Barrel mirages

[Thunder Chief]

So, today I ran 100 rounds through my mosin, and firstly the spare cosmo started to boil in the wood, and then the fun started. At say number 85, I looked down the sights and my target was moving. I thought I was going mad, then I realized that the barrel was sending up so much heat that it was jacking with my sight picture. I'd noticed it before, but it'd never been this bad. If I'd been killing Nazis, I'd have been in real trouble. Anybody got any thoughts on how to solve this particular problem?

Also, the heat shield and the rings have a tendency to shift forward after a number of shots and lodge behind the foresight. Any way I can fix this short of using duct tape or a staple gun.

 

[Centurian22]

Thunder Chief: first the heat shield (I call it the upper hand guard) shifting seems to be a semi-common problem. Its happening on my 91/30 as well and I've heard it can be solved by 'corking' it (which also can improve accuracy). Basic concept is placing thin pieces of cork between the barrel and stock and between the barrel and heat shield. The cork can be cut/shaved from a wine stopper or purchased at an auto parts store as 'gasket material'. There is lots of info and different methods if you just search "corking a mosin". You can start here:

http://www.thehighroad.org/showthread.php?t=660063

http://www.thehighroad.org/showthread.php?t=666135

As for the barrel mirage, I have seen bench rest competitors cut a piece of cardboard the length of the barrel and 2-3" wide and tape it in place over the barrel either flat or at a slight angle. This lets the hot air rise around the sides but insulates the 'sight column' to allow for a clearer sight picture. I've really only ever seen / heard of it done with scopes but don't see any reason it wouldn't work with iron sights as well.

Best of luck.

 

[Walkalong]

Shoot slower, with some breaks, and if you ever have to fight off a hoard of Huns, the mirage will be the least of your worries.

 

[adelbridge]

be glad you dont have a scope

 

[Thunder Chief]

"Shoot slower, with some breaks, and if you ever have to fight off a hoard of Huns, the mirage will be the least of your worries. "

But I was pretending I was a machine gun! Ratta-tatta-tatta!


"be glad you dont have a scope "

I assume that makes it much worse?

 

[Walkalong]

But I was pretending I was a machine gun! Ratta-tatta-tatta!

Always fun.

I assume that makes it much worse?

Yes, a scope magnifies the distortion.

 

[travisd]

I don't think I could put enough rounds through my Mosin to get a mirage in the first place.. lol

 

[animator]

I don't think I could put enough rounds through my Mosin to get a mirage in the first place.. lol

Hot texas summer afternoon will get it going within the first 10 shots. Once the gun heats up to ambient temperature, it'll never cool off, so it never goes away.


That's one reason I like shooting the mosin. It forces me to shoot slowly

 

[Driftertank]

...And don't you love that weeping cosmoline?

Had a white t-shirt with some brown stains from carrying my hot M44 at low ready on a hot day.

I should shoot the old girl more often.

 

[travisd]

I guess it doesn't get quite that hot here. I put about 25 rounds through mine before my shoulder was nicely bruised. Cosmo was coming out of everything but no mirage yet. No way in hell I could make it close to 100

 

[Cesiumsponge]

You can always whip up a mirage band. The kids at the range might might make fun of you though.

 

[Centurian22]

Mine must have either not had much Cosmo on / in the stock, and/or I did an amazing job cleaning it, because mine has yet to weep a drop.

 

[Trent]

Wait. You shot a Mosin to the point of heat-mirage on iron sights.

How's your shoulder feeling, dude?

 

[hang fire]

Here in AZ if using iron sights, mirage is a given in the summer. I use a high Lyman front globe and it seems to negate much of the mirage effect.

 

[Trent]

If it's a grave concern (or just really frigging annoying) get stick-on velcro pieces. Cut a piece of heavy cardboard to the length of your barrel and fold to a shallow U (almost V) shape. Spraypaint upper side black. Attach to barrel with the adhesive velcro at the range.

Will help prevent mirage, even in the winter shooting magnums.

 

[Thunder Chief]

"Wait. You shot a Mosin to the point of heat-mirage on iron sights.
How's your shoulder feeling, dude?"

I have shoulders of STEEL.
I have a cheap recoil pad on it that helps a bit.

As a conceptual question, could I replace the heat shield (slat covering the top of the barrel) with an aluminum(or something else) one that has holes drilled through the sides? Would that dissipate the heat at all?

 

[Trent]

Well, being that wood is going to act like an insulator, I would have to speculatively say "maybe". Thing is, I don't know if it'd make your mirage issue worse or better, because wood will delay the ONSET of heat mirage, but insulate the barrels ability to cool, resulting in it lasting longer once it starts.

Kind of a half dozen of one, 6 of another question. It might just change when mirage starts, and how long it lasts. But you're not going to get it to go away entirely; that heat has to go somewhere and air is the vehicle it uses...

 

[Thunder Chief]

Okay, update time.

Took the Mosin out yesterday. It was an all day shooting trip type thing, and I ended up shooting something like 330 rounds out of that rifle. It started getting noticeably hot through the wooden grip section of the stock. I also learned a few things:

1. Gloves are amazing for prolonged Mosin shooting.
2. I got really lucky with my rifle. I was hitting a ~7"x10" steel target at 120 meters. I've never adjusted my sights.
3. Surplus 7.62x54r steel core makes gravel out of concrete blocks and drills in deep when shot straight on.
4. And relevant to this thread, barrel mirage really doesn't seem to affect sight picture badly enough to matter. Things wobble a little, but the sights stay where they are and if you concentrate it's really not a huge deal.

 

[tryshoot]

You much man.

 

[madcratebuilder]

If I'd been killing Nazis, I'd have been in real trouble.

Just pee on the barrel.

 

[Creature]

Attach one...or several...of these to your rifle!

 

[Walkalong]

We used "mirage shields" on our barrels. The idea is to deflect the heat around the sight picture. Many of us used X-Ray film cut to fit. It is held in place with Velcro tabs.