Oil in the bore: documented cases of overpressure?

General Firearms Handguns - Semi Auto
1

Hey there everyone,

We’ve discussed shooting with oil in the bore for years, but I’ve never actually read of anything happening from it, just warnings of overpressure incidents. Does anyone have any personal experience with oil in the bore causing some kind of catastrophic failure, or know of any documented cases of it happening? Specifically incidents where other variables (overloaded ammo) were ruled out?

I ask because I have a hard time believing the warnings these days, even with gobs of oil in the barrel, considering most modern handguns seem to be able to fire underwater no problem, which if anything should cause the overpressure incidents constantly warned about.

On top of that, what would the oil even cause? A blown barrel? Popped primers? Incremental damage that slowly destroys your barrel over time? The worst I’ve seen is popped primers and bulged cases from shooting underwater, but nothing from above ground with liquid in the bore.

Overall, it just seems like either an antiquated warning these days, or like some type of gun shop wisdom, and I was wondering if anyone has any concrete experience with it or examples to share.

2

Anything can become a bore obstruction if there is enough of it. A lot of what comes up on the internet seem like page fillers, its just “common sense” imho.

Light oil can seep around a cartridge into the chamber and bore. Any gun I run: plastic, metal . . . If it fires a bullet it runs wet. Any handgun holstered, with varying temps., various weight lubes will follow gravity down. Large percentage of the handgun is the barrel, so a high likely hood of oil getting into the bore. Most anything will run with no oil to a point, but everything runs better lubed. As responsible owners of tools, machines, firearms = we have to do preventative maintenance, sometimes daily. If the barrel end drips wet or your pants have oil spots, might need to run the bore snake more often than not.

Also imho: I take a cartridge for what it is & within its designed pressures. Anytime you run anything man made to its extreme you greatly multiply the possibility of failure. Exp: If I need +P+ cartridge = change calibers, and works the other way as well.

3

The last step I’ve performed, when cleaning a rifle, for the last 30 years or so is to run a patch with oil on it to protect the bore. While this isn’t scientific proof, I can tell you I’ve never run into an issue in any of the rifles I shoot. With that said, I typically don’t take them right back to the range the next day either.

4

I have never experienced a change in pressure related to lubrication. However, I lightly oil my barrels cleaning, with a very light oil (ie rem-oil). The only change I have ever seen related to a lubricant in the bore is a mild POI shift until the bore is fouled.

I believe that caution is advised for this due to gun owners being notorious for OVER-lubrication. I have seen some weapons where there was literally heavy oil dripping out of the bore. I would still doubt that this would cause a serious over-pressure issue.

A bigger concern for me with too much oil in the bore would be ammo contamination, or oil running elsewhere where it shouldn’t be and eventually gumming up more delicate areas of the firearm.

5

If you can, check out the episode about lubrication on TacTV.

6

Yeah, I doubt that even a highly lubed bore, even to the point of dripping, would cause any barrel damage. Heck, there are videos on YouTube of people dumping entire magazines through Glocks and Berettas underwater without any bursted barrels. I just can’t imagine any overpressure problems actually occurring from oil in the barrel unless the damage is incremental and microscopic.

Hence, the question. :slight_smile: I’m just tired of reading the legends repeated ad nauseum on forums without being able to find any actual occurrences. I want to see some actual evidence of it!

7

It possibly comes from the days of grease, cosmoline, etc… JMO… Ron

8

Good point! That sounds really plausible.

9

Lubricant in the bore probably isn’t an issue. As described in Hatcher’s Notebook (http://www.amazon.com/gp/aw/d/0811703509) lubricant in the chamber can cause major problems.

If I recall correctly, lubricant in the chamber prevents the case from gripping the chamber walls as pressure builds. The case moves farther to the rear than usual and at a much higher rate, causing the same sort of stress on the action as high pressure even though pressures remain normal. This is consistent enough that when proof loads were not available, sometimes manufacturers used lubricated cartridges for proofing during WWII.

I know the military is very strict about not lubricating ammo. That’s probably the reason. I’d also venture a guess that it’s much more important with high-powered rifles, since they tend to run close to double the chamber pressures that are common in handguns.

Okie John

10

That makes a lot of sense, especially on rifles more than handguns. In either case, it increases slide/bolt velocity above expected values, and can cause (I’m guessing) premature wear or failures.

On the note of lube in the bore, I found this video (http://www.break.com/video/awesome-high-speed-compilation-206809) earlier this morning while searching for evidence of another gun shop legend I heard: that gas actually leads the bullet before exiting the barrel. Looks like it’s true when looking at the video aroud 1:20, where you see a quite-pertinent Beretta or Taurus 92 firing a shot. Before the bullet even exits the barrel, there’s a puff of gas that shoots out the muzzle.

Considering how fast this gas is moving and how hot it is, I have a hard time believing that there would be much lube left in the barrel to even act as an obstruction in the first place. Seems like it would all get burnt or blown out; maybe that’s why no one can actually cite a handgun blowing up due to oil in the bore?

11

This is about identical to what I was told from an old NRA instructor quite a few years ago. I don’t know if it is true or not, but I still have always put a very lightly oiled patch through the chamber and bore. Just barely enough to leave a very light film/coating.

12

See, that’s why I’m so skeptical about lube in the bore. I’ve heard it repeated by fudds, 75 year old NRA instructors who still believe in “knockdown power,” and guys in the gun shop that think DPMS is just as good as Noveske. I have yet to see a documented case of it, though. I mean, these things don’t even see damage under water, let alone with lube in the bore.

I guess we’ve kind of answered the question at this point. I don’t think it’s a true concern these days, otherwise someone would probably have posted an example by now.

13

SOME of what the fudds are telling you is correct–back in the day, the NRA was a superb source of scientific data on ballistics. In the 1960s, they took on a more political role and the technical/scientific stuff fell by the wayside. Unfortunately, it’s hard to tell whether what they remember is still accurate.

Okie John

14

yes, bolt thrust is increased with lube in the chamber but I don’t know what degree in an AR. I sometimes store my guns barrel down and once picked up one of my cases that was slick with lube. I don’t know what or if it had any effect…

15

A well lubed BCG is going to permit a decent amount of lube to spray/splash/drip/wipe onto the rounds waiting in the magazine. Same with a well lubed machinegun. Given that we see no spike in kBs with well lubed guns, I have to cast a skeptical eye toward the phenomenon unless lube quantity is greatly exceeding practical use.

I further have a strong suspicion that avoiding lubrication of cartridges dates back to chemicals and cartridge construction that would deaden powders and primers over time, and having no recent compulsion to reverse the practice for any practical necessity.

In my short time I have seen many sacred cows led to slaughter. There should be no personal emotional attachment to this topic, only data; and there is little data to support the conventional wisdom, at least not with contemporary systems.

Typos brought to you via Tapatalk and autocorrect.

16

Didn’t larry vickers drop an ar15 into a tub of oil and shoot it right after?

17

I’m not sure if this bit of information would be relevant here, but oil doesn’t compress.

So if the bullet is traveling down the barrel and it runs into a stream of oil, something has to give, or make way.

Right?

18

Neither does water.
A bore with standing liquid inside it is a bad thing.
Can cause damage to the barrel, depends on how readily the bore will permit liquid to be pressed out.

Still, there is a significant difference between something having a light coat of lubricant and a liquid obstruction.

19

Something like a bore packed with cosmoline would be the only plausible concern I could see…

I’ve heard of ipsc guys running an oiled patch down their bores before their turn on the chrono, saying it got them a few more fps on the first round or two… :secret:

-rvb

20

On your first point, that’s not necessarily true. There are thousands (millions?) of compressible liquids out there, oils included. Now, not all oils are compressible, but some are, so it depends on what we’re dealing with.

But even assuming the worst-case scenario (incompressible oil in the bore), something doesn’t necessarily have to give. As you can see in the video I linked above, gas actually leads the bullet, so it’s very possible most of the oil simply gets blown out of the barrel before the bullet even touches it.

And even assuming the oil doesn’t get blown out (!), again, something doesn’t necessarily have to give. If the barrel and bullet have sufficient material strength to resist a collision with an incompressible oil/fluid, it’s very possible the oil/fluid will just get pushed out the bore by the bullet. After all, that’s how modern hydraulics works: pushing and incompressible liquid through tubes (a barrel) with a piston (the bullet).

Judging by the fact that almost every modern handgun I’ve seen can be shot undamaged underwater with the entire barrel filled with, well, water (THE incompressible liquid, which is also denser than oil to boot), I have a hard time believing that oil does ANYTHING to the bore other than get flung out the muzzle by either the bullet or leading gasses.

Thus, why I started this thread. :slight_smile: Like F2S said, all that should matter here is data, and as far as I can see, there is absolutely zero data supporting the idea that oil in the bore causes damage to the barrel. I’d be happy to find some, but so far, it doesn’t look like it exists. To me, this looks like the aforementioned sacred cow, and as far as I’m concerned based on current evidence, it needs to be led to pasture.