Rifle shoots high?

[leslie]

You people are something else.You have created the course notes for ballistics 101 based on virtually no information.

 

[M. De Land]

Yup!

 

[PaulTBarton]

Wow, you folks are up to 5 pages. Amazing.

 

[M. De Land]

Interesting subject apparently and gets one to thinking outside the box. A good thing me thinks!

 

[Artificer]

IOW, if the bore is rising in the barrel as it goes toward the muzzle, the ball will exit in that rising path compared to a bore that is parallel to the outer dimensions of the barrel. This is often referred to as "bore run out." Is that what you meant?

Gus

Yup!

OK, sorry, I got sort of discombobulated when you were referring to a “curved bore.” However, then I got to thinking that barrel makers in the 18th century used a tight bow string in the bore or looked for shadows in a bore, to determine whether the bore was crooked. If so, they bent the barrel to straighten up the bore. During WWII and even though barrels were then made of steel and no longer 18th century Iron, the highest paid workers at Springfield Armory in Massachusetts were the ones who straightened the M1 Garand Barrels made there and those workers had some pretty fancy machines to do it.

M.D. I think perhaps there are not as many people who are used to reading about “bore run out” as there used to be. It was a pretty common thing in the 60’s and 70’s when a lot of Douglas muzzle loading barrels were sold and used. Back then, builders talked/wrote a lot more about looking at both ends of the barrel to see which end had the greater “barrel run out” or was off more from being centered in the outside dimensions of the barrel. The end of the barrel that had more “barrel run out” was recommended to be used as the breech of the barrel. If the front end of the barrel still was off from being centered in the bore, then it was always advised that where the bore was closest to the outer dimension of the barrel, or closest to one flat of an octagon barrel, then that flat should be used as the top flat when mounting the breech plug. This meant the bullet coming out of the bore would be slightly rising compared to a bullet that came out of a barrel with a bore that was centered in a barrel.

Gus

 

[M. De Land]

You got it Gus! I got bit one time when I didn't notice the run out.
The gun shot 6 inches left at 100 yards as I remember it and the fella wanted to know what I could do about it. He didn't like having to look at the front sight slightly off center.
I told him that was not much run out really and to just take half the correction up front and the other half on the rear sight .
He did say the gun was accurate though and the fix I recommended seem to satisfy him.
That was a GM barrel.
I don't like straightened barrels although I'm told it is still a pretty prevalent practice.
They use over head screw vices and look through the barrel against a good light or window at a plumb line. The line casts a shadow down the barrel and any where the shadow line is broken the bore is not straight. Bending the barrel to correct this works but it also sets up stresses in the steel that tend to walk when heated up.
Most muzzle loaders never get shot enough to heat up to the point they will move but I have seen several high intensity smokeless barrels do it.
With run out the bore is generally presumed to be straight but just angled ( not parallel) to the exterior.
What happens more often in my opinion is the bore will actually be in a curve and very often close to center at both ends.
This happens for a couple of reasons when deep hole boring an is what is corrected in the barrel vices with the shadow line technique.
A straight bore that has run out will not show as crooked with a shadow line.

 

[Twisted_1in66]

Is it time for intermission yet?
op:


Twisted_1in66:thumbsup:
Dan

 

[smo]

Is it over ? Have we all agreed to disagree or agree? Great debate with a Classy group of Guys . :hatsoff: Everyone remained civil & clam and treated each other with respect. :hatsoff: A lot of great information was given that's what's so great about this Forum. Now where's my file I'm taking that rear sight down some cause I'm still shootin" high :rotf: :surrender: :shake:

 

[Semisane]

Is it over?

Did you not hear the fat lady singing smo? :grin:

Regarding your assessment of the tenor of the thread.....RIGHT ON! :hatsoff:

 

[Leatherbark]

Looking at your 30 yard target it is hard to tell where it is zeroed at. I expect a rifle to shoot a ragged hole at 25-30 yards. Once I achieve that then I work on adjusting the sights to hit where I want them. I sight all my guns in for 100 yards and adjust from there. With a 100 yard zero I can hold dead on the NMLRA 100 yard target during NMLRA competitive events. With that setting at our annual turkey shoot we have to place the ball dead on an X at 25 yards. They let us use a shoot and see target dot placed on the X. I sink my front sight down in the notch and hold 6 o'clock on the dot and make meat (if I yank the trigger at the right time).

At 50 yards I have to shoot a little low also as the ball is still above the line of sight.
During silhouette competition I adjust from there by using reference points of the front sight from the bottom of the blade to the top and bottom of the base in order to hit at 150, 175 and 200 yard steel targets.

What I am ultimately driving at is assuming your rifle will shoot a ragged hole at 30 yards and looking at the three shots it is difficult to determine where the zero point is. But you'll figure it out I'm sure

Good Luck

Bob

 

[bpd303]

My first thought was the OPs rifle is sighted for 100 yards.

 

[smo]

LB so your saying your rifle will shoot one ragged hole at 30 and still be hitting high at 50 yards ? :idunno: If so I'm glad that my rifle is not the only one capable of this gravity defying act . :v You are talking about one of the 1/2" shoot & see dot at 25 correct?

 

[Devodud]

This is great.

Lets think on something though. Lets say his POA is the bottom of the orange cluster, and the top hole is his actual POI, then he would be a couple inches (or so) high at 30 with a still rising ball. Plug that into your ballistics calculator and it somewhat explains the very high impact at 50.......

:dead:

 

[mooman76]

I think we scared him away!

 

[Semisane]

The horse started to stink. :grin:

 

[bryon knapp]

I appreciate all the feed back. However I don't really feel that this would be an issue with sight picture or hold..... This is my 5th flintlock and my 30th year of shooting. I'm fairly certain I've got the sight picture concept down too. I'm going to use this rifle for deer so my Max distance is only 75 yards at most. Shooting these targets I was using a peep sight and I don't feel they worked well for me so I have switched back but hasn't had a chance to shoot with the new rest sight. So let's hope this works ....

 

[bryon knapp]

Also much assumption has been made to my sighting distance. And in actuality I was not sighting the rifle in, not has t been sighted. I was simply at the range shooting it. It was the first time sitting this rifle. I was merely asking if it was normal to have these results. However I am soon going to my local range the I use normally. Will be using sighting targets and known distances like I should lol

 

[Grenadier1758]

As far as your question, "Are these groups normal?" is concerned, I would think that getting 6 pages of comments there is something not normal about them.

Since the subject targets are the results of a first time shooting of the rifle and you don't know where the zero is for the relationship of the bullet trajectory to the sight picture, your comments are with respect to the point of aim to the group point of impact.

My observation of normality is the group size. The farther distance group should be about twice the size of the 30 yard group. The rise of the farther group with respect to the 30 yard group has everything to do with the relationship of the line of sight to the bore of the barrel. So the height above the target being higher at 50 yards than 30 yards is not unlikely if the true zero was about 125 yards. We have the benefit of all those ballistics tables to show that.

Yes, please go to your normal range. Practice to get the group size consistent and small. Shoot some targets at known ranges. Shoot 5 shot groups. Start a new thread with your updated results.

 

[longcruise]

As far as your question, "Are these groups normal?" is concerned, I would think that getting 6 pages of comments there is something not normal about them.

:haha: yes, but we can probably toss four and a half pages based on relevance. :haha:

Guess we would have to toss this post too. :redface:

 

[bryon knapp]

Relevant or not, I learned a fair bit of new information. And that's what the forum is about is it not? So now I can apply this new information to my next outing which should be this week and we will see what happens .