I was fly fishing during high water and had 2 mags of federal HST .40 180gr get wet, so i rotated them out. I figured if anyone had some suggestions to further expose the rounds to water I would test them. Keep in mind I have a life and no land so updates may not be immediate. Thoughts?

Just drop them into a 2 liter Coke bottle.  Leave them in the water for a couple of days.

Then fire them.

My money says you won't be able to tell any difference between the wet and dry cartridges.

Submerged for a couple days was the initial plan, just trying to contribute to the community for those in the market for specific defensive ammo. I also think they will be fine. In the gun for a year so they were due to be switched out

This is relevant to my interests.

I left a handful of .40 S&W 180 gr Gold Dot in a two liter bottle overnight and got several failures and some very low velocities. Be sure to chronograph. There are a lot of folks on this forum that think pistol ammo is impervious to water.

I may no be able to get my hands on a chrono, was thinking of if it can cycle the gun. I was thinking 10 rounds of a control group from the rounds that got wet fishing. 10 that I would spray over a 10 hour period that is exposed to air. Final ten would be submerged in a 2-liter for 24 hours.

Sounds like a plan. Borrow a chrono if you can.

I loaded some Gold Dots that I waterproofed by using a Q-tip to apply a light coat of lanolin to the inside of the primer pocket before priming and the case mouth after throwing the charge. They survived an overnight soak in a two liter and a couple days on my hip in and out of the river.

I will try and get my hands on a chrono. Also have a spare round that has not been exposed to water where I have the ability with the reloading equipment to pull the bullet and primer to show factory sealing. I am trying to do this Friday (7-11), but forgive me if I cant I am in the process of moving. Any thoughts are of course welcome.

So let me get this right?
Factory ammo failed, but the reloads with lanolin did fine?

I have always heard the "homemade case lube", which uses lanolin and 99% alcohol, may contaminate the powder and cause misfires.

Not interested.  You could leave them in a glass of water overnight and they would still work fine.  Ammo is waterproof.  

Sorry. I was on my phone and rushed so I didn't really have time. Yes. Factory S&B (the stuff with the bright red "sealant"), factory bulk pack Gold Dot, and hand loads with a medium crimp and no sealant, all produced some failures with an over night soak in the two liter. The hand loads with the lanolin did not. I was extremely careful to use only a small bit of it but I used it because I thought that lanolin would NOT be likely to hurt the powder. Shows what I know.

After testing with a soak overnight in the two liter, I painted the loaded rounds with nail polish at the case mouth and primer for my camping trip. I kept the rounds in the pistol on my hip for the whole three day, two night trip and I spent a significant portion of my time in the river with the pistol fully submerged. I went off the rope swing. I swam. I waded up and down the river. I soaked in the hot springs. On the way back, I fired all the rounds that were in the pistol with no stoppages.

The rounds that were treated with only lanolin were fired over a chronograph. I don't have the numbers handy but there weren't any anomalies.

Theoretically, the right amount of taper crimp would provide really good waterproofing, assuming the primer pocket was also nice and tight but it seems that water can still intrude without the use of some sort of sealant.

Are you fuckin' with me?  

Not sure if he is serious. They would get shot anyways so may as well test them a bit in other ways since I already know they feed. Test gun btw is a smith and wesson M&P made in 2012. Older trigger model but stock parts other than apex extractor and only failures (maybe 6 overall) were magazine related. Gun has roughly 8k rounds through it

SD ammo is too much $ to be purposely fuking with it.

Agreed, but like I said in the first post the ammo got wet on a fishing trip so it is either shoot it or test it

I have pics of the setup if anyone wants to see but the results are as follows. Keep in mind all rounds had been wet from a fishing trip before this was done.

Federal 40 S&W 180 gr. HST

10 rounds not further exposed - no failures

10 rounds kept wet for 8 hours with a spray bottle - no failures

10 rounds 24 hours submerged - no failures, but one round had very weak recoil and had just enough energy to cycle the next round.

Very nice OP, and very interesting since this is what I carry.

Pics would be great.

That sounds very similar to my own results. I don't believe that anything special is done to waterproof these factory rounds, just tight fitting components and a nice, tight crimp. I've pulled bullets from M855 ammo and there is some sort of tar material on the bullets that clearly is intended to keep water and other liquids out. Of course, I don't lock out of submarines for night insertions on enemy beaches, either. I think that most ammunition is generally waterproof enough to carry in inclement weather or even survive brief submersion. If you're planning on staying in the water for hours at a time with a pistol on your hip, it might serve you well to choose something different. I suspect that M882 and similar would probably survive days of submersion in several feet of water.

If anyone knows of a better (or easier) method of waterproofing ammunition than the lanolin method I mentioned above, I'd really like to hear it. The process worked but it was extremely tedious.

These were kept like this for 8 hours with primer pockets being sprayed as well


Submerged


Round dismantled and was new in the box


This primer was pulled with a reloading press and I am not sure you can see, but a clear sealant is on it


6.3 grains of powder were in the case....my bullet puller may have had some residual powder that I could not get out so it could be 6.2 grains

This is a cool thread.  Makes me think: watches, optics, electronics, etc. are always advertised as being "waterproof to X meters" but no one ever bothers to make a claim about ammo.  Marine Recon nor the SEALs carry some special water-proof ammunition.

I accidentally washed a speedloader full of .38s special 135 gr +P gold dots. They all fired fine.