.45 PRB Site-in and Load

[Rangefogger]

I Will lay out my situation for all you experts.
I Have Two .45 cal Kibler southern mountain rifle kits on the way, each with a 46 inch barrel. I am trying to figure out how I will sight them both in and what load I should use. I want them both set up for deer, but I also want to be able to knock down some tree rats here and there as well as other small game. My thoughts are on Zeroing the rifles at around 65-75 yards and working out a load that will give me around 2000ish muzzle velocity. This way the trajectory will be very flat and at no point between 10-65 yards will my shot deviate more than Around a quarter inch. I believe I would also be able to reduce my charge for small game substantially And at closer ranges around 25-50 the ball would deviate even less with the lower charge as it would drop further traveling at lower velocities.
so how many grains of BP should I use to attain around 2000 FPS with a .440 Roundball? What load would you recommend for squirrel with the same .440 PRB? Any tips are more than welcome.

also, does anyone know where I can find a chart or calculator that I can use to find what velocity a .440 PRB travels at with various Black Powder charges?? This would really help me to calculate the trajectory and determine different loads for different uses.

 

[ohio ramrod]

If I remember correctly dixie gun works catalog had a table in it that should give you a starting point for velocities and powder charges. All charts are really just a starting point since there are so many variables.

 

[hanshi]

In my 36" barrel 60 grains of 3F gets right at 1700 fps. Stop thinking in terms of velocity and instead think in terms of most accurate load. 2" high at 50 yds with that load should get you to point blank at close to 90 or 100 yds.

 

[Rodd Boyer]

I use 50gr of Swiss fffg for both .440 and .445 round ball in my 42" Green Mtn barrel, .45 flintlock. Its pretty much poa, poi from 25-50 yards. I found out that 50 gr was plenty for the buck I was lucky enough to bring home last fall. I have no idea what the velocity is....

 

[oldwood]

Had a .45 GM barrel on a custom Pgh./ Ohio half stock rifle used to shoot Iron targets with 62 gr. FFFG and .440 PRB. Also ,this rifle and load would hit 18" round iron out to 200 yds. , If the wind was calm...........oldwood

 

[Art Caputo]

I used to run velocities in the 2000FPS range years ago and have since backed off, finding the difference in trajectory/killing power on game difficult to distinguish in practice. I agree with focusing on the charge weight/velocity that delivers the best accuracy with minimal swabbing. This has been 55-70gr of 3F in my 45’s which are generally producing velocities in the 1700-1800FPS range with my rifles. The difference in trajectory between 1700 and 2000FPS out to 100 yards with a 75 yard zero which produces POI to 50 yards, and only about 1.5” more drop at 100 yards at the lower velocity.
I use the same load for deer, targets, and <25 yard head shots on squirrels.

 

[smoothshooter]

25 to 70 grains of powder will do everything you need to do with a .45 rifle.
50 to 55 grains is a pretty good general purpose load for target shooting, and animals above squirrel size.
Don’t lose any sleep over reducing your trajectory or group size by a quarter of an inch, or even a half inch with a flint muzzleloading rifle. The effects of wind, light levels, holding errors, sight picture errors, follow through, and range estimation errors are more detrimental to hitting than anything else.

 

[Robby]

https://goexpowder.com/wp-content/uploads/2018/06/rb-rifle-musket.pdfThis chart should give some right-a-rounds. My advice is like the other fellows, don't try to magnumize your guns, find the most accurate load for the game at hand. Working up loads is fun and working up two loads, one for squirrel and one for deer will be twice the fun, an added plus, you will learn the gun and learn your own limitations.
Robin

 

[Loyalist Dave]

My advice is like the other fellows, don't try to magnumize your guns, find the most accurate load for the game at hand. Working up loads is fun and working up two loads, one for squirrel and one for deer will be twice the fun, an added plus, you will learn the gun and learn your own limitations.

Agreed
Especially with the patched round ball which although is very accurate, loses velocity quite fast. A .440 round ball has a ballistic coefficient of .062.
What that means is that if you pushed it to have a 100 yard zero with a MV of 2000 fps, it would be just under 2" high at the top of the arc, which would be 60 yards. At the minimum deer load in my state, which is 60 grains for a rifle, you'd get about 1600 fps. The bullet path the highest trajectory point at 60 yards would be just a tad less than 3". Now to get the flight path difference down to 1"..., you'd need to push that .440 ball to 2500 fps.

Some of the folks that I hunt with have a measure that is set for small game. One fellow's measure is set at 35 grains, and he then uses two charges from that measure when loading for deer, so uses 70 grains. He also uses the 35 grain amount when shooting targets. Another hunting pal likes 30 grains for small game and 80 for deer, so he has two powder measures. Works for them.

I, on the other hand, have one powder measure that throws a charge that is accurate and works for deer. I tease my buddies with the two different powder loads, telling them that if they see a deer when hunting squirrels during deer season, by the time either pulls the ball, drops a second powder charge down, then load another patched ball, the deer will have died of old age. I see shooting as practice for deer. So I use the same charge regardless of small game or deer. My approach is to learn where to hold the sights, and to be able to have good range estimation out to 100 yards. Small game like a rabbit? Head shots.

LD

 

[longcruise]

I Will lay out my situation for all you experts.
I Have Two .45 cal Kibler southern mountain rifle kits on the way, each with a 46 inch barrel. I am trying to figure out how I will sight them both in and what load I should use. I want them both set up for deer, but I also want to be able to knock down some tree rats here and there as well as other small game. My thoughts are on Zeroing the rifles at around 65-75 yards and working out a load that will give me around 2000ish muzzle velocity. This way the trajectory will be very flat and at no point between 10-65 yards will my shot deviate more than Around a quarter inch. I believe I would also be able to reduce my charge for small game substantially And at closer ranges around 25-50 the ball would deviate even less with the lower charge as it would drop further traveling at lower velocities.
so how many grains of BP should I use to attain around 2000 FPS with a .440 Roundball? What load would you recommend for squirrel with the same .440 PRB? Any tips are more than welcome.

also, does anyone know where I can find a chart or calculator that I can use to find what velocity a .440 PRB travels at with various Black Powder charges?? This would really help me to calculate the trajectory and determine different loads for different uses.

The other consideration when it comes to trajectory is the height of the front sight above bore centerline. The greater the height, the more pronounced the trajectory.

Velocity charts may come close but can't be relied on for accuracy. It might simplify things to just settle on the load that will work for your primary use and sight in for your desired distance and then mess around with other shot scenarios that you plan to encounter.

 

[Zonie]

I Will lay out my situation for all you experts.
I Have Two .45 cal Kibler southern mountain rifle kits on the way, each with a 46 inch barrel. I am trying to figure out how I will sight them both in and what load I should use. I want them both set up for deer, but I also want to be able to knock down some tree rats here and there as well as other small game. My thoughts are on Zeroing the rifles at around 65-75 yards and working out a load that will give me around 2000ish muzzle velocity. This way the trajectory will be very flat and at no point between 10-65 yards will my shot deviate more than Around a quarter inch. I believe I would also be able to reduce my charge for small game substantially And at closer ranges around 25-50 the ball would deviate even less with the lower charge as it would drop further traveling at lower velocities.
so how many grains of BP should I use to attain around 2000 FPS with a .440 Roundball? What load would you recommend for squirrel with the same .440 PRB? Any tips are more than welcome.

also, does anyone know where I can find a chart or calculator that I can use to find what velocity a .440 PRB travels at with various Black Powder charges?? This would really help me to calculate the trajectory and determine different loads for different uses.

This is the trajectory of a .440 diameter lead ball shot at 2000 fps. The aim point is at 70 yards and the sights are .8" above the center of the bore.


Yards Vel Fpe Drop Drift TOF

0 2000 1135 -0.8 0.0 0.000

1 1989 1123 -0.7 0.0 0.001

2 1969 1099 -0.7 0.0 0.003

3 1958 1088 -0.6 0.0 0.004

4 1938 1066 -0.5 0.0 0.006

5 1928 1055 -0.5 0.0 0.007

6 1908 1033 -0.4 0.0 0.009

7 1899 1023 -0.4 0.0 0.010

8 1879 1002 -0.3 0.0 0.012

9 1870 992 -0.2 0.0 0.013

10 1851 972 -0.2 0.0 0.015

11 1833 953 -0.1 0.0 0.017

12 1824 944 -0.1 0.0 0.018

13 1806 925 -0.0 0.0 0.020

14 1788 907 0.0 0.0 0.022

15 1780 899 0.1 0.0 0.023

16 1763 881 0.1 0.0 0.025

17 1746 865 0.2 0.0 0.027

18 1738 857 0.2 0.0 0.028

19 1721 840 0.3 0.0 0.030

20 1705 825 0.3 0.0 0.032

21 1689 810 0.4 0.0 0.034

22 1674 795 0.4 0.0 0.036

23 1666 788 0.4 0.0 0.037

24 1651 773 0.5 0.0 0.039

25 1636 759 0.5 0.0 0.041

26 1621 746 0.5 0.0 0.043

27 1607 732 0.6 0.0 0.045

28 1593 720 0.6 0.0 0.047

29 1586 713 0.7 0.0 0.048

30 1572 701 0.7 0.0 0.050

31 1558 689 0.7 0.0 0.052

32 1545 677 0.7 0.0 0.054

33 1531 665 0.8 0.0 0.056

34 1518 654 0.8 0.0 0.058

35 1505 643 0.8 0.0 0.060

36 1493 632 0.8 0.0 0.062

37 1480 622 0.8 0.0 0.064

38 1468 611 0.8 0.0 0.066

39 1456 601 0.9 0.0 0.068

40 1444 592 0.9 0.0 0.070

41 1433 582 0.9 0.0 0.072

42 1421 573 0.9 0.0 0.074

43 1405 560 0.9 0.0 0.077

44 1394 551 0.9 0.0 0.079

45 1384 543 0.9 0.0 0.081

46 1374 535 0.9 0.0 0.083

47 1364 528 0.9 0.0 0.085

48 1354 520 0.9 0.0 0.087

49 1340 509 0.8 0.0 0.090

50 1330 502 0.8 0.0 0.092

52 1313 489 0.8 0.0 0.096

54 1291 473 0.8 0.0 0.101

56 1271 458 0.7 0.0 0.106

58 1251 444 0.6 0.0 0.111

60 1236 434 0.6 0.0 0.115

62 1219 421 0.5 0.0 0.120

64 1201 409 0.4 0.0 0.125

66 1185 398 0.3 0.0 0.130

68 1170 388 0.1 0.0 0.135

70 1156 379 0.0 0.0 0.140

72 1140 369 -0.2 0.0 0.146

74 1128 361 -0.4 0.0 0.151

76 1117 354 -0.5 0.0 0.156

78 1104 346 -0.8 0.0 0.162

80 1094 340 -0.9 0.0 0.167

82 1083 333 -1.2 0.0 0.173

84 1075 328 -1.4 0.0 0.178

86 1065 322 -1.7 0.0 0.184

88 1055 316 -2.0 0.0 0.190

90 1048 312 -2.2 0.0 0.195

92 1040 307 -2.6 0.0 0.201

94 1032 302 -2.9 0.0 0.207

96 1024 297 -3.3 0.0 0.213

98 1016 293 -3.6 0.0 0.219

100 1010 289 -3.9 0.0 0.224
�
As can be seen, the deviation in elevation is considerably more than 1/4".

A powder load of 120 grains of 2Fg or, 110 grains of 3Fg powder is needed to reach a MV of 2000 fps.

I've found that powder loads of 75-80 grains of 3Fg powder gives good accuracy and muzzle velocities around 1850 fps which is more than enough to take deer size game with a .45.

Here is a chart of the velocities Lyman shows in its BLACK POWER HANDBOOK & LOADING MANUAL, for a .45 diameter roundball. The first dot on the left is a 40 grain load. The last dot on the right is a 120 grain load.

Speaking of high velocities, the lead ball is very poor when it comes to maintaining velocity. The faster the MV is, the faster it loses velocity.
This chart below is for a .50 cal ball and it shows this rather clearly. The .45 caliber balls follow similar curves but they lose their velocity faster than the .50 does.

This means, starting with a lower MV doesn't greatly improve the downrange velocity.

 

[Flintandsteel]

My Kibler SMR likes 50g FFFg, .445 ball, .020” patch with liquid lube. Here’s the first 7 shots out of a new barrel. Adjusted sights from there.

 

[Pete G]

This means, starting with a lower MV doesn't greatly improve the downrange velocity.

I don't think that is what he meant to say

 

[Rangefogger]

thank you for all of the replies, I think I’ll go with a 65 yard zero and let the gun find a higher charge that it likes for accuracy, as well as a low. I like the idea of having a small game charge and a big game charge.

 

[Rangefogger]

I used to run velocities in the 2000FPS range years ago and have since backed off, finding the difference in trajectory/killing power on game difficult to distinguish in practice. I agree with focusing on the charge weight/velocity that delivers the best accuracy with minimal swabbing. This has been 55-70gr of 3F in my 45’s which are generally producing velocities in the 1700-1800FPS range with my rifles. The difference in trajectory between 1700 and 2000FPS out to 100 yards with a 75 yard zero which produces POI to 50 yards, and only about 1.5” more drop at 100 yards at the lower velocity.
I use the same load for deer, targets, and <25 yard head shots on squirrels.
View attachment 71437

WOW nice group!