got to ask

[earlwb]

I do a lot of pig hunting at night here in Texas where it is legal. Even the modern guns can have a lot of muzzle flash too. Yeah it can momentarily blind you. But black powder guns all seem to blow some powder out of the barrel that flashes. It even does it some with reduced loads too.

Heck I was impressed a while back when I was testing a new inline muzzleloader at home. Just the 209 primer. I wanted to see if the firing pin was working or not. Anyway with just the primer in place I pulled the trigger in the darkened room and it did the muffled bang as expected but there was a very noticeable flash out of the muzzle. I wasted another primer marveling the flash out of the barrel.

As mentioned earlier using a chronograph to watch your bullet speed is the way to go for determining the max load for a particular combination of gun and bullet. But only if your gun can handle it safely of course. Obviously some guns can’t be tested in that way.

 

[GBG]

IMHO maximum recommended projectile weight is equally important as max powder charge. All my CVAs are recently manufactured. According to the owner's manuals, all have a 300 grain bullet weight restriction for sabot-bullet combos and a 400 grain limit for full bore lead slugs.

I have an email from Knight answering my questions about bullet weight restrictions that states their .52 caliber rifles don't have a bullet weight limit with maximum powder charges. Even so, I never use max charges of BH209 or T7 with bullets above 400 grains (approx. the weight of their 375 grain bullet with a sabot). I switch to Pyrodex RS and reduce loads to no more than120 grains(Volume) RS in an attempt to keep pressures and recoil reasonable.

My .52 caliber adjustable weight RCBS Hodgdon bullet mold throws flat base or shallow hollow base slugs from 300 up to 600 grains. I have test fired 600 grain bullets over 150 grains of Pyro RS (remotely with Lead Sled) in both Knight plunger and bolt guns. This lifted the red FPJ off the nipple of a Bighorn and it was caught between the plunger and nipple at a 45 degree angle. Thats why I would never use 150 grains(Volume) T7 or 120 grains(Volume) of BH209 (in bolt guns ONLY) with a bullet heavier than 400 grains. Again, JMHO and YMMV.

 

[ElDiablo]

All my CVAs are recently manufactured. According to the owner's manuals, all have a 300 grain bullet weight restriction for sabot-bullet combos and a 400 grain limit for full bore lead slugs.

Interesting. I wonder if that is strictly a pressure (safety) limit or if they are factoring in twist rates (a 28 twist .50 barrel is unlikely to shoot/stabilize a 300+ saboted well)?

 

[Pierre]

Interesting. I wonder if that is strictly a pressure (safety) limit or if they are factoring in twist rates (a 28 twist .50 barrel is unlikely to shoot/stabilize a 300+ saboted well)?

Good question ...follow through on that & keep us informed. Also the depth of the rifling is a factor. I follow the old rule about flame & accuracy.

 

[ElDiablo]

Good question ...follow through on that & keep us informed. Also the depth of the rifling is a factor. I follow the old rule about flame & accuracy.

I’m afraid I’d be the last guy to follow through with CVA on anything. Im not a fan.

Depth of rifling is a factor in what? Stabilization? Accuracy?

 

[Pierre]

I’m afraid I’d be the last guy to follow through with CVA on anything. Im not a fan.

Depth of rifling is a factor in what? Stabilization? Accuracy?

In order for the rifling to have it's full effect it also needs a certain velocity...too fast the the rifling will not have a chance to properly grip & spin the bullet. Too slow again it will not stabilize the bullet. That's why I check both the flash at the muzzle & the accuracy. I have 2 50 cals one has a 1-38 & the other a 1-48...the Lyman with the one with 1-48 only likes patched balls very accurate with 110grains & some muzzle flash. I use 490 balls with mattress ticking.

 

[ElDiablo]

No doubt there are a number of (bullet/powder/barrel) factors that work together in the internal ballistics cycle to produce the desired result - number and dimensions of lands/grooves, bore dimensions, friction imparted by the lands and grooves, twist rate, length of barrel, pressure, velocity, bullet composition/dimensions/weight, fouling, barrel harmonics, and powder characteristics to name a couple. I think it’s significantly more complicated than most of us realize.

 

[Pierre]

No doubt there are a number of (bullet/powder/barrel) factors that work together in the internal ballistics cycle to produce the desired result - number and dimensions of lands/grooves, bore dimensions, friction imparted by the lands and grooves, twist rate, length of barrel, pressure, velocity, bullet composition/dimensions/weight, fouling, barrel harmonics, and powder characteristics to name a couple. I think it’s significantly more complicated than most of us realize.

Concur, well stated...