Author Topic: Colerain round bottom patch thickness  (Read 4074 times)

Offline Scota4570

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Colerain round bottom patch thickness
« on: November 14, 2016, 09:35:56 PM »
On a whim I used a Colerain round bottom 45 caliber barrel on a build.  My other rifles use Green Mountain barrels.  My 45 cal balls and patches are not working on the new barrel.

I assume I need a much thicker patch and possibly a larger ball.  I have .440 and .435 balls on hand.  Will the .440 work with a very thick patch?  Say denim?  I see Colerain claims 0.016" dept of grooves.  With a bore diameter ball we should be talking a 0.025" thick patch?  Should I buy some larger diameter balls?

Somebody must have already figured this out.  What has worked for others?

Offline Daryl

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Re: Colerain round bottom patch thickness
« Reply #1 on: November 15, 2016, 02:55:07 AM »
I would stay with the .440" ball and try 12 ounce denim - first. I mic 12 ounce denim at .025" compressed and get .030" on the same cloth, compressed as hard as I can between finger and thumb with my new Hornady Dial Calipers. This is the thickest 100% denim used for blue jeans that I've found. I buy the material at the sewing stores along with the 10 ounce and 8 ounce. I find 8 ounce too thin for accuracy in any of my guns.  It shoots cleanly enough  without burning or scorching in GM barrels, but the accuracy is not as good as the thicker 10 ounce denim.

If the 12 ounce denim fails, then go with a .445" ball and 10 or 12 ounce denim. I measure 10 ounce at .0225" with the calipers and .020" with the mic. This is actually the combination I used in my .45 GM barrel with 1/2" to 3/4" C to C accuracy (5shot groups) off bags at 50 yards.
Daryl

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Offline wattlebuster

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Re: Colerain round bottom patch thickness
« Reply #2 on: November 15, 2016, 03:12:30 AM »
I have 6 round bottom rifled barrels an with every one of them I get my best groups with at least .018 thick pillowtick patches an even better with .020
Nothing beats the feel of a handmade southern iron mounted flintlock on a cold frosty morning

Offline hanshi

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Re: Colerain round bottom patch thickness
« Reply #3 on: November 15, 2016, 07:23:01 AM »
I have two round bottom Rice barrels.  In the .50 I use a .490" ball and a patch that varies from .022" to .024".  This combo is accurate but I'm considering getting a .495" mold.  My .45 shoots the  .440" and .445" ball at the same velocity and with similar accuracy; it's a square cut bore.
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Offline Scota4570

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Re: Colerain round bottom patch thickness
« Reply #4 on: November 18, 2016, 02:35:48 AM »
I found a pair of old heavy duty work or painters jeans in my stuff.  They don't fit anymore so I cut them in to patches.  There was a thicker second layer of facric over the knee.  That measures over 0.030".  That will give about 0.010" compression per side with a 0.440" ball.  Seems like a good start.  I also have 0.433" balls.  Those would give about 0.006" compression.  I look foreward to trying it.

PS: I made a couple of patch cutters out of hole saw cutters.  I ground the teeth off and put a sharp beleved edge on the cookie cutter.  Those work slick in the drill press. 

Offline wattlebuster

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Re: Colerain round bottom patch thickness
« Reply #5 on: November 18, 2016, 03:47:19 AM »
I just cut mine square with scissors. I cant tell a bit of difference with round or square
Nothing beats the feel of a handmade southern iron mounted flintlock on a cold frosty morning

Offline Daryl

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Re: Colerain round bottom patch thickness
« Reply #6 on: November 18, 2016, 09:24:05 PM »
I just cut mine square with scissors. I cant tell a bit of difference with round or square

Oh -Ummm - the square ones have sharp, squared corners, the round ones have no corners. ;)
Daryl

"a gun without hammers is like a spaniel without ears" King George V

Offline RichG

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Re: Colerain round bottom patch thickness
« Reply #7 on: November 22, 2016, 04:30:46 AM »
I have a .45 colrain that shoots great with a .435 rb and .015 patch but I need 75 gr of 3f before it shoots good. loads without a starter or coned muzzle. I think the ball patch combo fits the bore just fine after the powder goes off! ;D for a plinking target load a .445 ball and a .02 patch works good with 60 gr 3f.

Offline Scota4570

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Re: Colerain round bottom patch thickness
« Reply #8 on: November 26, 2016, 11:46:59 PM »
.433 ball, .035" denim patch, WW2 gi bore cleaner, 60gr 2f  = about 1 1/2" at 50 yards.  The patches looked great upon recovery. The .440 ball was too large to load easily, it did not shoot any better than the .433.   I di dnto have time to really play with it and optimize things.  Previously, the thin store bought patches  is not do well at all.