Sand Blasting Brass

[Juggerxxx]

Looking for any and all feedback (lord have mercy) on an idea I have.

I see reports and even papers addressing pressure issues and they state oil, solvent and lube can cause these indicators perceive as over pressure. My guess is that the brass is unable to grip the chamber walls when it expands because of the lube? If this is the case; would making a rough surface on the outside of the brass help to grip the chamber walls? Would this allow you to increase a known load that was on the high side and eliminate flattened primers, ejector marks Ext....?

Is this just a bad idea in general even if it did work because those warning signs should be taken seriously?

 

[Fursniper]

You shouldn't have oil, solvent or lube on the outside of your finished rounds anyway, it's easy enough to remove using any of several different methods so for me at least, the idea of having any kind of gunk on the outside of a finished cartridge is a moot point. Ive certainly never known anyone to ever run loads through their guns that way, at least purposely. In either event, yes, pressure signs can be caused by several things and obviously need to be taken seriously. As far as the idea of sandblasting brass, yeah, that's the craziest idea I've heard of in awhile.....

 

[Threadcutter308]

You shouldn't have oil, solvent or lube on the outside of your finished rounds anyway, it's easy enough to remove using any of several different methods so for me at least, the idea of having any kind of gunk on the outside of a finished cartridge is a moot point. Ive certainly never known anyone to ever run loads through their guns that way, at least purposely. In either event, yes, pressure signs can be caused by several things and obviously need to be taken seriously. As far as the idea of sandblasting brass, yeah, that's the craziest idea I've heard of in awhile.....

Agreed, sounds like sandblasting is the wrong fix for a problem that shouldn't exist in the first place.

Once you've resized your brass, there's no reason for there to be anything on the exterior of it (the brass).

 

[Juggerxxx]

Sorry I did not explain correctly. The function of the beadblasting is not to remove the lube, rather to make the outside surface of the brass rough and grip the clean chamber walls better. If the normal pressure signs occur on the high side of a powder charge by losing grip with the chamber wall and slamming into the face of the bolt; would a rough brass surface grip the chamber better and prohibit these normal pressure signs?

 

[Fursniper]

I'll stand by my last statement, ie, sandblasting cartridge brass would be crazy, be it an attempt to reduce pressure signs or for any other reason for that matter. I think you're on the wrong track here Jugger. Besides, if it did become popular, think of all the media tumbler companies, sonic cleaner manufacturers, SS rotary tumblers and pin makers, media polish companies, walnut and corncob recyclers that would be put out of business, what would they DO? It could be an industry catastrophe to say nothing of the increased prices of factory ammo because the ammunition makers would start charging us for the extra step of sandblasting factory ammo if this were to catch on. Frightening indeed....

 

[sirhrmechanic]

I can't think of a worse thing to do to brass than sandblast it.

First, it will badly work-harden it. And it would probably stick into the chamber like glue on firing. Last, you won't get the bead/sand out of the brass fully, so it will erode everything from dies to chamber faster than lapping.

But if someone wants to try it in their rifle, I'll bead blast up some brass and send it your way. Let us know how it ends! I suspect not well.

Cheers,

Sirhr

 

[bogeybrown]

While sandblasting brass has been effectively dealt with above, your overall concept isn't completely ridiculous. JD Thomas, a great gunsmith in Yakima, WA does a roughing process on his chambers to allow a certain amount of friction during combustion to slow the casing in that millisecond and reduce the rearward forces on the bolt face and other related components. I have absolutely no idea if that's a common practice or not?

I think he mentions it in a YT video where he's chambering a rifle. His shop is High Speed Shooting Systems or HSSS if you hunt up the video.

 

[sirhrmechanic]

To Bogey's point, I think I recall that some machine gun chambers were serrated along the axis of the bore. It may have been to help cycle dirty rounds better. Or to keep firing when the gun was fouled.

But I can't remember timeperiod or gun. The Chauchat rings a bell. But that thing was a POS... and it's possible that the chamber made things worse not better. The Cetme also rings a bell, but I think that was to cause a delay in cycling.

If anyone recalls what I am thinking about, let us know!

Cheers,

Sirhr

 

[...]

Eley did something similar with their "Edge" line.....except instead of sandblasting, they put a black oxide finish on the brass to increase "traction".........i dont know if it works....but i can tell you most people in small bore are still shooting just regular Tenex if thats any indication.

http://www.eley.co.uk/eley-edge

 

[trophyhunter]

What about tumbling loaded rounds, this would remove most traces of lubricant.


But I've also heard that this not advised due to changing the composition of powder & may increase pressure. Truth ??



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[Supersubes]

What about tumbling loaded rounds, this would remove most traces of lubricant.


But I've also heard that this not advised due to changing the composition of powder & may increase pressure. Truth ??



Sent from my iPhone using Tapatalk

i tumble the case lube off sized brass. No need to wait till after it's loaded. I agree the tumbling would probably hurt the powder.



I havent done too many chambers, but i have experimented with chamber finish. At this point, the jury is out. I can see no difference, except slight variances in the fired brass finish. In my research, it is pretty common for smiths to hit the chamber with with a light abrasive. One of my mentors does it, the other does not. Ive used everything from lubed 320 grit to crocus cloth.

To the op's question, if you were going to texture one of the components, the soft brass would not be the one to address, because it will just iron itself out. Most importantly though, as sirh pointed out, the embedded material woul kill everything it touched.

Non-existant problem though. Dry ammo and a clean chamber is all you need.

 

[DAVETOOLEY]

Everyone seems to forget that there's a portion of the case that's unsupported. It can and does move every time upon firing. Think about case head separation. The brass having traction in the chamber is not about bolt thrust. Old wives tale. It has everything to with brass flowing forward. Over time the end result is the formation of a donut at the junction of the neck and shoulder as well as the case getting longer and requires trimming to length. Consider different shoulder angles. The steeper the shoulder angle the better grip the case will have as it tries to flow forward.
The easiest way to manage case lube is to use a bath towel, lay out your brass and spray with a degreaser then fold the towel back over and roll them back and forth.

 

[lash]

...
The easiest way to manage case lube is to use a bath towel, lay out your brass and spray with a degreaser then fold the towel back over and roll them back and forth.

I have been doing it this way for exactly your reason. It's quick and easy. I never validated it with anyone, just seemed to work is all.

 

[NCHillbilly]

I don't know how much effort or expense you're willing to put into your reloads, but fwiw, here's my procedure for large batches. If I'm using dirty or once fired brass, I tumble in crushed walnut to remove heavy grunge, then spray lube and resize/decap. Then wet tumble with stainless steel media, which will clean everything and remove the lube. Then trim, swage crimps and uniform primer pockets( if you choose). A final polish with corncob media and flitz polish will give you nice brass to handle and load. Just be sure to check the flash holes for obstructions before loading. Your brass will be as nice as brand new, and probably more consistent. Just my 10 cents worth.

 

[NCHillbilly]

Also, as far as sandblasting cases, not only will it work harden the brass as noted above, if you are actually using sand, it is so abrasive that, given enough pressure, it will remove material. When you're dealing with thicknesses measured in thousandths, you don't want to remove any. 50,000 + psi will find the weakest spot to get out.

 

[Juggerxxx]

All very good input and thank you. It's also nice to know I'm not the only crazy person out there.