Tumbling Media= MALFUNCTION

[BruceB]

My new Ruger Mini-14 is just as reliable as any other Mini-14 I've owned, which is to say VERY reliable, indeed.

I've had three recent malfunctions, due to (somehow) having a piece of corncob left in the chamber, where it impedes the entry of the next round. The round simply fails to chamber, and the bolt doesn't cam completely closed. I actually found the offending bits of cob after the malfunctions.

Okay, I can see that perhaps a bit of cob MIGHT be left in the case after polishing, but how in blazes does it stay in the chamber after being hit with 50K pressure????

I had about 500 rounds loaded when this came to my attention. The possibly-contaminated batch is clearly identified, and I'm shooting it up at a rapid rate. More importantly, I have now obtained a much-finer grind of cob. I was using '1/8" grind' from a local feed store, but obviously some pieces were larger than 1/8". I ordered some "14-20" cob from drillspot.com which is apparently an off-shoot of Grainger's.

Forty pounds was delivered to my home with FREE shipping in four days' time, for $21.00. The stuff is maybe 1/4 the size of my feed-store stuff, and it's reputed to not even clog flash-holes, let alone case-necks. It's finer than Cream of Wheat! The first polishing run with the new stuff is underway as I write. No further trouble is expected, and I will use up the remaining 1/8" cob on larger-than-.22 cases.

Just one more thing to be aware of, so be careful....

[mike in co]

My new Ruger Mini-14 is just as reliable as any other Mini-14 I've owned, which is to say VERY reliable, indeed.

I've had three recent malfunctions, due to (somehow) having a piece of corncob left in the chamber, where it impedes the entry of the next round. The round simply fails to chamber, and the bolt doesn't cam completely closed. I actually found the offending bits of cob after the malfunctions.

Okay, I can see that perhaps a bit of cob MIGHT be left in the case after polishing, but how in blazes does it stay in the chamber after being hit with 50K pressure????

I had about 500 rounds loaded when this came to my attention. The possibly-contaminated batch is clearly identified, and I'm shooting it up at a rapid rate. More importantly, I have now obtained a much-finer grind of cob. I was using '1/8" grind' from a local feed store, but obviously some pieces were larger than 1/8". I ordered some "14-20" cob from drillspot.com which is apparently an off-shoot of Grainger's.

Forty pounds was delivered to my home with FREE shipping in four days' time, for $21.00. The stuff is maybe 1/4 the size of my feed-store stuff, and it's reputed to not even clog flash-holes, let alone case-necks. It's finer than Cream of Wheat! The first polishing run with the new stuff is underway as I write. No further trouble is expected, and I will use up the remaining 1/8" cob on larger-than-.22 cases.

Just one more thing to be aware of, so be careful....

i keep telling folks.......

glad to see you have moved to the "fine" side.........
bedding and litter stuff aint gun stuff.....

guns are for blasting....the stuff is listed as "blasting" media.......lol

mike in co

[JIMinPHX]

I use lizzard litter for tumbling small calibers. It's a fine grind of walnut shell & pours out easily. It doesn't get stuck in flash holes.

[Shiloh]

My new Ruger Mini-14 is just as reliable as any other Mini-14 I've owned, which is to say VERY reliable, indeed.


I ordered some "14-20" cob from drillspot.com which is apparently an off-shoot of Grainger's. Forty pounds was delivered to my home with FREE shipping in four days' time, for $21.00. The stuff is maybe 1/4 the size of my feed-store stuff, and it's reputed to not even clog flash-holes, let alone case-necks. It's finer than Cream of Wheat! The first polishing run with the new stuff is underway as I write. No further trouble is expected, and I will use up the remaining 1/8" cob on larger-than-.22 cases.



I've had Mini 14's in the past. They were all reliable as well. My issue wasn't reliability, but accuracy. I've moved on. One heck of a lot of fun to bounce buckets with though!!

I purchased the same stuff from Grainger. Paid a trifle more than you, but have a supply for a lon, long time. Cleans great with a high polish and won't get stuck in the flash holes or primer pockets.

Had a bit of concern when I first opened the brown bag and saw the size of the grit.
Looked too small to be effective, smaller than my previous supply. My concerns were unfounded.
My old lot always got stuck in the flash holes and had to be individually removed.

Shiloh

[richbug]

I had a piece of ceramic media surprise me the other day. I found it laying on the tarp next to me at the High power match. Apparently it lodged in the case during tumbling, survived loading, dislodged on firing, and fell out when the 303 brass hit the ground. It seems to be lucky so I put it back in the tumbler.

[cheese1566]

"I ordered some "14-20" cob from drillspot.com which is apparently an off-shoot of Grainger's.
Forty pounds was delivered to my home with FREE shipping in four days' time, for $21.00."

Good prices and cannot beat shipping!
I get the same $0# bag of cob locally for about $35 a bag, and I have to drive 35 minutes to boot.

http://www.drillspot.com/power-tools-and-metalworking/finishing-supplies/pneumatic-blasting-media/?spc=Media%20Type%3DCorn%20Cob

Thanks for the info!

[44fanatic]

I can see the cleaning media being held or pushed to the corner/base of the casing as gas expansion occurs (*** pressure), then as the bullet exits the barrel, a vaccum (neg pressure) being created that pulls the media out of the casing.

[Shiloh]

I can see the cleaning media being held or pushed to the corner/base of the casing as gas expansion occurs (*** pressure), then as the bullet exits the barrel, a vaccum (neg pressure) being created that pulls the media out of the casing.

Wouldn't it be blasted out the barrel if it wasn't completely incinerated by the heat and pressure of the burning powder??

SHiloh

[BruceB]

[QUOTE=Shiloh;843255]" My issue wasn't reliability, but accuracy. I've moved on."

My experience with earlier Mini-14s was similar.

This latest one is a 581 series, with the heavier and tapered barrel. It's one of a run for Davidson's called the "Deluxe", because it has a Circassian walnut stock. Anyway, I HAD to buy it after it was shown to me. It now has a Leupold Mark AR 1-4x scope in its Ruger rings, and is giving consistent TEN-shot groups of just under 2" at 100 yards with 55 Vmax bullets. I haven't done any serious load work with it as yet, either. Even so, a short (16") carbine shooting like that is no bad thing at all, at all.

Now I'm trying to work up the ambition to try it with cast loads....I have a 225415 mould here which has never been used.

I polished a batch of .303 brass with the 14-20 cob last night, and it shines just as brightly as it did with the larger-grind stuff. You would NOT want to look at it in direct sunlight without sunglasses!

[45 2.1]

This latest one is a 581 series, with the heavier and tapered barrel. It's one of a run for Davidson's called the "Deluxe", because it has a Circassian walnut stock. Even so, a short (16") carbine shooting like that is no bad thing at all, at all.

Now I'm trying to work up the ambition to try it with cast loads....I have a 225415 mould here which has never been used.

The Ruger website doesn't have information right now. Can you tell me what the barrel twist is for your rifle? I'm in the process of designing a heavier cast boolit to fit the faster 9 and below twists.

[44fanatic]

Wouldn't it be blasted out the barrel if it wasn't completely incinerated by the heat and pressure of the burning powder??

SHiloh

Cant say anything about inceration. But if the media were near the base of the shell, during powder burn and gas build up, the media would be pushed in the same direction as the base of the shell...backwords away from the mouth of the case. Then as the pressure lowers it would be pulled forward out of the back of the case by the gas venting out of the muzzle.

If the media were forward of the initial powder burn or in front of the primer, it should go forward...but if to the side of the primer and near the base of the shell, it should initially go backwards.

These are all assumptions on my part...no proof, evidence, etc. Just seems like the logical answer to me.

[44fanatic]

http://i807.photobucket.com/albums/yy353/44fanatic/CLEANINGMEDIA.jpg

...dont ask about the pic....to much time on my hands

[montana_charlie]

I had a piece of ceramic media surprise me the other day. I found it laying on the tarp next to me at the High power match. Apparently it lodged in the case during tumbling, survived loading, dislodged on firing, and fell out when the 303 brass hit the ground. It seems to be lucky so I put it back in the tumbler.
If you find it beside you at the next match, you will know that the two of you have bonded...