BLOWN OUT PATCH'S

[M. De Land]

Yeah, both my .45 cal match guns ( one flint the other underhammer percussion) with 1-60 pitch like the same ball diameter and patch thickness with a 65 grain charge of 3F.

Both rifles have GM barrels and cut patches for the first 100 shots or so. I remember lapping the bore with very fine grit in the flint gun before firing it the first time and it still cut patches. I think I had to give it another lap job with 240 grit before it stopped the patch cutting.
I lap so many barrels it's hard for me to remember exactly what was done to each one after some years pass.
The percussion gun I think just stopped cutting patches on it's own after about a 100 shots.
GM barrels have deeper rifling than do TC barrels from my experience.

I used the oversize patch and it was definitely snug. No small cut that I could find, and I looked close. I removed the barrel from the stock and scrubbed it with hot water and dawn liquid. Dried the inside and used JB bore clean and when finished with that, as directions, used JB bore bright. finished with a wet patch of ballistol, put a few patches over the muzzle to catch any ballistol that may run out. I'll go back to .440 RBs, going to start with a 50-grain load. I have OX Yoke precut, pre lubed .015 and .010 patches. The oversize patch showed that I wasn't getting the barrel as clean as I thought I was! I agree that adjusting my powder charge is one issue and I think I know what else I was doing that contributed to the blowouts. I'll know for sure my next trip to the range. Thanks for everyone's help

You might want to try some steel wool over a patch some folks talk about which has a burnishing effect on land corners. I've not done this but have heard many testimony's of it's effectiveness to reduce barrel fouling and stop patch cutting.

 

[Big Tom 52]

Both rifles have GM barrels and cut patches for the first 100 shots or so. I remember lapping the bore with very fine grit in the flint gun before firing it the first time and it still cut patches. I think I had to give it another lap job with 240 grit before it stopped the patch cutting.
I lap so many barrels it's hard for me to remember exactly what was done to each one after some years pass.
The percussion gun I think just stopped cutting patches on it's own after about a 100 shots.
GM barrels have deeper rifling than do TC barrels from my experience.

You might want to try some steel wool over a patch some folks talk about which has a burnishing effect on land corners. I've not done this but have heard many testimony's of it's effectiveness to reduce barrel fouling and stop patch cutting.

I've watched UTube video where a that showed the use of a scotch pad instead of steel wool. I was thinking about using steel wool, I'm a little concerned about the scotch pad getting stuck. I learned the hard way about using metal bore brushes and don't want to go through that again. Some of the problem was my fault for not cleaning as thoroughly as I thought I was.

 

[ETipp]

I've watched UTube video where a that showed the use of a scotch pad instead of steel wool. I was thinking about using steel wool, I'm a little concerned about the scotch pad getting stuck. I learned the hard way about using metal bore brushes and don't want to go through that again. Some of the problem was my fault for not cleaning as thoroughly as I thought I was.

Big Tom, You can use some lapping compound just as easy, or easier actually. Apply to a cleaning patch and swipe the bore about 100 times. That will work just fine. I did this on my GPR and no more cut patches.

 

[Ditt44]

Great info here and in a couple much older threads. I just ran into the same issue with a 'new to me' .45 Seneca. I could not show you pics of 15 of the 18 shots and the three that I could show you are nothing but black carbon as they burned up to almost nothing. Several times I had to go stamp out the smoldering remains. In my case, I think this Seneca was shot very little and from the stock, it seems most markings are from storage. Either way, Scotch-brite green pads have worked before and I think I have it ready for another session.

My patches were new Ox-Yoke .010 with a .440 Hornady ball. The short starter took a whack or very firm push to get moving and then the ball loaded a bit too easily so I believe my issue is what so many have said, the crown was cutting the patch. Accuracy at 12.5 yards was not terrible but that was only 12.5 yards getting the sights figured out.

 

[Big Tom 52]

Big Tom, You can use some lapping compound just as easy, or easier actually. Apply to a cleaning patch and swipe the bore about 100 times. That will work just fine. I did this on my GPR and no more cut patches.

I'm going to the range tomorrow morning and see what happens. The lapping compound will be my next step. What Grit would be good?

 

[longcruise]

In the past many rifle makers used a lead lap method as a final finishing to their product. Ned Roberts mentions this in his book on the cap lock rifle. It's a fairly elaborate project and involves casting lead lap slugs in the bore.

Here's a link to a post by one of our members @boberator that he placed in the crafting area. It's probably not been seen by many of our members because of that.

https://www.muzzleloadingforum.com/threads/adjustable-barrel-lapping-tool.173921/

I haven't tried this yet so I'm not vouching for it. However, I do have a barrel with two tight spots in it and plan see if this tool will take them out.

But irregardless, I have "smoothed" a bunch of barrels by firelapping but this tool/technique could simplify things and has the added benefit of being done right in the shop.

 

[ETipp]

I'm going to the range tomorrow morning and see what happens. The lapping compound will be my next step. What Grit would be good?

BT, I'm not sure what I used but I have some out in my garage. I'll go out there in a little while and check for you.

EDIT:

I looked in my garage but didn't find any lapping compound. I now remember using it all.

 

[M. De Land]

BT, I'm not sure what I used but I have some out in my garage. I'll go out there in a little while and check for you.

EDIT:

I looked in my garage but didn't find any lapping compound. I now remember using it all.

I lead slug lap quite a few barrels and always start with 240 grit , progress through 320 and always finish with 400 grit. It must be remembered that the compound grains are breaking down and rounding out through the hole process so the finish grit size is much smaller and less aggressive than when introduced.
Years ago I used to progress through 1200 grit and even rouge but that is not a good practice as years of experience have taught me that muzzle loaders do not like super polished bores very much. Let the patch be it paper or cloth do the final polishing.
It shouldn't take much to make then stop cutting patches as all your doing is taking the rough out of the land corners.
Another thing that will tear patches is if you have accidentally ringed your bore and have not noticed it yet. You will notice that if it's there when loading a tight patched ball in a clean bore.

 

[ETipp]

I lead slug lap quite a few barrels and always start with 240 grit , progress through 320 and always finish with 400 grit. It must be remembered that the compound grains are breaking down and rounding out through the hole process so the finish grit size is much smaller and less aggressive than when introduced.
Years ago I used to progress through 1200 grit and even rouge but that is not a good practice as years of experience have taught me that muzzle loaders do not like super polished bores very much. Let the patch be it paper or cloth do the final polishing.
It shouldn't take much to make then stop cutting patches as all your doing is taking the rough out of the land corners.
Another thing that will tear patches is if you have accidentally ringed your bore and have not noticed it yet. You will notice that if it's there when loading a tight patched ball in a clean bore.

I also mixed the lapping compound with some sort of fine machine oil. I still have some of that oil.

 

[M. De Land]

I also mixed the lapping compound with some sort of fine machine oil. I still have sone of that oil.

Yeah, I always lube the slug and traverse the barrel several times before applying the lap compound on about 1/3rd of the slug length. It's pretty easy to stick a slug and have to melt it out of the bore. I've had to do that many times as well on a particularly rough bore.

 

[45man]

To fit a patch---Take a large hunk and lube a spot. short start it and use the cloth to pull the ball out. Study the ball for cloth weave marks. The lead should show weave marks at the grooves also, those are the highest spots on the ball. If none there you have gas leakage and need a thicker patch.
To measure cloth you need to compress it with a mike. Calipers will not work. Make sure the balls are pure lead, hard lead will cut patches because it will not compress.

 

[M. De Land]

I lead slug lap quite a few barrels and always start with 240 grit , progress through 320 and always finish with 400 grit. It must be remembered that the compound grains are breaking down and rounding out through the hole process so the finish grit size is much smaller and less aggressive than when introduced.
Years ago I used to progress through 1200 grit and even rouge but that is not a good practice as years of experience have taught me that muzzle loaders do not like super polished bores very much. Let the patch be it paper or cloth do the final polishing.
It shouldn't take much to make then stop cutting patches as all your doing is taking the rough out of the land corners.
Another thing that will tear patches is if you have accidentally ringed your bore and have not noticed it yet. You will notice that if it's there when loading a tight patched ball in a clean bore.

Bores will regularly have tight and loose spots from boring and reaming but these are different from ringing a barrel with partially seated balls or conicals that have worked forward.
One uses plug gauges or poured lap slugs to find diameter variance from machining which will be in the ten thousands range where as ringing will be much larger in diameter and will often show externally. Only fix for ringing is relining or re-barreling.

 

[ETipp]

Big Tom. My guess is it might only take a few swipes up and down the bore with bore paste mixed with cutting oil to take care of any rough spots in the bore. I’d try maybe 25 strokes or so, then clean it out well and test shoot it.

It may not be the best method of dealing with cut patches but it is quick, easy and effective. Just don’t overdo it.

It certainly worked well for me.

Good luck.

 

[Big Tom 52]

Big Tom. My guess is it might only take a few swipes up and down the bore with bore paste mixed with cutting oil to take care of any rough spots in the bore. I’d try maybe 25 strokes or so, then clean it out well and test shoot it.

It may not be the best method of dealing with cut patches but it is quick, easy and effective. Just don’t overdo it.

It certainly worked well for me.

Good luck.

Thanks Ed. I started a new post," Big Improvement" I used steel wool around a snug patch and reduced my powder charge and went back to a .440 RB I don't think it was so much cutting as just not cleaning as good as I thought I was and thinking more is better with the powder.

 

[#blackpowderbill]

Looking at those blown patches. I say the weave is too big not tight.
I noticed a lot of patches the weave is just way too big. The threads per inch.
Ox-Yoke used to make some really nice patches, tight weave fine thread. They were slick and the threads per inch you could hardly count them.

You really want to patch to hold up, you get yourself some good linen material

 

[M. De Land]

Looking at those blown patches. I say the weave is too big not tight.
I noticed a lot of patches the weave is just way too big. The threads per inch.
Ox-Yoke used to make some really nice patches, tight weave fine thread. They were slick and the threads per inch you could hardly count them.

You really want to patch to hold up, you get yourself some good linen material

I have totally switched to cotton shirt felt .018 thick from worn out Cabella's work shirts for cleaning and shooting patches. Tight weave and very strong. I can't remember when I've had a blown or even holed patch.
I could easily collect them after a match, wash out and reuse if I wanted.