must be doing something wrong

legi0n

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Soooo, I bought this Ruger 77/357 bush rifle with a 18.5" barrel (not that there's any other options)
And took it to the range. It's been sighted in last week and this week I focused on it's accuracy.
It happened all day long, first 3 rounds group tightly, the last 2 way off (5 hole group since the mag holds 5 rounds).
Targets at 100m, scope Simmons Blazer 3-9x40, parallax free at 100m.

2012.07.29-1.jpg

2012.07.29-2.jpg


next I adjusted the scope 6 clicks to the right and focused some more on my breathing

2012.07.29-3.jpg

2012.07.29-4.jpg


What am I doing wrong? :bangHead:
 
Barrel heating up and thus shifting point of impact? I'm not sure how hot a 357 rifle barrel will get.

Could be. After 10 rounds in 5 minutes the barrel is at the edge of too hot to touch.
But there's no consistency in the fliers.
Second pic they're way off to the left while in the 4th they're centered but off
 
Accuracy seems to be there initially since the first three rounds looks to be grouping pretty tight. Like previously said, maybe check to see if the barrel needs to be free floated a bit more-could be touching when hot. I don't think its anything major or you would not get any grouping at all.
 
Accuracy seems to be there initially since the first three rounds looks to be grouping pretty tight. Like previously said, maybe check to see if the barrel needs to be free floated a bit more-could be touching when hot. I don't think its anything major or you would not get any grouping at all.

True, the 3 round groups mean the rifle is accurate.
But I have already shaven enough of the (synthetic) stock to clear the barrel by 2mm or more. Not that Ruger would agree with that (actually they specifically prohibit any modifications to the stock in the owner's manual).
I have a feeling we'll get to the bottom of this.
Keep the suggestions coming.
 
The kid's Stevens 200 in 308win has the tendency to do the same.
First three are clover leaf and the four and five open up.
Not sure as wide as yours?
And with the summer temperatures, barrel cooling will be longer.
Open the bolt and stand the rifle upright, stove pipe effect to
cool it down.
 
guessing the barrel has stress and raises it ugly head when heated. heard a old gun smith say once to fire two boxs of rounds as fast as possible. heard it worked can't comfirm a last case sanario perhaps for you.

or scope is junk but i don't think its the problem
 
I read an article on another forum somewhere about shimming the bolt on some of the 77 actions. The bolt was taken apart & a 4-5 thou shim put in to tighten head space when the bolt was closed.

Might be something look into....

That would be easy since the bolt is not that difficult to take apart.
But I don't have any headspace gauges handy and certainly don't plan buying any.
Being a new gun I'd rather send it for repairs.
 
Getting to hot would be exactly what is happening, barrel tolerences increase with heat.

Temps as low as 100 celcius an have a noticable expansion difference, the outside may not feel that hot but the surfaces inside the barrel (especially at the throat) will be reaching that temp in short order.
 
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