Need help with some grouping issues.

[jsimonh]

I did some load testing yesterday at 250yds. My rifle is a 28" .284 win with .220 freebore.

Problem 1: I was testing the 180 SMK and had pretty good results. On one target shooting 3 shot groups I had 3 groups at .589, .607, and .965 at 250yds. All decent groups, actually those are great for me, the problem was the first group was low and right of the dot, second group was high and left, and the third was straight underneath the dot. All shots were shot within 10 minutes. No adjustments were made, just loaded and shot.

Problem 2: The cold bore shot on this rifle is all over the place every time. Yesterday it was about 12 inches low at 250, today it was 3 inches high at 100. After the first shot, it usually shoots everything I try decent, but the first shot is unpredictable and frustrating!!!

 

[dozernomore]

do you clean your gun after every session?
if so,maybe you need some fouling and copper deposits to bring back accuracy(a repetitive barrel harmonic)

P.S, I am definitely not a guru,,lol just a gut trying to learn myself.

 

[jsimonh]

At first I was, and I was just assuming thats what was causing it. The last few times have been on a "dirty" barrel. Only 30 or 40 rounds per session though.

 

[K22]

Cold Barrel Flyers: Assume you've checked at the usual suspects - mounts, bedding screws, scope reliability, etc.

1. If flyers are occuring from a clean barrel check to see if you leaving any high viscosity oil in the barrel after cleaning? This could account for a radical first shot.

2. If cold barrel flyer is occuring from a fouled barrel the first place I'd look is to see if the stock is touching the barrel anywhere - if it is you may want to consider free floating.

 

[Nomad47]

jsimonh, I also shot my 284 28" Criterion today. But at 100 yards. The first shot, cold clean barrel was one of the two that were touching in Group 1. And that was 4000-MR powder. The other three groups were with RL-17.

On your Problem #1, were all three groups shot with identical loads? And how is parallax on the scope?

And I haven't a clue for Problem #2.

 

[fdshuster]

jsimonh: Don't discount the scope as being a possible cause.

I had similar experiences in the match's when the shots just weren't going where they normally would.

Could not believe it might be the high end ($$$) scope, removed it, mounted one of my spares, problem went away, remounted the original, problem returned, off to the factory for a warranty covered repair.

When it happens we just don't want to believe it could be the scope.

If you don't have a spare scope to use, shoot the box at 100 yards, or click-off, fire a shot, click back, fire, click off same amount, fire, etc. and you should have 2 distinct groups. Check for windage & elevation repeatability.

 

[Erik Cortina]

#1. If they were the same load check scope mounts and scope. If they were different loads then it's normal, barrel harmonics will do that.

#2. Believe it or not, some guys always pull the first shot.

 

[M-61]

I once (years ago) sold a beautiful Sako in 220 Swift because I thought it just wouldn't shoot any kind of group without a flyer. 3 shot groups..two almost touching and the 3rd anywhere but near the other 2. Sold it, mounted the scope on another rifle months later....same thing. Couldn't believe it was the scope. Put it on a 3rd rifle..same results. Never forgot that Sako and never forgot NOT to discount the scope as a possible problem.

 

[Nomad47]

Ouch, that had to hurt, M-61. :'(

 

[M-61]

Nomad47...so much that 30+years since then I still remember a painful lesson as if it were yesterday. Light blonde stock on that Sako.......

 

[jsimonh]

Thanks for all the replies!

This is on a fully floated barrel, bedded, and using a Rock front rest with rear bag off a bench.

I'm not discounting the scope, but I will usually shoot 40-50 shots and other then the first all the rest seem to be where they need to be.

The groups playing ring around the dot was very frustrating, I will re-check all my mounts and take a little more time with shot number 1 and see how everything goes.

 

[fdshuster]

Also don't forget the wind ( shoot over wind flags), and watch the changing light conditions. If it's a partly cloudy sky with the sun going in and out behind the clouds, that too will change your point of impact.

 

[bozo699]

I did some load testing yesterday at 250yds. My rifle is a 28" .284 win with .220 freebore.

Problem 1: I was testing the 180 SMK and had pretty good results. On one target shooting 3 shot groups I had 3 groups at .589, .607, and .965 at 250yds. All decent groups, actually those are great for me, the problem was the first group was low and right of the dot, second group was high and left, and the third was straight underneath the dot. All shots were shot within 10 minutes. No adjustments were made, just loaded and shot.

Problem 2: The cold bore shot on this rifle is all over the place every time. Yesterday it was about 12 inches low at 250, today it was 3 inches high at 100. After the first shot, it usually shoots everything I try decent, but the first shot is unpredictable and frustrating!!!

jsimonh,
Problem #1 your load is not in tune, the rifle is probably capable of shooting well just need to tune the load, or you have something touching where it shouldn't be.

Problem#2 If it's not you jerking the trigger then I would say again it's your load or something is touching where it shouldn't be.

Problem #1&2 someone gave me good advice years ago,...
CHECK THEM DARN SCREWS!! I mean all your screws, action,scope, mounts, all of them! Best of luck.
Wayne.