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Old October 2, 2013, 09:27 PM   #1
Metal god
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Seeing a pattern in my grouping , Is it me or the gun ?

went shooting today and shot some 4rd strings and some 10rd strings . most of the time when shooting in general the hits seem pretty random . but I got some patterns today and have seen this before . It appears I get two different groups in the same string and wanted to get your thoughts on what you think is going on .

first pic is a 10 shot group the rest are 4 shots
.




EDIT . just had a though , could it be the cheek weld and sight picture is not consistant ?
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Old October 2, 2013, 09:58 PM   #2
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Did I miss the target distance?
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Old October 2, 2013, 10:20 PM   #3
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It appears to be a bedding issue.
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Old October 2, 2013, 10:58 PM   #4
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100yds and I'll check the action screws . The rifle is a Savage FCP-K with accu-stock . IMO one of the best factory bedded rifles out there . The rifles has 930rds through it and I have never even looked at the action screws Ok i've seen them but that's about it .
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Old October 2, 2013, 11:02 PM   #5
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good call on the bedding . Just checked the front screw and I was able to turn it quite easy . Before I do any more I need to get the torque specs .

EDIT : Well just went back and looked at all my targets for the last month and a half or 600rds of 4 and 5 shot groups for my load work ups . I can see the pattern in many of them . Some not as much as others but I'm 100% sure the rifle was doing this from almost the start of my reloading and testing .

Oh well I guess I'm upset about this because I feel I waisted money on materials but at the same time I think I may have many more good loads then I thought . I'm pretty sure I have 3 good loads right now with the way the rifle is shooting now . Those in theory should get better and some of those other groups that were just over 1 moa that I dismissed may shrink up in to the sub moa area .
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Old October 3, 2013, 07:21 AM   #6
Bart B.
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I suggest getting a set of socket head screws for your rifle and a torque wrench with a hex tip to fit the screws.

Loosen them after each shooting session. Then torque them back to whatever amount gives best accuracy. My guess is somewhere between 40 and 50 inch-pounds.
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Old October 3, 2013, 12:27 PM   #7
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What is the duration between shots??? If the barrel is heating up, then those groups look normal.
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Old October 3, 2013, 01:51 PM   #8
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Mystro : the 10 shot group was done in 3 min or less , the 4 shot groups are under a min for sure . I've been keeping track of my ammo temp and my barrel temp before each string . I never start a string with the barrel more then 10* hotter then the ammo . The ammo tends to never be more the 2* off the ambient temp so that means the barrel is never more then 12 degrees hotter then it is outside when I start . There was a day when the temp was 96* and the barrel would not cool down fast enough so I shot it when the barrel was a little hotter . On that day it would take up to 30 min for the barrel to cool to the outside temp . ( always shooting from a covered shooting area )

I don't want to discount your point of the barrel heating up and there being a POI shift . I feel these are to distinct for that . The barrel in these groups did not walk over it appears it jumped over .

EDIT : did some simulating of firing a string and I believe my timing above is off . These times will now reflect what I believe would be the max amount of time to complete the string . At times I'm sure it would be less but these are the max

10 shot string = 5 min

4 shot string = 2 min
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Old October 4, 2013, 09:57 AM   #9
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While you're at it, check the barrel channel to assure that the barrel is fully free-floated and not within 1/16" of the channel at any point. With standard hunting rifle contours, barrels can vibrate that much, especially near the end of the forend. If there's a barrel pressure-point, consider removing it for more consistent accuracy.
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Old October 4, 2013, 12:13 PM   #10
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Thanks for the heads up on making sure the barrel is not touching the stock . I did check that out and although the stock was loose-ish .It did appear it was not making contact with the barrel . The rifle has a thick heavy fluted barrel so there is not a whole lot of whip going on and there is enough room between the barrel and the stock that I can see the bedding system inside .


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Old October 4, 2013, 03:29 PM   #11
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Use a dollar bill to slide down the barrel and make sure it clears all the way back to the action.

If you really want to get involved, here is a good break-down of finding the best torque settings. Otherwise, just do 15 in-lbs on both and hope it's good enough. Add a little if it's not.
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Old October 4, 2013, 04:55 PM   #12
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Thanks Brian but I no longer use the dollar bill trick . My Ruger American would allow a dollar bill to slide freely in between the barrel and the stock . The problem is the stock has way to much flex and the stock and barrel would touch anyway .

The Savage has close to no flex in the stock and I can slide 2 playing cards stacked together up and down the barrel Chanel . the playing cards are 22 thousandths and the dollar is 5 thousandths

Quote:
I suggest getting a set of socket head screws for your rifle and a torque wrench with a hex tip to fit the screws
Well again it looks like you have a really good idea there Bart

Quote:
Before I do any more I need to get the torque specs .
FAIL

I was not going to say anything but what the hey . Like any good heavy handed gun smith I stripped the head out on one of the screws . The screws are tight but I have no idea what the torque is and now I can't get it out . I talked with Savage , they're sending me new screws . I guess I'll wait for the screws and most likely shoot the rifle before attempting to remove the screws . If the rifle shoots real well I'll wait to fix what was not broke
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Old October 5, 2013, 06:51 PM   #13
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I'd glass bed it and be done. Even though it is an Accustock the fit between receiver and bedding block isn't going to be perfect. They are both mass produced and there will be slight variations between the two surfaces. Glass bedding will remove all those variations and when done properly give you perfect mating surface for receiver and stock.

Order up some replacement screws as well from Savage and get everything working properly.
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Old October 5, 2013, 07:48 PM   #14
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Quote:
Just checked the front screw and I was able to turn it quite easy . Before I do any more I need to get the torque specs .
Do it like Stan Pate...

http://www.accurateshooter.com/techn...torque-tuning/
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Old October 6, 2013, 02:33 AM   #15
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Nice sofa, the guns not bad either (LOL). Is that cheek rest tight?
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Old October 6, 2013, 09:35 PM   #16
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cheek rest is pretty tight and does not move when shooting .

I went shooting today to see how the rifle would act with the action screws being what I believe is to tight now. I had a pretty big POI shift from the last time out with loads the rifle was zeroed for . I'll start with saying I was not shooting well today , to be more specific . I could not get the reticle to stop moving . Half the time I was trying to time the reticle between jumps . I was not having a good day and that is why I'm not sure what to think about my grouping . The two different groups in one string thing seems to be gone although 1 of the groups had the look of two groups but it could have been a random thing .

I shot a few loads that had been shooting well before ( sub moa ) and now only one is still sub moa . Thing is that could have been me not shooting well . I guess I'll wait for the screws to get here . Replace them and torque them down correctly before waisting any more ammo . After that , I'll take what I thought were good loads before and see if they are in fact good loads .
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Old October 8, 2013, 06:55 AM   #17
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Quote:
I could not get the reticle to stop moving.
Are you holding the rifle against your shoulder as well as gripping the stock with both hands, one on the fore end and the other on the grip?

If so, it's your pulse beat that's moving the rifle and causing the reticule to move around.

Take three deep breaths, then hold your breath while aiming; that may help. If you don't get your shot off within 15 seconds of cutting off your breathing, stop then start over.
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Old October 8, 2013, 01:19 PM   #18
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then hold your breath while aiming; that may help.
You can also try exhaling about half of your air (or more) then holding your breathe. Personally I am much more relaxed only holding a portion of my breathe than with my lungs full of air. Try it.

Not sure exactly what the gremlin is in your set up. You might try timing your shots; as in really waiting for the barrel to cool. Perhaps take 10 minutes between shots with the action open between shots; or take two or three at a time, then the lengthy break between groups. I would suspect barrel heating, could be a barrel to receiver mating issue. Groups appear to consistently move right/left. Just a thought.
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Old October 8, 2013, 02:10 PM   #19
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Thanks guys , I do hold my breath . I take one deep breath in and exhale about half and hold . I will try taking a couple more just before the hold and see if that works .

Quote:
You might try timing your shots; as in really waiting for the barrel to cool. Perhaps take 10 minutes between shots with the action open between shots; or take two or three at a time
This must not be the thread I talked about barrel temp in but I keep track of my ammo temp as well as my barrel temp before each string . I try to start each string of the day at the same ammo and barrel temp . That temp changes from day to day do to the ambient temp . The other day it was 91* out so my barrel never got below 89* . About a month ago I was shooting when it was 70* out and my barrel barely past 90* after a string .

Bart : I have one hand ( palm & thumb) on the side of the stock , 3 fingers from that hand under and gripping the stock and that hand is what I use to pull the gun into my shoulder as well as pull the trigger , The other hand is squeezing the rear bag and I'm pretty sure the hand on the bag is not touching the rifle at all .

I've talked about my reticle moving a little when I take aim but the other day it was moving double if not triple the amount I'm used to . There was a point that I was trying to time when my reticle was with in a 1" area of my intended POA . I have become to except my reticle to move about 1/4 to 1/2 moa but the other day it was moving at times as much as 1.5 moa . I was shooting 100yds .
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Old October 8, 2013, 02:20 PM   #20
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This must not be the thread I talked about barrel temp
I realize that you did discuss this earlier in this thread. Where are you taking the temp of the barrel? Barrel receiver mating would be where the heat is effecting that area of the barrel; which might retain heat differently than where you are measuring. Maybe Maybe not. Just my first thought regarding your gremliins.
YMMV
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Old October 8, 2013, 03:51 PM   #21
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The temp is being taken on the barrel just in front of the chamber . I have taken the temp of the barrel where the chamber is and it does not seem to get very hot compared to right in front of the chamber but I have not meassred the chamber temp enough to say it does not heat up as much for sure .

Next time out I will try your idea of one shot at a time and let the barrel cool . That will help me on another issue I'm having with first shot velocities .

Let me ask this , would the berral walking do to poor barrel to action seating be consistant ? The reason I ask is I've had some good 10 shot groups where all 10 shots are just about 1 moa . That for me is good shooting and would seem to say It does not happen all the time . Although now that I look at my targets above . Even the those are right around 1 moa or less ,so I think I might have just answered my own question
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Old October 8, 2013, 05:30 PM   #22
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Are you loading one at a time, or the entire mag? One more variable that you can check by loading one at a time. You could possibly be getting bullet setback with recoil; albeit small, yet can be measurable.

I have a target that I recently shot comparing factory to my handloads. I shot out of a lead sled to minimize movement. Three factory rounds went left of POA and were about 1 MOA, my loads went to POA and all in the same hole.

Having the barrel trued to the receiver pretty much can remove stringing caused by heat. Check with some of the custom rifle makers. Check with some of the competitors. Once the barrel starts heating up, very small variances on the rifle become large variances at a distance.

Trick to one hole targets is consistency in everything; shooter included.
Good Luck and definitely keep us posted.
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Old October 8, 2013, 06:49 PM   #23
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Are you loading one at a time, or the entire mag?
I have a 4 rd mag

When shooting 4 shot strings I load the mag full . When shooting 10 shot strings I load 4rd , 3rd , 3rd .

Your not the first person to talk about bullet set back . I had it suggested as a possible problem for this and my first shot lower velocity issues . I have not ruled it out because I have not measured the bullets in the mag after a few shots . I plan to do that next time out . I want to measure that very thing on some hunting loads I'm working on ( for a different rifle ) that I don't want to crimp . That means I'll have my comparator with me to check bullet set back on all my loads . I meant to take it last time but forgot it .

The only reason I'm really giving bullet set back any thought is I just switched to a FL neck bushing die and I now have less neck tension then I used to . Before IMO I had enough neck tension to shot out of a AR10 and alike . Now just enough to where I can't push the bullet into the case by hand . Meaning I place the tip of the bullet against my bench and push on the case rather hard . If the bullet moves I went down a bushing until I could not force the bullet deeper by hand .
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Old October 8, 2013, 08:28 PM   #24
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Metal God, how still can you hold a rifle on target (minimum reticule movement) with an unloaded rifle held hard against your shoulder?

How still can you hold a rifle on target (minimum reticule movement) with an unloaded rifle held but not touching your shoulder?

Do both ways have less reticule movement on target than you can hold a loaded one you're getting ready to shoot?

If they're not all very small and the same size, well. . .you know what the problem is.
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Old October 8, 2013, 09:15 PM   #25
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well. . .you know what the problem is.
Oh ! I know the problem is me , I'm just trying to understand what I''m doing wrong and how to fix it .

I will have an answer for you on how still I can hold the rifle after my next range trip . I don't have any where to check that here . I don't dare take my rifles out side here in Californistan . I'm in a very Urban area with a school across the street . Don't think I want to pull on that thread .

I will say I do believe the reticle moving does have a little to do with My bi-pod and rifle set up . I shot another guys rifle that had a rock solid fixed bi pod the other day . I was able to hold that rifle very still compared to mine . I then tried to use just a front bag rather then a bi-pod with my rifle and was able to hold the reticle much more still . The problem I was having with the front bag is that it would smash down after a few shots or move in some way that I was having to adjust it all the time . I hate that when I'm shooting 150rds that day and I need to adjust my front rest every 3 to 5 shots . I feel I can get behind the rifle more consistently with a bi-pod I just can't hold the rifle as still .

None Of my shooting buddy's are in to shooting as much as me . I have one friend that goes shooting all the time but you can't get him to stay longer then a hour or two . I have another friend thats very knowledgeable about shooting but is so busy in his life he never goes shooting .

Why do I say this . I'm often at the range for 8 or 9 hours working on things by my self . Alot of the time I can work through an issue by asking here and applying that info at the range . Then there's days like Sunday when it seems nothing I do works . It's those days I need somebody there to slap me around and tell me what I'm doing wrong .

I should start asking for help from the Range Officer or fellow shooters while at the range . I would love to have somebody willing to just sit there and load my rifle for an hour so I don't know if it's loaded so I can work on my flinch .

There was something I used to do but have not done it in a while . That is take my target 22lr with me and when I start to feel or see a flinch . I'd put down the 308 and just plink with the 22 to work on the fundamentals and just relax . I would then go back to the 308 and be more relaxed and the flinch would be gone-ish
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