50 PRB speed over a chrono

[DixieTexian]

I don't know what I'm missing but 100 grains of 3f to reach 1300 fps with a 28" barrel seems way off to me.

I've shot my .50 caliber Traditions Deerhunter flintlock over the chrono a total of 13 shots using only 50 grains of Schuetzen 3f and averaged just a little over 1300 fps. And that rifle only has a 24" barrel.

I went back and checked my notes, and you are correct. 70 grains gave me velocities in the 1300 range. 100 grains got me up to about 1600.

 

[Snydly]

Try shooting through a 12"X12" piece of stretched Cheese cloth. The ball will go completely through, unimpeded but the patch and the smoky crap will get caught and not give false readings on the chronograph. FYI... don't have your wife hold the cheese cloth while you shoot at it.....

 

[pacanis]

I bought some cheese cloth about 20 years ago for something I ain't gonna tell you about.
I just knew I'd have another use for it some day

 

[tenngun]

Let's just pretend he meant to type 182.5 grains.
Any further discussion of wrong weight will be removed as superfluous.

Beating that horse isn't helpful.

I often type on my phone. I get s when I was trying to get a, q-w and-z-x too. On 1-2 I often get the wrong. And rarely catch it

 

[Eterry]

Not sure how accurate this can be with all the variables when shooting black powder but thought some might find it interesting. It's a velocity calculator for black powder.

P-Max black powder internal ballistics

I tried it with 2 loads I'm very familiar with. Both showed roughly the same velocity as the Lyman Handbook.
I saved it to my smartphone.
Thanks.

 

[Sun City]

Get out of the modern mode! 100 gr. 2F will give all the fps you need!

 

[hanshi]

The chrono was 15-20 yards from the muzzle. A little farther than where my patches were landing. I had to move it our after testing the evil black rifle rounds.

A distance of 15 to 20 yards!? Sounds a bit excessive to me. I set mine up at about 20 feet.

 

[pacanis]

I was watching a YT video of someone shooting his ML over a chrony and it looked like he took 4-5 regular steps and was halfway there so he could read it. I guesstimated it was 20' away. It had the two sunscreens on it.

 

[BillKilgore]

A distance of 15 to 20 yards!? Sounds a bit excessive to me. I set mine up at about 20 feet.

The chrono was not detecting shots when it was closer. I moved it out to about 20-25 feet after testing the centerfire rounds, but it was not detecting rounds fired. The third move placed it around 20 yards. It may have been a little farther than necessary, but the ball would not slow much at that distance and I was definitely beyond the muzzle blast.

 

[longcruise]

but the ball would not slow much at that distance and I was definitely beyond the muzzle blast.

I had a ballistics program that would calculate muzzle velocity based on what was measured at a known distance to the chrono. Can't remember what it was though.

 

[kyron4]

I had a ballistics program that would calculate muzzle velocity based on what was measured at a known distance to the chrono. Can't remember what it was though.

Was it this one ?

P-Max black powder internal ballistics

 

[zimmerstutzen]

I had the chrono set up at the range to check some evil black rifle rounds, so I thought, what the heck.

I use Hornady 0.495 pure lead balls with an average weight of 182.5 grains. 0.018 pillow ticking patch and Track's mink oil patch lube. Powder was Schuetzen FFFg. I also swabbed and dried between rounds.

My rifle is an early Lancaster with a 42" Rice swamped Southern Classic barrel and a Chamber's large Siler lock.

63 gr = 1460 fps average
1473
1479
1427

72 gr = 1579 fps average
1600
1558

97 gr = 1858 fps average
1835
1973
1762

Fun times.

That is only half the story. a ball traveling over the speed of sound decelerates faster than a sub sonic ball. What matters is the speed down range at the target. Figures found by Lyman in their first edition Black powder Handbook show that sometimes there is an insignificant difference at 100 yards between one load and another 10 or even 20 grains higher.

 

[longcruise]

Was it this one ?

P-Max black powder internal ballistics

No, that's a different methodology. The methodology used that I'm referring to was much simpler. It took all the input that one would enter into the program and with distance from muzzle to chrono and velocity measured it calculated the typical table of trajectory, velocities down range, energy, etc. Entering a distance from muzzle to the chrono allowed it to calculate the same data to the rear for that distance.

Using a program such as Point-blank you can do it manually by changing the muzzle velocity entered until it calculates the same velocity measured at the known distance of muzzle to chrono.

 

[hanshi]

The chrono was not detecting shots when it was closer. I moved it out to about 20-25 feet after testing the centerfire rounds, but it was not detecting rounds fired. The third move placed it around 20 yards. It may have been a little farther than necessary, but the ball would not slow much at that distance and I was definitely beyond the muzzle blast.

I've thought about what you posted about chrono distance from the muzzle and the problem of not getting a shot read. There may be some other variable causing the problem. What it could be I have no idea. I get good reads as close as 15 feet from the muzzle.

 

[stikshooter]

Get out of the modern mode! 100 gr. 2F will give all the fps you need!

Not what you need but what you'd like to (KNOW) jeeze/Ed

 

[stikshooter]

I've thought about what you posted about chrono distance from the muzzle and the problem of not getting a shot read. There may be some other variable causing the problem. What it could be I have no idea. I get good reads as close as 15 feet from the muzzle.

And my Magneto Speed is not bothered other than getting crapped up with smoke ,attached to barrel/Ed

 

[Okie Hog]

I get good reads as close as 15 feet from the muzzle.

15-20 feet from the muzzle works for me.

 

[DixieTexian]

15-20 feet from the muzzle works for me.

Yeah, when I've used mine, I've had no problems getting readings at about this distance. And the ballistics calculators pretty well line up with the amount of drop I've seen at 50 and 100 yards, so it seems like it is reading the velocity of the ball and not something like the patch.

 

[Mike in FL]

I had a Chambers rifle exactly as you described. But greed and stupidity made me sell it. Maybe you ended up with it? If so, I will trade yoh my house and truck and wife and dog for it. Well, maybe not the truck.

 

[Newtire]

And my Magneto Speed is not bothered other than getting crapped up with smoke ,attached to barrel/Ed

That's a great unit so far as I've used mine. A friend of mine has the more expensive one that sits on the bench and you shoot right next to it. It also does a great job. I was worried that he was going to get mad when my gun sooted it all up but he just laughed and wiped it off. Some people are just great sports. I was wondering how my barrel mounted one would do with the holy black and now I know!