not.   All the way in and just past flush are one and the same.

Don

I respectfully disagree with this approach and the notion about luck of sensitivity while seating primers on presses.  After reloading 1/4M rounds, I can feel how each primer is being seated regardless whether I use Dillon or Star presses.  I also can feel when there is no primer for one or another reason, or if case didn't get de-primed.  Seating primers via means of press provides for uniformity and consistency, and it is almost mindless.  With priming properly set up and lock, presses provide same range of motion cycle after cycle.  Variations only come from primers themselves, - different brands have ever slight dimensional differences.  On Star and Dillon 1050 presses adjustment for primer depth seating is very easy.  A bit more complicated on 650 and 750 (I presume, 550 is the same as 750, but I don't know for sure as I do not have 550 nor SDB), but also, once it is set, seating is very consistent.  At the same time hand priming requires same force to be applied in order to have consistent seating.  I do not know about others, but I personally can't seat more than couple hundred of primers by hand in one session.  And even with that I sense that I am not applying same force every time.  I know, that many reloaders prefer hand priming for different reason, - specifically due to safety concerns that stack of primers in primer magazine can go off should something happen during seating.  I have not had such experience, and do my best for not having it.  However that is different issue / topic.

All of the above is, of course, IMHO.

AP

Here of lately I had a problem with miss fires and light primer hits with my 1911 45 so I got to looking at everything changing firing pin spring and hammer main spring to try and solve the problem. I went as far as weighing different firing pins to see if the weight was a problem and the length to make sure the firing pin wasn't too short. 
One or both springs seemed to be the problem since it went away after the replacing them.
I also inspected the primer seating depth and the primers were flush with the case rim and some were a little proud. Not knowing how many reloads were on them I decaped and inspected the primer pocket. Though I normally don't clean the primer pockets on pistol cases I decided to do some and see what would happen. I used a Reading primer pocket tool and cleaned the pockets down till I started seeing brass shavings. The tool was for rifle primer pockets, so I didn't go as far as to square the bottom of the pocket since that may make them too deep. 
The results were a nicely seated primer just below the rim. I use a 450/550 Dillon press for my 45acp reloading and primer seating. 
A lot of extra work but it gave me piece of mind and may do it to more of my brass since it does help with rifle accuracy and it might help with my pistol reloads.
When you start seeing flattened primers after seating them it's time to clean the primer pockets.

If I recall correctly my old Lyman manual added another reason to seat a few thousandths below flush — to avoid inadvertent ignition. High primer being susceptible to being hit during feeding, it provides a margin of safety I guess for minor variations. Not sure how that squares with the misfire issue with primers not being fully seated.

Dave wrote:
Question? Do you decap your brass and wet wash it with pins? (i.e. clean primer pockets.)

Curious to learn if "Krud" in the primer pocket could be an influencing factor. - Not sure..




I do the wet/pins now,  but for several years after I started hand priming I was still cleaning brass w/ walnut shells & vibe tumbler. - I did & do size, deprime, & flare (powder funnel propped up w/plastic wedge) before cleaning. -  I have a system so it's not toooo bad-do 6000± cases at once.  -- the hand priming is the least of the "time adders".
I haven't had a priming system on a reloader for 12 years.
When I make ammo, the case are clean, primed, sized, And pre-belled.

I have never cleaned a primer pocket in my life.
Before I started wet/pin tumbling(=clean primer pockets) I noticed a lot of very hard black crud priming breaks loose. 
Wingdings Capital J, Russ

I use the RCBS bench priming tool, I have tried hand primers and just could not get consistency, just my experience. Some reply's mention seating depth, but primers vary in height by brand as well as primer pocket depth in brands of brass, .004 below flush may or may not be fully seated.