[heilung]

I like to use my buddy's M1a Springfield Armory with Shepherd scope. I get it sighted in at 50 yds then it cant hit the paper at 100yds. Im working on ways to make sure the removeable mount stays tight, but could the scope be bad? Those Shepherds any good? Im running out of Barn targets.Heilung

[rfc357]

Heilung,

If the rifle shoots to point of aim at 50 yards, it should be on the paper at 100. For a 168 grain bullet, if it's dead on at 50 it should be a little over an inch high at 100 and about about an inch low at 200. Your results will vary, but not by much. A 150 grain bullet won't make much difference.

Does the rifle shoot a tight group at 50? Even a crummy barrel on an M1A should shoot a 1-inch group at 50. If the group is a lot bigger than this, something is wrong.

The mount should not move at all. If you can detect any movement at all in the scope or the mount, that is enough to throw the shots off at 100.

I have no experience with Shepherd scopes. Can't comment.

Try the iron sights. If everything works, then it's the scope or mount. If the rifle hits at 50 but misses at 100 with the irons, there is something wrong with the rifle. Don't adjust the sights when going from 50 to 100, just shoot.

[heilung]

Watching the groups, and using the iron sights are good pointers, thanks

[Gyrene]

rfc357 - The M1A/M14 has the same parallax problem the M1 Garands' M1C and M1D have. Since the scope is mounted up and to the left, it will not follow the pattern of the iron sights, where the bullet rise is predictable. By the way the bullet does not rise, it begins dropping when it leaves the muzzle, and if you could drop a bullet of the same weight, from the muzzle height, at the exact instant the bullet exits the barrel, they will strike the ground at the same time. This is assuming the ground is flat and the barrel is level with the ground.

The bullet "RISE" is a result of the barrel muzzle being elevated above the breach.

[rfc357]

Gyrene,

I have never shot an M-1 or M-14 with a scope. Thanks for the explanation of the parallax effect.

You are exactly right about the bullet "rise." I was just trying to keep it simple for a newbie.

[Gyrene]

rfc357 - I was sure that you knew, sometimes the newbie has a fairly good grasp of what they ask about, and need confirmation. Sometimes it really does need to be kept simple for them.

Actually, the M14/M1A/M1 Garand parallax problem (when a scope is mounted on a Military scope mount) is due to the fact that the barrel bore and the center of the scope are in two different planes with the scope center line being above (elevation) and to the left (windage) of the barrel center line. For instance at 50 yards the scope centerline, when zeroed, will be pointing down and to the right (of the centerline of the barrel), so when moving to the 100 yard line (and not readjusting the scope), the bullet strike will be up and to the left. Beyond that, without readjusting the scope, it just gets worse up and left.

In order to hit where the center of the bullseye is (with the scoped M14/M1A/M1 Garand) , at several distances, you need to zero the scope at ALL of those distances, and record the (elevation and windage) changes on your databook. The next time you shoot, you will have to remember what distance you were zeroed for (the last time you shot).

When the scope is mounted directly over the barrel, the only parallax you need to deal with is the difference in the vertical plane (how high the center of the scope is above the center of the barrel). This will cause your hits to rise as the distance increases (if you do not adjust the scope). Most hunting and other bolt action rifles deal with this.

The Shepard scopes are good scopes, and if you understand the method that is used to zero it, they are easy to work with. My experience with the Shepard scope, is, it is a bear to get it zeroed, once zeroed, it is easy to use, on a bolt action rifle. However, it would have ALL of the same problems, magnified, if mounted on a military mount on an M14/M1A/M1 Garand. You would need to sight it in at every distance you plan to shoot it, at.

`

[rfc357]

Gyrene,

Makes sense. I guess you would have the same problem with a side-mounted scope on an old '94. Buy you would probably just sight it for 100 yards and leave it alone. It would hit minute-of-deer out to any reasonable range.

I only shoot my gas guns in service rifle competition, so I have no occasion to use a scope. My club shoots the reduced course at 200, so sight changes are minimal, a click here and there. Wind is not much of an issue, nor is mirage. Not like Perry!

We're building a 1000-yard range. I'm going to dust off that heavy-barrel .300 Mag I built a few years ago...................

[pickle]

I alway's found it helpful to practic with the positions on the living rm. floor, or in the yard. You can get adjusting the sling down and may even mark for prone, sitting and offhand positions. Might sound stupid, But in the Corps, we used a lot of school circle's for recruits and I used the same technique for the next 27 years, always seemed to help streach out the muscle's and get a little more solid.

Semper fi

[rich adams]

Board Message here is a link to a great high power shooting website. you will need to register but you wont believe the info they have.

Rich Adams