RUBLINE
Well-Known Member
Using a CVA Optima elite loaded with 100 grains 777 pellets and a Hornady xtp 3oo grain bullet, where must the bullet strike at 50 yards for a 100 yard zero?
SIGHTING IN
- Thread starter RUBLINE
- Start date
+ 1.1 - 1.4 inches at 50 = zero at 100
Of course you need to shoot at 100 to verify.
A handy site:
http://www.jbmballistics.com/~jbm/cgi-b ... mp-5.0.cgi
Of course you need to shoot at 100 to verify.
A handy site:
http://www.jbmballistics.com/~jbm/cgi-b ... mp-5.0.cgi
Stalker said:
Physics does not care if it a muzzleloader or rifle (or brick).
It's all the same.
Enter bullet wt, bc, time, atmo conditions -
poof. Like magic, it will all be there.
(and be dam close to what one would see in the field)
In the above example, I varied the speed, hence the 0.3" variation in elevation.
It's been awhile, but I believe that the ballistics calculator on Hornady's website has a section for muzzleloaders.
Those charts are just beginning values anyway. You should shoot several shots at various distances to be sure of results in your particular gun.
Like EWC says, the results should be darn close if you have the right velocity, bullet weight, BC, and inches above bore measurements.
Those charts are just beginning values anyway. You should shoot several shots at various distances to be sure of results in your particular gun.
Like EWC says, the results should be darn close if you have the right velocity, bullet weight, BC, and inches above bore measurements.
Too many variables in Muzzle Loading to safely use a website calculation in my opinion. There are no standards for muzzle loaders...barrels are differnt diameters, rifling is different depths and both play a role in trajectory. Those results are no where near what my guns shoot. My old Genesis shot a 300gr SST with 105gr 777 2" high at 50yrd and 0'd at 100yrd...
This might help for the 300gr XTP but it is for a 150gr charge. Not 100gr charge as descibed above...
Hornady 300gr XTP
This might help for the 300gr XTP but it is for a 150gr charge. Not 100gr charge as descibed above...
Hornady 300gr XTP
Barrel dimension and rifling depth are moot (irrelevant to your argument). Measure speed, bc, scope ht, and atmo conditions. Fill in the blanks with what you can measure and it will predict close to what you will see.
So what was your bc (I know the answer here), time, atmo conditions, and scope height?
It's all physics. I could plug in the bc, speed (time), etc and get what a BRICK drops to 1000. I didn't say it would be dead on, but it will be really close (close enough for testing drops).
Obviously, in your case, your probably shooting less than 1500 fps (but we don't know that unless YOU measure it).
I shoot to 400+ (with a muzzleloader) and those formulas have always put me CLOSE.
So what was your bc (I know the answer here), time, atmo conditions, and scope height?
It's all physics. I could plug in the bc, speed (time), etc and get what a BRICK drops to 1000. I didn't say it would be dead on, but it will be really close (close enough for testing drops).
Obviously, in your case, your probably shooting less than 1500 fps (but we don't know that unless YOU measure it).
I shoot to 400+ (with a muzzleloader) and those formulas have always put me CLOSE.
ewc said:
I do not know why you are trying to take positions? I am not doubting physics...I am saying that ML ballistic calculations can not be derived from a web link designed for centerfire weapons. Totaly different and the calculations are not correct. You are guessing at data entry.
Tell me why one ML will shoot the exact same load as another gun but point of impact is different?
Look, all I am saying is for the average person asking where to set 50yrd impact for 100yrd shot not to trust a ballistics calculator...GO SHOOT it. That is the only way to know what your ML will do because of the variables in ML vs the standards in centerfire weapons.
And no at 100yrds .6" is not close enough for me...I want the orange dot blown out and clover leaf patterns. I have one gun that will not shoot any of the powerbelts that I have tried or any of the sabots that I have tried at least past the 50-75yrd, any further and it may miss the paper all together. But you take the same weight conical bullet with same charge and get clover leaf at 100yrd. What I am saying is that you must shoot to find what your Muzzle Loader gun likes. Shoot your gun do not use a ballistics calculation to set your scope and then go hunting...that is all I am saying.
Please no hard feelings I'm done with this conversation. All I wanted was for the question asker to understand that shooting his ML is the only way to determine it's impact at 100yrds. No one can tell you where to set the hold over at 50yrd to get accurate results. You could use any advise given as a starting point but please do not set your scope by a calculation...go shoot it and find its' mark. It's more fun that way anyway...don't you just love that smoke!!!!!
Here is some useful data for you since you are all into calculations and what not...
Pay special attn to this paragraph:
"The ballistic coefficient changes with both distance and velocity. Few bullet makers acknowledge this, but Sierra Bullets is the rare exception. Here is an example: one of Sierra's .458 diameter, 300 grain bullets has a BC of .120 @ 2400 fps and above, .145 between 2400 and 1900 fps, .185 between 1900 and 1400 fps, and .210 between 1400 and 1150 fps. It is dynamic, not static, and muzzleloading rifles use a wider range of ballistic coefficients than many projectiles, as we can load the example bullet to a .145 or a .185 BC at the muzzle, and may well be using the .210 BC prior to taking our animal."
Muzzle Loader BC
Me too DA. In the first reply to this thread, I said close then go shoot.
Stalker thinks our formulas are way off (1/2" :confused:). However, with my muzzleloader, that same program and point blank have proven close out to 400 yards. Would probably be good to 1000, but I've not gone there yet with my muzzleloader.
Oh well, you can lead a horse to water....
Stalker thinks our formulas are way off (1/2" :confused:). However, with my muzzleloader, that same program and point blank have proven close out to 400 yards. Would probably be good to 1000, but I've not gone there yet with my muzzleloader.
Oh well, you can lead a horse to water....
I have no idea about HIS load VELOCITY or YOUR load VELOCITY.
I made a guess - and the intention of that guess was to get close. Not absolute in any fashion.
What is your velocity? Have you timed it? At various temps?
I know MY load VELOCITY at temps from 20 to 80 deg. and I use it and other variables to get close, then I verify in the field.
I have all my drops verified with MY muzzleloader to 400. And a cheat sheet taped to the side of my stock so I can dial them in.
I made a guess - and the intention of that guess was to get close. Not absolute in any fashion.
What is your velocity? Have you timed it? At various temps?
I know MY load VELOCITY at temps from 20 to 80 deg. and I use it and other variables to get close, then I verify in the field.
I have all my drops verified with MY muzzleloader to 400. And a cheat sheet taped to the side of my stock so I can dial them in.
RUBLINE
Well-Known Member
sighted it in at 50 about 2.5 inches high. At a hundred I was about 1.5 high
Stalker asks "...Tell me why one ML will shoot the exact same load as another gun but point of impact is different?"
Because those two rifles shoot the same load at different velocities, of some other variable varies. Even if the loads (powder type, amount, sabot, bullet, and primer) are identical, the rifles themselves are not. Even two guns of the same model will have slightly different tolerances or smoothness in the barrel. Then there's the the variances of the shooters themselves; how tight they push the load, etc.
The formals do work if you accurately input all the variables. Most important is the actual velocity as measures by a chrony. Height of sights above line of bore is another.
A agree the charts aren't very good if you they just say "150 gr of 777 with a 300 gr bullet will be +2 at 50 yrds, 0 at 100, -2 at 150, so on. But if they say a "300 gr bullet with a BC of .262 at a muzzle velocity of 1990 fps will drop xxx" then they're pretty good.
It doesn't matter what powder charge got the bullets to the right velocity, once there it will perform as the charts indicate. (Assuming sight height is accurate.)
Because those two rifles shoot the same load at different velocities, of some other variable varies. Even if the loads (powder type, amount, sabot, bullet, and primer) are identical, the rifles themselves are not. Even two guns of the same model will have slightly different tolerances or smoothness in the barrel. Then there's the the variances of the shooters themselves; how tight they push the load, etc.
The formals do work if you accurately input all the variables. Most important is the actual velocity as measures by a chrony. Height of sights above line of bore is another.
A agree the charts aren't very good if you they just say "150 gr of 777 with a 300 gr bullet will be +2 at 50 yrds, 0 at 100, -2 at 150, so on. But if they say a "300 gr bullet with a BC of .262 at a muzzle velocity of 1990 fps will drop xxx" then they're pretty good.
It doesn't matter what powder charge got the bullets to the right velocity, once there it will perform as the charts indicate. (Assuming sight height is accurate.)
ewc said:
I will say that I clutched this part...even copied it and still did not see it...SORRY!
That was my whole point to start with. I will agree that the calculator will at the least get you on paper and more than likely get you with in a few inches (so will a few rounds at the range). The trouble I had was reading the original post I thought he wanted to sight in at 50yrds so high and rely on that for 100yrd shot. That also was obviously not the case as he replied with results from both 50 and 100.
The trouble I have with the calculator is that you must make a good educated guess to get the results you are looking for. You (ewc) obviously have enough data to make a good educated guess. Where would a regular weekender find BC for Muzzle Loader bullets? Since most are not easily excessible due to the variations and low velocities that make it hard to accurately depict a coeficient and bullet manufacturers have not readily made this data public as they do with centerfire? I do agree that what ever you are using, probably some where between .17 and .21, is a very good guess.
No, I do not know my velocities at different temps or other weather related factors either. But I do not see where that is relivent to the discussion, I see it as you trying agitate the situation. I do know that my new CVA is shooting arround 1950fps with a 300gr Hornady SST & 110gr 777 loose...with holes touching at 100yrds when the sun was out and a slight breeze from southwest and 57F.
And look man...I am not trying to argue with you. And seriously missed what I stated above, I thought Rubline was looking for hold over on a 50 yrd sight in with out having to shoot the 100...I was wrong there. Again...Sorry.
No problem. I think we agree for the most part. Ballistic calculators are a useful tool that give you an idea of where things should work out in the field.
As far as b.c. goes, most of them can be found on the internet. The published bc's are a starting point too. Actual bc's may vary some from published, but they normally won't be off by more than a few hundredths (ie .210 vs .242).
You'll find this out when you chrono a load, go back home and plug in your info to the calculator, get your print out, and go back to the field.
Everything is perfect (you have measured speed, temp, humidity, altitude, etc) but your drops are off from predicted.
Go back home and adjust the bc till it matches what you measured in the field. Like I said above, bc will likely be within a few hundreths.
As far as b.c. goes, most of them can be found on the internet. The published bc's are a starting point too. Actual bc's may vary some from published, but they normally won't be off by more than a few hundredths (ie .210 vs .242).
You'll find this out when you chrono a load, go back home and plug in your info to the calculator, get your print out, and go back to the field.
Everything is perfect (you have measured speed, temp, humidity, altitude, etc) but your drops are off from predicted.
Go back home and adjust the bc till it matches what you measured in the field. Like I said above, bc will likely be within a few hundreths.
