.54 Green Mountain Barrel Max Charge?

[68K20]

I have always enjoyed flintlock hunting, but never had a decent gun. That ended this christmas, when I got a used Christian Springs rifle with a 38" Green mountain .54 swamped barrel. The gun was purchased from TOW.

When I was purchasing the gun, I asked what they thought a good range of powder was to use in rifle. they recommended 55-80 grains of 2F, 80 grains being a max load. That is what I used in my CVA .50 before, it listed 100 grains as a max load so it seemed in line with what I knew.

Fast forward to now- I have been playing with loads and reading online, and it seems everyone is using much heavier loads than this. Looking at ballistic charts it seems the prb is anemic at 80gr of 2f. Everyone seems to be using 100-140 of 2f or 80-120 3f. Confused, I decided to call green mountain. They were no help, did not have any data on a swamped barrel, and could only offer data on their recommended loads for their current barrels of 80-100gr. of 2f.

Looking at other barrel brands, I see 80-100 2f as the max loads quite often.

So my question is this- am I over thinking the loads and will be fine with a 80gr. 2F hunting load? I will probably only hunt deer with the gun, but would like to hunt black bear with it as well if it was an option. It just seems a little under powered for even a 50 yard shot by the numbers.

I have tested it with 60-80 grains of 2F and it shot no different other than a little change in recoil.

Side note and a big thank you to Colerain Barrels- I got about 2" groups at 50 yards, but it was shooting way left. I dropped a little mini mag light down the barrel with an unprimed 7mm casing and was able to project light rings on the wall and could tell the barrel was bent. Green Mountain wanted nothing to do with it, but recommended talking to Colerain about straightening it. They laughed when I explained the situation, but for the cost of shipping straightened the barrel for me! I have the gun back together and it looks great, but have not shot it since. I want to find it's best load, but not sure what my limits are.

Thanks for the help!

 

[Kansas Jake]

I can't recommend on the upper end of powder charge, but I often have shot 90 grains in a Thompson Center 50 caliber with a 15/16" barrel. I would not be afraid of 90-100 grains of 2f in a 54 caliber.

On the 80 grain charge in a 54 for deer, that would not be underpowered unless you are shooting way beyond reasonable deer distance. For me and my eyes, that is about 75 yards, but it should be good medicine out to and beyond 100 yards.

 

[Walks with fire]

My GM manual for the interchangeable drop-in barrel states 80-100 gr. 2f for a .54 round ball and 0 to 50 yards. The conical loads for a 460 gr. is stated to be 100 to 110 gr. of 2f.

 

[azmntman]

60 would be a bit low but would knock the critter loopy if hit well. I never hunt with more than 80 gr, even in my .58. Youll be fine. Practice and shoot only within your KNOWN kill range (say a 6" group) and even 60 gr will turn that beautiful innocent lil creature into beautiful innocent lil white packages of protein!!

After all in the WBS they were shooting 60 gr in .58 and tearing off arms n legs :idunno:

 

[Zonie]

Welcome to the forum. :thumbsup:

You asked TOW and they gave you their opinion.

Their opinion is just a little bit lower than many others for a .54 caliber bore.

As for powder loads over 100 grains, IMO, it is just a waste of powder.

Yes, the initial velocity of a patched roundball will be higher but roundballs lose speed quickly and the faster they are going, the faster they lose velocity.

Take a look at this chart:

The first dot on the left is the muzzle velocity. Each dot to the right represents a distance of 20 yards starting with 20 yards and ending at 120 yards.

Notice that although the 100 grain powder charge starts considerably faster than the 80 grain powder load by the time it reaches 100 yards the velocity has dropped almost down to the velocity of a 80 grain load.

Any of these velocities out to the 120 yard distance and beyond will allow a patched roundball to easily kill a deer.

 

[Walks with fire]

Don't under estimate the power of a .54 patched ball on deer. I can't say about larger stuff because all I hunt is deer. Shoot what ever charge is most accurate.

I am currently working with a Lyman .54 Trade and Deerstalker. The Trade barrel is being tested with Goex 2f going up the ladder in 10 grain steps and it's starting to tighten up real well at 100 grains with a .535 ball and .020 Eastern Maine patch. Lyman manual say's 120 max. charge of 2f. I will move up 5 grains from there up to my max of 115 grains in the next range session.

Still getting a torn patch now and then but I smoothed up the crown a bit already for the next session with a little sand paper.

I don't know if a swamped GM barrel would stand up as well as a straight barrel or not. I have never owned a swamped barrel.

 

[tenngun]

As Zonie noted PRB velocity decreases shortly no mater how fast you start it out. The barrels on modern guns are pretty tough. Sam Fadala ran god awful charges but could not blow a barrel until the barrel was obstructed. Ted Kirkland of Dixie arms did the same thing. This is not to say you should try god awful charges only that your gun will LIKELY stay safe. Your gun will become unpleasant to shoot before you max out your gun. At about 100 grains you top out your down range performance, and out to a hundred yards that will cut clean through most animals in North America. Much smaller charges will make American deer French in ml hunting ranges.

 

[Sparkitoff]

I have a green mountain 54 caliber barrel however is not swamped. I intend to use eighty grains if the groups are right but I would like to stay no more than 100 grains with the PRB.I hunt deer and hogs in the south west and elk deer and bear in the Midwest and I have no issues with a 54 ball running out of a barrel in front of 80 g of powder for shots to 100 yards.

 

[Snakebite]

I have a TVM Late Lancaster in .54 with a 42" swamped barrel and they told me 95grs of 2F was max for that barrel.

I also have a .54 Hawken with a 34" Douglas XX barrel and the person who built it back in the late 1970s said 120grs of 2F was about max for that. For 100yds plus I load it with 110grs of 2f which gives me good trajectory at the longer ranges. I have shot it with 120grs but got no better accuracy than with 110grs.

 

[Smokey Plainsman]

I've fired 120 grains in my Lyman's gun with no problems. But I would go no further.

 

[Vaino]

My Hawken has a 1" straight bbl in .54 and my elk load is 120 grs 3f w/ zero complications. It's not that a lesser amount of powder wouldn't kill an elk, it's a flatter trajectory I'm after. Works for me......Fred

 

[SDSmlf]

Assuming the breach area is one inch or more across the flats with modern barrels I would be very comfortable at 120 grains plus powder charge with a round ball. Unfortunately, my shoulder wouldn't like it. That said, depending on rifling depth and twist, would step up change until accuracy degradation or your shoulder suggested stopping. Unless you have a very slow twist (say 1-72" or greater) and a very strong shoulder, you will find your accuracy load before reaching a charge of 120 grains of powder. Also likely if you go the other way you will find a 30 yard squirrel head load somewhere around 30 grains without having to touch the sights. TC Manual is a good reference. Check out page 78 in attached for round ball load recommendations. https://www.scribd.com/mobile/document/321169256/Shooting-TC-Side-Lock-Black-Powder-Guns.

 

[Spikebuck]

I have a green mountain swamped in .54 and 44" long. 1-70 twist. Best accuracy is with 105gr of 2F. I don't really WANT to shoot that much powder, but this was one of the most finicky guns I worked up a load for and 105gr with a .018 pillow tick patch lubed with mink oil and a .530 ball was the magic combination.

I agree with the comments of "shoot what groups best." If that's 80 grs, that's plenty...all day long. :thumbsup:

As a side note, I have a number of .54's and all the rest like 90 grs of 2F...but all are slower twist at 1-66 as well. With 90 grs, I'm shooting through pretty much all deer I've hit with them. In Brian Beckums videos, he's stacking up deer with his preferred load of 80 grs 2F (in a .50).

 

[TerryK]

I like Zonie's chart. 80 grains is most efficient, and will slam any deer within 100 yards. Where I hunt, 30 yard shots are the norm. I never tried a 100 yard shot at a deer due to the brush in the mountains here. I like shorter barrels, so excess does not burn anyway.

 

[Spikebuck]

the initial velocity of a patched roundball will be higher but roundballs lose speed quickly and the faster they are going, the faster they lose velocity.

Take a look at this chart:

The first dot on the left is the muzzle velocity. Each dot to the right represents a distance of 20 yards starting with 20 yards and ending at 120 yards.

Notice that although the 100 grain powder charge starts considerably faster than the 80 grain powder load by the time it reaches 100 yards the velocity has dropped almost down to the velocity of a 80 grain load.

Hard to tell exactly on the chart, but what appears to be rather constant is the percentage difference in velocity over distance. If the top numbers for 80 and 100 grs are 1600 and 1700 fps initial velocity, 100/1600=6.25% faster with a 100 gr charge. If the 120 yard numbers are 900 and 950, that's 50/900=5.6%.

One would have to have a chart that's more "readable" to get the exact numbers. Net...if that chart was in percentage difference in speed over distance instead of actual speed, it would look quite a bit different.

 

[Siringo]

I have a TVM Fur Trade with a swamp 42" Colarine 54 caliber. My accuracy load is 90 grains of Old Eynford with a 0.020 patched .530 round ball. I have used Swiss #2 with the same patch/ball/powder combo, but need to use a backer patch to prevent blowout. At 50 yards, I can get it group 1 inch. For me, going above 90 grains with a 50 yard gun anyway was self defeating.

 

[Snakebite]

My Hawken has a 1" straight bbl in .54 and my elk load is 120 grs 3f w/ zero complications. It's not that a lesser amount of powder wouldn't kill an elk, it's a flatter trajectory I'm after. Works for me......Fred

Back about 40 years ago when I was a young stud, our club in Austin TX (The Hill Country Free Traders) had monthly shoots and at 100yrds with 120 or 110 grs of 2F I could hold right dead center on the target. We had some iron targets we'd shoot at too, it would ring them pretty good. Could pretty much do that all day back then.

 

[Rifleman1776]

Whenever I see questions like this the question that comes to my mind is: Why?
What do you mean by max load? Is that point just before your barrel blows up that you want?
Why are you even thinking about this?
The load you should be seeking is what works best in your rifle. e.g. most accurate at 50 yards. and for hunting. If yer rifles sweet spot is with 80 gr. charges, that will bring down anything on this continent short of an angry grizzle bar. Why would you want more? However, I believe your barrel should be able to shoot charges up to about 140 gr. or even more but there is no sensible reason to use loads like that. :nono: Before proceeding, please reevaluate yer priorities. Good luck, Bro. :v

 

[68K20]

I want to know the max load just so I can stay safe trying to find the sweat spot of the gun, with enough energy to get the job done.

Right now, the rifle shoots the same groups from 60-80 grains, but I am sure it could shoot better. I was told 80 grains 2f was the limit, but everything I read with the 1 in 70 twist says they like 100+ for accuracy.

My confusion was looking at ballistics charts. I found this for a harper's ferry .54 35.5" barrel, 1 in 66 twist. With an 80 grain load, they listed MV of 1519fps with 1,142fpe. At 50, it is down to 1,143fps and only 649fpe. I'm sure it would work, but am used to hearing the 1000 foot pound rule, which this is well short. Everyone seems to think this is plenty for hunting, so I will believe.

Long story short, I want to develop a safe, accurate load in this rifle that will humanly kill.

 

[BigBoreBLR]

I shoot 70grns of 3f in a 1 in 66 twist lyman gpr. Between u80 and 90 it groups a touch better.

However, the deer in my freezer thinks 70grns is too much.

Past 100 to 125 yards, the bullet drops like a rock... depends on how much you want your shoulder thumped.

70grns will crush bone and spit it out the side.

If you hunt elk or moose, you will want to shoot more than 80 grains for sure.

Find a good patch, then rune the load for best group. Then consider if you want to go up or down in load.

I'm happy keeping an extra 20 grains in my horn every shot.

I'm tempted to shoot past 100, b it try it on a so what windy day and see what happens.