Scope problem

[N80]

Thanks for the data. I shoot Remington Core-Lokt bullets almost exclusively. They are cheap and at the ranges I shoot (always well under 200') they are accurate enough for me. I shoot the 150g in my .308's. I use the 180g in my 30-06's. But, your data pretty much confirms my typical practice with the .308 and 30-06 sighting in at about 1" high at 100'.

 

[EE_Bota]

Good advice....wanna buy a Remington Model 7 in .308?:laughing:

Sure! I've been saving up for years.:laughing:

 

[sshaw]

Here's a similar setup for the 150 gr Core-Lokt at 2,820 ft/sec. Zero is now set at 180 yards. Point of impact is still 1.5" high at 100 yards, but the trajectory is a little flatter.

Range Elevation
(yds) (in)
0 -1.5
25 -0.3
50 0.6
75 1.2
100 1.5
125 1.4
150 1.0
175 0.2
200 -1.0
209 -1.5

 

[studor]

Even with the "whippy" barrel that gun should shoot a lot better than that. From the sounds of your post, the stock has a pressure point at the front of the forearm -- put a piece of oiled cardboard in there and increase the tension at that point -- in many cases with a little fiddling with cardboard thickness and screw adjustment it should shoot a lot better. If that doesnt work try sanding out the contact point completely and free float the barrel. Shoot three shot groups not five over short dsitances and let the barrel cool between groups -- even the whippiest barrel should keep it together for three shots. I have a Ruger 270 that drove me crazy until I figured out that when the barrel heated up a bit, it made contact with the synthetic stock and things went non functional (groups went from sub 1/2 inch to strings and barn door accuracy) . A bit of sanding and consistency was achieved. Might be worth a bit of fiddling around to see if it will shoot - JMHO

 

[scott_vt]

I think the screws have a minor amount of slop and there are springs inside pushing in a certain direction to make sure that slop is always taken up. It could be this is only for low end scopes, though.

Inside a Variable Power Riflescope - YouTube

It looks like the type of spring used has to have one end slide. Perhaps the tap eliminates the possibility of sticking on that end.

Good Evenin EE_Bota,
That was an excellent video ! Thanks !

I would pay real close attention to how it sits in the stock and how the action is tightened down. What does the pressure point near the end of the stock look like? From various browsing, I was under the impression that thin sport barrels need the pressure point to minimize whip, where heavy/bull barrels do not. Did your synthetic stock have a pressure point?

The issue you saw originally sound like it could be improper bedding, or screw/bolts that are loose, or the other extreme, too tight?

If it still acts up, I'd be tempted to put a heavier barrel on it, and maybe glass bed. I think a 7mm-08 with a varmint weight or bull barrel would be cool.

Good Evenin Robert,
Good advice IMO...

A friend of mine also had an issue with one of his rifles shooting erratically, the problem ended up being a loose mount between the stock and gun, drove him crazy for quite some time.... He originally thought the issue was the scope, couldnt have been futher from the truth...

In any event, good luck with your problem George !

 

[RobertBrown]

Thanks for the data. I shoot Remington Core-Lokt bullets almost exclusively. They are cheap and at the ranges I shoot (always well under 200') they are accurate enough for me. I shoot the 150g in my .308's. I use the 180g in my 30-06's. But, your data pretty much confirms my typical practice with the .308 and 30-06 sighting in at about 1" high at 100'.

Try 165's and see if your groups don't tighten.
I don't expect a light gun to shoot the same when the barrel is hot. It's Ok because you're only going to need 1 shot anyway. Or ....most likely, you're only going to get 1 shot.
Every .308 cal. gun (30.06 included) I have ever owned, likes 165 grain ammo. I have never been able to get 150's or 180's (forget 200 -220") to group. The old adage that the 30.06 is versatile is only true if your hand loading and then it's a stretch.
You said that the gun shot well once so it shoots well. You just need to find out what it shoots well. You've got this much time into it, I suggest you get a box of these,(Graf & Sons - HRN AMMO 308 WIN 168gr A-MAX MATCH 20/BX 10/CS) sight the gun in as Eddie Walker suggested, (That's the way I do it), The barrel should be ambient temp before every shot, Do not shoot past 50 yards unless your have your group under 2 inches.
This shouldn't take but around 5-7 rounds, so use the rest of the ammo when sighting in the old scope that you took off.... if this doesn't work.
look around the peripheral of the scope from the objective end, as if you were using it to view something, only instead of looking through it, look up at the inside of the tube, look for cracks or facets in the glass. When the scope of off the gun put it in the frig and see if it fogs when you take it out, on the inside of the glass.

If this doesn't work it's the gun or the scope, most likely the scope, as the gun shot well with the other scope.

 

[N80]

If this doesn't work it's the gun or the scope, most likely the scope, as the gun shot well with the other scope.

I think you missed the part where I 'fessed up about the gun shooting well with the other scope.

To repeat, I assumed that it was sighted in before my daughter started hunting with it a few years ago. In truth, all I did was shoot at a paper plate somewhere out around 75 or 100 yards. It hit somewhere near the middle. She has killed 5 deer with it but I have no idea when it was shot from a bench rest. So I do not know anything about its previous level of accuracy. I know it was accurate enough to hit a deer in the chest at well under 100' but that is all I can say for sure.

Shooting 165's in it is probably a good idea but they are going to be pricey compared to the cheap stuff I shoot and probably won't help this gun. I'm too much of a tightwad to throw any money at this gun.

I've got another .308 (Husqvarna) that shoots cheap 150g bullets extremely well.

 

[scott_vt]

Good Evening George,
I think I remember you saying that you used a gun vice at one point in the thread for siting the gun.

By any chance would you own a dial indicator ? If so you might try setting up the gun in the vice along with an indicator positioned farther out on the barrel, and see if your getting any movement between the clamped stock and the end of th barrel...

A small amount of movement would cause erratic results... just a thought and maybe worth trying if nothing else works...

 

[scott_vt]

Good Morning George,
I should have explained where I was going with that last post last night...

I have seen where the screws that fasten the gun to the stock are apparently tight, but actually the thread of the screw have bottomed out, and therefore allowing a tiny amount of movement between gun and stock.

You might not necessarily feel or see that movement unless you set the gun up in a clamp and check with an indicator...

This has never happened to me but has happened to a friend of mine who is much more knowledgeable about guns than myself...

 

[EddieWalker]

I think we need a baseline before accusing the rifle of not being accurate. Every factory rifle has the ability to be improved on, every factory rifle also has the basic ability to fire to a certain degree of accuracy. You will NEVER know how accurate that rifle is at close range shooting. Close range shooting is only to get you on paper.

90 percent of the guys with a rifle are average to not very good shots. 9 percent are good and 1 percent are good. To define if you are a good shot you have to be able to honestly say what size groups you can shoot at one hundred yards. If you can consitantly put five shots in a one inch group, then you are a good shot. If you are happy with most of your shots in the black, then you are average to poor.

When I shoot, I put the targe up backwards and put four one inch orange dots on the target, equally spread apart at 100 yards. I aim for one target and shoot. I wait five minutes or more, then shoot again. I will shoot five times at the same target without touching the scope. That is my baseline. For me personally, I want to hit two inches high at one hundred yards.

Depending on where the holes are, I go from there. If they group tite and are not where I want them to be, then I adjust the scope. If they are spread out, I know it's either my shooting or the ammo. I always assume the rifle is fine because I've already gone over it when I cleaned it and I know everything is tite and clean.

Finger placement, breathing and how you hold your rifle is all part of knowing how to shoot. If you are surprised every time you shoot and you dont flinch, if you have a solid rest and are light on the trigger, you use the tip of your finger and you are relaxed every time, then it's probably the ammo.

Most ammo is pretty good and most shooters are pretty bad. I don't know how you are, but I do know that the difference between my abilities and a person who competes is night and day. Saying that, I shoot one inch groups fairly regularly. I think I'm a good shot. I also know that I can't shoot those one inch groups cold and after not shooting for awhile. On a good day, I've had five shot groups all touching, on a bad day, I'm not even close.

If you are a good shot, try different ammo. Bullet weight plays a HUGE part in accuracy. Powder type and quantity also makes a huge difference. Every barrel has the perfect round for it. There are pros out there that do nothing but try different loads all day long, week after week. It is a time consuming, trial and error process that doesn't have a short cut. I did it while reloading and became a better shot. I also got lucky and found a premium ammo that shoots as good as the best reload I ever came up with.

Step one, put it together and shoot it at one hundred yards. The pattern will tell you more then anything we can come up with.

Eddie