Can someone please explain...

[T-Rex]

I went to shoot my brand new 10fcp-hs today. Last night I made-up some loads for it. 5 of each load: 42.5, 43, 43.5, 44, 44.5. I needed to zero the scope so I made 10 extra 43.5 (middle of the road). I wet patched then dry patched between every 2 rounds and was not in a rush (it took me 2 hours to fire 35 rounds). I zeroed the scope @ 100 yds (just 1/2" high and right). I then proceeded to check these loads.

308 Win
Win brass (brand new)
CCI 200 primers
Varget
Hornady 168 BTHP

42.5g
http://i122.photobucket.com/albums/o270/premiumtommy/425.jpg
3" right

43g
http://i122.photobucket.com/albums/o270/premiumtommy/43.jpg
5" right

43.5g (what I used to zero scope)
http://i122.photobucket.com/albums/o270/premiumtommy/435.jpg
all over the place LITERALLY

44g
http://i122.photobucket.com/albums/o270/premiumtommy/44.jpg
6-1/2" down and 1-1/2" right

44.5g
http://i122.photobucket.com/albums/o270/premiumtommy/445.jpg
6-1/2" down and 2" right (best group @ 3/4")

why would the rounds switch from zero to 5" right, then go crazy w/ the zeroed load, then drop 6" and come back left 3"??????

It was gusting wind but, like I said, I was not in a rush. I waited for dead calm to fire.

I am going back out saturday w/ more 44.5 and some 45 and 45.5. Then I'll mess w/ the inbetweens and length.

Oh, I worked-up some subsonics using 220 SP's, 9.3 Titegroup, flashhole @ 9/64". 990 fps average 50 degrees, 65% humid and 396ft above sea level. I believe barometer was about 30.2 ish.

[82boy]

Are you using wind flags?
I have shot some of my wose groups in a "Dead Calm." In a dead calm you can have all kinds of things going on and without flags you will never see it. It dont take much to affect a bullet. To add did you pay attention to Mirrage? Changes in mirrage, can affect how you see the target, and will affect your groups. There may be more changes than you are aware of. Changing charge weights will affect barrel harmonics, and you may be hitting diferent nodes. Could also be a scope problem.

[T-Rex]

Thx 82boy

I had a ribbon just before the targets @ 100 yds. There was no mirage as I was shooting up a slight incline w/ slight undergrowth on a 50 degree overcast day. I understand where you're going w/ charge weights and harmonics but the radical shift.... idk.. Plus, the 43.5 group that was just everywhere, was the load I used and had no problem w/ zeroing the rifle. I think we can rule out a scope problem. As you can see the rest of the groups are not bad and the last one at 3/4" would not have been possible. The first thing I did was give the rifle and scope a rattle and they were solid.

I am still scratching my head. Making more loads from 44.5 and up for saturday. We'll see

I guess you can't learn to fix a problem if there never is one...

[sharpshooter]

Scope would be the first thing I would check.

[kleeber]

The 43.0 and 44.0 are reasonable groups, but they are 7 inches apart--that's surprising. Do you recall doing anything after the bad group at 43.5 that may have changed things--tightening screws, rapping on your scope, fixing an issue with the way you were supporting the gun, etc? You probably would have mentioned it if you had, but that is a huge shift.

If I were you, out of curiosity, I'd also make 5 more at 43.0 just to see if the point of impact change is still there between 43.0 and 44.xx

[EFBell]

stop cleaning so much and see what happens.

[zap]

It could be an internal scope issue. Those are very big shifts.
Good luck,
Lee

[LG]

Those are huge shifts. There should be something loose somewhere. Action screws or scope mounts or maybe the scope itself is not holding adjustment.

[Budweiser360]

stop cleaning so much and see what happens.


Yeah, why are you cleaning it after every second shot?

[T-Rex]

I understand why so many have said check the scope and in most cases would make sense. But for the scope to print a 5 shot group and then decide it wants to change poi for the next 5 shot group is unbelievable. Or even the fact I would be able to print groups with drastic changes such as those.

As for the barrel cleaning.. why not? It keeps a constant and gave me something to do between shots while barrel was cooling. Regardless of anyones beliefs, if you keep a constant in any scientific experiment you are more likely to come out with accurate and repeatable results. Some asked if I changed position, did I move? Yes of course. I was cleaning the barrel, taking notes, etc. However, I returned to my natural, comfortable shooting position. The same way I returned the barrel to a clean state prior to shooting.

Regardless of the drastic POI shift, why would the same load used to zero the rifle print all over the place when you can clearly see I have the ability to make decent groups. Jury is still out...

Thanks for opinions

[82boy]

But for the scope to print a 5 shot group and then decide it wants to change poi for the next 5 shot group is unbelievable. Or even the fact I would be able to print groups with drastic changes such as those.... Regardless of the drastic POI shift, why would the same load used to zero the rifle print all over the place when you can clearly see I have the ability to make decent groups.


Well I can contest that I have seen and had it happen to me and on more than one occasion. I had a gun that would print a awesome 5 shot group, and the next few groups was horrible, then it would go back to shooting awesome, and so forth. Guess what it was? The answer is the scope. One time I had a gun that did the exact same thing as yours is doing, and when I took the scope off the gun , I heard a plinking noise inside, as I tilted the scope I found a round ring was bouncing inside the scope. With a new scope it shot every group good.

Scopes are a funny thing, and they will drive you made trying to diagnose them as a problem. Most times they do stuff you will find unbelievable.

[dnuke146]

Great, I just ordered, and should be here today, the same rifle, wont be able to shoot it till Monday or Tuesday... Ill lay awake at night until I get to shoot it, worrying mine will shoot the same way :(

Doug

[T-Rex]

82boy

just locked the rifle in vise. went up 50 clicks, down 100 clicks and back up 50. Same POA. Did same with windage no prob. Gave it a good shaking and I hear nothing. Checked all the ring screws and base. All is tight.

Maybe it was just an odd moment in time when everything was seating together. We'll see if prob persists tomorrow and if not, blame it on the gods...

[Dennis]

Scope would be the first thing I would check

It's the only thing it could be!!!!!!!

[T-Rex]

I have to apologize to everyone. Upon further inspection, the front 2 scope base screws had somehow come near loose (eventhough they had been locktit-ed). When I shook the rifle nothing moved, but I would assume recoil gives a little more kick than just me shaking it. I believe this would explain the drop in the last rounds when the front of the base lifted slightly.

Thank you again to all for your patience. I apologize for any ignorance on my part.

[dnuke146]

WHEW!!, I can sleep over the weekend!! ;D

[Dennis]

It's happened to all of us and once it does, you will no very quickly the next time you have the same situation.

I knew it wasn't the Savage . . . . . . . . . ::)

DITTO on the sleep tonight!!!!!!