I went out yesterday and shot the rifle to get a zero at 200. It was not shooting well and kept giving me flyers. This is after I took the scope and base off and red loctited, torqued, etc. I also tried a box test again after just to ensure all was fine. It seemed fine so....
1. I took all my reloading stuff to the field and shot my main load first at 100. 57.5 grs. I had 2 that were ok then a little verticle flyer. I reloaded 3 at 56.5 and they all hit the same area as the 57.5, so I had a 6 shot group that were all together.
2. Since the 56.5 seemed to work I loaded up and shot a 4 shot group that stacked up well. Yay.
3. Decided to give 57 a try and they strung out vertically. No go.
4. Took it to 200 with 56.5 and it shot terrible.
5. I was frustrated so I loaded up 58.5 to test pressure and shot at the left target. It was high, ok, more powder more speed right?
6. Went back to 56.5 and shot 2 x 2. WTH. It went from being low to high?? No adjustments made.
7. Adjusted turrent up and down and back to orginal, shot low. I give up.
IF your not useing a bullet comparator to measure each bullet depth that could be your problem. Bullet depth is more important that grns of powder. When you find the right bullet depth by ojive it will most likely shoot the same even with one grn higher or lower. That is at 100 yrds. Still lots of things besides that... that it could be but thats where I would start.
IF you are using the comparator I would make sure the barrel is floated properly and also that my cases were from the same lot. Also if they have been fired more that 4 times they should be annealed which will give them a more even tension. Another question is do you know where your gun shoots best as far as how clean the barrel should be? Most guns have a sweet spot as far as how clean they should be to shoot best. Also make sure you have a really great rest!!! When you move to longer distances it really matters!! When trying to get a gun to shot the best groups... dot move the scope untill you find what it likes best (as long as its on paper).
Ok the fact that the same load shot well at 100 and then a move to 200 caused a problem then I think your shooting techniques and rest system is no good or at least not consistent .
Stop all the powder and load changes and load up the 56.5 loads that shot well at 100.
Stop playing with the scope and concentrate on firing one 3 shot group on each target center .
It would be real helpful if you told us exactly how the gun is fired , like from a bench rest , what type of rests , bags or bi-pod used , free recoil , not free recoil ,etc etc ?
When moving the guns elevation from 100 to 200 you should try to preserve the rest positions and tracking as much as possible .
A photo of how you shoot is worth a thousand words .
You will have to watch the wind and either shoot when the wind condition is very low or at a consistent wind speed and direction .
Once you consistently get three shots close together in a group .
Then you can step up to 5 shot groups.
3 shot groups save ammo and if you can't group 3 then what is the point of wasting another two shots on an already bad group.
3 shots also cuts down on barrel heating , shooter fatigue , wind changes and cost .
3 shots tests the gun 10 shots tests the shooter .
"Ok the fact that the same load shot well at 100 and then a move to 200 caused a problem then I think your shooting techniques and rest system is no good or at least not consistent ."
BINGO! Whats it group at 50 yards? If you dont have 3 shots dammed near touching....you wont have jack squat at 200.
Get a ballistics calc done on your load and shoot at 50 yards. If you dont have 3 holes touching...keep practicing till you do. Move to 100 yards and do it again and you should at least have a 3 shot group you can cover with a quarter..?? On to 200 yards and you are locked and loaded for the group you want.
Shot from a bench rest. It was clean and shot the tighter at 7 thru 10 rounds. 15-19 were at 200 on right side, and 20-25 on the left side.
Lapau brass (same lot, shot 2x), neck sized with .002 bushing, concentricity corrected, berger VLD hunting 140, .075 off lands, retumbo powder. Action screws torqued properly, etc.
The fact that the rounds moved up 4.5" at 200 yards with exact same load doesn't surprise you guys? I am very surprised it started shooting high all of the sudden. rounds 15-19 are by a ruler 4.5" lower. That is just weird. I didn't touch the scope settings yet, not even the power, just the parallax.
Before I suspected the scope issue or some other issue I could group this rifle fine at 200 with less than .5 MOA. However, I kept having a verticle flyer issues here and there and point of impact changes that made no sense. This is after a scope bump.
Another thing that surprised was the last round (25) impact that was 2.25" lower than 20 and 21.
I have talked to Night Force and their customer service so far has been very good. It will be 4 weeks before any repair could be made so I am still trying to figure out if it is my base, mounts, scope, rifle, me etc. before sending it in. I am not sure I see any issue from shooter point of view but you never know I guess. Put it this way, I have never had a POI issue changes of 4.5" in my life based on technique. When I was shooting this rifle at 800 yards I consistently grouped .5 MOA....4x4 groups from a bipod and rear bag. A bench would have been better.
I'll bet you have a bedding issue.
Definitely some wierdness going on.
What kind of action? Remmy? Savage?
I'm thinking either the scope or the action or both are slightly tweaked.
If you have any bedding material under the barrel, try removing it.
Do you think the action could be twisted in the stock?
You could try taking a quarter turn tension off the rear action screw and almost no tension on the center action screw if you have one.
Savage model 116, accustock. This model has two screws instead of the wedge style. I torqued front and rear to 40" lbs like the manual says. I did remove the base and reinstall with loctite etc, mounts rechecked.
I will remove the action and bbl from the stock and look it over again. This rifle has been shooting lights out until lately. Now has 250 rounds through it. Barrel cleans up well and I confirm zero copper with CL or CR 10, whatever it is, with a 10-15 min soak time and patch it. If it is not colorless I keep cleaning until it is. I checked for a carbon ring as well, bore is smooth and consistent. No black comes out after a good initial scrub with a nylon brush. After that it is just blue until that is gone.
Anyway, thanks for all the replies. I am just trying to ensure I have not missed something simple and I am considering all input. Several weeks back my scope was bumped and was off 6" to the right at 100. I re-zeroed but NF has me convinced it is not the scope. I was convinced as well with the 56.5 4 shot group at 100. Thought I hit a nice node and took it to 200. I thought about form and all that but if you can shoot .5 at 100 you can usually shoot that at 200. I can not imagine myself shooting a 4.5" spread at 200 with any rifle that can shoot .5 or less at 100.
I have a aluminum weaver picatinny 1 piece base. It seems to be built fine enough, it is my first base of this sort. It does not have a recoil lug, no moa, and does not show signs of wear from the mounts etc. Mounts are Leupold PRW steel. I DID NOT check the base last night to see if the screws were loose.