Strange patch shred phenom

[scottmc]

I have a relatively new .60 I finished and have been shooting with a wrought iron barrel with hoyt gain twist.  It seems to like 75 grains of swiss 2f with a .023 ticking patch with my home made moose milk concoction.
When trying various greases yesterday like bore butter and bear grease at 80 grains, it had a big hole blown in the center and was pretty charred.  Dropped back to 75 with grease and not so much but some fraying on a couple lands.  But every now and then a blown patch with 75 grains, too.
My only conclusion is that the water base lube of moose milk tightens the weave, hence no blow outs and the grease don't tighten or shrink the material.
I want to use some sort of grease for hunting instead of water based lube but the occasional blowout concerns me. 
I'm shooting a .588 rb, too, so it's not super tight but I have to whack it with my short started into the barrel.
Thoughts??

[scottmc]

Pictures of the issue.  Patches on right are 75 grains bear grease.  Patches on left are 80 grains and bore butter lubed.  Why would it blow with 5 grains s more.  Also attched is respective target.  The bull is 2" and target was at 50 yards.

[Eric Krewson]

Smack a patched ball in about 1" into the barrel and pull it to see if your patch has been cut by the crown, it looks that way to me.

If that isn't it change to a pocket drill patch.

If that doesn't correct the problem it is time for a good scotch bright barrel scrubbing.

The inside of a new barrel is rougher than you would expect.

This is how rough a new TC barrel is.



A Hoyt rebore before I gave it a scotch bright scrub.

[Daryl]

The patches on the right show gas blowby on each groove. This is what it looks like to me.
That means the patch is not tight enough.
A .588 ball is .007" undersized for the patch you are using, imho.
It is also possible/probable your muzzle's crown needs
smoothing.

[Daryl]

You should be able to use well over 120gr. powder & have the patches reusable.
Bore butter is $#@* as a patch lube.
For hunting  use Track's Mink Oil or Neetsfoot Oil or a combination of the two would also work, as Muskrat Mike uses.

[scottmc]

Thanks for the responses and I think a few of you may have nailed it. After posting, I went down and looked closely at the crown and saw that grooves had none and the edges were sharp.  The lands had just a hint of chamfer.  So I took it to my mentor/teacher and he immediately saw it. Took his cherry and worked the end of the bore a bit and things are MUCH better.  I will shoot it again tomorrow or Monday and cross my fingers it is resolved.  We also scrubbed the bore with some #1 steel wool so we'll see.
Thanks for your observations and suggestions! 
Picture of the bore

[Daryl]

As you noted  too many sharp corners due to it being machine cut.
The end of your thumb  pushing on a piece of 320 wet/dry (black) sand paper, with some WD40 on the paper. Rifle
or barrel vertical, rotating your wrist back and forth, back and forth, rotate the barrel 90 degrees every 30 seconds and in 2 or 3 minutes you will have a crown perfectly radiused. This crown will allow you to load much tighter combinations which will allow you to reuse patches(if you want)  but these combinations will allow unlimited shooting without having to swab or clean the bore - with no loss in accuracy.
Suggestion is to put a patch or kleenex into the muzzle to "catch" the grinding of steel and stone.
If you search for muzzle crowns, you might bring up some of my.pictures. I'm not on my main computer, so do not have access to those pictures.

[Daryl]

Check out JB's crown in the 5 or 9 groove thread.

[scottmc]

Well, the crowning wasn't the problem as it continued to fray in the grooves and sometimes shred.  So I did try some thinking, denser patching I had and it didn't fray or tear anymore.  The groups aren't as good but I'll work that out.  At least it is hitting consistently.  Photo of bad patch good patch.

[Daryl]

The last patch picture finally loaded for me(on my phone).
The brown scorching still bothers me and I still see some cuts from the lands.
This can show a lack of lubricant as well as needing a smoother crown.

[scottmc]

Dary, I typically only grease one side of the patch.  Is it advisable to do both?  I figured the side facing the rifling would be the only one that matters but perhaps not.  I will also sandpaper the crown a little more as you suggested.

[Hawg]

Fraying around the edges and scorching doesn't bother me. Burn through does. These are canvas duck patches out of my .54 Kibler Woodsrunner with 90 grains of powder lubed with Dawn and water.



These are pillow ticking patches out of my .54 Hawken with 90 grains of powder lubed with olive oil.

[Daryl]

The scorching that bothers me, is not the ring & not where the ball's base is, but the short lengths were the flame ran out from under the ball in the grooves. This shows that the patch is not sealing and needs to be thicker.
These bottom patches still show cuts from the lands upon loading into the muzzle.

[WadePatton]

Dary, I typically only grease one side of the patch.  Is it advisable to do both? ...

A thicker patch carries more lube. I'm no Daryl, but in response to above.

[smylee grouch]

I use bear oil or bear oil with tracks grease. Melted and patch dipped and  saturated with excess squeezed out!. I can shoot 40 shots with out any fouling problems if I don't let the barrel sit too long between relays.

[recurve]

 Any cut barral Hoyt,Green mtn..... will have burrs and micro burrs that cut/tear patches , you can shoot them smooth 200-300 shots or do like Chuck Dixon advised me smooth the barrel with fine steel wool and oil on a loading jag 50 strokes clean and repeat till smooth


before steel wool



after


Hoyt barrels after steel wool smoothing

[Hungry Horse]

 I think I would be VERY careful if I were shooting a wrought iron barrel with a wall thickness as shown, and a gain twist. The old timers made wrought iron barrels thick for a reason. And, they didn’t overcharge them for the same reason.

Hungry Horse

[Scota4570]

The s or hing that bothers me, is not the ring not where the ball's base is, but the short lengths were the flame ran out from under the ball in the grooves. This shows that the patch is not sealing and needs to be thicker.
Thise bottom patches  show cuts from the lands upon loading into the muzzle.

A round bottom barrel with deep skinny grooves and wide lands may be part of the problem.    Colerain barrel???  My experience is that a barrel rifled like that has limited accuracy potential.  I found it impossible to load a patch thick enough to seal the grooves.  I threw the barrel away. 

Real lead lapping with cast slugs can be used to remove all the machine marks.  A little choke can be added.  Both of those help a lot.     A properly finished smooth barrel is easier to load, requires less cleaning and can be  more accurate. 

[Daryl]

Dary, I typically only grease one side of the patch.  Is it advisable to do both? ...

A thicker patch carries more lube. I'm no Daryl, but in response to above.

Like Taylor, my patches are saturated, then the excess is pressed out back into the appropriate container.
This "happens" whether I am shooting a water based "lube" for target shooting, or Neetsfoot Oil or Track's Mink Oil for hunting.
If you "take" the measurement of your barrel, groove to groove, then add double your patch thickness to the ball's actual diameter, they should come out at .005" or over, over the groove to groove measurement.
For me, getting way with merely meeting the groove to groove measurement happened in my .69 due to the weight of the ball obturating 'some' upon ignition.
It also occurred in a progressive depth military barrel in .577 cal. The load combo was a very tight one on the lands, and recovered patches showed no scorching in the grooves even though the patch did not go to the bottoms of them, at the breech, but a perfect seal still occurred, as is needed for good accuracy.
A barrier patch or wad between the patched ball and powder will actually help with inferior combinations, though, as many people have found.