Side spray from a revolver

[Blackhawker]

I have noticed for many years that certain revolvers tend to spray very tiny particles at very high velocities and are quite painful when hit by them.  These particles tend to come out of the side of the revolver.  I am guessing that they come from the gap in front of the cylinder.  I typically get hit by them when I'm standing next to someone that is shooting a revolver but occasionally, I have been hit with the spray (or at least one particle) when shooting my own revolver, despite standing behind it.

Observations: 
This typically occurs with the following calibers:  30 carbine, 357 mag, and sometimes .44 mag. 
I tend to notice it occurring when using jacketed bullets and ball powders such as 296 and H-110 and sometimes even IMR-4227 and 2400. 

Questions:
What are these particles? 
I have been assuming that they are tiny, burned or unburned particles of the ball powder but I find it unusual that they tend to only spray when one shoots jacketed bullets.  My .45 Colt never side sprays and I always use plain based cast bullets in it with HS-6 or 2400 powders. 

How does one prevent these particles from spraying?
I have been hit by these things often and on rare occasions I have had them embed themselves under my skin.  If they hit me in the face, they can really sting.  I would imagine that if ever hit in the eye, it would definitely cause permanent eye damage.  I NEVER shoot or stand near a shooter without wearing safety glasses.

[huntswithdogs]

My older BH does it, no matter the load. With mine I think it's powder instead of lead or plating from the bullets. When the bullet makes the jump from the chamber to the forcing cone, you get some blowby on all revolvers. How much, is going to be determined by how much gap is there. Shoot your revolvers right at dusk some time. You'll be surprised with the glow show!

Remember in some of the old westerns where the guy lays the 6gun across his forearm to make a really long shot? Makes for good movies but in reality somebody is fixin to cuss!!!!!

HWD

[Flash]

There was a video floating around of someone who held a 454 with their thunb next to the forcing cone. It blew the tip of their thumb wide open. Revolvers are nasty.

[Savage .250]

I`ve had that happen a time or two.   Mostly from cheap revolvers. 

[His lordship.]

You mention a problem that I have with my Ruger Super Redhawk in .454 Casull, it does this sometimes, but not consistantly, it can happen 2-4 times a box, or only once per 50.  I feel a slight stinging on my left cheek, but there is no mark.  The timing seems right on, bought the gun new, and I have also checked the airgap between the forcing cone and cylinder front.  I shoot .45 long colt handloads around 99% of the time, have been using Unique powder, around 8 grs, and have tried different bullets.  The gun is very accurate.
 
The possibility that it is a powder thing might make me try "Trail Boss" next time.  I also handload for my .270 win. rifle and the .45 colt cartridge uses very little powder per round compared to the rifle.  I am still working on my first 1 pound bottle of Unique after many loads.  I am on my 3rd lb bottle of IMR 4895 with the rifle, what a powder hog!!

[SHOOTALL]

the gap between the cyl and bbl can cause or keep from happening the blow torch effect. I had a super blackhawk that the cyl. bbl gap was touching after a couple shots and dragging after a few more. This gun had little to no side flash. I have had others more open that were bad about it. Cyl to bbl alingment also plays a part. Some revolvers have perfect alingment on some chambers and not so good on others. Ammo that is not well made can cause the problem. If the bullet yaws as it comes out the case it hits the forcing cone off center . This could shave lead or direct powder out the side. As for the shooter getting it in the face it could be wind blowing burning particles or just the way the particles bounce off the gun as they shoot out.
As for powder it could be shape of powder or burn rate , when it peaks etc. or maybe over or under loads ?

[44 Man]

You need to remember that load like a full blown .44 mag load peaks at or over 38,000 psi.  That will spray powder particles out any opening of opportunity at a very high velocity.  Even a .22 revolver will sting your hand if you get it in front of the cylinder and one like the .454 will actually cut your fingertip off.  Stick a carrot out there sometime and try it.  It is normal for all revolvers, but it gets worse as the pressure goes up with magnum loads.  That's one of the reasons when they always recommend eye protection when shooting.  And definately don't stand right next to someone else shooting.  Try to be back a little behind the shooter.  Yes, we have to love that Unique, don't we!  44 Man