Humidity,Flyers and water in the barrel

C

Charlie Murray

Guest
I have not posted this to try and upset anyone,I am just writing what my expeirence has been.
How this applies to centre fires I have no idea, this is what I have noticed
with rimfires and Air guns.



A few observations,
I have been testing rimfires and there accuracy or lack of it caused by flyers in differing
humidity conditions for over a year now.
In Humidity over 75 % my 17 twist Anschutz will often throw shots, regardless
if you shoot slowly or rapidly.The Highest velocity Eley Match Ammo[chronographed at 1080 fps] hangs in the longest but as you climb to 100% Humidity the flyers are regular and on occasions I have seen elongated holes form in the target.I assume this is from the projectile not being
stabilized.
So next test is with a 16 twist barrel to see if the elongated holes stop
but the flyers continue.
The 16 Twist will shoot up to probably 85-90 % Humidity and then they also
start throwing shots, at 100% humidity the thrown shots get pretty
regular,the holes in the target are still round and not noticeably
elongated.

I have read about water in the barrel thing causing flyers I decided I would sit behind the best shooter at our club to see if different plumes of smoke coming out of the barrel would be any indication in 100% Humidity on which shot would be flyers and if different time lengths between shots also had made any notable difference to these smoke plumes and flyers.
Mick was shooting his rifle [16 twist barrel] and has been on a hot steak this past year and has made the most of the great ammo Eley is making. It really did not make any difference if Mick [who was not told about this test untill he finished shooting]shot slowly or quickly the thrown shots
were still happening and the amount of smoke etc that left the barrel was no indicator to this thrown shot.
[Some shots from the barrel show very little to nearly no smoke at all you
could just see the projectile leave the barrel with a hint of smoke, others shots there was a
very large plume of smoke etc as the projectile left the barrel.]

I assume that the thrown shot because of water in the barrel would be
noticeable as the smoke exiting the barrel would be noticeably more or less
,different colour etc.

Next we went to the club house and shot my FWB 600 single stroke pneumatic
Air gun off a bench in the 10 meter indoor range.These guns at this distance
shoot amazingly small groups time after time so any water in the barrel and innaccuracy
problems would be really noticeable.The other advantage using an air gun is that there is no powder combustion to add to the issue.

Several times now over the last 6 months with this gun and in 100% Humidity
you can get some really impressive plumes of condensation coming out of the
barrel.
Once again you cannot tell which shots are going to land in the bullet hole
size group or step out of it by the water condensation clouds.
I only fired 5 shots last night as I really did not want to risk damaging
the barrel[fingers crossed I have not] and they went into a .05 group which
is pretty normal ,the plumes of condensation although varying greatly from
shot to shot made no difference on target and this has been what I have experienced in the past.

So the water in the barrel thing and its affects on accuracy really intrigues me,Have I missed something obvious and that is why the smoke etc clouds that leave the muzzle or lack of it are not a
good indicater and its relationship to why shots step out?

Also because water is not compressible if a projectile goes over the top of it could we
assume that,

The projectile would be damaged?Causing the inaccuracy for that shot.

The barrel would be damaged?causing permanent inaccuracy

Gas passing the damaged parts of the projectile may cause lead or jacket
fouling?

I would also asume that that any water condensation
in the barrel would be pushed out by the pressure wave in front of the
projectile,would it not?


The one thing I have found that is repeatable with a rimfire at our range is that with a 17 twist rimfire barrel you start getting flyers at 75% humidity and it get worse as the Humidity climbs.
16 Twist barrels start at 85-90%.
At 50% Humidity both barrel twists shoot well the unexplainable flyers become less frequent and the scores at our club pick up noticeably
At 100% Humidity it is better to invest your time in a cup of tea and some shooting related bull session then shoot Targets.



Good Luck
Charlie.

I noticed on the "BILL Calfee water test thread" Mr D.Moran post
47 has added some great images to see and ponder.
Hopefully he will post these again.
 
I gotta ask why is #4 a worry? Also moisture in a bore from a different perspective " black powder shooter" is a good thing it helps keep fouling soft and barrel conditions consistant. BP cartridge shooters blow down the bore to introduce moisture into the bore. I missed the halabalo over this idea recently and am still trying to catchup, if somebody could give me a quick picture of what is up it would be great.
 
Thankyou for Donavan for posting the pic's,I really apprciate it.

Something about the water in the barrel thing and its affects with a centre fire that make me wonder are that,
You are working at much higher pressure.
The projectiles are not soft like the lead projectiles in a rimfire or black powder gun.
In the event a projectile does go over the top of water in the barrel I assume there is a good chance not only will the projectile suffer damage causing innaccuracy but also the barrel is at risk of permanent damage which I assume would be detected by a bore scope and be causing permant inaccuracy.

Any thoughts,fire away,

Good Luck,

Charlie
 
Charlie --

The pictures obviously aren't enough, so I will try to draw a even better picture for you know for a centerfire....

- The trigger gets pulled and the explosion cycle starts to a controlled explosion.
- The brass cartridge and barrel chamber control the launch.
- The bore controls the direction and the parallel waves and gases of the explosion/combustion.
- Between 2500 to 10,000-psi (depending on seating tension) the cartridge will release the bullet and it will begin it's forward motion.
- Depending on the load and cartridge used, around 2 to 4" of travel down the barrel, peak pressure will be reached (40 to 70,000-psi)
- The bullet and all the explosion gases, vapor, and remnants will be thrusting forward and acting as a compression stroke
- The temperatures to go with this explosion cycle can be expected to be around 3500 to 5000-Faht.
- All this compression, pressure, heat, and gases will clear the bore of most any foreign materials which will be blown clear of the "sealed" bullets travel, in front of the bullet (which can clearly be seen in the pictures you ask for)
- With in a couple milliseconds of time, the bullet will exit the barrel an begin its flight to the target, passing throw the debris and energy wastes undisturbed do to it's own shock-wave (search for "shadowgraphing images" to see bullet waves)

With this picture I have tried painting by words, and the pictures attached above, should give a descent explanation to form an opinion from.
My opinion being, and loose liquid material would be long gone before the bullet would have time to come in contact with it, do to the compression of air and escaping gases in front of the bullet.
Any moisture left in the bore that the bullet would come in contact with would be in terms of "oxidation" and in a fouling state.

The magnitude of the explosion cycle (combustion) in terms of heat and pressure alone should bare a fruitful opinion.

Happy Shooting
Donovan Moran
 
Evidence (or assumption) otherwise

A representative of a major barrel maker told me that when a shot was fired through a barrel wet with solvent the bullet would push a wave of solvent and ride over the wave at a random point leaving a permanent "ring" in the barrel.

The assumption was made when a customer sent a barrel in for inspection and it had rings in the bore. They went to the range with a new barrel and were able to reproduce the problem shooting it "wet".

For what it's worth...
 
And Skip Otto used to lap his bores by firing with tranny fluid.......

for what it's worth

al
 
Wilbur and Al --

I respect that a "bonding liquid" such as bore cleaner and/or oil could very well do as you both report.

A lot of difference between a petroleum and/or ammonia based liquid then condensed water..... or so I should think.

Happy Shooting
Donovan Moran
 
How Many Angels???

I really believe we are getting into the "how many angels can dance on the head of a pin" thing here.
Go back and read some of this stuff. And then think about the realities of actually going to the range, or better yet, a match, and shooting.
Trust me. There is a whole different world out there.........jackie
 
jackie schmidt said:
I really believe we are getting into the "how many angels can dance on the head of a pin" thing here.
Go back and read some of this stuff. And then think about the realities of actually going to the range, or better yet, a match, and shooting.
Trust me. There is a whole different world out there.........jackie
Click to expand...
You may be right Jackie. But how long ago was it that people said the same thing about neck tension, meplat trimming, primer pocket uniforming, and any number of things now known to be critical to performance.
 
30+years

and much more,you forgot neck turning thats been around a while too
 
Vibe

Since I only shoot "point blank" Benchrest, there are a few things I do not do.
Of the three you mentioned:
I never change neck tension, in fact, my die is solid .265 for my .269 neck.
The only thing I do to the Lapua 220 Russian primer pocket is run a 1/16 drill in the flash hole, mainly so the decapping pin won't stick.
As for metplate trimming, that is a long range thing. Or, at least, I sure don't know anyone doing it in 100-200 yard Benchrest.

Things I do:
I concentrate on making my chambers as close as possible,and all machined surfaces truly straight.
I pay a lot of attention to consistant neck dimensions, and straight loaded rounds.
I also use new cases for every Registered Competition. All of these shooters who say you can wear out a barrel with 15 cases. Ask them how many aggs they won doing that.
I put a great effort into finally achieveing what I consider a 100 percent reliable scope and mounts.
And then, the tuner.........jackie
 
Last edited:
j mckinnie said:
and much more,you forgot neck turning thats been around a while too
Click to expand...
Those were just examples, it wasn't intended to be an all inclusive list. Never-the-less I think I made my point. Modern competitors are WAY past what would have been considered the point of diminishing returns even just a decade ago.
 
Thankyou Donovan,Wilbur etc for your input and insight.
It is great that all the little bits of information gathered make the big picture a lot clearer.
I now have a much better understanding about is happpening inside our barrels when you pull the trigger.


Good Luck,
Charlie
 
to Wilbur...

Regarding the formation of a ring in the barrel from the "wave" of liquid ahead of the bullet...I doubt it. The pressure build up in liquid as the fluid is wedged between the bullet and barrel might be on the order of 3000 psi but I doubt it would reach the 100,000 psi or higher probably required to yield barrel steel. I understand the barrel maker did mark a barrel by firing with solvent ahead of the bullet but I suspect he created a "mark" of some sort in the barrel but not a "ring" as sometimes occurs when firing a bullet into another bullet in the barrel.

I've never been exactly sure why a bullet running into the base of another bullet leaves a ring but suspect it might be due to a rapid rise in air pressure along with ignition or dieseling of the air/oil mix between bullets. There could be what might be considered detonation occurring with a very high temperature spike that along with the high pressure will yield or "ring" the barrel. This type of ring results in the whole cross section of the barrel expanded to a larger diameter.

If it was just liquid ahead of the bullet causing the mark, every time we fire a bullet with oil in the barrel it would ring it. Maybe the fact it was a solvent rather than oil had something to do with the mark that was left.
 
That's interesting. An air gauge is probably capable of detecting differences of around .0001 or less so we may be talking just a very slight change in the bore surface.
I've had experience where ethylene plus a mild acid (which could be considered a solvent) will cut or erode steel surfaces if pushed through small clearances at pressures from 30,000 to 60,000 psi. I'm not sure how this would occur at the bullet-to-bore surface but as we've seen funny things seem to take place around a bullet moving under high pressure and at high velocity. Every body knows what a high pressure water jet is capable of cutting so I'm kinda starting to think we might be dealing with something like that here.
 
Vibe said:
You may be right Jackie. But how long ago was it that people said the same thing about neck tension, meplat trimming, primer pocket uniforming, and any number of things now known to be critical to performance.
Click to expand...

I don't think those things are critical.
 
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