Why?

[rodwha]

I have a .50 cal Lyman's Deerstalker. It states that they come with a 15/16" barrel. Mine has a 90 grn 3F max load with a PRB. Had I have bought (And kinda wished I did now) .54 cal the max load is 100 grns of 3F with a PRB. If the walls are thinner, and the additional weight adds pressure why did the max load go up?

In my quite limited scope of understanding/logic I figure the larger bore reduces pressure with the same load, i.e. 100 grns of 3F would actually have less pressure in the .54 bore, but the walls are still thinner, and the weight of the ball ought to add to the pressure as I understand it. And so it goes back to wall thickness...

 

[unspellable]

load

I suspect it's more of a case of a sensible load that will be somewhere near the sweet spot for accuracy and what not than any real consideration of anything coming unglued with either.

As for 50 vs 54, I have a 54 and I find it's easier to find 50 size bullets, sabots, etc, Seems like there has been a consolidating trend towards the 50 caliber. I also have a 58 and that's even worse for finding stuff in the local stores.,

 

[BigG]

When you shoot the muzzle loader you'll find the one that shoots to point of aim is more like 70 or 75 grains of BP or Pyrodex. That's the load you want, not necessarily max.

 

[zimmerstutzen]

Part of the reason is the amount of bore space taken up by the powder under the ball. The length of the 90 grains in a 50 caliber bore is probably a shade longer than 100 grains in a 54 caliber bore.

For each increment of extra powder, the ball is displaced further down the bore and there is less bore ahead of the ball for the powder to burn. In addition, the weight of the powder becomes an extra weight to be moved by the powder at the breach.

A 54 caliber also burns larger amounts of powder in a given inch than a 50. While 45's and 50's have a definite velocity curve as charges increase in a given barrel length, the 54 has a less defined velocity curve. So in 45's and 50's there is a definite point of diminishing returns in velocity, the 54 has no well defined point of diminishing returns.

 

[rodwha]

When I chose .50 cal it was due to the plethora of accessories for it. But initially I thought I'd be shooting saboted bullets. As this rifle was purchased with stalking in mind its unlikely to be used past 100 yds, and from what I've read a ball is more than adequate.

I do, however, want a drop in barrel with a Malcolm scope for hunting fields and such. Since a ball is too easily blown off course I'll either use a full bore conical or an aerodynamic saboted bullet. And for that a .50 cal still makes sense.

I have considered a very short barrel for hog hunting, and a .54, unless I can find a .58 in a 15/16th in .58 seems good. Since the range would be fairly short a ball would be my choice.

 

[zimmerstutzen]

As a rough rule of thumb for round balls, a 50 caliber retains about 50% of its energy at 100 yards. A 40% retains about that much/ A 58 cal retains about 58% of its energy at 100 yds. Given the reduced energy of the smaller balls from the get go, you are always better off with a larger round ball gun for down range energy.

For bullets however, a longer heavier bullets always retains its energy better down range than a short bullet. Even though a 45=70 has an arc like a rainbow, a 500 grain bullet still packs a mighty wallop at 500 meters, where some of the short 45 caliber bullets are lucky to travel that far.