Need help interpreting targets


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wsryno
March 3, 2012, 04:51 PM
I bought a used Remington 788 this week and today was range day. I shot 3 targets and need some help figuring out where to start troubleshooting.

All ammo: Winchester Super X Powerpoint 150gr .308
My skill level: I would guess intermediate. I can hold 1 MOA very consistently with a decent load in my Bar II / .270 Winchester.

I know I should only change one thing at a time, I'm just hoping for some level-headed guidance as to what order I might consider troubleshooting. Scope? Ammo? New shooter? Should I carefully load some Sierra GameKing with IMR4895 in the middle of the load range and see if the results are at least somewhat more consistent? Thanks in advance.

TARGET 1: 25 yards, 3 shots, wanted to make sure I hit paper before moving to 100 yds. Looks okay to me, I'm not a benchrest shooter so one little flier doesn't hurt my feelings.
http://i1221.photobucket.com/albums/dd468/wsryno/scan0037.jpg

TARGET 2: 100 yards, 3 3-shot groups. First group was a little wide, but hey it's the first time I've shot this rifle. I was a bit surprised by how high the POI. I adjusted the POI for 6" down and 6" right. Second group was more like it for MOA, I would be okay with this for this rifle and a factory load, but I realized I had over-adjusted the scope by a factor of 1. So I adjusted 3" high and 3" right. 3rd group surprised the heck out of me because it was SO wide. Closer to center of target but wide group.
http://i1221.photobucket.com/albums/dd468/wsryno/scan0038.jpg

TARGET 3: 100 yards, 2 3-shot groups. All over the place.
http://i1221.photobucket.com/albums/dd468/wsryno/scan0039.jpg

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Cypress
March 3, 2012, 04:57 PM
With groups opening up that much I would first check the scope and mounts. I've had a couple shoot loose when they were not installed correctly or were cheap mounts.

Art Eatman
March 3, 2012, 05:14 PM
Definitely odd.

From what you said about adjusting the scope, it sounds like it's okay. With the groups opening up like that, it might be as simple as if that particular barrel is picky about being clean. Your post doesn't come across as though you were shooting rapidly.

Just for drill, after cleaning--and particularly making sure it's "de-copperized" :), since it's been used--I'd try a group or two with the remaining ammo, and try a box of, say, Rem 150-grain Core-Lokt.

Two MOA isn't a bad starting point...

wsryno
March 10, 2012, 05:44 PM
Art, thanks for suggesting a thorough cleaning but I think I still need some help. I spent 3 days running patches until the blue was gone; I had cleaned it but not as well as needed.

Today was range day. I loaded Sierra GameKings over IMR4895 in 4 different charges, 40-43gr. After 2 fouling rounds, I shot 4 groups of 3 with the best group the first one at 1" and the worst the third one at 3". I didn't clean between any of those groups. Then I shot another 4 groups of 3 but snaked the barrel after each group. The groups were larger but more consistent, with the best at 1.5" (same load as the best group previously) and the worst at 2" (same load as the worst group previously).

Looks like I just need to keep the barrel squeaky clean?

Redlg155
March 10, 2012, 05:56 PM
A solution you might want to try is a bore lapping kit from Midway USA. Lapping the barrel should help with fouling build up and may increase accuracy. Wheeler makes a compound that you imbed in your bullets and fire to polish the bore.

Flintknapper
March 10, 2012, 05:58 PM
What scope and rings do you have on it?

Check them to make sure they are tight...but also consider that the scope might not be holding "zero" after adjustments.

If you are a new shooter, confine your shooting to 50 yds. (for now) until you can positively rule out a scope/mount problem. Any small amount of movement on your part will be greatly magnified the farther you are from the target.

Unless the barrel is shot out, the crown damaged, etc....you should be able to easily shoot 1"-2" at 50 yds. (if you do your part). Once doing that...you can move to 100 yds.

Keep us updated and good luck.

H2oPumper
March 10, 2012, 06:13 PM
First, I'd make sure the scope mount is sound. Next, check to see if the barrel was floated, the 788 can be a little picky about that and make sure the action screws are tight. I'd also have someone else shoot it that have proven they can shoot a reasonable group to rule your shooting technique in or out. If none of that helps, recrowning and bedding may be an option. The 788 is also known for a weak bolt handle where they can break off. There is a fix, but it needs to be done right. What are you using for a rest? Make sure nothing is touching the barrel when you pull the trigger.

newbuckeye
March 10, 2012, 06:26 PM
First, I'd make sure the scope mount is sound. Next, check to see if the barrel was floated, the 788 can be a little picky about that and make sure the action screws are tight. I'd also have someone else shoot it that have proven they can shoot a reasonable group to rule your shooting technique in or out. If none of that helps, recrowning and bedding may be an option. The 788 is also known for a weak bolt handle where they can break off. There is a fix, but it needs to be done right. What are you using for a rest? Make sure nothing is touching the barrel when you pull the trigger.

I did that with a new pistol recently......:banghead:

wsryno
March 11, 2012, 12:45 AM
The crown looks flawless. The bolt has not been rewelded; I checked that before I purchased it. I am resting the stock's fore end on a sandbag on a block, with sandbags under the butt and the butt tight into my shoulder. I hold 1MOA with my 15 year old BAR II / 270 so I think my technique is reliable but it would be worth having a better shooter than me give it a go. That's probably the best first step.

I'm not sure about bore lapping; I'd rather rule out other possible problems first.

The barrel is floating and has not been bedded. I did have to sand down a high spot about 3" back from the front of the stock. I did that between the first targets shown and today's range trip. The bridge between the trigger group and magazine is split all the way through but I think this probably wouldn't affect accuracy. Photo might show it.

Let me show my ignorance: Action screws? Do you mean the 2 screws that hold the entire barrel assembly into the stock? If so, yes they are tight.

Scope is as old as the rifle, it's a run-of-the-mill Bushnell 3-9 on Weaver mounts. It all feels tight, but I was planning to take a known-good scope off one of my other rifles anyway and maybe I should mount it on the 788 for kicks. This would probably be a good second step.

http://i1221.photobucket.com/albums/dd468/wsryno/DSC_4284.jpg

Flintknapper
March 11, 2012, 01:06 AM
If it were me...I'd swap out the scope and rings and give it another go.

That particular scope (and rings) might have been intended to go on a rimfire rifle.

I suspect there is nothing wrong with the rifle...though I would repair that crack in the stock with some epoxy or Acra-glass.

You'll get it to shooting, stay after it.

Old Dog Man
March 11, 2012, 03:14 AM
The 788 is a known shooter, you said you were using Weaver bases. I would remove the scope. rings and bases. Check the bases over real good. I have seen the bases wear around the screw holes, some time you can't tell it by moving by hand, but they will move under recoil. You may just need new bases. look at the bottom of the bases to see if they have been shifting on the action, it will be polished on the action and reciever.

Longrifle2506
March 11, 2012, 03:25 AM
Although the scope is considered cheap by many people; I like those older Bushnell Sportviews that were made in Korea. They are not that bad. They're not as bright as Leupold, Burris Signature, and Bushnell's Elite scopes; but they are clear and they hold zero in my experience. However, in this case; I'd upgrade Mounts and Scope. I highly recommend a solid steel scope mount. If you do not have or cannot get a secondary scope; then you may get lucky and fix the problem by upgrading to good steel rings; and use the same scope. But if you are able; I'd upgrade Both. If you order from online; Burris Zee Rings will be all you need; $25 max; and Walmart has Weaver Grand Slam solid steel rings for around $20 I think. Either one should work; but the Burris is a better mount. When I got my Grandfather's Remington 700, it had old Weaver aluminum rings and bases and my impacts were all over the place. I upgraded to a Millet one piece base(made of heat-treated nickel steel) and millet angle-lock rings. The rifle has shot around 3/4" to 7/8" ever since. Good Luck

helotaxi
March 11, 2012, 03:57 AM
I would look for good rings rather than simply steel rings. Material isn't nearly as important as people make it out to be, mostly irrelevant in fact. What matters is design and manufacturing quality.

Even the best rings can be rendered worthless if installed poorly so make sure that you do it right.

All that said before you go swapping out parts that may well be just fine, how does the rifle shoot with factory ammo? A box of Federal Gold Medal Match ammo will set you back less than the cost of the least expensive scope rings you should be considering and will likely be much more telling. If the rifle doesn't group well with FGMM, something is wrong with the rifle.

I would spend $200 on a Bushnell Elite 3-9x40 regardless.

Art Eatman
March 11, 2012, 10:58 AM
One simple tweak to be tried would be a shim at the front of the forearm. I cut a 3/4" strip of kitchen wax paper and fold it back and forth until it's just barely too thick to fit between the forearm and the barrel. A slight pull and it's an easy insertion. Trim with a razor blade. I've found that there is some sort of damping effect which tends to make for uniform vibrations from shot to shot.

FWIW, I've never had Weaver mounts be a problem, these last sixty or so years...

nickn10
March 11, 2012, 08:32 PM
Art, thanks for suggesting a thorough cleaning but I think I still need some help. I spent 3 days running patches until the blue was gone; I had cleaned it but not as well as needed.

Today was range day. I loaded Sierra GameKings over IMR4895 in 4 different charges, 40-43gr. After 2 fouling rounds, I shot 4 groups of 3 with the best group the first one at 1" and the worst the third one at 3". I didn't clean between any of those groups. Then I shot another 4 groups of 3 but snaked the barrel after each group. The groups were larger but more consistent, with the best at 1.5" (same load as the best group previously) and the worst at 2" (same load as the worst group previously).

Looks like I just need to keep the barrel squeaky clean?
If I read you correctly you are trying 3 different powder charges and comparing them. That's ok, but don't expect consistency if you are using them to check the accuracy of the rifle. The load is the variable. Take the best load, thoroughly clean the rifle, I used wipe out, then shoot at least 5 rounds about a minute apart. I then used that load as a basis for a ladder test. I went 1.5 grains lower and increased by .5 grns until I was 1.5 grains over my initial best load. I thoroughly cleaned the rifle after EACH tested load. My groups varied from 1.75 inches to .40 inches. In my .308 I used HDY168 gr HPBT match and H4895. My best load in my LH 788 is 40.5 grns of H4895. I bought the rifle used and the bore was filthy, I cleaned it with Butch's, then wipe out, then ran bore paste through it for about 25 strokes, cleaned that out with Hoppe's and oiled the bore with Kroils, let it sit for a couple of days Then ran a few clean patches till it was dry. It shoots great now. Good luck, the 788s are accurate.
Nick

Freedom_fighter_in_IL
March 11, 2012, 10:02 PM
If the rifle doesn't group well with FGMM, something is wrong with the rifle.

Horse Pucky!!! I actually have 3 rifles that will clover leaf, if not one ragged hole, at 100 with my hand-loads that wouldn't group minute of county with Fed Gold. Not all rifles are the same and some can be EXTREMELY picky. I have one rifle that I don't know HOW many times it almost got wrapped around my range post before I finally landed on the winning load.

H2oPumper
March 11, 2012, 10:48 PM
Are those see-through rings on that scope? If they are, I'd get rid of them and go to the mediums (or low if the clearance works). Do you still have the iron sights mounted on the rifle? If so, see if you can hold a group with the irons. Maybe someone can answer this: is the 788's barrel supposed to be tight to the stock right under the chamber and the rest of the barrel floated? One more thing to try would be to what happens if you put some shims between the tip of the stock and the barrel. It's hard to say what will happen, but if you can gain some better groups, at least that will give you some direction.

JRH6856
March 12, 2012, 12:54 AM
That particular scope (and rings) might have been intended to go on a rimfire rifle.

Good call. If I'm reading that model number right, that is a rimfire scope and it is not likely to hold zero on a .308

wsryno
March 12, 2012, 10:46 PM
Okay, it's taken me a while to think about all of your ideas. Here's what I know for sure:

-After de-coppering the barrel and removing a high spot from the stock, groups went from more than 6" to 3", and swabbing between groups brought max groups down from 3" to 2". I would call that a significant improvement.
-I have a specific load that groups better and more consistently than the others (150gr Sierra GameKing over 40gr IMR4895).
-I can consistently hold 1MOA with a 3-9x scope on my BarII .270 with my handloads that I have optimized for that rifle, in the same conditions that I was shooting the M788. I have been shooting the BarII for 15+ years and the M788 for 2 range trips.
-My 8 year old son will not complain one little bit if his 10/22 suddenly has a 3-9x scope mounted on it.

Here's the list of suggestions for improving consistency/accuracy:
-Try different scope, mount, and rings (scope might be for rimfire).
-Try highly skilled shooter instead of me :scrutiny:
-Try iron sights to rule out scope.
-Try shooting from 50 yds to rule out shooter.
-Try "cushioning" or "shimming" the forend.
-Try optimizing the handload.
-Try factory match grade ammo.
-Try lapping the barrel.

The deer will die of old age before I get through that list :banghead:

Given all these variables, I think I will load up a bunch of the "most consistent load", change out the scope and mount since I have a known good scope and rings available, and spend a month at the range with me and better shooters. If that doesn't work, then I'm on to the next in the list.

Thanks for your encouragement and help. When I get it worked out I'll post results. In the meantime if you have thoughtful suggestions, I would certainly appreciate it. Yes I know, I should have bought a 4-lb jug of 4895!

dampoo
March 13, 2012, 12:52 AM
This is almost 50 years old but it is the best grouping discussion I have ever read. Also you can learn a lot about the British firearms history.

http://rifleman.org.uk/Fuller_group_diagnosis.htm

nickn10
March 13, 2012, 10:28 AM
wsryno, seems like you are going about your mission very sensibly and patiently. You've made some substantial improvements already, keep us informed.

wingman
March 13, 2012, 11:23 AM
Never owned or seen a 788 that would not shoot 1 moa, change scopes and repair stock and /or replace stock it may have been torqued too tight at one time and your getting movement in the action doesn't not take much but honestly the scope is poor I've owned them but only on a 22.

Also at bench move your rest/sandbag back near trigger guard will give you a better idea of stock problems.

USSR
March 13, 2012, 11:51 AM
If the rifle doesn't group well with FGMM, something is wrong with the rifle.

+1. You need a base line that only factory match ammo will provide.

Don

wsryno
March 13, 2012, 11:08 PM
@USSR, which do you think is the greater variable:

-hand loads with Sierra 150gr GameKings on top of IMR4895, measured to +/-0.1gr accuracy, using same 1x brass and primers, which through 9-shot groups of 4 different charges have shown the most consistency

or

-a completely unknown rifle (barrel, action, stock, scope mount, scope)

I am experienced at troubleshooting other types of problems, but unfortunately not at troubleshooting inconsistent groups. So given my experience with this rifle so far, I would expect the scope and/or mount and the shooter to now be the greatest variables. I am not opposed to buying a box of match grade ammo, I just want to do my best to eliminate the most likely problem first.

This is almost 50 years old but it is the best grouping discussion I have ever read. Also you can learn a lot about the British firearms history.

http://rifleman.org.uk/Fuller_group_diagnosis.htm

EVERYONE should read the link provided by dampoo, the information is priceless. Thanks dampoo!

Freedom_fighter_in_IL
March 14, 2012, 12:25 AM
+1. You need a base line that only factory match ammo will provide.


USSR, Sorry to bust your bubble, but ALL factory ammo, including "match grade", is still more prone to inconsistencies than a careful hand-loader. The OP hand-loads and seems to know what he is doing in that respect. Unless that factory hand weighs each and every charge (and no Fed Match Grade is NOT), and every charge comes from the same lot, (Again Fed Match Grade is not), then there is no possible way to be as consistent as a careful hand-loader. Plain and simple. So that "base line" is not really a base line at all. A careful hand-loader would be able to provide a much more consistent load value than ANY mass produced ammo.

USSR
March 14, 2012, 11:10 AM
@USSR, which do you think is the greater variable:

-hand loads with Sierra 150gr GameKings on top of IMR4895, measured to +/-0.1gr accuracy, using same 1x brass and primers, which through 9-shot groups of 4 different charges have shown the most consistency

or

-a completely unknown rifle (barrel, action, stock, scope mount, scope)

I am experienced at troubleshooting other types of problems, but unfortunately not at troubleshooting inconsistent groups. So given my experience with this rifle so far, I would expect the scope and/or mount and the shooter to now be the greatest variables. I am not opposed to buying a box of match grade ammo, I just want to do my best to eliminate the most likely problem first.

Assuming you have first checked you scope mounts for not being loose and tried a different scope that is known to be good, then the next step I would take is going with a load with a known history (Federal Gold Medal Match), so as to develop a baseline and eliminate your reloads as a factor.

USSR, Sorry to bust your bubble, but ALL factory ammo, including "match grade", is still more prone to inconsistencies than a careful hand-loader. The OP hand-loads and seems to know what he is doing in that respect. Unless that factory hand weighs each and every charge (and no Fed Match Grade is NOT), and every charge comes from the same lot, (Again Fed Match Grade is not), then there is no possible way to be as consistent as a careful hand-loader. Plain and simple. So that "base line" is not really a base line at all. A careful hand-loader would be able to provide a much more consistent load value than ANY mass produced ammo.

Hmm, if all that is necessary to develop extremely accurate ammo is consistency and being careful, then all handloads would be accurate and there would be no need for load development work. You can develop various handloads, all carefully and consistently put together using different powders, charge weights, COAL's, primers, etc., and you will have varying degrees of accuracy. As previously stated "If the rifle doesn't group well with FGMM, something is wrong with the rifle". It's all about eliminating a variable; his handloads.

Don

Freedom_fighter_in_IL
March 14, 2012, 12:13 PM
As previously stated "If the rifle doesn't group well with FGMM, something is wrong with the rifle". It's all about eliminating a variable; his handloads

No it would rule out "that particular load". He just needs to continue varying his loads until he lands on one his particular rifle likes. As I said previously, I have three VERY good shooters that couldn't consistently hit the broad side of a barn from the inside with Fed Match. To say something is wrong with a rifle because it doesn't group well with Fed Match is just plain silly. Yes they are generally a good ammo for range and generally shoot well in most rifles. But not ALL rifles. Some rifles are just picky as hell. Just because it is a "known history" doesn't really mean anything except it has a good reputation for a factory loaded product.

USSR
March 14, 2012, 02:14 PM
Yes they are generally a good ammo for range and generally shoot well in most rifles.

Thanks for validating my point.

Don

R.W.Dale
March 14, 2012, 02:31 PM
Bad scope.
Plain and simple

Ditch the see thru rings too while your at it. They aren't helping.

Try a flat based bullet. IMO they're much easier to get good groups out of than boat tail bullets when testing a rifles accuracy potential.

Skip the FGMM. You can't hunt with the stuff and even if it shoots good you still have to get this rifle to shoot HUNTING bullets satisfactory

posted via mobile device.

gamestalker
March 14, 2012, 07:43 PM
If your groups are degrading that quickly, I would second the notion to lap the barrel.

You didn't say anything about barrel cool down time between shots. I give the barrel about 5 minutes cool down between shots and it seems to do the trick.

bubba15301
March 14, 2012, 09:52 PM
bad scope- need to glasbed the stock

wsryno
March 15, 2012, 12:28 AM
@ussr: I haven't yet swapped out old, unknown scope and see-through mounts with known good scope and mounts yet. That is this weekend's project.

@bubba et al: bad scope and glass bed the stock, replacing the scope/mount is in the works. Would you agree that of the two variables, scope and glass bedding, that in most cases the scope would be the one to cause the greatest variation? (assuming the barrel is free floating, which in this case it is)

@RWDale: From what I've read flat base bullets may be more accurate in this rifle. Assuming I am able to squish down the groups with known good glass and mounts, I will try Sierra Pro Hunter and see if I can squish them a bit more. This is probably a better hunting bullet for me anyway; given my current hunting grounds I can't see a shot greater than 150 yards.

@freedomfighter & ussr: For the next phase of troubleshooting, I will use the same hand load that has shown the best groups and most consistency until I've eliminated the next greatest variable(s). Again, all else being equal, I think the scope/mount/bedding/stock are probably greater variables than my ability to load rounds that are as consistent than even match grade ammo, and are verified in the rifle. (I have dialed in sub-moa loads in my .270 so I know enough to be dangerous with a stack of bullet making supplies.)

@gamestalker: 5 minutes between shots? I don't mind spending the whole day at the range but my wife, well she doesn't understand 1 hour to squeeze off 12 rounds... @nickn10 suggested a minute between shots. That's a wide range.

Freedom_fighter_in_IL
March 15, 2012, 12:45 AM
@freedomfighter & ussr: For the next phase of troubleshooting, I will use the same hand load that has shown the best groups and most consistency until I've eliminated the next greatest variable(s). Again, all else being equal, I think the scope/mount/bedding/stock are probably greater variables than my ability to load rounds that are as consistent than even match grade ammo, and are verified in the rifle. (I have dialed in sub-moa loads in my .270 so I know enough to be dangerous with a stack of bullet making supplies.)

Didn't doubt it a bit. Was just busting at the people that think just because it says "Match" on the box that every rifle will be able to shoot it accurately and that, if they don't, then something was wrong with the rifle. Not all rifles like it. And some, like a few of mine, actually hate the stuff. And as someone else pointed out, trying to get a hunting rifle to shoot good groups with match grade ammo is not the brightest move to make.

I am in definite agreement with the scope and mounts more than likely being your problem. More than likely it's the see through rings. Those, generally, are not the best in performance. Get you a quality set of base and rings and try that scope. If that doesn't solve your issue, try another scope. If that still yet doesn't cure it up, then a good bedding job may well be in order. Though that one is doubtful since you said the barrel is already free floating. It could very well be that you may need some forearm tip pressure ON the barrel. Had a few like that. The would generally string UP. Once I added a bit of pressure from the forearm tip, cloverleafs.

Rifles are a wonderful thing but like any wonderful thing, they can make you want to pull your damn hair out by the roots!

nickn10
March 15, 2012, 03:11 PM
from wysrno:

[gamestalker: 5 minutes between shots? I don't mind spending the whole day at the range but my wife, well she doesn't understand 1 hour to squeeze off 12 rounds... @nickn10 suggested a minute between shots. That's a wide range.]

to wysrno:
I use 1 minute with the following steps, fire fouling shot then wait one minute
fire next shot, remove bolt, stand rifle vertically in the shade, feel with hand to get approx same barrel temperature, fire 2nd shot, repeat. Consistency is the goal, firing the rifle is the last step in the process.
Nick

wsryno
March 17, 2012, 04:18 PM
Mods: Installed known-good scope with new steel rings. Bore sighted.

Range day: At 25yds, shot 3 individual shots, adjusting scope between each one to bring impact near center. At 50 yards, 3 3-shot groups with 2 minutes pause between each shot, all groups well under 1", last group the shots were all touching.

Diagnosis: Initially very bad copper fouling, when fixed the bad scope/rings showed themselves. So I've installed the "bad" scope and rings on my son's 10/22 where it will be fine for him to practice. Now I can start whittling at the other ideas you've given me. If I manage to bring down the group considerably again, I'll post the results. Thanks a bunch!

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