swamped barrel load

[2 shots]

hi all, have a new [ to me] rifle i picked up at the market faire in nazareth pa. last weekend. it has a green mountain b weight .50 barrel on it. cant find any info on max. load. the waist is about .712. this is my first swamped barrel so not sure on loading. will 80 grs. 2f be ok?? how about 80 grs. 3f? thanks. mike

 

[sb 54 cal.]

Have a swamped .40 cal. And have loaded 60 gr. 3 f with ball and bullet with no problems.

 

[tenngun]

Sam Falada tried to blow a .58 1” barrel. Went to god awful charges and up to five 600 grain minie ball. He couldn’t blow it until he left a ball half way down.
some where between 60 grains and a hundred will be your best load. Probably 70-80 grain. Your gun will hold an accidental double charge without difficulty.... provided you get that ball down the bore.

 

[rich pierce]

You’ll be fine if nothing unusual was done putting it together.

 

[Art Caputo]

My swamped 50 cal with similar barrel dimensions handles the loads you describe with no problems.

 

[Spikebuck]

Mike, I have a swamped green mtn in .54 and the waist is .7615...so considering my larger bore (and not knowing your groove depth but assuming the same) we would have about the same amount of steel remaining. With it's slow twist, mine likes 105 grs of 2F, so that's what I feed it. Also keep in mind that the waist is WAY down the barrel where the pressures are less than at the breech. Any reasonable load is going to be fine.

Mike

 

[Loyalist Dave]

My Swamped .54 is actually thinner due to the larger inside diameter, and I use 70 grains of 3Fg. I use it as I also use the same powder to prime my lock, as it keeps things much simpler.

LD

 

[hanshi]

The swamped .50 in my stable usually gets 70 grns of 3F which is a "middling" load, IMO. Heavier charges do fine but 70 grns is nice and accurate and more economical.

 

[Tom A Hawk]

I shoot 100 grains 3F Swiss in a 7/8" straight .50 . Wonderful flat trajectory and excellent accuracy.

 

[Archer 756]

don't any one proof barrel.

 

[Loyalist Dave]

don't any one proof barrel.

A lay person can perform a crude test of a barrel...,
A trained person can perform a rather in depth test, or can have it done by an engineering firm..., for example we had a used artillery barrel on our militia cannon, and had it magnafluxed, back in the 1990's, and again when we went to sell it.

BUT to actually "proof" a barrel, which is a highly specific term that carries legal results, that barrel MUST be submitted to a proper "proof house" for testing, and upon completion, that barrel gets a "proof stamp" and the person or company selling it may claim the barrel has passed "proof".

Modern cartridges are standardized for proofing pressures, BUT black powder barrels to be proofed at a legit proof-house meet that particular house testing standard for black powder proof, and the proofing houses do not use the same standards when it comes to proofing black powder barrels.

There is no such proofing house in North America, and no barrel made in the United States is "proofed". They may, however, be tested.

So the next time somebody says "I proof all the barrels that I use...," well, they didn't, but they may have performed some sort of test.

LD

 

[tenngun]

I don’t worry about any barrel I buy. If I ever buy a curry popper it would be from Loyalist Arms.
I don’t think I ever accidentally double charged. The biggest charge I ever shot was 140 grains 3f in a one inch .54 barrel behind one PRB Green River barrel( now out of business)
Let us say x gun should take a 200 grain charge and two minnie balls to be proofed. So the gun stands it fine. Though now I’m worried that I stressed the metal. Will it take a normal charge now? Umph.
I’ll trust my gun to normal charges. Maybe it will fail some day ‘ tween breakfasting with my family and dinner with my ancestors. That is a worry but I don’t want to go ridiculous just to see if my gun is safe for normal.

 

[2 shots]

thanks all, just wanted some ideas. i figured an 80-90 gr. hunting load would be fine.

 

[Loyalist Dave]

i figured an 80-90 gr. hunting load would be fine.

As long as it's accurate, it will be dandy!

LD

 

[Huntschool]

OK.... So, this is a .50 cal B weight barrel. First thing I would want to know is what is the twist rate. As was stated above, the pressures at the waist are much lower then the pressures at the breech. Swamped barrels were designed to have heavy breech weight and then reduce and then enlarge as a means of reducing overall barrel weight while allowing for heavy charges.

Knowing the twist rate may help you design a load. Slow twist 1:66 and up are really designed as heavy charge RB barrels. 1:48 or so seems to perform better with lesser charges. I have found over the years that there will be several charges that should work well in the slower twis barrels. For instance, I have a .40 cal barrel built by Getz quite a while ago that has a 1:66 twist. My dead on at 40 yards and under with this barrel is with 35 gr. of 3 fff. However my dead on hunting load is 90 gr. of 3fff still with a patched RB and that load will shoot through a hardened disk coulter at 100 yards. Go figure. The barrel will hold that load.

Just my thoughts

 

[hanshi]

I once owned a nice Virginia flintlock .50 and killed lots of deer with 100 grains of 3F Goex. The barrel was straight, however, and 42" X 7/8". I even killed deer with a US M1841 .54 (replica) using 110 grains of 3F Goex. But both these guns would really shoot with these loads.

 

[bldtrailer]

I use 70grns swiss 3f out of a 36 inch green mnt straight barrel with mutton tallow lube .020 patch .490 ball 1-70 twist

 

[Cruzatte]

hi all, have a new [ to me] rifle i picked up at the market faire in nazareth pa. last weekend. it has a green mountain b weight .50 barrel on it. cant find any info on max. load. the waist is about .712. this is my first swamped barrel so not sure on loading. will 80 grs. 2f be ok?? how about 80 grs. 3f? thanks. mike

You'll have to take your rifle to a shooting range and test this out for yourself. And then come back and tell us. Either load sounds like a good candidate. Experimenting with different loads is half the fun of shooting muzzle loaders.

 

[Pete G]

don't any one proof barrel.

A deliberate overload can damage an otherwise sound barrel and/or breech. That is why most experienced builders don't.

 

[Johnny Tremain]

Not into wasting powder, used the Davenport formula to figure out my max load 74.5 gr, and worked backwards until the group tightened up. 54.5 is the minimum load inside of 100 yards.
Mine is 45 cal so what the OP says, 80 grains sounds, about there.