Recovering from Covid sucks and I’m bored. So I’ve got my Mityvac vacuum pump hooked up to a fired Winchester White box 45ACP case mouth. Set to 27 inches of mercury initially.
5:30 25 inches of mercury. I figure I’ll try a few empty cartridges, maybe pull some live ammo and test those too. Then seal the primers with nail polish and compare.

1:58 minutes from 27 inches to 0

So, you’re putting live ammo in a jar and measuring to see if you can draw air from a live case?

Try a military round . The bullet is sealed with asphalt varnish, the primers are sealed and staked. IIRC the military ammo was supposed to be waterproof down to 90’ (I could be off by a few feet)

For some reason I’m kinda thinking we could find a better task or experiment. For the average, shooter, bloke, hunter & such, moisture getting in then rendering the round inoperative seems very unlikely.

Say one carried ammo on a cartridge belt in the rain, even that can’t say I’ve ever done it where the rounds weren’t at least partially protected. Of course any water would have zero pressure pushing it past the primer or bullet.

I’m always a little behind on cleaning up & organizing my reloading area. It’s also a good idea to clean & lightly lube dies once in a while.

Actually no Mike, I plugged the mouth of a fired 45 ACP case and was drawing 29” Hg of vacuum from there to see how long the vacuum would hold before enough air leaked past the fired primer and brought the vacuum back down to nothing.
I forgot to do a control on the system yesterday. I’m doing that now. The control being drawing a vacuum on the hoses and connectors without a cartridge on the end of the hose. If the time it holds vacuum without a cartridge roughly equals the time with a cartridge, then I’ll know that there is a leak in the system and yesterdays test will be invalid.

After 1 hour the system has held 27” so there are no leaks. I’ll try some nail polish on the primer, let it dry, then see if it holds longer. Any requests for a different sealer, let me know.

Interesting experiemnt. I've dunked ammo a few times (kinda by extension, really... I dunked myself, and my gun was on me, and the ammo was in the gun), but it was always federal HST that has sealant on the primer from the factory. I replaced the ammo as a precaution, but it all fired when I took it to the range. I was only in the water for a minute or so, though...and only seconds the second time.

I believe I have some HST in 45. I’ll pull one round if I do and see how the vacuum holds through it’s unfired primer.

I've accidentally run reloads and factory ammo through the clothes washer numerous times.

It fired each and every time when I took it to the range.

No sealant, no nail polish, nothing but neck and primer pocket tension.

I found some HST in 45 ACP. I’ve got a hose over the projectile with vacuum on it. I’ll give it 45 minutes or so and check it.

No loss of vacuum there. I emailed Federal earlier and they did confirm they seal their HST ammo. Looks like it works.

Back to the fired cartridge this time with cheap nail polish around the primer.

The nail polish did the trick on the fired case. No loss of vacuum.

quote:

Originally posted by Flash-LB:
I've accidentally run reloads and factory ammo through the clothes washer numerous times.

It fired each and every time when I took it to the range.

No sealant, no nail polish, nothing but neck and primer pocket tension.

Same here.

Cool experiment 400m.

I have vacuum on a fired .38 spl case right now. No nail polish on the primer and vacuum is holding.
I realize statistically my experiment means nothing but it has led me to believe that 99¢ of nail polish on the primers of ammo meant for serious business can’t hurt.
I doubt Federal Cartridge would go through the trouble on their HST ammo if it didn’t make a good deal of difference.
Another observation that some may find a bit silly and unnecessary is that even at the dollar store there is a nice selection of colors. It might come in handy for identifying range/match/practice ammo.
Next I think I’ll flip some loaded rounds around and see how airtight the projectile/case mouth junction is and if nail polish helps any leaks there.

If anyone can figure out how to make a primer fall out of a loaded cartridge I’m all ears. I’d love to eliminate the primer from the equation when testing the case mouth but I’m not willing to risk eyes and fingertips to do it.
Also I was thinking of loading cartridges with cobalt chloride test paper and tossing those rounds into a pond for different lengths of time. So if anyone has access to a private pond/lake within a few counties of DuPage county Il, let me know.

quote:

Another observation that some may find a bit silly and unnecessary is that even at the dollar store there is a nice selection of colors. It might come in handy for identifying range/match/practice ammo.

I know guys who use colored sharpie markers to do exactly that. Nail polish isn't a bad idea...and it adds another layer of protection. I'm not really familiar with the stuff...it can't flake off when struck by the firing pin and over time gun up the channel, could it?

I’m not sure if it would or not. I’m pretty sure the military uses sealed ammo and I’d be surprised if it wasn’t a lacquer based product. Something to research unless anybody knows the answer.

I’m not experienced enough on the forum to know how to capture a quote but if you scroll up and read what MikeinNC said, that may be the answer.