Accuracy gone?

[rdmega]

I have had a Savage 10fp for about 5 years now in .308, up until a couple weeks ago I have had a cheaper Nikon scope on it. It shot really well, I used to hold uner 1 MOA all the time out to about 400 yards. I changed it over to the new Vortex Viper PST FFP. I dont know if this is related or not but I finally got it sighted in at 100 yards, when I went to zero at 200 I was all over the paper. So .75 at 100 yards and 8 inches at 200. These were handloads done by a friend, also I noticed a little copper inside the barrel right near the crown.

I am not good at diagnosing problems and was wondering where to start? I guess ammo first as well as some really strong cleaner on the barrel. Any other thoughts?

Thanks guys.

 

[WildRose]

I have had a Savage 10fp for about 5 years now in .308, up until a couple weeks ago I have had a cheaper Nikon scope on it. It shot really well, I used to hold uner 1 MOA all the time out to about 400 yards. I changed it over to the new Vortex Viper PST FFP. I dont know if this is related or not but I finally got it sighted in at 100 yards, when I went to zero at 200 I was all over the paper. So .75 at 100 yards and 8 inches at 200. These were handloads done by a friend, also I noticed a little copper inside the barrel right near the crown.

I am not good at diagnosing problems and was wondering where to start? I guess ammo first as well as some really strong cleaner on the barrel. Any other thoughts?

Thanks guys.

The first thing I'd do is go back to the old scope and give it a cursory cleaning before firing. Then try some 100 and 200 yds groups with the OLD ammo.

There's a very good chance something came a part/loose in the scope.

.308's are well known for going many thousands of rounds before there is enough throat erosion to cause a loss of accuracy.

My feeling is there's just way too much variation for it to simply be an ammo issue and throat erosion should not be a factor unless you've been running super hot loads through it for a long time.

 

[rdmega]

Thank you. I will give that a try first then. It's only had 500 roughness total and most were factory. I think you're correct.

 

[The Surgeon]

WildRose is right.

The only thing I would add is, after you go back to the original scope and give it a good cleaning and you still are having trouble, check the crown.

 

[Kevin Thomas]

Not to overlook the obvious here, but have you gone back and tried the factory ammo that was giving good results earlier? The "handloads done by a friend" part concerns me. Major variable there that needs to be eliminated before we start jumping towards other "solutions."

Do you yourself handload? Might be something to consider getting into if you're not already there, as it gives you so much more control over the final product.

 

[Broz]

Why not clean first and shoot again, then change scope if needed. Only make one chage at a time that way you will know what fixed it.

Jeff

 

[WildRose]

Why not clean first and shoot again, then change scope if needed. Only make one chage at a time that way you will know what fixed it.

Jeff

Because there's no amount of dirty that could cause this short of a barrel obstruction.

 

[Broz]

Because there's no amount of dirty that could cause this short of a barrel obstruction.

I agree that 8 inches at 200 is definatly pointing at the scope way more so that fouling. But why .75 at 100 and 8" at 200? I was just saying it is usually better to change on component at a time to find the true culprit.

Sorry to interupt.

 

[WildRose]

I agree that 8 inches at 200 is definatly pointing at the scope way more so that fouling. But why .75 at 100 and 8" at 200? I was just saying it is usually better to change on component at a time to find the true culprit.

Sorry to interupt.

Because if something broke loose inside it would equal that kind of inconsistency. Nothing else I can think of right off the top of my head does.

The only other thing I can think of that might explain it is if he's shooting reloads that are so far over pressure they're bout to blow his rig up but he's not stating there's any pressure signs on the brass.

Again, the most likely culprit I can think of is that something has come loose inside of the scope.

Although you made me think of one more... Loose scope mounts.

 

[Catfish]

Have you used a copper soulvent when cleaning the rifle? The other thing that comes to mind is your new load are eather to heavy or to lite for the twist of your rifle.

 

[rdmega]

Thanks guys. I'll try all of these one at a time! I'll post results. Haven't had time yet.

 

[rscott5028]

The good news is that it's a huge/obvious problem. So, you'll be sure to find it by changing one variable at a time.

-- richard

 

[rdmega]

Well, finally made it to the range. Before leaving I cleaned the bore with Hoopes 9 copper solvent per the instructions on the bottle. I grabbed some 168g HPBT Match ammo to eliminate that culprit of the bad ammo. I fired an initial cold bore shot and it was about on. While I waited a little I looked over the scope mounts and checked. It seemed one of the nuts on the ring wasnt as tight as the other. I tightened that and fired 4 more shots waiting a couple of minutes between each. They were fairly consistent, about a 1" grouping.

I should point out that the range was crowded from people getting ready for the deer hunt and I was stuck with a terrible bench that I fear was making me inconsitant.

I cleaned the rifle and moved to 200 yards. It was much better, it was still worse than I had been before but I think it was human/bench position this time. I was in an uncomfortable position and still managed a 1-1.75" grouping three times in a row (5 shots each).

Thanks everyone for the help, I thin it was a combination of a slightly loose scope mount and some ammo that was a little too light and may have been slightly over pressured. I should have my bench set up in the next two weeks to start loading again. I think this will help, and if I can get into a better position and tighten up the groups. If its still that wide I may have the crown redone and my action trued, time will tell.

 

[WildRose]

Well, finally made it to the range. Before leaving I cleaned the bore with Hoopes 9 copper solvent per the instructions on the bottle. I grabbed some 168g HPBT Match ammo to eliminate that culprit of the bad ammo. I fired an initial cold bore shot and it was about on. While I waited a little I looked over the scope mounts and checked. It seemed one of the nuts on the ring wasnt as tight as the other. I tightened that and fired 4 more shots waiting a couple of minutes between each. They were fairly consistent, about a 1" grouping.

I should point out that the range was crowded from people getting ready for the deer hunt and I was stuck with a terrible bench that I fear was making me inconsitant.

I cleaned the rifle and moved to 200 yards. It was much better, it was still worse than I had been before but I think it was human/bench position this time. I was in an uncomfortable position and still managed a 1-1.75" grouping three times in a row (5 shots each).

Thanks everyone for the help, I thin it was a combination of a slightly loose scope mount and some ammo that was a little too light and may have been slightly over pressured. I should have my bench set up in the next two weeks to start loading again. I think this will help, and if I can get into a better position and tighten up the groups. If its still that wide I may have the crown redone and my action trued, time will tell.

Good deal! Sub MOA at 200 from a cramped/uncomfortable position ain't bad at all.

Glad it wasn't something really ugly!

Try running your scope up 20moa/down 20moa, then left and right the same.

Then see where you are on paper just to be sure.

Hopefully all the trouble is behind you nowgun)