Need help interpreting targets

wsryno · Mar 3, 2012

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.

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.

TARGET 3: 100 yards, 2 3-shot groups. All over the place.

Cypress · Mar 3, 2012

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 · Mar 3, 2012

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 · Mar 10, 2012

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 · Mar 10, 2012

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 · Mar 10, 2012

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 · Mar 10, 2012

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 · Mar 10, 2012

H2oPumper said:
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 · Mar 11, 2012

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.

Flintknapper · Mar 11, 2012

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 · Mar 11, 2012

Shooting bad groups

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 · Mar 11, 2012

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 · Mar 11, 2012

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 · Mar 11, 2012

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 · Mar 11, 2012

wsryno said:
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 · Mar 11, 2012

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 · Mar 11, 2012

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 · Mar 12, 2012

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 · Mar 12, 2012

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 · Mar 13, 2012

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 · Mar 13, 2012

wsryno, seems like you are going about your mission very sensibly and patiently. You've made some substantial improvements already, keep us informed.

wingman · Mar 13, 2012

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 · Mar 13, 2012

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 · Mar 13, 2012

@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 · Mar 14, 2012

+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.

Need help interpreting targets

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