seating primer question

bluesclues

bluesclues

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Last week at the range, I was shooting some of my reloads when a couple of rounds did not fire after the primer was struck. A fellow shooter picked up the two "dud" rounds and frankly stated that I was not seating my primers deep enough. Now this was a little puzzling as this is the same reloading combination and technique that I have used for thousands of rounds.

However, out of a batch of 250 rounds shot last night, I had 5 "duds". As this has never been the case in the last 4 years of reloading of .40S&W.


Anything to this statement about primer seating?

thanks
 
The typical spec for primer seating depth is 4 thou below the case head surface, this means the primer is bottomed out in the pocket which is necessary for reliable ignition. If the primer is protruding slightly, easy to tell by running your finger over it, you can get FTF's.
 
No chance that you got some "rifle" primers mixed in with the pistol ones? This can cause FTF with some short arms, plus they will stick up a tad. Regards, Eagleye.
 
Thank you for the information. I am using a Lee hand held primer seater.
Although, I have never had this problem before, I will most certainly check EVERY single round from now on.

No to the rifle primers, only reload for pistols at the moment. Hopefully .223 very soon though.
 
I think i read in the Lee handloading manual that if you seat too hard (meaning that once the primer is bottomed out, you continue to put pressure) you can distort the innerds and cause FTF's.

With that said, the 4 thou in is even more important to prevent slam fires in semi's.
 
Did you switch to a different brand of primer?? I know when I started reloading, I had a few fail to fire, but they went on the second strike. After that, I gave more pressure either with the hand prime or the ram prime. I used to be paranoid the little buggers would go off if I bottomed out hard.:redface:
 
bluesclues said:
I am using a Lee hand held primer seater.
Click to expand...

I have had that same problem with the Lee primer tool. The tool linkage wore to the point the primers were not being seated firmly in the case which is required for consistent ignition.

Usually when insufficient seating depth is an issue the rounds will fire the second time you try them as the first firing pin hit seats the primers.
 
good info, thanks again. Am going to check the primer tool for wear etc.
Primers are Win small pistol. Have used these almost exclusively with no problems.

Now I have to check the 500 or so that I have loaded...
 
You might also look at a light hit from the firing pin,might be time to check it.
Plus one on it will often go bang on the second try.
 
OK, I think that it is probably the primer seating depth that has caused these recent FTF. I completely detailed stripped my XD40 and checked the firing pin. The firing pin is good to go. So cleaned everything again. Loaded some more ammo last night and will take it to the range tonight. I love Christmas holidays... been to the range more times this week than I have been in the last 2 months:D
 
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