Is primer seal necessary


April 19, 2008, 11:42 PM
almost all the Magtech cases had it around the primer and was wondering if it's necessary. About the only thing I guess is it helps keep the primer/powder from getting damp. Is there another reason that I'm missing?

If you enjoyed reading about "Is primer seal necessary" here in archive, you'll LOVE our community. Come join today for the full version!
April 20, 2008, 12:42 AM
If you store your ammo inside, and you aren't exposing it to wet conditions, you really don't need to seal primers. Primers have enough of a seal from their friction fit to keep the powder dry, if stored correctly.

Most of the ammo which is sealed is so because it may need to last many years exposed to different climates and humidity, like mil surplus ammo.

Steve C
April 20, 2008, 12:53 AM
Primer sealer isn't needed but if you where going to take your ammo on safari into the dark jungle when you'll get wet as well as your ammo then it couldn't hurt.

April 20, 2008, 12:56 AM
I hear nail polish works well, but there really isn't a point to it, provided you aren't running around in extremely adverse conditions...

April 20, 2008, 04:38 AM
No. It's a factory thing only.

April 20, 2008, 07:12 AM
Thanks, I wasn't sure. I'm starting my first ever batch of cases and am a little nervous about it. I think what worries me the most is getting the right amount of powder, the correct head space, the proper length, and about a gazillion other small but critical things you have remember. And then taking them out to the range and pulling the trigger for the first time. (That's what I'm thinking about most of the time now). :uhoh:

April 20, 2008, 08:00 AM
On occasion over several decades, I've had random rounds left in a pocket and run through a full wash cycle in the laundry.These were all cast-bullet handloads without any sort of extra sealant.

Every single one of them fired normally.

Primer sealant is not necessary. I do use colored model paint around the primers as load identifiers in calibers that are used at several different power levels, such as .44 Magnum, which I load at 800, 1000, and 1200 fps.

April 20, 2008, 12:38 PM
I guess it depends on what your planning on doing. For me its a waiste of time and energy

April 20, 2008, 12:43 PM
Same here.

It was nice to have when I might have been setting in a foxhole full of water all night in a rain storm, waiting for someone to shoot at me.

Other then that, there is no need whatsoever for sealing primers.

If you know your reloads are going to get soaking wet, put them in a plastic ammo box or zip-lock bag.


April 20, 2008, 04:26 PM
I soaked primed brass in water for 7 days, the primers were still alive and well after that week.

April 20, 2008, 04:48 PM
Not for the most part.

Posters have covered what it is useful for.

Dumpster Baby
April 20, 2008, 09:16 PM
Years ago I worked a temporary security job for about 9 months. I carried a 9mm and various other handguns at different times, depending on what the job was. A fair amount of the time I was in civvies and carrying in a shoulder holster and had a backup piece stuck in my pants in the back.

At about the 6 month point I had an opportunity to shoot, and decided to shoot off the carry ammo. What a surprise - the muzzle blast and recoil were all over the place. Some of the 9mm's, .357's, and .44 magnums went off like .22's, and the rest were very inconsistent in power level.

My carry ammo had absorbed water vapor from being in close contact with my body for weeks and months. After that I rotated all the carry ammo out on a monthly basis and replaced it with fresh stuff.

Sealing primers is easy but totally worthless without also sealing the bullets. It doesn't take but a microscopic pin hole for water vapor molecules to get in, and I believe water vapor molecules are smaller than water molecules.

I haven't researched what is available commercially for reloaders to seal bullets with. My own brainstorm would be to melt some high temp wax from those pink camping candles at Wal Mart and dip the base of the bullet in the melted wax just before seating it in the case neck. Wipe off the excess wax while it's still soft. Later, seal the primers with nail polish.

If I had to carry concealed like that again I would only use sealed military ball ammo, or sealed reloads, or frequently rotate the ammo out into containers marked "suspect" or "unreliable".

It's scary how many people are carrying around ammo that's been in close body contact for months or years, and might go "pop" instead of "kapow!".

April 20, 2008, 09:31 PM
I soaked primed brass in water for 7 days, the primers were still alive and well after that week.Priming compound is stored and handled wet at the factory to prevent 'incidents'. Once it is dry, it's good to go.

Factory ammo is sealed to prevent issues like fail to fire and squibs, which can be due to being kept for longs periods of time in an excessively oiled gun, or wet conditions. Factory ammo is also used by special ops that may entail extended exposure to salt water or other potentially corrosive environments. They test it before they use it.

April 21, 2008, 11:02 PM
For underwater use (power head), hard as nails works great to seal the primer and the mouth of the brass where it meets the bullet. It works well in salt water, i have never had a misfire using 308 & 223. but will reseal before each use.

April 22, 2008, 08:37 PM
Probably not unless you are going to bury your reloads in the back yard to hide them from the Government.

I live in one of the dampest parts of the US and have had no issues on some reloads I kept around for over 20 years.

May 9, 2008, 05:53 PM
Recently, I shot several hundred rounds of about 20 year old ammo, the stuff stored in a canvas bag laying arround in several different garages was very inconsistent with multiple failures, most primers went off but the powder burn or lack of it was in the 20%+ range. This ammo was frozen and thawed several winters and was exposed to Colorado humidity (low). Similar ammo stored in a closed "ammo can" performed much better but not faultlessly. This was old "match" ammo for IPSC competition, Federal primers, 5.7gr 231, 200 gr SWC, (Thousands of rounds shot with no malfunctions). I also reloaded some Federal Mag primers, that were kept in the same conditions as the bagged ammo and they were very inconsistent. I had loaded some "hot black powder loads 37 grains of FFF" for my 45 colts. Pop-Bang-BOOM-BOOM-Pop not exactly what I was looking for for Accuracy testing. I have 800 left! BTW I have had no failures using 15 year old shot shell primers exposed to same conditions. (I had quit shooting/reloading for 13 years)

Now, I store bulk primers in a sealed ammo can with desiccants.

Given my experiences, I would put sealant on any ammo that you plan to load and stockpile for the "end of the world".....or a more likely scenario Ted Kennedy legislating away access to reloading components.

June 8, 2008, 05:59 PM
I have a question about what to use for bullet/primer sealent. Dose it hurt the primer or powder charge if you use nail polish. I used it before but the ammo got fired the next day. So if you can do this how long should the ammo last?

June 8, 2008, 06:04 PM
It isn't necessary.

Handloads will last for decades without either end sealed if stored properly.

Unless you are standing in water up to your neck in a foxhole, or jumping off landing craft into the ocean, it really is a waste of time.

If you hunt during monsoon season, keep your extra ammo in a plastic ammo box or Zip-Lock bag.


June 8, 2008, 06:10 PM
The only story I can relate that may or may not pertain to this is that I had some .45 ACP "reloads" that I loaded up in the mid 80's and when I sold off my reloading equipment the first go round I forgot I had them and they were packed away in a box of "gun stuff" that was stored in the uninsulated attics of the garages I lived in for the next 22 years. In the midwest we go from 85% humidity and over 100 degree temps in the summer to -20 below in the winter.

Every single one of those rounds fired with no problems and no ill effects when I started reloading in 2003 and wanted to reclaim the brass.


Matt Dillon
June 8, 2008, 09:24 PM
Folks, I was wondering where I might purchase some silica dessicant packages - About how many packets and what size should I look for for 50 cal ammo cans, and who sells them?

June 9, 2008, 06:05 AM
You can get them pretty much anywhere. I buy them off of Midway most times. I like the one's in the little aluminum cans as they seem to hold up to the most recharging. They're overkill for .50 cal cans but I'm into overkill. :)

June 9, 2008, 12:59 PM
The Army doesn't use silica dessicant packages in ammo cans.
Why should we?

Unless there is mosture in the ammo can when you put the ammo in it and lock the lid, there isn't going to be mosture in it in the future either.


June 10, 2008, 05:04 AM
Out of curiosity, I once left 6 out of 50 .38 spl. reloads fully immersed in a can full of water during 24 hours. Their performance was exactly the same as that of the 44 others that were kept dry.

June 10, 2008, 05:57 AM
I agree: Unnecessary!

I think the variations were probably more the result of ambient heat degradation of the powder over time rather than moisture degradation... Heat and cold cycles WILL affect powder- heat more so towards degradation, cold more for burn rate/characteristics.

Many times failure to detonate reloaded primers can be traced to handling the primers in the loading process- Back in the old days of hand loading an individual primer onto the anvil, oils from the hand would transfer by handling the primers and they would be compromised.

I do use diluted colored enamel paint on primers to differentiate between loads on my 45-70 for black powder / pyrodex or smokeless rounds...

Store em in a cool dry place and they'll last for many, many years.

I would be very suspect about dipping bullets into any waxy substances prior to loading!! You're asking for trouble there! That wax will flow when it gets warm/hot and WILL contaminate the powder and primer eventually! Your BOOM may become a Pfffft at the most inopportune time!!

Marlin 45 carbine
June 10, 2008, 11:11 AM
some years back I inadvertly left a box of reloaded .45acp (I load others also) at a remote area I go to camping/shooting. about 6-8 weeks later I returned to this spot and found the ammo, the box(re-used factory light cardboard) had nearly disintregated due to dampness of our humid/warm summer area here. the brass was even tarnished up noticeably but every round fired good as new. if I knew I was takeing my ammo into a wet area hunting likely I would use thin lacquer to seal the primer and carry in a heavy zip bag available from tobacco/pipe shops.

June 10, 2008, 12:20 PM
I use nail polish to seal the primer on my carry ammo. I fire-up my carry ammo every 1-2 months. On 3 separate occasions, I had a fail to fire on the rounds I typically kept chambered. After examining the dud rounds (very strong pin strike/doubled strike) I noticed a lot of oil around the base. Since then, I use nail polish over the primers on my carry ammo and had no more problems. The ammo was Remington Golden Sabers in 45 ACP.

June 10, 2008, 01:35 PM
A better solution would be to use way less oil in the gun!

If it's running out and soaking primers, you need to cut back!


June 10, 2008, 02:03 PM
A better solution would be to use way less oil in the gun!

If it's running out and soaking primers, you need to cut back!


I agree that in these instances there may have been too much oil however; how many times have you or others seen oil, or traces of it, on the base of the rounds (in particular semi autos after cleaning)? I just use the polish as a little extra insurance...takes less than a minute of my time.

June 10, 2008, 02:39 PM
Ya know, I've heard about gun oil fouling primers many times so I did an unscientific experiment. I submerged 5 handloaded 9mm rounds in a cup of KROIL for two weeks. KROIL claims "Penetrates to 1 millionth inch spaces". I wiped off the excess and shot them out of the gun I use for testing my loads. All rounds fired perfectly and chrono'd within the averages for those loads.

I still wipe down my weapon very carefully after cleaning but I don't worry about it nearly as much as I once did.

June 10, 2008, 02:50 PM
how many times have you or others seen oil, or traces of it, on the base of the rounds (in particular semi autos after cleaning)? Personally?

I don't use oil in the firing pin channel, and haven't since Unkle Suger told me not too in Army basic training in 1964.

Excess oil just collects dirt & crud in the firing pin channel that would otherwise fall or work it's way out.

If anything, I use a light shot of Remington Dri-Lube spray, but never oil, unless I wipe it all out with Q-Tips, etc..

Regardless, I use an air compressor & 120 pounds of air to blow out any excess before putting the gun back together & in service.


June 10, 2008, 02:57 PM
I guess it has a lot to do with the ammo. The Box of Truth did a similar experiment and had no ill effects. My failure to fire was with Remington's Golden Sabers. I used a few drops of Vans super fine oil on the firing pin and channel and did a wipe down but with the pistol holstered, a small amount of the oil seeped down onto the chambered round and somehow fouled the primer. I only seal the primers on my carry ammo.

If you enjoyed reading about "Is primer seal necessary" here in archive, you'll LOVE our community. Come join today for the full version!