RB point of impact vs. Maxiballs

[ttusmc81]

Can anyone tell me the difference in point of impact between a patched RB and a maxi ball of the same approximate weight and powder charge?
The reason I'm asking is I had a t/c hunting tang peep installed on my .54 Renengade and have to replace the front sight. I know the height I need with with a 380 maxi and a 90gr charge. I would like to start shooting pached R/B's. Will they genneraly shoot to a higher point of impact due to their faster velocity? I've had a hard time getting the right front sight through trial and error and don't want to do it again. I'm realizing the gunsmith may have mounted the tang to high. He did not use the lower tang screw. He mounted the sight between the screws ( higher on the tang). I now need a .600 high front sight and if R/B's shoot higher I would need to install a ramp which looks out of place on the rifle.

 

[wtilenw]

I was told that to get a pistol with fixed sights to shoot higher, use a heavier bullet. This is so the slower bullet exits the barrel later in the recoil cycle, thus the muzzle is higher as the bullet exits the barrel.
Any comments from someone more technical than myself?
Idaho PRB

 

[Brian Rice]

My rifle has a much lower point of inpact with Maxi-balls. You should be able to use a good bit lower front sight from my experience.

YRMV

Brian

 

[Lonegun1894]

Not to be a smart-aleck, but no one has mentioned this yet. How about just getting a taller sight than you need and just filing it down til it shoots to where you want it? Seems simpler than trying to do the math involved in figuring out sight height, and then hoping that the theoretical result of your calculations corresponds to where the ball actually hits. Thats what i'd do, but there's amny people here MUCH smarter and more experienced than i am, and i'm sure they'll be along shortly.

 

[paulvallandigham]

It obviously depends on what powder charge is used, the velocity achieved with both projectiles, etc. With a heavier bullet at short range, impacts are usually higher than a bullet of lighter weight shot at the same velocity. At long range, gravity becomes more a factor, and the heavier bullet will drop faster than the lighter one, all other things being equal. A round ball and a conical are not "equals". So, any comparison between the two projectiles will be comparing apples and oranges. Because of the extra weight, conicals can be expected to penetrate deeper in flesh and bone. The Round ball will mushroom quicker, assuming it is pure lead, while the conical, even pure lead, will hold its shape, and penetrate further.

Even if you could hold the weight close, you have the different length of the two projectiles whick affects how the Rate of Twist of the rifling will spin each of them, and contribute or NOT contribute to accuracy. The longer conical shape requires a shorter Rate of twist than a round ball does. Most manufacturers who make a barrel in a caliber that is suited to both RB and conicals will use a compromise ROT so that the gun handles both pretty well, but not as good as a barrel rifled for each of projectiles separately.

 

[ttusmc81]

I was just trying to find out if PRB's shot higher or lower if you use a sight setting set for maxi's. I'm at .600 for front sight height with the rear peep flush to hit center at 50 yds with maxi's. I was wondering what would happen when I swithced to PRB's with my point of impact. I cant go much higher in the front with out a ramp ( not very tradiional looking). I'm new to this forum. Thanks for all the help guys but the MODERATORS keep moving my posts to "crafting" ( deer leg knives and possible bags) there are no "SHOOTING" posts in those threads. What am I doing wrong? If the accuracy or percussion rifles are not correct for this post ,which forum is ?

 

[paulvallandigham]

Again, without knowing the powder charge, the brand and size of the powder, the length of your barrel, the caliber, the weight and diameter of the round ball, and patch thickness, then the weight and diameter of the conical( maxiball), it would be hard to estimate where one would shoot in relation to the other. There are too many possible variables that would affect POI. Sights on a rifle are usually set to make the ball rise from a line draw through the center of the muzzle down the bore of the barrel, to the target. That allows the ball to cross the line of sight- the line between the rear and front sights, and the target, and come back down to line of sight so that you can hit the POA. You would normally want POA and POI to be the same at some given range. That is what is meant by " zeroing " a gun. When you shoot two different projectiles that weigh different amounts, have different lengths, have different barrel times( Time from ignition to exit from the barrel), you add all kinds of things that affect where each is going to hit ( POI) on the target. Change the powder charges and anything can happen with the POI.

as to the forum, sometimes the administrators are not sure what your question is really all about. New guys don't always draft a question correctly, since the are NEW. Sometimes we think you are asking one thing, and the administrator will switch your question to the best topic section in hopes that the members who read that regularly are most likely to help you out. Then, after a little back and forth, it becomes apparent that your first choice was correct. So, don't get in a stew about where your question ends up.

If only gravity were involved, or if we fired both a round ball and a maxiball from the same gun at the same velocity, the maxiball would hit the ground first, simply because it has the most mass( weight.) But when we throw in wind and air, and humidity, and shorten the distance down to 50 yds and less, you might get the maxi hitting higher than the PRB at that distance and closer. That has to do with the ballistics coefficient of both projectiles, and sine a round ball is " terrible" in the BC department, a maxiball is likely to perform a little flatter for awhile when comparing bullet drop and rise, or trajectory. Recoil contributes to muzzle rise, and that will cause a heavier slug to hit higher on the target, than a lighter one. At 50 yds, I don't think the difference in impact points would be much more than about 3-4 inches using the two projectiles, with a reasonable powder charge for each. that is less than " minute of deer", shooting at a broadside shot at deer, so a hunter would be likely to kill his deer shooting either. Since a maxiball is totally unnecessary to kill animals like deer, I always recomment that new shooter develope their target and hunting loads using the patched Round Ball ( PBR ), as they can practice more, and learn to shoot their rifle accurately with the PRB. The Maxiball are heavier, and cost much more to shoot, so shooters tend not to practice as much with them.

Hope this helps.

 

[bpbrs]

God save me from screaming.........
Take the gun out and shoot it...then you can see where it hits.
If you had a peep installed then you are no longer are shooting at the maxi setting.
You have no idea where it will hit till you shoot the thing with a PRB.

If you do not like where the gunsmith mounted the peep tell him to get his act together & place it where it is suppose to go.

Not much of a gunsmith... IMO

Bill

 

[chgraf]

At 50 yrds out of my bobcat I get about 10" difference in POI with the same POA, both loads 90 grs of pyrodex P the PRB hits high, maxiball hits low. I have tried using oxyoke wads and didn't get much change in POI, however the groups are tighter. I said to heck with the maxi's & hunt with the PRB. just my 2 cents :winking:

 

[ttusmc81]

Thanks for all the help, I have been shooting the gun with an adjustable front sight, just needed some help to determine the final front sight height switching to a PBR. Thanks again, I did not have a lot of experience shooting the PRB"s but have decided to shoot them in the .54, thanks to these posts. Yes my questions were poorly drafted, after reading them again at a later time I realized they were convoluted!! TIM

 

[YONAH MT]

I also had a T/C Peep sight mounted on my .50 cal Hawken. Tha instruction states that the sight should be mounted evenly between the upper and lower tang screws.Your gunsmith did not mount the sight incorrectly. I'm with some of the above posts. You should just shoot the rifle and then you will know where that rb will land.

IMHO,
YONAH MT.