Patch with 8 Little Holes

[Hawken2012]

Question:  I have a Green Mountain Barrel that is 1" and .54 caliber.  I am shooting 60 grains of 2F Goex, pure lead ball that measures 0.533, and 0.020 thick patching lubed with TOTW Mink Oil.  This gun/barrel was brand new when I got it and I have put about 300 shots through it. 

When I shoot, my patches come out with 8 tiny little holes in it.  What is causing this? 

The gun shoots excellent.  25 yards and same hole.  50 yards and it cloverleafs.  I have tried Daryl's soft crown/polishing method to help smooth things out.  The bore is shinny and smooth, no rough spots detected. 

Is my crown still too sharp?  Is the patch too thick and it's rubbing on the lands?  I have tried different lubes (mink oil, neatsfoot oil, Wonder Lube 1,000 and spit) and the patches all come out looking like this one. 

Thanks Guys! 

[Vomitus]

  Hmm, a few options. Try a thicker patch, maybe 22 thou, or a fatter ball....a .535 or both. If looks like a small amount of blow by is burning thru your patch in the groove. How deep are your grooves?  Some round bottom grooves are very deep. Before lapping, I'd try a few options.

[Hawken2012]

The square bottom grooves are 0.011 deep.  It takes a few good whacks on the short started to get the ball started with the 0.020 patches. 

[Hawken2012]

I just loaded a patch/ball in a clean barrel and pulled the load to see if it was cutting at the crown.  Here is the picture.  I can see where the lands compressed the patch, but no cuts or holes.  The patch also left an impression on the soft lead ball and you can see the thread pattern. 

[hanshi]

Those holes are being caused by the lands, which are not smoothed to a gentle slope into the muzzle.  When the prb is started at the muzzle, the ends of the lands cause an abrupt entry into the muzzle.  They should be polished with sandpaper where you can't feel them with a thumb turning around the crown.

In all honesty, if it shoots that accurately, it won't hurt to leave it as is until you decide otherwise.

[hanshi]

Your combo allows powder combustion to blow by, helping burn the holes.

[Hawken2012]

Hanshi, I took some emery cloth around my thumb and polished the crown as Daryl suggests when I first purchased the rifle.  I didn't get too aggressive and went pretty light (I didn't want to wreck anything).  Are you talking about very slightly coning the muzzle when you said you shouldn't be able to feel the lands with your thumb around the muzzle? 

[wattlebuster]

If your getting groups like that at 25 an 50 then I would not worry about it. Shoot then shoot some more an be happy.

[J.E. Moore]

The lands may be weaking  those points on the patch enough to when you build a fire behind it that it blows em out. I'll second the gentleman about the groups, if it shoots that good I wouldn't worry about it. I've noticed some of my patches will look fine and some will have holes or if you hold them up to the sun you can tell it's wanting to blow em out like that, same charge, ball, patch material. Mines radius rifled and may need a hair thicker patch but it shoots very well and I don't bruse my hand loading it. May try a thicker patch one day but I don't expect to see any changes in accuracy.

[Marcruger]

I would try a tighter-weave, tougher cloth. 

I use the untreated cloth from "The Minute-Men".  You can get it in various thicknesses.  Not inexpensive, but worth every dime.  It won't burn through. 

When I see holes burned through, it tells me several things.  First, the gasses are cutting your patch with blow-by.  If gasses are cutting holes, then gas is passing at varying speeds per shot.  This will result in velocity variations.  Short range accuracy may be okay, but it would be better without the blow-by.  At 100 yards you may see large groups....I'd bet on it.

I am using either Hoppe's BP lube or Lehigh Valley Lube now.  Both work the same for me, though the Hoppe's goes down a little easier. 

Green Mountain barrels will certainly shoot!  Congrats on that part. 

BTW, blow-by tends to make clean-up worse.  More crud in the bore. 

I pick up each patch I fire (that I can locate).  If I can hold my fired patch up to the sun and see light, it is too weak in my opinion.  I have never had that problem with The Minute-Men patching. 

I would not call the muzzle smoothing "coning".  I'd say more....."crown smoothing". 

I shoot a .005 under ball with an 18 patch.  I think you'd do better with a .535 ball. 

Best wishes for good shooting sir.   God Bless,   Marc

[Vomitus]

   Try some denim at your same thickness. Might be your looser weave?

[stubshaft]

Thicker and stronger weave patch.

[Daryl]

Thicker and stronger weave patch.

Both stubshaft and LB are on it.  By the looks of the retrieved patch - although not appearing cut, it is heavily stressed at the lands.  There really is no such thing as too tight, within reason, that is.
With a nice smooth crown, we were loading a .508" ball in a Rice .50, with a .022" denim patch.  There was no cutting and no burning.
Indeed, in my little .32, I was using a .320" round ball (dead soft - as pure as I can find) with .0235" heavy mattress ticking patches. They were not cutting & I did not really need a starter. If I pressed the stub of the starter on the ball (or end of the rod) I would apply pressure and the ball would form into the rifling inside the patch. No cuts.
Stubshaft - you are on the right track with the crowning, just a bit more. should do it. I would also, as LB suggested, try a denim - 10 ounce will do the trick with the .533" soft lead ball.
It could also be that your lead is not as soft as it could be, thus stressing the patch more than necessary.
It does appear you are getting a seal or close to it, in the bottom of the grooves, meaning the patch is thick enough.  the visual evidence suggests it is just the extra stress by the still too-sharp lands that are causing the trouble.
Thais for making this thread.
Cloverleafs at 50 yards shows the load certainly wants to shoot.
I just re-looked at your shot patch - it is showing blow-by in the grooves. A bit thicker or stronger material is what I would try.
GM barrels really shoot well.

[Daryl]

This is Lyman's attempt to show what a ball should look like, if seated into the muzzle and pulled back out. When you do this, you

should use a long strip, rather than running a screw into the ball to pull it. Using a screw will expand the ball and give erroneous visual

results.

[hanshi]

I can't add much else to what's been said already so I will just answer your question.  No, it's nothing like "coning".  What you're after is where the lands start perpendicular to the squared muzzle, you want to polish it to a gentle curve just a small fraction of an inch deep.  If your thumb can feel the ends of the lands at the muzzle, it needs more polishing.  As for patching just use what gives the best accuracy.  I'll pick a material and examine the fired patches.  If they're not sans holes, stress marks or burns; I go to a thicker material.  Also thicker is not everything in a good patch material.  The material should be tight weave and strong; that's why I have gotten to using heavy, unbleached canvas and sometimes denim.

[Daryl]

The square bottom grooves are 0.011 deep.  It takes a few good whacks on the short started to get the ball started with the 0.020 patches.

Use a heavier knob on the starter, or learn to hit it hard enough OVER what is needed, that one whack puts it down.  I had a small nub on my starter to put the ball just below the muzzle- usually 1/4" down.  To get the ball there, I put the little "peg" on the ball, then hit the other side of the starter knob with my palm - 1 smack only.  If you have to hit it twice, you deform it more each time.
Hit is once only.
As Hanshi noted, the crown is only abut 1/8" deep and loading becomes easy, using the starter, of course, for calibres over about .36. Below that and you can push the tightly patched ball into the bore with just hand pressure on the starter knob. or choked up rod.
starters with knobs:
The shallow hole you see on the starter knobs, is to put over the rod tip, t finish putting the ball on the powder. I like to give it a little smack- exactly the same (as much as possible) so the ball is seated on the powder with exactly the same pressure each time. This reduces shot to shot velocities and pressure variations, thus making each shot, potentially more accurate.



Here I am, whit Hatchet Jack, loading and shooting for the video, after we've fired off 50 or more (especially for him) shots, without wiping.
I was using a ball .005" smaller than the bore along with a .0225" denim patch - called "10 ounce" denim.

[Leatherbark]

Those Green Mountain barrels are hard to figure out sometimes.  My friend had an IBS for a TC Hawken.  It would blow the patches to shreds but still shoot cloverleafs at 50 yards.  After a while it stopped shredding the patches.  He said the reason it stopped was that he quit using rotten cloth.  He had been using old blue jeans. When he started using Jo-Anns duck cloth his patches looked normal.

Bob

[Hawken2012]

Thank you everyone for the replies!  I greatly appreciate the help.  I plan to polish the crown a little bit more as suggested.  I also ordered some of the tighter weave patches from the Minute Men.  I think a little thicker patch and a tighter weave will help.  I will give those a try and if they work, I will be able to take one with me to the fabric store and compare the weave and thickness when I buy bulk patch material.   

[D. Taylor Sapergia]

I've always been able to find what I need for patch material at the fabric store, without having to resort to more expensive specialty cloth from ml purveyors.  I agree that you are losing gas past the patch in the GROOVES.  A tougher material will likely be all that is needed, though slightly thicker will work to your advantage in two ways...1)  it will give a better seal without burning through, allowing more powder for accuracy at long range.  2)  It will carry more lube for easier loading over a longer period without cleaning...should never need to clean during shooting.
I like denim cloth because of the link weave, yielding a much tougher fabric.  Simple cross weave cloth has less integrity.

[Don Steele]

Good conversation here regarding the difference between "thickness" and "toughness".  I have some generic "blue stripe" material that measures thicker but fails miserably at higher powder charges than the Drill fabric I get from JoAnn's.

[Daryl]

I was in the Joanne's shop in Yuma checking out their material as we do not have Joanne's stores here. I was quite pleased to see they had 11 ounce denim.

That would work splendidly in about all rifles and especially in the deeper rounded grooves some barrels have, notably Getz and Rice barrels.

[Spentprimer]

Years ago, 1970's, when I first started shooting muzzle loading rifles I was told that linen fabric makes the best patching material and the stuff was readily available.  Fast forward to 2018 and I have been learning that:

a)there are darn few fabric stores around here anymore.
b)the fabric stores that exist are mostly a nationally recognized chain.
c)chain fabric stores do not appear to have employees that know that linen is a flax product and not cotton.
d)flax linen in the USA is almost extinct.

My brother gifted me a John Bergmann built .32 caliber about 15 years ago and I have not shot it yet.  I am hoping to change that soon.  When he gifted it to me he never mentioned and I failed to ask what thickness linen he was using.  As a result I have been on a search mission to locate varying thicknesses of linen material to use for patching.  After driving 60 miles yesterday to a store that told me over the phone they have linen on hand in the store and then finding out the people at the store did not know linen is made from flax I restarted my continuing search for linen.  I am hesitant to mention that I did find a place where they know linen is made from flax.  This store also carries varying weaves and weights of linen.  Downsides are it is 81 miles away from my home and they do not do mail order.  I intend on going there in the next couple of weeks and return with some samples to try.  If you are in St.Paul, MN you can find TREADLE YARD GOODS @ 1338 Grand Avenue.    http://www.treadleyardgoods.com/

The Treadle Yard Goods store may possibly be the only store that carries linen in Minnesota.

[Daryl]

I did have some nice linen back in Smithers in the 1970's. It was about .020" compressed and shot exceptionally well. I have been unable to find it since and have switched

to using denim only now. I would like to find some more of that drk blue, light blue, red and white striped mattress ticking again as it was nicer to use than the denim. It was .0235" thick,

compressed in calipers and .022" in the mic.  Wonderful stuff, shot well in every gun I own - so does this newer .022" light canvas I found. Otherwise, it's 10 oz., 12 oz. and 14oz, depending

on the gun, ball and load.

[LH]

https://www.bigduckcanvas.com/army-duck/10-10-oz-60-inches-wide/
This stuff mics .021 with a ratchet knob micrometer.  Its very tough cloth. 

[Martin S.]

I would try a tighter-weave, tougher cloth. 

I use the untreated cloth from "The Minute-Men".  You can get it in various thicknesses.  Not inexpensive, but worth every dime.  It won't burn through. 

When I see holes burned through, it tells me several things.  First, the gasses are cutting your patch with blow-by.  If gasses are cutting holes, then gas is passing at varying speeds per shot.  This will result in velocity variations.  Short range accuracy may be okay, but it would be better without the blow-by.  At 100 yards you may see large groups....I'd bet on it.

I am using either Hoppe's BP lube or Lehigh Valley Lube now.  Both work the same for me, though the Hoppe's goes down a little easier. 

Green Mountain barrels will certainly shoot!  Congrats on that part. 

BTW, blow-by tends to make clean-up worse.  More crud in the bore. 

I pick up each patch I fire (that I can locate).  If I can hold my fired patch up to the sun and see light, it is too weak in my opinion.  I have never had that problem with The Minute-Men patching. 

I would not call the muzzle smoothing "coning".  I'd say more....."crown smoothing". 

I shoot a .005 under ball with an 18 patch.  I think you'd do better with a .535 ball. 

Best wishes for good shooting sir.   God Bless,   Marc

Do you have a link to their website?

I did a search, but all I got was lots of history links.

Thanks.