What's my malfunction?

[Khavic]

I only ask because I went to a 1000yd range recently and was getting odd results using inputs based on the data posted. Pulled out my range finder and discovered that I was high on the 1000yd because it was 989yds from the firing line I was low on the 700 because it was actually 723yds. Just asking based on my own experience.

The question about components was because I had great results from RL17 when the temps were low, but miserable consistency above 70degees.

Just trying to paint a clearer picture based on things I've battled in the past.

 

[WeiserBucks]

Both rifles have been very consistent up to this point, Its frustrating but I'll figure it out one way or another.

 

[Brianc74]

I would check your drag settings also your bc can go up or down depending on atmospheric conditions and rifling twist and velocity.

Brian

 

[dfanonymous]

All shooting is at a private range and i update the inputs each time i go . Not even close to time to rebarrel and the issue exists with clean and fouled bore . Muzzle velocity is not increasing, I record velocity at the beginning and end of my range trips.

1. Having copper in the barrel has nothing to do with being time to rebarrel, the effect takes places through out the entire lifetime of your barrel.
2. You can clean that barrel till you blue in the face, but the patches you use are what need to be blue to get copper out. Most people just leave it in.
Well if you are sure it's not mv then as the other poster said, you need to true the bc..or true the mv or the bc to match reality.

 

[WeiserBucks]

My barrels are both pretty young, sub 300 rounds each and never fired rapidly. I'm also very meticulous about cleaning bores , I'm not that guy who pulls a bore snake through it once a year before hunting season and declares it clean.

 

[dfanonymous]

Yeah as the barrel breaks in velocity changes. As copper lines the bore...it increases. Are you cleaning with ammonia? Because the copper ain't coming out unless your using sweets 7.62 or something like wise. The peanut gallery will have all the other solvents made directly for copper, it's irrelevant. My point is you have said you cleaned the bore well and a lot...but are you sure you got copper of the bore?

http://www.sniperforums.com/forum/cartridges-calibers/36710-copper-fouling-vs-velosity.html

 

[WeiserBucks]

I soak the bore in an ammonia based solvent for 2 hours and then run soaked patches through the bore utill they come out clean . Both of my barrels seem to have very smooth bores that pick up very little copper and clean very easily.

I think it's got to be something to do with truing the MV vs BC relationship, that's about the only thing I haven't eliminated as a possible issue.

 

[dfanonymous]

I soak the bore in an ammonia based solvent for 2 hours and then run soaked patches through the bore utill they come out clean . Both of my barrels seem to have very smooth bores that pick up very little copper and clean very easily.

I think it's got to be something to do with truing the MV vs BC relationship, that's about the only thing I haven't eliminated as a possible issue.

I agree. Truing is the ultimate fix. There's still many things it could be to explain the shift however. Was the ammo factory or reload?

 

[WeiserBucks]

I hand load for both exclusively.

 

[Brianc74]

It's the BC.
Your bullet is flying more true do to dryer atmosphere and warmer temps. Also now that your bore is more pollished, less distortion caused to the bullet from bore to bullet contact.

Brian

 

[Clucknmoan]

I was having the exact same issues about 2 weeks ago with a rifle that had just over the round count you are describing. I was dead on out to 500, but high at 800. After all was checked and rechecked, I adjusted my BC up .11 and I am back in business.

 

[Switchback2]

I too would say maybe this Lot of bullets you shooting now have a Higher BC then the Lot you used for load development.

 

[Kmccord]

I am sure you have verfied, but are you using the G7 BC for calculations? I have always been told for anything over 500yds, it is better to use the G7 BC.

 

[WeiserBucks]

Correct, I use G7 for everything