HELP! .40 S&W Dimpled primers

[300blackedout]

Hey Guys. Need some help with my .40 loads. The problem I am running into is about a 10% failure to fire due to primers not igniting. I have tried exchanging every component I am using including using both CCI and Remington Primers; Power Pistol, IMR and Winchester powders; as well as both new and once brass of different brands. Also I have tried not touching the primer pocket as well as cleaning/resizing using a lyman hand tool. I am seating my primers using the hornady hand primer.

If pull the bullet on the dud round it is clear that the primers have not gone off, yet there is a clear dimple in the primer. Also note that using the same primer and equipment I have never had a bad rifle round.

Has anyone else had a similar experience or have an idea what could be going on here? THANKS!

 

[Rule3]

99.9999% the primer was not seated deep enough. Did you try a second strike (refire) the ones that did not go off? If they do, then the primers were not seated firmly to the bottom.

Does the gun fire 100% with factory ammo?

 

[243winxb]

Slow velocity of the striker/firing pin. Clean gun. Weak springs may do it also. Make/model firearm?

 

[gamestalker]

Yep, they're not seated all the way to the bottom of the pocket.

Some folks worry about seating primers too deep, thus they constantly experience mis fires. The proper way to seat a primer, is to seat it until you can feel some obvious resistance as the anvil gets pre loaded.

GS

 

[300blackedout]

follow up

thanks everyone for the thoughts.

Make Model = S&W M&P .40. and yes it does fire 100% with every brand of factory ammo i've tried.

Yes usually I can get the rounds to go off eventually I reload and try to fire them again.

So if they are not getting seated enough what is the solution? I am seating them as far as I can with the hornady hand primer. Is there a better option?

 

[Walkalong]

Is there any adjustment with that priming tool? Anything loose on it? Sure you are getting them seated as far as the tool will allow?

Don't worry about being to easy with seating them. Try again with more force and see if they all seat below flush. If they still won't all seat below flush, and you can't find anything wrong with the tool, call Hornady.

 

[243winxb]

Headspace is on the case mouth. Dont over crimp.

 

[rsrocket1]

Be sure your striker channel is clean. Never squirt cleaner or lube into that spot. If the light primer strikes are off center, the slide is not closing 100%. You will be able to pull the trigger when the slide is almost, but not 100% closed. The case is fully in battery, but the barrel is still tilted slightly. You can try that out yourself with a fired case in the chamber. Ride the slide very slowly and keep trying to pull the trigger. You'll see that you can pull it just before it is fully closed. The result is a light off-center strike on the primer.

Culprits can be a weak recoil spring, dirty extractor hook, dirty extractor cavity or reloads that are too snug to fit easily into the chamber and are causing resistance in the slide closing. That often also results in not being able to pull the trigger sometimes when the slide is stuck back even further.

 

[Rule3]

thanks everyone for the thoughts.

Make Model = S&W M&P .40. and yes it does fire 100% with every brand of factory ammo i've tried.

Yes usually I can get the rounds to go off eventually I reload and try to fire them again.

So if they are not getting seated enough what is the solution? I am seating them as far as I can with the hornady hand primer. Is there a better option?

OK that pretty much "proves" there is no issue with the gun or the primers.

When you seat a primer a little to high. it does not go bang the first time. The fire pin pushes it in the rest of the way and then the second strike makes it go bang (talking thousands here)
So as mentioned squeeze the primer tool hard you will feel it seat and bottom out. No it will not go off when you squeeze it hard. Sometimes when doing a lot of them by hand you just use less pressure as it gets tiring or not paying close attention or whatever. It happens.

I used to use a hand primer but now prime on the press and the leverage of the press really seats them in there!

I do not know anything about the Hornady tool, I used to use the old LEE and RCBS Universal version. They both worked well but my thumb would get a work out with the LEE

 

[murf]

squeeze harder!

murf

 

[[email protected]]

Double tap the seater handle. Let off the pressure after initially seating the primer and give it one more press.

 

[Shootshellz]

I also use the 'old style' Hornady priming tool. Do yourself a favor and purchase the RCBS primer depth gauge. Very easy to use and then you will absolutely know when the primer is seated to the correct depth. No more guesswork regarding 'squeeze harder' which is subjective to the user of the priming tool.

 

[horseman1]

The Hornady hand primer tool comes with two different trays, for use with different brands of shell holders. Green for RCBS and a black one for use with Hornady shell holders if I recall correctly. You might want to double check to make sure you have it configured correctly.

H1

 

[Shootshellz]

FYI the 'old style' Hornady hand priming tool has two different shell holder inserts (one for RCBS shell holders, the other for Hornady shell holders) not two different trays.

 

[horseman1]

The two Hornady hand primers that I own have different trays, so it must depend on which version the OP has. Either way, that would be the first thing to check.

H1

 

[BYJO4]

I agree with others that it more than likely a primer seating problem. If they will fire on the second try, depth of the primer is your problem. If this is not the problem, I would check the spring and firing pin.

 

[300blackedout]

Thanks

Sorry for the delayed response, thanks for the all the input! I will continue to investigate the primer issue and see what I can figure out about seating them further