Traditional Muzzleloading Association

Traditional Firearms => Caplock Long Guns => Topic started by: Jim in Wisconsin on August 07, 2023, 07:17:48 AM

Title: estimating velocity
Post by: Jim in Wisconsin on August 07, 2023, 07:17:48 AM
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.
Title: Re: estimating velocity
Post by: PetahW on August 07, 2023, 09:52:12 AM
.

https://www.youtube.com/watch?v=FZxizte6foI


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.    :toast
Title: Re: estimating velocity
Post by: Ohio Joe on August 07, 2023, 01:23:09 PM
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...  :shake
Title: Re: estimating velocity
Post by: Jim in Wisconsin on August 07, 2023, 06:19:05 PM
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.
Title: Re: estimating velocity
Post by: Hanshi on August 08, 2023, 03:58:29 PM
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.
Title: Re: estimating velocity
Post by: Winter Hawk on August 08, 2023, 04:27:58 PM
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~
Title: Re: estimating velocity
Post by: Jim in Wisconsin on August 08, 2023, 09:25:12 PM
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!
Title: Re: estimating velocity
Post by: Ohio Joe on August 11, 2023, 01:38:41 PM
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.
Title: Re: estimating velocity
Post by: Jim in Wisconsin on August 11, 2023, 03:17:01 PM
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!
Title: Re: estimating velocity
Post by: Ohio Joe on August 11, 2023, 11:22:29 PM
Sorry to hear about those emerald ash bugs, Jim...
Title: Re: estimating velocity
Post by: Ohio Joe on August 16, 2023, 07:56:59 PM
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.  :shake
Title: Re: estimating velocity
Post by: Jim in Wisconsin on August 16, 2023, 09:23:03 PM
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"
Title: Re: estimating velocity
Post by: Bigsmoke on August 17, 2023, 03:32:07 PM
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)
Title: Re: estimating velocity
Post by: Jim in Wisconsin on August 18, 2023, 07:10:37 PM
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.
Title: Re: estimating velocity
Post by: RobD on August 20, 2023, 06:12:25 AM
Most screen chronos will work with black powder fueled muzzleloaders, no big deal.
Title: Re: estimating velocity
Post by: KDubs on August 20, 2023, 09:13:26 AM
I bought my chrono years ago, like 20, for archery and bow tuning.
 Ill be trying it on my front stuffer today.  I'll let ya know .
 needs to be atleast 15 ft in front of ya, I saw a post somewhere for making baffles to stand up in front of the chrono to protect it from the blast.  not sure thats necessary at 15 ft.  guess we will see......
kevin
Title: Re: estimating velocity
Post by: Winter Hawk on August 20, 2023, 03:17:27 PM
My chrony is 28 years old now, a gift from my Sweetie.  I tried it with my muzzle loader and got over 17,000 fps!  I thought the patch right behind the bullet made for the erroneous reading.  That was at 10' from the muzzle.  What John suggests about putting attaching paper to the frame is great!  You could make an aiming point on the paper so the ball would not hit the chronograph.  Good idea, John!
 :hairy
~Kees~
Title: Re: estimating velocity
Post by: RobD on August 20, 2023, 06:06:54 PM
...  What John suggests about putting attaching paper to the frame is great!  You could make an aiming point on the paper so the ball would not hit the chronograph.

Ya need to be VERY CAREFUL with where to aim with regards to "screen" type chronos - too many folks aim either dead center or low and wind up trashing the chrono.  At such a short distance 'tween muzzle and chrono, bullet POI will be LOW, sometimes drastically low, ask me how I know this ....

Title: Re: estimating velocity
Post by: Bigsmoke on August 20, 2023, 06:27:49 PM
One day I was chrono testing a 2 bore rifle, the projectile weighed 3,500+/- grains and we were starting out at about 350 grains of Fg Goex.  The chrono was set about 20 feet ahead of us and I was shooting it offhand.
I must admit, I was a bit intimidated by this behemoth and pulled down a tad as I pulled the trigger.  Well, maybe more than a tad, as the bullet hit the darn chrono and destroyed it.  Hah, it took a while for all the pieces to hit the ground.
I should have fired it once to get the feel of it before shooting over the chrono, but I was in a hurry and as a result,  severely mutilated it.  Oh well, live and learn.
John (Bigsmoke)
Title: Re: estimating velocity
Post by: Winter Hawk on August 24, 2023, 04:42:30 PM
Ya need to be VERY CAREFUL with where to aim with regards to "screen" type chronos - too many folks aim either dead center or low and wind up trashing the chrono.  At such a short distance 'tween muzzle and chrono, bullet POI will be LOW, sometimes drastically low, ask me how I know this ....
That is why I suggested putting an aiming point on the paper, so a person doesn't shoot too low and destroy the chronograph.

And John, I can't even imagine the recoil of 350 grains of Fg pushing a 3500 grain projectile!  How is your shoulder now, after all the years of punishment you gave it?  :o

~Kees~
Title: Re: estimating velocity
Post by: Bigsmoke on August 24, 2023, 08:03:10 PM
Quote
And John, I can't even imagine the recoil of 350 grains of Fg pushing a 3500 grain projectile!  How is your shoulder now, after all the years of punishment you gave it?  :o

Surprisingly enough, the right shoulder is doing OK, considering, as you put it, all the years of punishment.
Sorry to say, however, that the left shoulder is the one bothering me, rotator cuff ripped and arthritis and bursitis diagnosed and treating it with shots.  Plus tendonitis in the left elbow.  Them "itis" brothers seem to be out to get me.  Oh well, I guess they are right when they say that getting old ain't for sissies.  ;banghead;

John (Bigsmoke)
Title: Re: estimating velocity
Post by: RobD on August 24, 2023, 08:43:38 PM
Ya need to be VERY CAREFUL with where to aim with regards to "screen" type chronos - too many folks aim either dead center or low and wind up trashing the chrono.  At such a short distance 'tween muzzle and chrono, bullet POI will be LOW, sometimes drastically low, ask me how I know this ....
That is why I suggested putting an aiming point on the paper, so a person doesn't shoot too low and destroy the chronograph.

And John, I can't even imagine the recoil of 350 grains of Fg pushing a 3500 grain projectile!  How is your shoulder now, after all the years of punishment you gave it?  :o

~Kees~


No, that might spell disaster because at 10ft to 15ft or so there can be a Huge difference 'tween bore sight and actual sight ... and this WILL happen with long guns that sport high sights.  Been there, didn't do the bore sight, bullseye into the chrono face.  In the best of worlds it's bore sight that should be employed with all screen chrono's.  Easy to do with any long gun that can have an open breech (bolt, break open, etc), difficult for muzzleloaders and other "closed breech" guns.

Title: Re: estimating velocity
Post by: Winter Hawk on January 07, 2024, 02:50:36 PM
I was looking in in the back of my 2023 Dixie catalog the other day and noticed an article on estimating bullet velocity.  I think the Lyman handbook with empirical data is probably more accurate but this is another source for "guesstimating" how your loads are doing.

~Kees~
Title: Re: estimating velocity
Post by: RobD on January 07, 2024, 03:13:13 PM
Sticking in one of those muzzle bore lasers will quickly show where the bbl needs to be pointed at the chrono.