Pre priming cartridge cases, problems?

[Slash2]

I'm having some primer issues with a batch of .45 colt rounds I loaded and I'm trying to narrow down the causes.

I primed a batch of .45 Colt brass a month or so ago to test out a new RCBS hand priming tool and left the unloaded primed cases sitting in a small box. In addition I recently had the cylinder of my 45 Colt Ruger Redhawk machined to except moon clips for both 45 Colt and 45 ACP. I loaded the primed 45 Colt cases, put them in the moon clips and went to the range to check them out. Around 10% of the rounds miss-fired. When I pulled them back at home they all had a load of powder and they all had solid hammer strikes. The primers didn't fire. These are WLP primers from a large batch that has never had a problem.

I've never pre-primed cases before, could that be the problem, or maybe miss-fires are a common occurrence with moon clips? I don't know. I'll load a fresh batch of 45 Colt to see if that solves the problem, but in the mean time I thought I'd check to see if there is an obvious "duh dude, never pre-prime cases" answer.

[AndrewTannerCA]

Never had a problem with priming and storing cases. Assuming they weren't stored in a humid place I would think the moon clip mod isn't allowing your firing pin to firmly hit the primer.

I would confirm this by testing some factory loads and see if you have the same problem.

[Slash2]

I would think the moon clip mod isn't allowing your firing pin to firmly hit the primer.

At the time I removed the miss-fired rounds from the moon clips and ran them through the gun again, still without joy. The primers are definitely getting smacked hard enough.

This mod allows me to run .45 Colt with or without moon clips, the rounds still headspace off the rim. The moon clips just make it easier and faster to load, but mainly I did it so I could run 45 ACP in the gun. The moon clips for the .45 ACP haven't arrived yet so I haven't been able to do a comparison.

[joelogic]

They sell pre-primed brass so that cant be the problem but 10% is pretty high. I have had pre-primed brass sit around for month or longer without problems.

[Fjold]

I've never seen any issues from loading primed cases. I was given a bag of primed 30/30 brass that were 11 years old and they all fired.

[Slash2]

They sell pre-primed brass so that cant be the problem but 10% is pretty high. I have had pre-primed brass sit around for month or longer without problems.

Well, now that's interesting, I was kinda hoping it was the pr-priming, and that it had nothing to do with the moon clips or the $$$ modification. Now I'm worried.

[XDRoX]

Did you try firing any again? Is it possible that you didn't seat them all the way.
It can look like a solid primer hit, but if the primer wasn't completely seated it won't detonate.

[Slash2]

Did you try firing any again? Is it possible that you didn't seat them all the way.
It can look like a solid primer hit, but if the primer wasn't completely seated it won't detonate.

Yeah, I ran 'em all through again, both with moon clips and without moon clips, and no bang. They all looked like they had been smacked harder than a dinosaur hit by a meteor 65 million years ago.

[Bill Steele]

When I loaded all my handgun rounds on my Rock Chucker I always pre-primed my cases, doing them in batches. I live in a pretty humid environment (about 100 yards from the Pacific Ocean, many days with London style fog) and have had cases primed with WLP's sit for over a year. They all work fine.

Having said that, I have had some issues with WLP recently. Mainly cup burrs and cracks on hotter loads (10mm nukes). I have not had a detonation issue yet. I was told Olin had recently moved their factory and that was the root cause of the teething problems of primers coming out of the new facility. Wish I could be more helpful.

[Slash2]

I live in a pretty humid environment (about 100 yards from the Pacific Ocean, many days with London style fog) and have had cases primed with WLP's sit for over a year. They all work fine.

Having said that, I have had some issues with WLP recently.

These were all from a batch of 5000 WLP primers I bought a couple of years ago. The primed cases sat in small open box in a dry sun room. Some in the box may have been exposed to some sun light filtered through a UV film on the window glass. Are primers UV sensitive?

[Bill Steele]

These were all from a batch of 5000 WLP primers I bought a couple of years ago. The primed cases sat in small open box in a dry sun room. Some in the box may have been exposed to some sun light filtered through a UV film on the window glass. Are primers UV sensitive?

I think I would call Olin and ask them. Most things are UV sensitive to one degree or another.

[TheExiled]

I pre-prime about 100 at a time, but if Im not finishing them that night, I cover them just to be safe

[Pete1979]

I have had a friend's .260 and .308 refuse to light the Winchester primers even if you hit them twice. They too look like a proper primer strike but no bang. Switch to Federal, Remington, Wolf or CCI primer and no issues. Really strange, I think the Winchester has a hard cup which I like for my gas guns in case I run out of 31s or 41s.

I would take the same rounds and try to fire them in another gun. I prep batches of .308 100 or 200 at a time, bag em up and they sometimes sit for as much as a year. Never had a failure to fire.

[bandook]

I pre-prime cases by the hundreds and they sit around in the shed for weeks before being loaded. (Magtech and S&B)
Load up a new batch and see if that works... I don't think storage would do anything to the primers.
As a last resort, bash a failed primer with a hammer on concrete to see if its really dead.

Alternately, prime using both 'old' and 'new' ways and see if the problem persists with the cases primed using the 'new' way.

If you don't have access to the 'old' way, see if you can bum 5-10 primed cases off a neighboring re-loader. I'm across the Bay from you, but will be in SSF (near SFO) on Saturday morning - so if you want me to bring some primed 45ACP cases, let me know. It will help isolate/eliminate at least the priming issue.

[Slash2]

Thank you all for your feedback, because of the your reassurances I was able to rule out pre priming as a possible cause and move on.
I have since learned that some Redhawks are known to be susceptible to light strikes, and that often removing some metal in one spot, installing a longer firing pin and using an extra heavy duty hammer spring solves the problem. Removing the metal wasn't enough so I'm waiting for my extra heavy duty hammer spring to arrive. Thanks again for the help.