Blown Patches

[ScottGustaveson]

When I lived in So. Cal. I traded with a small gun shop in Downey. I would always have them re-crown my barrels. I never had any problems after that, but sadly, they are gone like so many others, including me.

 

[nkbj]

ScottG,
Have used Clover compound and J&B.
Started using the silty clay because it's gritty, sticky, it works and it's here. That good old rice paddy gumbo mud from the coastal plains like down around Johnson Space Center would probably be great.

 

[Paul R]

Mike, those patches actually look pretty good compared to what mine were. I'm shooting a new Rice .58 jaegar w/round bottom rifling, trying both .570 Speer balls & home cast .575s. I tried several lubes & a variety of patches, all with the same resulting patches & shots all over the board with no consistancy. Goex 2F was the powder of choice from 70 to 100 grains. I polished the crown & ran steel wool up & down the barrel. Nothing worked.
The last time out I tried 5/8" leather overpowder wads I had punched out. All the difference in the world. Patches were immediately looking good enough to reuse & accuracy settled down to 5" groups off the bench at 75 yards. That was with .575 balls, .019 pocket drill patches, & 90 grains 2F Goex. I had started with olive oil & finished with TC T17 lube. Probably not the best choice, but all I had with me & worked a whole lot better then the olive oil I started with.
Now I want to find an easier loading ball/patch combo & play around with different powder loads. Have to get the new sight on when it gets here. The TC hawken front sight I put on was too high, so ordered a lower fiber optic to replace it. I had run out of elevation on the Lyman peep & was still hitting about 6" low.
I had finally finished the gun a couple weeks ago, so it is really tight getting it figured out in time for my moose hunt the 29th. It's pictured on the builders bench right now.
Paul

 

[Rifleman1776]

I describe them as blown. They are cut around the base of the ball where it would meet the rifling. I'm guessing there is a sharp spot in the barrel somewhere.

After the ignition of the powder I'm experiencing large tears in the fabric.

I'm shooting again next week, if he problem hasn't corrected, I'll post some pics.

Yes, cut patches can get that way upon loading in a new barrel. It usually doesn't take a lot of shooting to smooth out the sharp spots. Several easy ways to 'break in' a new barrel, not true lapping. Steel wood, bronze scrub pad material or the green scrubbing material on a jag will work just fine. A little oil and a few minutes work. Lots of other ideas out there, some mentioned already. I have heard some say toothpaste on a patch is a very good 'sorta' lapping material.
I suggest that "blown" is not an apt description of what you are experiencing.

 

[hoochiepapa]

I tried the steel wool on the brush trick, to no avail. I did it twice, the steel wool was wound around the brush, and if I recall correctly, pretty snug in the bore. I will stick with my felt wads, rather than wearing out my bore.

 

[hoochiepapa]

Moose, I hope you get it figured out in time. I saw your rifle on the gunmakers forum, it's not my cup of tea, but then I don't have the cahonies to step out that far.
Have a good hunt, and please show pics!

 

[mooman76]

I none of these other things help you could try a different lube. I get burned out patches with BB but never to the point of poor accuracy but I usually shoot light loads.

 

[meanmike8665]

If not "blown" what do you call it?
Michael

 

[Dphar]

My blown patches are about to blow my mind! My GPR was just beginning to settle down and shooting great groups when all-of-a-sudden everything began to spread. I checked my patches and as suspected I was blowing them out. 65g with .15 pillow ticking lubed with bore butter. Checked bore, ok didn't find any sticky spots,tried different patches, lighter loads.... nothing works. Any ideas??

Sometimes light loads are the problem.
If you have a 50 caliber and are shooting 65 grains this could be the problem. 65 grains is a 45 caliber load.
Maybe you need a larger ball size.
Maybe you need a different lube.
Try putting a patch over the powder. Start it in the bore to form a cup then load the patched ball.
The patch on the ball should then be perfect.
If not then its the crown or you need to polish the bore with a white scotch brite pad (auto parts store) or 0000 steel wool on a jag. It needs to be tight in an oiled bore (oil the material) in any case.

If you have patch material in as yard goods lube up a place on a strip and seat it flush with the muzzle then use the excess to pull it back out, Look for fraying or cuts. This indicates a crown with sharp edges and it needs a polish.

Dan

 

[ebiggs1]

Before I got the polish, steel wool and lapping compound in my barrel, or even leather or felt wads, I would try MORE lube. :hmm:
Pretty easy and if it don't work nothing is damaged or much additional expense is made. :grin:
There is no need to make this harder than it needs to be. :wink:

 

[Dphar]

I tried the steel wool on the brush trick, to no avail. I did it twice, the steel wool was wound around the brush, and if I recall correctly, pretty snug in the bore. I will stick with my felt wads, rather than wearing out my bore.

Brush is not tight enough. It needs to be on a JAG and be pretty tight in the bore.
Use 0000 steel wool or white scotch brite pad.
Steel wool will not "wear out" the bore you will wear out first.
It takes HOURS with 280 abrasive compound and a lead lap to take out .0005. I have a 54 GM I decided to lap and spent most of a day on it. Now its much brighter internally and should load and clean easier. Steel wool and white scotch brite is not nearly as abrasive.
The rifle has to WORK. Having to use felt wads or extra patches indicates a problem.
Blown patches are;
Bore condition which polishing should fix or
Crown or
Patching too weak or too thin or
Lube is causing problems or
Ball size is too small or
Powder charge is too light or maybe too heavy or
Barrel problems that are not curable by lapping or polishing. Its unsuitable for cloth patched projectiles.

A first rate ML barrel costs 300 dollars plus if you can find a maker to make one. Made of good barrel steel and carefully drilled, reamed, rifled, lapped and in at least one maker's case TESTED for accuracy.
But you will not find a barrel like this in a $300-500 mass produced ML. The whole gun is cranked out at the least cost so they can sell cheap. Entry level MLs and then the entry level shooter has problems that he cannot resolve and either gives up completely and buys an inline or ends up shooting grease groove bullets because the PRB will not work, or he cannot make it work in the rifle he bought, he has no real recourse since the people who make and sell the thing only know how to make and sell it for the most part.
When the makers of these look at their ML they don't see the history.
They don't see the grace and beauty of the lines of a good ML or the art that accompanies a proper "Kentucky" made before 1820 or so. They just see the profit margin. Nothing else matters.

Dan

 

[ScottGustaveson]

Started a patched ball yesterday and pulled it. Nothing cut. Repeated it, with a new patch and ball, pushing them all the way to the bottom. Even resistance all the way down. When I pulled it I saw a very small hole, just a couple fibers, cut where the patch was under the most pressure. I'm sure I have a sharp land somewhere.

Also, went to the fabric store and purchased three different materials including denim. If I can get them down, I'll let you know how they work.

I really appreciate everyones help. I fired several shots that were touching at 50 yards and was very excited. So, when my patches began to shread with my groups, I became aggrivated. Conversely, I am excited to seen the true potential of the .54. Taking a deer this year with it would be the ultimate prize.

Again, thanks for aa the ideas.

 

[ScottGustaveson]

By they way Dan, you are 100% correct about the manufacturing, care and forethought, put into some of these guns. I did my research, read all the insightful posts in this forum, and came to the conclusion that a GPR kit would be a resonable alternative to the more expensive kits out there. I do believe in,"You get what you pay for." But to what extent.

Investarms and the like, have the knowledge and ability to put out a first rate product, or at least close to it. During my build I saw severa small issues which I was able to correct. I expected these. My barrel will shoot in, I just need to adjust the nut behind the trigger a little.

 

[Dphar]

Before I got the polish, steel wool and lapping compound in my barrel, or even leather or felt wads, I would try MORE lube. :hmm:
Pretty easy and if it don't work nothing is damaged or much additional expense is made. :grin:
There is no need to make this harder than it needs to be. :wink:

Deburring with steel wool has been a standard with ML makers for a very long time.
A maker who values his reputation will not send out a rifle that does not shoot or blows patches.
Nor does he have time to shoot 50-100 rounds to deburr the lands. So they use a polish of some type. Steel wool and lately white Scotch Brite is widely used. Sure you might damage the bore to the point of accuracy loss. In several thousand strokes 5000 or more maybe... Damage in 20-30 strokes?
Its like "ramrod wear" people should try wearing a groove in piece of iron or steel with a hickory rod. Its not going to happen.

Dan

 

[hoochiepapa]

I'm sure you are right, you have much more experience at this than I, but the way things are with my barrel now, I get excellent accuracy for hunting. My dad used to say, "If it ain't broke, don't fix it". In your view, it may need fixin', but I'm happy with the performance. :v

 

[cynthialee]

Dan,
Of all the things you list that can be a cause of blown patches they all make sense except where you mention that too light of a powder charge can cause blown patches.
How does that work?

thanks for the information provided, it is apreciated

 

[ScottGustaveson]

I took Dan's advise, cleaned the bore with well lubricated 000 steel wool. After this I gave it a good flushing with some spray brake cleaner. I couldn't believe what washed out, lead shavings and some brass? There must have been some sharp lands in there somewhere.

This morning I shot. I was very pleased. No "Blown" or "cut" patches. In-fact, I could have reused them. My group settled down and I was quite happy. Can't wait to get a couple hundred more shots through it.

Thank you everyone.

 

[BrownBear]

You're on track now. Well done, and enjoy!

 

[Matt85]

good to hear your problem was resolved!

-Matt

 

[jamesthomas]

Good to hear you have the problem solved! alot of folks don't tells us if if have helped them or not just silence after they post.