Reading patches

[kelvinator]

I got to shoot my new GM-IBS barrel this past Sat.
It's a .50 cal drop in for T/C Renegade.
I tried every powder I had with me, Pyrodex 2f, Goex 3f, and 777 2f.
Varied the charges from 50 to 90 gr.
.490 RB with .018 pillow tick patches lubed with mink tallow.
Accuracy was there, but VERY inconsistent, no combination yeilding anything decent.
Of the patches I could find, which were mostly just pieces, they looked REALLY tattered.
Non were burned or charred at all, just shredded.
Any Ideas?
I'm hoping it's just a new/rough barrel that will come around with more shooting, but the shredded patches have me a bit concerned.

 

[rabjr]

New gun? Get some green scotch pads and scrub the barrel, if the problem is sharp rifling that should help. Or just shoot a 100 rounds though it before sitting down and sighting it in. Those patches shouldn't be in pieces like that.

 

[David W.]

It sounds like the barrel may need to be lapped to me, too.

 

[Zonie]

All patches show severe shredding down to the place where the ball was squeezing the patch against the bore. It's what happens when some woven cloth meets a blast of supersonic air as it leaves the muzzle.

If the shredding was in the circle where the ball meets the bore then yes, it might be due to a rough bore or insufficient patch lube.

 

[kelvinator]

It seems like maybe the patch is hanging up on a rough spot in the barrel or a rough groove or two?
I found only 2 patches out of over 25 shots that were somewhat intact.
Couple of 'em had a 1/3 or so ripped out of one side.
The majority were just shredded pieces about the size of a dime.
No indication whatsoever as to ball location left on any of them.
Patches would ooze lube when started in the muzzle.

 

[ohio ramrod]

Sounds like a rough spot in bore, burrs on the lands, or too sharp of a muzzle. Cutting at the muzzle can be cured with a piece of emery cloth and a few twists with your thumb centered on the bore, rough spots or burrs can be smoothed out if light with a bronze bore brush and some rubbing coumpound, or some scothbrite pad scrubs (or old fashined steel wool. If heavy burrs and rough spots lapping with a lapping coumpound may be useful. But I would lap a new barrel only after all else has been tried. :hmm:

 

[Zonie]

OK. I was misled by your comment about them not being burned or charred.
Sounds like the area that shows burn marks got completely burned or blown away.
It's no wonder the accuracy was inconsistent. :hmm:

If it were my barrel I would resort to the old #0000 steel wool wrapped around the cleaning jag method of smoothing out the bore and breaking the sharp edges on the rifling. A few hundred strokes with this (changing the steel wool every 20-30 strokes) can do some really good things and it will not wear out the rifling or the bore.

Some folks use the Scotch green scrub pads but I haven't tried them.

As you may have read, your 777 powder is notorious for burning patches so until you get this problem under control I would advise you to use the other powders.

 

[kelvinator]

Thanks all.
Actually, I only shot it 3 times with the 777 @60gr. AFTER every thing else. Just a last resort/what the heck thing.
The majority was with the Goex-3f @ 50-80gr.
And a few shots with the Pyrodex before the 777....but no change.

Oh, and I did a damp swab with track's bore clean after every 5 shots or powder change. Followed by a squib shot before shots on paper.

When I look down the bore with a light, the lands appear mirror smooth, but the grooves......well.....not so much.
The grooves look clean, but dull. And I can see fibers from the cleaning patches hanging in the grooves after final oil patch swab.

 

[David W.]

[quote And I can see fibers from the cleaning patches hanging in the grooves after final oil patch swab.[/quote]

Having fibers hanging on the rifling definately is machine burrs. Go with the 0000 steel wool as stated.

 

[chapmans]

You may want to try some .495 balls and drill cloth or denim patch.

 

[1sgt]

I have a new .45 cal GM with about 200 rounds thru it. Its getting better all the time. I used emery cloth at the crown to remove sharp/burrs. Denim patch, .018 with Ballistol/Murphys oil soap for lube. 45 or 50 gr powder until the barrel is ready for more. It may take a few more rounds. Thats half the fun.

 

[William O.]

The only thing I could add to the good advice already given is that you might want try some JB's bore paste for smoothing out the sharp spots in addition to the steel wool.

 

[jerrywh]

Take one of your balls and drill a 1/8" hole in it. Then patch it and push it down the bore just as you would normally load the gun. The hole must be facing up towards the muzzle . Now with a ball puller screw on the ram rod, pull the ball and patch back out of the barrel. Now examine the patch for damage. If it's damaged you have a bore problem. you should be able to tell what the problem is by looking at the patch.
I once found that I had a bunch of old patches that were rotten.
The green scotch pan deal works pretty well.

 

[dckcrk]

I'm thinking that bacteria has gotten to your patch material, try tearing it with you hands or teeth.

 

[william bradley davis]

before you go running anything abraseve up and down your barrel try putting a BORE BUTTON over powder. i just got a new 54 cal ibs barrel for for my tc this fall. i had the same problem shredded patches. the barrel has about 100 shots thru it and still pretty much tears up the patch. just basic load ive shot it from 70 to 110 grains .530 ball with .015 and .020 patches. i have always shot bore buttons over the powder but this is my first 54 cal and i didnt have any so yesturday i took some of my 12 guage wonder wads and trimmed them to size and shot three of them. PERFECT PATCHES WHEN RECOVERED. shot three more shots with no button over the powder and those patches were tore up. bore button drastically reduces the amount of fire that will reach you patch and drastically improve your accuracy. i am going to be on the phone today ordering me up some 54 cal bore buttons.

 

[kelvinator]

That sounds like a good idea.
Patches are new, just got 'em but will check them anyway to be sure.

Thanks for the great advice all.

 

[Rogue River]

Where do you get your .54 OP buttons? I can't find any! :idunno:

 

[Jim Evans]

Where do you get your .54 OP buttons? I can't find any! :idunno:

Midsouth shooters supply $7.50 a 100
page 52 of the catalog.

 

[Rogue River]

Thank you! :grin:

 

[kelvinator]

OKay.....been iced in here in north Texas last couple days, so had some time to work on this barrel.
Went ahead with the 0000 steel wool ordeal.
After about 150 +/- strokes, it seemed to smooth up nicley.
I tried the green scotchbrite pad after 40-60 strokes of the steel wool, but that seemed REALLY agressive compared to the 0000.....so I shyed away from that pretty quick. Less than 10 strokes with that.
Went back to the 0000 for another 100 or so strokes or so for a total of 200 giv'er take.
Gave it a thorough cleaning.
Then, ran a pre-drilled patched ball down it and pulled it back out with the puller.
Patches come out clean, no hang up's or tight spots.
Hardly any patch fibers left in grooves, WAY less than before.
So.....whenever it warms up 'nuff to get to the range......guess we'll see.

K