Sighting in another rifle
- Thread starter drache
- Start date
burnt_servo
CGN Ultra frequent flyer
- Location
- right in the middle of b.c.
aim for your grouping between 1 inch and 1 1/2 inches high at 100 yards and you should be pretty close to dead center at 200 , it may be a hair low , but you will find out after you pull the trigger on a 200 yard target .
books , charts and tables can tell you all sorts of things , but there are so many variables involved , it is best to actually fire the rifle at targets at several different distances ( ie 100 , 200 , 300 , 400 yards ...ect.....)
books , charts and tables can tell you all sorts of things , but there are so many variables involved , it is best to actually fire the rifle at targets at several different distances ( ie 100 , 200 , 300 , 400 yards ...ect.....)
Yeah it will either be today or tomorrow to sight in the scope on it but wanted to get a rough idea though.
Last 5 times this rifle was taken out it would place three shots on target then any shots after would be all over the place (we're talking 2-3 inches in any direction). Three different people had this problem.
So we were hoping it was the scope so he bought a new scope, new rings, and I made sure his bases were tight and all that. Hopefully the rounds all go where they should.
Last 5 times this rifle was taken out it would place three shots on target then any shots after would be all over the place (we're talking 2-3 inches in any direction). Three different people had this problem.
So we were hoping it was the scope so he bought a new scope, new rings, and I made sure his bases were tight and all that. Hopefully the rounds all go where they should.
It was the scope. The rifle shot an entire box perfectly fine.
The only problem I forsee with the rifle is the trigger being really stiff... well at least to me although Ive been using Accutriggers for awhile now.
in order to properly answer this question you need the fol info:
calibre: got it
weight: got it
muzzle velocity: should chrony it. you can make a fairly accurate estimate if you know the brand of ammo you are using.
Since we don't have that, we can make the fol assumptions with a pretty good chance of getting close.
Almost all of the manufacturers list similar trajectories . Between 1.7 and 2.0 inches high at 100yds. However, that is most likely from a 24" barrel. Most commercial barrels are 22" so that would make it a little slower, but not much. So, most manufacturers list MV at 2860 fps. So, let's use the trajectory for 2800fps. If you were to sight in 2" high at 100yds you would be zeroed at 200yds, 7.5" low at 300yds, and over 21" at 400yds.
When used for hunting applications, we want to hit a 8" circle everytime. (Yes it changes for each animal, but if you can keep it at 8"", you will be better off).
Maximum Point Blank Range (MPBR) is the maximum range you can fire with the bullet never being more than 4" above or below the line of sight. With that round, if you were to sight in 4" high at 100yds, you would be 4" low at 325yds and only 11" low at 400. This eliminates most of the guesswork when shooting. You know that if you hold centre of mass anywhere out to 325yrds, then you will hit in the circle. A kill shot in anyone's book.
calibre: got it
weight: got it
muzzle velocity: should chrony it. you can make a fairly accurate estimate if you know the brand of ammo you are using.
Since we don't have that, we can make the fol assumptions with a pretty good chance of getting close.
Almost all of the manufacturers list similar trajectories . Between 1.7 and 2.0 inches high at 100yds. However, that is most likely from a 24" barrel. Most commercial barrels are 22" so that would make it a little slower, but not much. So, most manufacturers list MV at 2860 fps. So, let's use the trajectory for 2800fps. If you were to sight in 2" high at 100yds you would be zeroed at 200yds, 7.5" low at 300yds, and over 21" at 400yds.
When used for hunting applications, we want to hit a 8" circle everytime. (Yes it changes for each animal, but if you can keep it at 8"", you will be better off).
Maximum Point Blank Range (MPBR) is the maximum range you can fire with the bullet never being more than 4" above or below the line of sight. With that round, if you were to sight in 4" high at 100yds, you would be 4" low at 325yds and only 11" low at 400. This eliminates most of the guesswork when shooting. You know that if you hold centre of mass anywhere out to 325yrds, then you will hit in the circle. A kill shot in anyone's book.
Yup, he wanted me just to make sure it was the scope that was the problem.
sir_springer
Regular
- Location
- East Kootenays
About the grouping problem...
Most older (and maybe newer ones, too) Remingtons with wood stocks have a pressure point built in at the end of the forearm, about an inch or so long. You can see it when you remove the stock. The idea is to tame, at least to some degree, barrel vibrations and thus provide better grouping, which sometimes works, and sometimes doesn't. (IMHO, most of the time it doesn't.)
As your barrel heats up it will start to deflect off this pressure point and throw shots as you describe. My Vanguard would shoot 3" groups no matter what. I replaced the stock with a good synthetic that free floated the barrel. The first group I shot during sight in was 5/8", and it consistently group under 1" now.
My belief is, when in doubt, float the barrel.
This can be done with a bit of judicious work with sandpaper...or have a smith do it for you if you're not comfortable with that kind of work.
Can almost guarantee you this will solve your problem.
Or...
It should take no more than about 10 lbs of pressure, which isn't much, to pull the forearm away from the barrel so that it's not contacting. If it takes more than this, too much pressure. Again, sandpaper is the solution, taking it down a tad bit at a time until you get a reasonable level of pressure.
But, again, floating it completely is usually the best solution.
It's highly doubtful that the scope is the problem.
IMHO.
Most older (and maybe newer ones, too) Remingtons with wood stocks have a pressure point built in at the end of the forearm, about an inch or so long. You can see it when you remove the stock. The idea is to tame, at least to some degree, barrel vibrations and thus provide better grouping, which sometimes works, and sometimes doesn't. (IMHO, most of the time it doesn't.)
As your barrel heats up it will start to deflect off this pressure point and throw shots as you describe. My Vanguard would shoot 3" groups no matter what. I replaced the stock with a good synthetic that free floated the barrel. The first group I shot during sight in was 5/8", and it consistently group under 1" now.
My belief is, when in doubt, float the barrel.
This can be done with a bit of judicious work with sandpaper...or have a smith do it for you if you're not comfortable with that kind of work.
Can almost guarantee you this will solve your problem.
Or...
It should take no more than about 10 lbs of pressure, which isn't much, to pull the forearm away from the barrel so that it's not contacting. If it takes more than this, too much pressure. Again, sandpaper is the solution, taking it down a tad bit at a time until you get a reasonable level of pressure.
But, again, floating it completely is usually the best solution.
It's highly doubtful that the scope is the problem.
IMHO.
More accurately,you need to know the ballistic co-efficient of the bullet,the muzzle velocity,and the sight height above the center of the bore.If you don't have a chronograph,you are only guessing at the velocity,since it can easily vary by over 100fps from the velocity supplied by the ammunition manufacturer.
I was able to make a fairly good guess on that. 5 out of the 8 commercial offerings have BC's of .428. Of the remaining, one is .418, one is .506, and the other is .463.
Again, assuming the OP went with one of the commercial offerings, none were different enough in trajectory to really affect the sight in statement by more than 1/2" between 5, and overall, even accounting for the larger BC's, no more than 1". The smallest, when zeroed at 200yds had a drop of 22.4 at 400yds. The largest BC again zeroed at 200, had a drop of 21.0".
All those with a BC of .428 had an avg drop of 22.5" at 400yds when zeroed at 200yds. At least by the book. Actual firing will produce different results, but not enough to matter to the hunter. Just the silhouette shooter.
