Strange Behavior of Molied Bullets in Rain?

[243Mendoza]

I was shooting a 260 at 1000 yd with molied Sierra 142mk at about 2850fps when it started to rain. Once the ammo was getting wet, the hits on targets were hitting low and right and with a muzzle velocity 50fps less! In a later relay when the rain had stopped, the bullets were back to about 2850fps. Usually in rain, I do not notice any change in velocity when under cover. I was wondering whether the molied bullets are 'slicker' when wet?

 

[338 dude]

Never heard any such thing ever in my life do you really think Molly had anything to do with it if it even happened at all could it possibly be just changing environmental conditions?

 

[rwh]

I'd expect that water on the ammunition would increase chamber pressure, since the water is taking up space in the chamber and doesn't compress. That could make a difference.

 

[338 dude]

I'd expect that water on the ammunition would increase chamber pressure, since the water is taking up space in the chamber and doesn't compress. That could make a difference.

He actually said he had slower ammo and was hitting low on target which would mean less pressure none of this makes any sense to me And who would put wet ammunition in their rifle anyway it does not sound good a liquid cannot be compressed and I would not want a bulge in my barrel

 

[GuitarmanNick]

Since he said he was under cover, not sure he means they get wet before they are chambered. Guessing that the increased humidity caused a slower burn of the powder which would result in lower FPS. There is not much water vapor inside of a chamber, but some powders are more sensitive than others to temperature and humidity.

 

[rwh]

I tried to parse the OP, sounded to me like it was raining and the velocity went down then it stopped and it went back up, and when he shoots under cover this doesn't happen. But he gave the impression that he was not shooting under cover when his ammunition got wet. Either way, for best results do not put wet ammunition into your chamber.

 

[243Mendoza]

Yes i was not under cover when shooting the match.

When shooting a match, and it starts to rain, you either quit and forfeit the match or continue to complete the match unless the match director calls a cease fire and cancels the match because the targets are not longer visible or winds are blowing the targets off the frame or lightning. In highpower competition, it is not unusual to shoot in rain in the open with no cover and you do your best to keep the ammo dry.

 

[243Mendoza]

Here is another thought. I had the Labradar measuring muzzle velocity in Doppler mode. Could that be the cause of low readings?

 

[mikecr]

Loaded ammo powder does not get wet in rain.
And air density goes down with increases in humidity, so if anything, downrange velocity would be higher in rain.
Wet moly could change MV though.
Moly takes energy from the charge to flash(latent heat of vaporization), and wet moly could take even more.

Simple to test the notion (for you, I don't use moly)

 

[INTJ]

This is just another reason not to use moly......