I think I've sand blasted my K624i with my muzzle brake

762libertarian

Private
Full Member
Minuteman
Feb 24, 2012
149
75
35
A couple of days after getting back from the range last time I noticed that my scope objective lens had a lot of dirt and muck on it. I had covered it up with the flip up before sticking it in the bag. By the time I opened the lens cover again it had dried. Last range trip involved some prone shooting in the rain, lying in the grass with some gravel and mud. The only way I can understand it is that my no name over the counter muzzle brake accelerated dirt so that it bounced up into the scope lens.

I didn't get around to cleaning it until last night and man was it a heart break. It was no use to start off with a brush so I used lukewarm water just so dissolve the dirt so the grains of sand could come loose and run off. After a million careful steps with a brush, lens cleaning solvents and bellows I finally got the lens clean, but there are tens of little spots that light up like a starry night when you shine a light on it.

As far as practical performance, I'm sure the scope will be fine, and any invisible damage to the coating can probably be rectified by Kahles if I ever send the scope in for service, but it sure is a disappointment. Yeah I know I look like an idiot, I'm sharing my story so that others may spare their scopes from idiocy.

Be wary of shooting prone in sand with an aggressive muzzle brake mounted on a relatively short barrel on a rifle with a giant scope with no sunshade or killflash.


I've since placed an order for a suppressor and I'm contemplating wether to get a sunshade, a beehive killflash or both.
 
A couple of days after getting back from the range last time I noticed that my scope objective lens had a lot of dirt and muck on it. I had covered it up with the flip up before sticking it in the bag. By the time I opened the lens cover again it had dried. Last range trip involved some prone shooting in the rain, lying in the grass with some gravel and mud. The only way I can understand it is that my no name over the counter muzzle brake accelerated dirt so that it bounced up into the scope lens.

I didn't get around to cleaning it until last night and man was it a heart break. It was no use to start off with a brush so I used lukewarm water just so dissolve the dirt so the grains of sand could come loose and run off. After a million careful steps with a brush, lens cleaning solvents and bellows I finally got the lens clean, but there are tens of little spots that light up like a starry night when you shine a light on it.

As far as practical performance, I'm sure the scope will be fine, and any invisible damage to the coating can probably be rectified by Kahles if I ever send the scope in for service, but it sure is a disappointment. Yeah I know I look like an idiot, I'm sharing my story so that others may spare their scopes from idiocy.

Be wary of shooting prone in sand with an aggressive muzzle brake mounted on a relatively short barrel on a rifle with a giant scope with no sunshade or killflash.


I've since placed an order for a suppressor and I'm contemplating wether to get a sunshade, a beehive killflash or both.
Man that's tuff. I'm glad u shared the story I had never thought of the break doing this.
 
The front lens of almost all pistol RDS optics gets hammered with powder particles and even sometimes ejected brass. It's sitting almost right over the ejection port.

So at this point as long as I don't have a long-ass scratch on any of my optics' lenses, I don't really care.

It is what it is
 
I know when you shine a light into the objective end of some scopes that are clean you see all sorts of stuff that makes you go WTF. Are you sure you aren't just seeing imperfections in the glass? They generally show up like little dots of light.
 
I learned from photography to never look at the front glass under any sort of light until you actually notice an issue looking through the lens as its meant to be. Shining a light into a brand new $4k camera lens can have little stars floating in space, so I would disregard it unless you knew what it looked like when new under the same lighting.
 
I know when you shine a light into the objective end of some scopes that are clean you see all sorts of stuff that makes you go WTF. Are you sure you aren't just seeing imperfections in the glass? They generally show up like little dots of light.
I really don't think these dots were there the last time I cleaned the scope.

In addition to plainly visible blemishes, I'm sure this ordeal wasn't very healthy for the coatings and such on the surface of the lens. I can't imagine any other way for the dirt to get onto the lens than being thrown by the brake, and there's no way that's good.

However, I'm not the most experienced shooter and I know there are a lot of people here who should have observed this phenomenom if it exists.

Here's a picture of the objective before cleaning.
IMG_20210222_193002255.jpg
 
Last edited:
Yeah that's the reaction I had. Don't think it came like that from the factory. I have the vortex flip caps closed at all times except for when I'm actually behind the gun.

I'll ask Kahles what they'd charge to switch out the lens. It really is not noticeable when you're not shining a light on it.
 
Scopes are wear items.

From the day they are made, the coatings begin breaking down and lose their luster. The most expensive optics I own all look worse today than the day they were taken out of the box. Smudges, scratches, pits, and various things on the objective lens rarely, if ever, affect the functionality of the scope.

Were I you, @762libertarian, I would rejoice in the fact that you now have a decent quality scope that you no longer have to treat like a safe queen. Put it on a rifle that is equally tarnished yet capable, and beat that rifle. Not intentionally, but truly use the rifle as a tool. This is something I think every serious shooter should do at some point in their career. The use of expensive rifles and accessories without the underlying fear of scratching it up... is a liberating experience. Enjoy it.
 
Assuming those are actual pits in the glass they will have little to no effect on the picture quality. It may send your OCD into fits, but it will be ok. Like Orkan said, now you can enjoy it without really caring ;-)

 
  • Like
Reactions: 762libertarian
Since you already have a maybe messed up lens I woul dsee if you can feel the dots with your finger nail. Looks like stuff is still stuck on there to me rather than coatings etc missing.
I'll give it a shot! It seems kind of weird to me that those particles would come on to the glass with enough force to cause these blemishes. With that said, it's not good to have your rifle throw sand and muck on your glass...

While I agree that there is absolutely zero noticable detriment to the image quality, I'm sure I've lost about 15 seconds of shooting time in dusk. And I have to believe that over the lifetime of a scope, it's not good for it to sit behind a brake that throws sand at it.
 
What do the ports of your brake look like? Most of use know that for rifles that will be shot while prone, you are best served with a brake that ejects gasses to the side and not on the bottom. At less than $200 for good quality brakes, there’s little reason or excuse to cheap out and buy something that will cause issues.

That being said, what Orkan said above is spot on. Just shoot it and stop obsessing over something that doesn’t matter in the scheme of things.
 
Wow my scope was only 2500 and that would kill me so I can only imagine. But if u can look threw the scope and not see them then roll with it put a few hard years on it them maybe replace the lense. I would also get a new brake but that's me. What brake did u have?
 
A mini buffing wheel on a dremel will shine that baby back to new 😁

By chance did you have oil in the barrel or something that would blow onto the scope and trap contaminants. I would think if there was enough blast to cause actual damage to the scope as shown that it would be very noticeable to the shooter

Was someone shooting next to your rifle with a brake?
 
I was shooting the Navy Fleet Matches at Dam Neck in 90 or 91 and it was raining pretty steady. Lying in a puddle on the 300yd line, shooting the Prone Rapid match, each shot the bolt would flip water back into the rear sight aperture. Had to blow the water out of the aperture each shot. Good thing you get 70 seconds to shoot the string of 10 with a magazine change.
Also saw some well-known stainkess M14 barrels start to rust that afternoon. It happens.
 
Wow my scope was only 2500 and that would kill me so I can only imagine. But if u can look threw the scope and not see them then roll with it put a few hard years on it them maybe replace the lense. I would also get a new brake but that's me. What brake did u have?
If it ever would become a problem due to light artifacts... the attachment of an ARD (honeycomb) will fix it right up.
 
Scopes are wear items.

From the day they are made, the coatings begin breaking down and lose their luster. The most expensive optics I own all look worse today than the day they were taken out of the box. Smudges, scratches, pits, and various things on the objective lens rarely, if ever, affect the functionality of the scope.

Were I you, @762libertarian, I would rejoice in the fact that you now have a decent quality scope that you no longer have to treat like a safe queen. Put it on a rifle that is equally tarnished yet capable, and beat that rifle. Not intentionally, but truly use the rifle as a tool. This is something I think every serious shooter should do at some point in their career. The use of expensive rifles and accessories without the underlying fear of scratching it up... is a liberating experience. Enjoy it.
Agree 100%. My TT that I purchased from you a few years back has a few dents / scratches & a little degradation on the lens coating side but she still is true.
 
  • Like
Reactions: lash and orkan