estimating velocity

[Jim in Wisconsin]

I was shooting my 36 cal. mule ear rifle yesterday and wondered how fast those balls are going. Hornady .350 that weigh about 65.5 grains with 31 grains of 3f black powder and a pretty tight mink oil patch shoots accurate (if I don't wiggle). The barrel is 32 inches long
There is a dead ash tree with the bark off about 50 yards from where I was shooting, so I shot it. The ball made a dent about half it's diameter deep but didn't stick in. That wood is real hard though.
Is there any way to estimate speed without a chronometer? I think that ball is just sort of loafing along.

[PetahW]

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IMO,  velocity for a .36, usually used on small game or targets, doesn't really matter because the PRB will usually puncture either for a good effect.   

[Ohio Joe]

I would say you're getting close to (possibly) 1457+ FPS at the muzzle... Round ball looses velocity quickly, so at 50 yards you may be in the 978 fps range, and at 100 yards about 786, maybe??? Conditions play a big part in this.

This info is from the; old Lyman Black Powder Handbook... There's probably more up to date information out there. My book is from the 1970's, and I don't know if it was ever updated in later years, and of course the Powder you're using plays a big part... 

[Jim in Wisconsin]

Thanks, that sounds about right. Not even close to the "crack" of speed of sound. The old books are still useful, somethings haven't changed since then.

[Hanshi]

Unless you have a chronograph it's more of a "guessing game".  I say this because speed per grains of powder isn't always linear.  In my .40 the velocity of a prb was almost predictable until five grains of powder was added to a 35 grn charge causing the velocity to jump 200+ fps.  That anomaly never repeated at any other charge other than the 35 grn that was increased to 40 grains.  Over several sessions it happened every time at that load.

That being said it's possible to be in the ballpark if the following steps are taken.  Using a uniform testing material, wood will work, that has been shot previously and velocity measured.  The penetration has to be measured for the test shot and another shot with 5 grns added.  At least at certain charges the penetration will give a general idea.

[Winter Hawk]

Speed of sound varies because of temperature and humidity, but is pretty much 1084 fps. so you are well exceeding that.

I agree with Joe.  Looking at my Lyman BP handbook it shows 1457 fps at the muzzle for a 32" barrel with a charge of 30 grains of FFFg behind a patched 71 grain bullet.  You are lighter than that with one grain more powder so the MV is probably around 1500 fps.  The ballistic tables for .350 round ball at 1500 fps MV shows 1023 fps at 50 yards and 812 at 100.  With a 50 yard zero, you should be .31" high at 25 yards and 7.42" low at 100.

As Joe said, depending on powder and conditions. And, I bet they didn't actually measure these at the varying distances, but used the measured MV plugged into a formula to develop the rest.  But for ball park figures they should be "good enough".

~Kees~

[Jim in Wisconsin]

I see Dixie has that Lyman b.p. handbook, I need to order one.
Today I shot that tree from the same distance with a 6.5mm Swedish Mauser just to compare. That jacketed hollow point penetrated 2 inches - quite a difference!

[Ohio Joe]

Jim, just by chance is that tree an oak tree?

I ask because of the old history of the American warship "Old Iron Sides" - and the British complaining about their cannon balls just bouncing off the ol' gal when hit, and she was made of oak... I know it's comparing an iron ball to lead, but it's still interesting to think about.

[Jim in Wisconsin]

No, it isn't an oak tree. It's one of real many dead trees around here - ash I guess- they have all been killed by those emerald ash bugs that have invaded us. It is pretty hard wood though.
I have 5 acres with lots of trees on it, but I don't think there are any oaks on it at all.
I would love to go aboard Old Ironsides though!

[Ohio Joe]

Sorry to hear about those emerald ash bugs, Jim...

[Ohio Joe]

Jim, it might be possible to find a Bow Maker who would be interested in some of those  dead Ash Trees... I have a couple Ash Bows (which I never guessed one could make a Bow out of Ash), but they do it... Mine are simple longbows. Just a thought. 

[Jim in Wisconsin]

There are lots of them around here! Seems like every other front yard in the country has a rack with pieces of firewood for sale. $10 for a bundle you could carry in your arms. The ones in my yard are big enough that I don't want to cut them down. Too much work for this old guy. They are easily big enough to get bow size pieces out of them. The wood is light colored and pretty darn hard - sort of "stringy"

[Bigsmoke]

For a hundred bucks you can get a new chronograph from Midway.
Good enough to take the guesswork out of the game.
If I really cared about velocity, I would get one.  But I don't, so I won't.
I have had a couple of them, mainly for testing when we were making the big bore guns.
Hint:  If you are shooting black powder guns, I found it a worthwhile thing to fasten a piece of paper on the leading sky screen frame to keep the burnt powder from messing up the eyes (I guess that is what they are called).  On the really big guns (8 bore and 4 bore) where I was shooting larger amounts of powder (over 250 grains), I had to move the chrono out about 10 or 15 feet to get a reading. 
John (Bigsmoke)

[Jim in Wisconsin]

I had wondered about chronographs, whether they would work with muzzleloaders. I thought maybe the patch, and all the smoke and sparks would be a problem. Sounds like they do work though. I had one many years ago, borrowed it to someone and never got it back.

[RobD]

Most screen chronos will work with black powder fueled muzzleloaders, no big deal.