Pet Loads for a Green Mountain 45 cal

[Top Jaw]

Just picked up a used rifle over the weekend with a Green Mountain swamped 45 caliber barrel. Haven’t got to shoot it yet. Looks to be fired very little.

I have owned others (50 Getz, 50 Colerain, and currently a 40 Rayl) but never a Green Mountain.  Have heard good things about them down through the years.  Do any of you have a favorite pet 45 cal load that you like in your GM as a starting point for this one? 

Thanks

-Brian

[smylee grouch]

65-75 gr. of 2f, 445 ball and 18-20 thousands denim patch with bear oil lube.

[Kevin Houlihan]

 60 grs. Swiss 3F, .440" ball & .020" patch lubed with Mr. Flintlock's Lube

[Daryl]

My GM .45 bl liked a 10 ounce(not .010")denim patch with about any lube other than a slippery oil one, and 65gr. of 3F GOEX. I could count on 1/2", 5 shot groups at 50 yards from a rest  virtually all day long. No wiping needed. The current 10oz denim have measures .021" compressed in my calipers. The previous 10 ounce denim I bought measured .0225" thick. Loading is virtually identical = easy.
A smooth radiused and polished crown makes loading easy.
I also used a .0235" mattress ticking which shot identically.
With a slippery lube such as LeHighValley I had to increase the powder by 10gr. whether using 3F or 2F. Tjusbtje accuracy load with the LHV lube was 75gr. 3F and 85gr. of 2F. Almost identical vel. but the same POI AND same 1/2" accuracy.

[hortonstn]

.445 ball .020 teflon patch 80 fff schutzen powder

[P.W.Berkuta]

I have two .45 caliber rifles - one with a 35" Orion barrel and the other has a 42" Green Mountain barrel. My go-to load for both is a .440" ball (either cast or swaged) - 0.018"-0.020" pillow ticking patch lubed with a liquid lube - i.e. - windshield washer fluid, Mr. Flintlocks lube, moose milk, etc. They all work well in both of my rifles. I have also used a 0.445" swaged ball using this combo and have not noticed any noticeable difference in accuracy only a difference in loading. My powder charge is 60 grains of Goex 3F. You have to find what works in YOUR rifle and what amount of accuracy is acceptable to you. Good luck.

[Daryl]

My .45 GM barrel was the only barrel I've tested accuracy between .440" and .445" cast balls as well as swaged.
The .440" and .445" were very close in accuracy, as well as both being more accurate than the swaged Hornady of Speer versions.
I do not remember the particulars, though. I do recall they all shot sub 1" for 5, at 50yards from the bench.
As to lubes, Paul pretty much covered them. I also used LeeHighValley lube, original and subsequent formulas. I have already noted
the increase in powder needed when switching to the VERY slippery LHV lube.

[Regular Joe]

I use 50 grains of 3f and a .451 ball for target shooting.  Patch is about 0.018.  It works great. GM recommends a .445 for hunting and a .451 for target with 50 - 75g of 3f. 

[Regular Joe]

[satwel]

I shoot 55 grains of 3f with a .440 ball and a 40 lb pocket drill (.020") patch in my Green Mountain .45 flinter. I use jojoba oil for lube. At 100 yards, I up the powder to 65 grains.

[stubshaft]

My GM 45 barrel likes 45 gr. 3F behind a 440 balll and #40 pocket drill lubed with Lehigh Valley.  When I try to increase the powder charge I get patterns rather than groups.

[Daryl]

My GM 45 barrel likes 45 gr. 3F behind a 440 balll and #40 pocket drill lubed with Lehigh Valley.  When I try to increase the powder charge I get patterns rather than groups.

This situation shows your patch material is not up to the job of handing higher pressures.
Using a .445" ball and 10 ounce denim I measured then, at .0225", I needed to use 75gr. 3F GOEX and 85gr. 2F GOEX with LHV lube to achieve the same accuracy at 60gr. 3F gave with the same
ball and patch combination when using a water based lube. The velocity for those two heavy loads, was 2,240fps. As far as accuracy is concerned, I am talking about 1/2" for 5 shots at 50yards
from a rest.

[Scota4570]

My GM 45 barrels do good with about 50 gr 3f, 440, and a snug patch. I get fabric from the store and cut my own patches.   I use water and ballistol to make a wet patch.  I wring them out, not dry, not dripping wet.  I have recently gone to looser combos.  They shoot as well as I can off hand and then some.  I stopped seeking the last tiny bit of accuracy with super tight combinations.
I find that really difficult to load combos will mess up my ability to hold steady.  The slight trade off in accuracy is gains back with a more steady relaxed off hand shot.   

https://www.joann.com/p/richloom-solid-duck-canvas/19837988.html

[Daryl]

Unfortunately, the link didn't give the weight.
Have you measured it with calipers compressed?
It looks like some canvas I purchased some time ago, that ran .022",
but loaded harder than 10 ounce denim. I assume, because even after washing, it was stiffer, perhaps just tighter woven.

[Scota4570]

I measured a patch several ways, take your pick:

Digital caliper blades pinched tight with my fingers ,    0.015
Digital caliper pinched tight then released,                  0.018
Digital MIC- clicker used                                            0.019
Digital MIC- snug with fingers                                    0.015

A sticky on a standard ALR way to measure patch thickness would be great.

[hanshi]

My .45 GM barrel really perked up when I fed it 70 grains of 3F, a .440" ball with a .023"-.024" canvas patch (measured with calipers while squeezing the jaws together as hard as possible) and Hoppes BP Lube.

I have a bit of trouble squeezing the calipers with the same force each time resulting in the variation.  Substituting .445" ball appeared to equal the accuracy of the .440" but did result in a slight velocity increase.  Patches are reusable.