BarnesX.308

I was shooting in a friends rifle for him and developing some handloads to use this season and I noticed something I never experienced with my rifles. The point of impact between 25, 50 and 100 yards was different and by several inches. The gun has see-through scope mounts and the scope sits pretty high off the barrel. Has anyone else experienced this before. My rifles are bolt guns and my scopes are pretty flush with the barrel so I don't think it effects them as much. Thanks.

droptinewv

I noticed that shooting my rem. 30-06. the p.o.i. got higher the farther the shot. I am using a bushnell elite 3200 and weaver? see through scope mounts. I am going back to the range in a couple of days and will post my results.

stubblejumper

That is normal because the scope is so high above the bore.What is also normal is that with the scope so high,you can't get as good a cheek position on the stock.As well the see through mounts are not as sturdy as lower mounts so it is easier to have the scope knocked off zero.

Paul L Mohr

Play with a ballistics calculator and will it show the effects of sight height. They have an input for sight height on most of them. It has to do with the line of sight vrs the path of the bullet. That is why it seems like a bullet rises and then drops again when you shoot it. That is not what really happens at all. The bullet is constantly dropping after it is fired. But because the sight is higher than the bore of the barrel your barrel is actually pointed upwards to a certain degree when you shoot. The point where the bullet is higher in the trajectory path is where your line of sight intersects the path of the bullet.

The higher your sight height, the more flat the rifle seem to shoot at longer distances. But like said above you will have to raise your cheak off the stock to look thru the scope. Not that big of a deal if you are shooting where the parallex is set for (100 yards normally), but if you are shooting at like 150 or 50 yards it may cause you to be a little off. Unless you have a scope with an adjustable objective, if it set properly for the yardage you are shooting you should be able to move your eye around quite a bit with it effecting the impact point.

Paul

jmfa1957

I put see through mounts on my Remington 742 back in the early 1980s right after I bought it. I never shot it at over 100 yards because it never seemed to group that well. I never liked that rifle and regretted buying it for years.[:@]

This year, on a lark, I bought some low mount steel Leupold mounts for this rifle. I was not ready for how different this would be. All of a sudden I really, really like this rifle. The gun looks better and shoots better, or more appropriately, I shoot better with it than before. It is much more comfortable to shoot. WIth the right factory load it will still only group about 2" or so at 100 yards; I never played around with reloads much for it because I never saw the point. I still wouldn't care to take a long shot with it, but for chasing hogs in the shrubbery it is actually not a bad set up.

Try to find out why your friend feels he needs see through mounts. In my experience they really are awful. If he thinks he needs to use iron sights in a pinch, a screwdriver or torx wrench doesn't take up much room in the backpack. Another option would be Leupold's quick release scope mounts. If he put the see through mounts on because they were the most affordable mounts he could find, tell him that he really might want to rethink this strategy.

Just my 2 cents worth.

skeeter 7MM

Yeap typical performance of the see thru mounts, as stated to high and nopt sturdy enough. Tell your buddy to replace them and he'll thank you for more than your load developing.

BarnesX.308

Thanks for the replies. He has no objection to replacing them except that our opening day is just 3 weeks away, we both have 2 little children and the range is far away. The gun used to be his dad's and always had the see-through mounts. The is the first year he is going to hunt with them. The rifle is actually very nice. It's a Winchester Model 88. It's a lever but the action has a lot in common with a bolt-action. It groups nice, too.

dvdegeorge

If you want the benefits of a see thoough mount,I suggest Leupold QR mounts and rings.They allow you to remove the scope with the twist of 2 levers and then just pop off the scope to use opened sights.The scope mounts back on just as quickly and easily and point of impact will be the same.These are good solid mounts that allow you to mount your scope low to the barrel.

UncleNorby

Assuming the same POA, all rifles will shoot to a different POI at 25, 50, and 100. The difference is more noticeable with high mounts.

Hey Droptine - your problem is simple. You just need to sight your gun in.
When you sight in, you need to shoot at a target that is far enough away to be near the crest of your trajectory. 100 yds seems to be about right for most calibers and most shooters. If you sight in to be say 2 - 3" high at 100, you will NOT be higher than that at 150 or 200. If you sight in at 50 yds to be "about right", you'll have no idea what will happen downrange.

droptinewv

Hello again, I went to the range today and with my rem. 30-06, 165 sierra gameking btsp, bushnell elite 3200 set on "6" power, weaver see through mounts. My shot placement was,
about 1 1/2 inch low at 100 yards and about 1 in. low at 50 yards. I am going back again to get my group a little higher. It was getting dark so I had to leave.