Shooting expert opion needed?

[triggertrav]

I have been woking on sighting my 270 in and after about 60 rounds i am starting go get good groups at 100yds. i have it at 2 inches high. i would expect to be 1 inch low at 200 yards based on the ballistics on my cartridge (130 gr fed). i back out target to 200 yds and put three shots in a baseball sized area, 5-6 inches high and 4 inches left. there was a slight breeze right to left(less than 10). Would the breeze be enought to push 4 inches at 200 yards? Any explanation why my groups would be high at 200 yards? Or just held wrong for three shots? I ran out of time and only took the three at 200.

Any advise is welcomed.

Thanks

[troutkingmaster]

I would log on to Winchesters HSOforum and find the load with the closest specs to the one you are using from fed. Then use that load in winchesters ballistics calculator and you can input crosswind speed and everything and see what that says for trajectory, etc.. Probably wont be spot on, but can at least tell you if you are in the ballpark.

[littlebear]

By no means an expert, but if shooting through scope, make sure the screws are tight. Also, a good solid rest and letting barrel cool after 3 shot groups may help.

[eyehead]

How long should a guy let the barrel cool???? I'm having the same problem sighting in my .243 when I move from 100 to 200.

[NETim]

Allowing the barrel to cool is done primarily to extend barrel life. Some will actually ice down a barrel to hasten cooling between strings of fire.

Some barrels will shift their point of impact as they heat up.

200 yards is much more than 100 yards more than 100 yards.

[picksbigwagon]

letting it cool is good, but were you cleaning the rifle at all? What I mean is after 60 rounds of getting it nice and tight and then your group opens up could be that your barrel is getting dirty. my AR takes 4-5 rounds to get dirty and it shoots straight then. After that I get maybe 50 rounds before i start seeing my groups detiriate......

[Ufatz]

Something moved.

[jabug]

it has to do with the tragectery of the bullet. at 100 yds the bullet is still rising. i shoot the same caliber plus a few others that i reload and have found the tables are a guide but each rifle acts different. give your gun a good cleaning shoot a couple of rounds to dirty it up a little and sight it in spot on at 100 or maybe 1/2 inch high and you should be right in there at 200 that is what works in mine and i shoot 130 grain tsx as lead

[Archerysniper]

Is it a auto I know the remington 7400 will come loose on the forend screw and start shooting high, otherwise I know with my rifles a 1" high at a 100 yards puts me pretty darn close to dead on at 300.

[triggertrav]

the gun is a bolt and it was cleaned prior to shooting the other day. i am ok with my group at 200, just more curious if the round could possibly be rising another 2-3 inches from 100-200 yards? ballistics call for it to drop 3" from 100 to 200. otherwise maybe something did move, i will have to run some more rounds thru it.

[HNTNBUX]

Trajectory can be affected by scope height but I am not suprised by your results. I sight my 7mm 1.25 inches high at 100 to zero at 200 yards. Any little bit you are off will be magnified at longer range. My suggestion would be to zero at 200 yards and then check at 100 to have reference to verify your zero in the future.

[vister]

with most calibers, bullets hit the same at 27 yards as they do at 100 yards. the ONLY reason there is any rise at all, is because you are aiming the gun up for the rise. when you sight in a scoped rifle, the crosshairs are are fixed an inch or more above bore. so when sighting in, the plane of the bore is raised slightly to accomodate this. thats why we've always done the rule of 27/100. sight in at 27 yards, usually means sighted in at 100. laws of gravity say that bullet will only fly straight and fall towards the ground unless acted upon by another force. a bullet fired out of a gun never rises on its own is what im getting at!!

by the way, a slight breeze shouldnt have any profound effect on a bullet hitting at 200 yards. it would have to be gusty, 20+ mph winds to blow that far of course in that short of a range

[triggertrav]

so based on that - either something moved or my scope is improperly mounted? or test to make sure it is hitting same hole at 27 and 100. if that is off scope is incorrectly mounted - would that be a proper assumption?

[HNTNBUX]

Scope objective size and ring height to ensure the scope bell clears the barrel is what will effect where the trajectory lines will intersect. Once as it rises to line of sight and again as it drops below line of sight. I would not assume your scope is mounted wrong unless your rings are higher than you need. It is just difficult to make generalizations about someone else's rifle and load. From your original post I would still recommend sighting in at 200 yards and call it good. I have shot plenty of deer at or over 300 yards with that zero.

[SmilinBob]

Lets start with the basics. First, what are you calling a "good" group at 100 yds? Second, are you following good breathing techniques? Third, do you have high quality ammo? Forth, are you performing a consistent trigger pull? Fifth, how much experience do you have shooting at these ranges, an inch at 100 will lead to more than 2 at 200. Sixth, was the scope mounted level, torqued to the correct settings (as tight as possible is NOT correct), and are the bases torqued correctly also? Next, are you using a rest or freehanding it? A three shot group is not enough to start messing with multiple things at once, you need trigger time and to narrow it down with one possibility at a time. Start simple and work your way out from there.

[nonteepical]

I have the feeling it's technique. after 60 shots you might be expecting the recoil and simply flinching and pulling the trigger fast instead of squeezing. like bob said you need a steady/fixed rest.