primer seating question

[paradox998]

Hello all

I am using a Lee handheld shell primer for a large number of 223 rounds. Lake City brass is extremely difficult to slide into the #4 shell holder lee specifies for 223. I have two #4 holders and both are a PIA. I read that other reloaders have found a similar problem. I did some experimentation found that the #19 shell holder works well with LC brass. Is there any reason not to use the #19 holder? I noticed the #19 base is a little thinner than the #4. Is it possible to seat primers too deep? The tool feels like it is seating them correctly and they are all lower than flush with the bottom of the case. Thanks for the guidance.

 

[LiveLife]

Is it possible to seat primers too deep?

Once they are seated to the bottom of the primer pocket, you can actually start to flatten the cup (Yes, I have done it with pistol primers and the Lee Auto Prime with two thumb pressure).

I start out with one thumb pressure to catch any military crimp primer pockets and then seat them until they are "fully" seated with two thumbs - You can tell by the firm "feel" and the resistance as you reach the bottom of the primer pocket.

Rifle primer cups should be harder than pistol primers. I wouldn't worry about seating them too deep, as the concern should be not seating them deep enough (flush).

 

[ArchAngelCD]

I use a hand held primer tool because I can easily feel when the primer is bottomed. I'm guessing you can feel it too. When you feel the primer is correctly seated stop pushing. You can't really seat a primer too deeply because bottom is bottom but you can crush the primer. You might not want to do that especially if you don't have your eyes and ears on..

 

[Steve C]

Worry about not seating the primer into the bottom of the pocket and not about flattening the primer.

With a hand primer you can feel the primer bottom out and that's when its seated correctly. Failure to seat the primer into the bottom of the cup will result in failure to fire. Flatten the primer with extra pressure and the rounds will still reliably fire so there's no real downside if that happens.

 

[BADUNAME37]

As others have stated, you are looking for several thousandths of an inch below the case bottom (just a hair, literally).

I agree with others, no matter what "method" you use, you will eventually get to the point where you can "feel" the primer bottoming into the primer pocket.

I happen to use an RCBS bench-mounted primer-seater tool. It has a handle about 10" long. I get a nice smooth action as the primer is being seated, then it stops.

One thing:
Some primer/case combinations are harder to press the primers into place while other combinations may be way easier to set. When I find an occasional one that is really easy (almost as if the primer may fall out - however I know they are secured harder than that), I discard the case after placing a drop of oil into the primer hole and crushing the case with pliers.

If the primer was just a bit easier going in than my liking, I mark the entire case bottom with a black permanant marker so I know I will get one more firing out of it, before I throw it out. On those with the black base, I seal the perimeter of the primer with nail polish just to be on the safe side should any gases want to escape.

This method has worked for me for over 25 years without any problems.

 

[JimKirk]

One more reason I like the Forster CoAx press, it always seats the primer .005 below flush. The design makes sure of that, unless there is something in the primer pocket to keep it from doing so.
In 40+ years of reloading and many many thousands of primers, I have had one CCI 200 rifle primer fail to fire! I am sure that was due to a bad firing pin as the rifle would fail on factory rounds and fire my reloads. The rifle had a somewhat over length chamber.

Jimmy K

 

[Walkalong]

While it can be done, it is hard to "crush" a primer. Don't be afraid to seat them with a good amount of pressure. You are more likely to leave them seated high than crush them. Most primer seating tools are set up so they can only seat the primer just so deep. One more reason I like the hand primers, but the setups on single stage presses work just fine with a little practice.

If they are below flush, you are almost surely good to go. If they are hard to get in the shell holder, try another one.