Somewhat reloading related - Lake City / Primers

[BeeKay]

I see this is the Ammo Forum but all I see here is Reloading - So I'll post here and see how it goes.

I have some Lake City Ammo that I'm seeing light primer indentations with.

And with my handloads using Federal, Winchester or CCI primers the primer indentations seem fine.

But I thought I'd try a stiffer hammer spring since I have one in my parts box, and even with the stiffest spring (.048 wire - not sure about the rating) I still get shallow indentations using the Lake City Ammo - I don't think it's surplus ammo, the primer pockets aren't crimped.

Is this common with Lake city Ammo ?

I was also getting ignition failures at the range with that ammo 

 

Picture coming  -  Thanks in advance

[BeeKay]

 

The Lake City case is on the right, I'm not sure if the pic shows the difference.  I actually re chambered the spent brass and re struck the primer a second time with the stiffer spring in there and those primers are obviously harder than the primers I reload with

Thanks  - Feedback Appreciated

[Armed Eye Doc]

I do not reload but thought I would ask these questions for information.

Does the ammo fire when you pull the trigger?  Or do you get failure to fires?

@98Z5V, any ideas here?  Also @NF1E, have you seen this issue?

Edited October 30, 2023 by Armed Eye Doc

[BeeKay]

27 minutes ago, Armed Eye Doc said:

I do not reload but thought I would ask these questions for information.

Does the ammo fire when you pull the trigger?  Or do you get failure to fires?

@98Z5V, any ideas here?  Also @NF1E, have you seen this issue?

About 1 out of 5 shots is FTF with the LC ammo 

I get no FTF using my handloads.

The one on the right in the pic was one that was a FTF and I pulled the trigger on it a second time.

I got poor primer indentations using this ammo with another .308 as well.

It just seems really odd

[NF1E]

I would check firing pin protrusion for a start. Could be the LC cases have too short a BTO and are bouncing around in the chamber.

Edited October 30, 2023 by NF1E

[BeeKay]

17 minutes ago, NF1E said:

I would check firing pin protrusion for a start. Could be the LC cases have too short a BTO and are bouncing around in the chamber.

Is there a spec for FP protrusion ?
I have a set of Go/ NoGo gauges and a cartridge length checker and the unfired Lake City  cases are within spec by comparison to other cases and checked in headspace length to be the same as the gauges...   But that doesn't mean there couldn't be another measurement error that I've overlooked.

Not sure what BTO is

Edited October 30, 2023 by BeeKay

[BeeKay]

This is Lot # SMO2OE305-037

Lake City Ammunition Co
It seems odd to me that there would be a box of ammo that has primers that are too hard, but consistently that's what I am seeing.                                So it's either that, or another issue somewhere  

[BeeKay]

Here's another pic of 2 LC cartridges vs 2 of my handloads with CCM primers.

I originally had a lighter tension hammer spring in there, but not the lightest available - Then I tried a hammer spring with more tension and It dented the primers deeper but didn't do what I expected on the LC primers.

The 1st one closest in the pic is a LC with the lighter hammer spring - Barely dented - about 20% of those were Fail to Fire

The 2nd one was LC primer after I changed the spring to a heavier one 

The 3rd one is the indentation on a CCM primer

And the 4th one is a CCM primer with the stronger spring.

 

Thanks for any suggestions solving this problem

[98Z5V]

In that first pic you showed, it's easy to see that the case on the right has the primer seated deeper.  Also, it looks like .308 Win, from what I can see on the cases, blowing up the pic.  It gets blurry, blown up to far.  Those primers are going to be CCI 34, and they are harder (and hotter) than alot of other primers.  Firing pin protrusion shouldn't be a problem here, because the other stuff you chamber goes bang.  Primers seated too deep will cause this problem, though.  Look over the other unfired ammo you have, and check 'em out.

[NF1E]

9 hours ago, BeeKay said:

Is there a spec for FP protrusion ?
I have a set of Go/ NoGo gauges and a cartridge length checker and the unfired Lake City  cases are within spec by comparison to other cases and checked in headspace length to be the same as the gauges...   But that doesn't mean there couldn't be another measurement error that I've overlooked.

Not sure what BTO is

As mentioned, because you have good strikes on some ammo, protrusion should not be the problem.

As used, my BTO reference is for the distance from the Base of the cartridge to the datum point on the shoulder. BTD is also used to describe this measurement. Too much shoulder setback in some cases could possibly cause light primer strikes as the cartridge could be setting further forward in the chamber than desired.

[BeeKay]

8 hours ago, NF1E said:

As mentioned, because you have good strikes on some ammo, protrusion should not be the problem.

As used, my BTO reference is for the distance from the Base of the cartridge to the datum point on the shoulder. BTD is also used to describe this measurement. Too much shoulder setback in some cases could possibly cause light primer strikes as the cartridge could be setting further forward in the chamber than desired.

Also - The fact that I was getting shallow primer indentations with a different rifle, using the same ammo, tells me something.

I won't call it light primer strikes anymore.

If I had a better camera, I'd make a video of how tough these primers appear to be - Maybe I will when I have more time,

There are still things about this that make very little sense to me.

Thanks for the helpful information to anyone who contributed

[BeeKay]

16 hours ago, 98Z5V said:

In that first pic you showed, it's easy to see that the case on the right has the primer seated deeper.  Also, it looks like .308 Win, from what I can see on the cases, blowing up the pic.  It gets blurry, blown up to far.  Those primers are going to be CCI 34, and they are harder (and hotter) than alot of other primers.  Firing pin protrusion shouldn't be a problem here, because the other stuff you chamber goes bang.  Primers seated too deep will cause this problem, though.  Look over the other unfired ammo you have, and check 'em out.

My camera exaggerates some reflections and some shadows in close up shots.
I should try taking some shots with a different camera - I need to read the instructions on how to interface it with this computer, first.
I'm beginning to think that possibly I bought a box of 250 rounds of ammo that has primers that are too tough to work reliably in either of my rifles.
It's sort of difficult to believe though.

[BeeKay]

21 hours ago, 98Z5V said:

In that first pic you showed, it's easy to see that the case on the right has the primer seated deeper.  Also, it looks like .308 Win, from what I can see on the cases, blowing up the pic.  It gets blurry, blown up to far.  Those primers are going to be CCI 34, and they are harder (and hotter) than alot of other primers.  Firing pin protrusion shouldn't be a problem here, because the other stuff you chamber goes bang.  Primers seated too deep will cause this problem, though.  Look over the other unfired ammo you have, and check 'em out.

My camera exaggerates some reflections and some shadows in close up shots.
I should try taking some shots with a different camera - I need to read the instructions on how to interface it with this computer, first.
I'm beginning to think that possibly I bought a box of 250 rounds of ammo that has primers that are too tough to work reliably in either of my rifles.
It's sort of difficult to believe though.

[BeeKay]

So now I'm trying a few different hammer springs .

The trigger kit I have came with springs in increments of .003" between .038" and .050"

Of course the results are predictable,  A harder trigger pull but no misfires.

I'll just keep the stiff spring in it until I get some different ammo

[BeeKay]

It all started to make more sense when I remembered that I also did a trigger job on my .308 hunting rifle 
Which also included a lighter hammer spring

[shooterrex]

I don't know about Lake City but some ammo makers load ammo with harder primers for machine guns. Firing from an open bolt. 

[98Z5V]

1 hour ago, shooterrex said:

I don't know about Lake City but some ammo makers load ammo with harder primers for machine guns. Firing from an open bolt. 

Lake City does that on all the linked 7.62 ammo.  It's all CCI 34 primers, for that very reason.  No reason a standard trigger shouldn't set them off though.

@BeeKay, are any of those primers seated too deep?  Are the flat surfaces of the primers below the lip of the rim?

[BeeKay]

I'm going to run a test tomorrow with some different springs and some reloads using the CCI primers that I usually use.
Today i tried a .044" spring and the indentation is better - They fired - No misfires
With a .042" spring which was actually lightened even further by tweaking the legs of the spring, I was having about a 20% misfire rate with the Lake City Ammo
But 0% failure with my handloads.
I'll attempt to get some quality pics with my digital camera - I can zoom in on a fly and focus on the hairs on it's back with that camera.

[98Z5V]