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Old October 16, 2012, 01:10 AM   #1
Jason_2594
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Help explain why this is happening!

Can someone plead explain why this is happening. I have a Ruger m77 chambered in .338 RCM. I outfitted it with a Leopold VX-3 3-9 power scope and and am shooting Hornady 200 grn sst bullets out of it.

I have it zeroed at 200 yards, however when I shoot a 3 round string my 3rd round is always high and to the left. For example if I shoot 3 rounds and let the rifle cool then shoot 3 more rounds let it cool again and shoot 3 more I will have 6 rounds on target and a 3 round group at the 11 o'clock position about 6 inched from the bullseye.

Can some one give me a logical reason this is happening and how to fix it?
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Old October 16, 2012, 01:38 AM   #2
Ben Towe
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What does it do if you fire, say, a five round group? What it does after that third shot could be indicative of the problem. Does the group go wild? Does it continue stringing high and left?
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Old October 16, 2012, 02:28 AM   #3
Jason_2594
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I have never shot a 5 round group with it. The first time I started zeroing it I would shoot 3 rounds make some quick adjustments and shoot some more. I noticed that if if I didn't let the barrel cool then as it got hotter then my hits were really spurattic and impossible to zero.

I took the rifle out today to finish zeroing and made sure the barrel never got too hot so I would only shoot 3 rounds at a time and let it cool. After shooting about 12 rounds I had 8 rounds in a tight group right where I was aiming and the 4 stray rounds were in a tight group in the upper left. With a cold bore I was able to hit a can of shaving cream at 200 yards on the first shot. I will be using this rifle to hunt with and am worried if the occasion arises to where I need to take multipl shots then after 2 rounds my accuracy is shot?

The next time I take it our I will shoot a 5 round group and see what happens. If my 4th & 5th rounds are in the same spot as my 3rd what is the cause and fix? Now if my 4th & 5th round continue to go higher and to the left then what? Thanks for the help.
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Old October 16, 2012, 02:38 AM   #4
Jason_2594
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Here is a very crude drawing illustrating what I'm talking about.
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Old October 16, 2012, 02:46 AM   #5
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Try what Ben said - shoot some 5 round groups and report back.
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Old October 16, 2012, 03:05 AM   #6
Ben Towe
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I don't expect the 4th and 5th shots to group with the third, that would be strange. I expect it to string or go completely sporadic. You might even shoot a six or seven shot group just so we can study the rifle's behavior as it heats. Bedding problems can cause either issue. Check all your action screws as well.
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Old October 16, 2012, 03:37 AM   #7
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Sounds like uneven pressure on the barrel as it warms up. Is the barrel free-floated or is it touching the stock somewhere?
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Old October 16, 2012, 04:11 AM   #8
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in for an answer. curious about this.
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Old October 16, 2012, 06:27 AM   #9
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Six inches away from the bull is a lot. Having the first few rounds on target and the next few wander is not that unusual with lightweight barrels. I used to have a Remington Mt. rifle that would always put the 1st two shots into 1 ragged hole @ 100 yards. The 3rd shot would open the group up to 1"+. The rare times I shot more than 3 with it the groups would open up to 2-3". Never bothered me because I knew I'd never fire more than 2-3 shots at a game animal anyway and the 1st shot was always right on the money.

At this point I'd probably hunt with it as is since you are getting good accuracy with the 1st 2 shots and that is likely all you will fire at game anyway. Unless you are willing to hunt with another rifle during this years hunting season. After hunting season I'd be contacting Ruger. It sounds like a bedding issue that I'd let them look at first before letting a gunsmith do anything.

Ruger does not free float their barrels, nor do they advise you do it. I've read mixed reports from those who have done it. Some say it helps, others say it makes things worse. Something about the angled action screw. This is why I'd let Ruger have a chance at it first. In this case it appears uneven pressure on the barrel is causing this.
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Old October 16, 2012, 08:08 AM   #10
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What I want to know is...who was holding the shaving cream when you shot it? LOL

Actually, what you describe is quite unusual, but may be caused by a combination of barrel warping that may put it close enough to the barrel channel to make it bounce off when it vibrates. The location of the contact may be on the lower right side of the channel.

If there is at least 1/16" of space between barrel and forend, bounce may not be the problem. If there's a pressure pad at the end of the forend, see just how much force is needed to lift the barrel away from it. If it's less than 3 lbs, it could be the problem. However, if the barrel is fully free-floating, you might consider installing a pressure point with about 5 lbs of upward force.

If you have sling swivels on your rifle when shooting from the bench, the front swivel stud could be contacting the rest. That could cause the problem you describe.
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Old October 16, 2012, 01:38 PM   #11
Jason_2594
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Thank you everyone for the responses. I will be looking at the rifle later today to check everything that was suggested. I will also be contacting Ruger
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Old October 16, 2012, 02:06 PM   #12
Jason_2594
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Ok so I just looked at the rifle and took it apart. The three screws that attack the stock to the action were really tight. Like jmr40 said the barrel is not free floated the stock makes firm contact with the barrel. I looked at the underside of the barrel to see if there was any marring to indicate if anything was making contact with the barrel and the only mark was where the very end of the stock touches the barrel.
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Old October 16, 2012, 02:12 PM   #13
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It sounds like whoever put that rifle in the stock was of the "stronger is better" school of thought. You want the front screw tight (about 35 in-lbs), the rear screw not quite as tight, and the center screw just snug (just barely tight). If your accuracy issues contiune, you may want to consider bedding the reifle or free-floating the barrel.
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Old October 16, 2012, 02:50 PM   #14
Jason_2594
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Thanks scorch I backed out the screws and used a wheeler F.A.T wench to torque the front screw to 35 in-lbs and then just hand tightened the middle and rear screws. Hope this helps, now when I was zeroing I was using a lead sled. I have never heard of people having issues with them but could the rest play a part in this problem?
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Old October 16, 2012, 04:14 PM   #15
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I don't like the lead sled concept. Not sure if it makes a difference.

I put my Ruger 77 Mk II in a Boyds laminated stock and it didn't shoot until I took it to a gunsmith and had them pillar and glass bed it and free float the barrel. Now it shoots almost one hole if I'm holding good.

Could that 3rd shot be from "flinching"? Just threw that out there.

Sounds to me like the barrel needs to be free floated. And don't listen to the bull about Rugers not shooting well when free floated.
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