Frustrations in zeroing (long) - any advice?

[campergeek]

Let me get this out of the way first - this situation deals with a Remington 742 semi-auto .30-06 - which otherwise hasn't been bad to shoot (I keep it REALLY clean) - with a Simmons scope mounted on Weaver hinged rings.

I've been working with this rifle for two purposes; first to get the scope zeroed, and second to work on my own shooting skills. I've avoided using a boresighter, mainly because I don't have one but also because the "old way" of shooting a group, adjusting, shooting another group, etc. gives me extra practice at shooting groups. I'm about to give up this technique. Here's the story:

On the first outing I shot two boxes of Winchester SuperX 180 gr., starting at 25 yds. and working my way out to 100 yds. By the time I got done the zeroing wasn't bad and my shoulder and I conferred and decided to finish the job another time.

Back to the range, looking forward to more practice. This time with 1 box of Federal American Eagle FMJ boat-tail (cheap from CheaperThanDirt), and another box of Remington Core-Lokt; both in 150 gr. My idea is that I can save some money shooting the cheaper target ammo (can't use FMJ for hunting) and then double-check with the Remington. So, I set two targets at 100 yds., shoot two 4-shot groups, and find that I'm barely hitting the right edge of the paper, about 9 m.o.a. from center. Griping under my breath I adjust and bring the groups back to (roughly) center and after 40 rds. I'm done for the day.

I should interject here to say that with this rifle, having heard its reputation, I'm not expecting tack-driver accuracy. The targets I'm shooting have a 6" green area surrounding a 1" white center. If I put the shots in the green - dead deer. While I cast longing glances at other shooters' 1" groups with their bolt-action rifles, considering my tool and my experience I'm pleased with 4" groups right now - if I can get there consistently. Now back to the story:

Today I go back to the range, half expecting my groups to be way off in oblivion somewhere. To my surprise, I'm hitting just a bit high and to the right, but still on paper. Adjust down & left, now a bit too far left. Back a bit to the right, and I'm happy. Up to this point I'd been shooting with a rest under the forearm. Knowing that I won't have that benefit in the woods I decide to begin practicing by holding the rifle myself with my front elbow resting on the table (baby steps, here).

This is when everything breaks loose.

The target stand has enough space to mount two paper targets (~12" h x 16" w) one above the other. I begin by shooting at the bottom target, but can't really see what I'm hitting. Not a big deal - I often find it hard to see my shots from distance when they're in the green. After four rounds I shift to the top target and the fireworks REALLY begin.

First shot - the whole target stand tilts slightly in one direction and the lower target now has a large gash at its bottom. "Wow!", I think to myself, "I must be really pulling the shots low when I shoot from hand. I'll have to watch that."

Second shot - the stand tilts back and there's a new gash next to the first.

I shoot two more to complete the "group" before the range goes cold. Once I get down to the targets I marvel at the ability of Remington Core-Lokt to cut through the steel stand, and I mutter angrily at the fact that the affected brace is about 20" lower than my point of aim. Knowing full well that the definition of insanity is trying the same thing again expecting different results, I decide to shoot two more groups to confirm the wierdness.

This time I shoot the first group at the low target and again can't tell where I'm hitting. Then I shoot the second group at the high target. This time I'm figuring that I've got nothing to lose and I need to vent some frustration, so I decide to mix things up by trying this group with both eyes open. I still carefully concentrate on each of the four shots.

When examining the targets, I found that my second group was the best I've ever shot with this rifle - about 2", and then only because one shot was slightly astray from the other three. However, the group was fully 15 m.o.a. low and 7 m.o.a. left of my point of aim. In short, it was on the lower left corner of the low target.

Can anyone give any expert insight as to what is causing the problem? My initial impulse was that the cause is the trigger actuator (me). To test that theory I then ran about 50 rounds thru a .22 rifle at 50 yards, again shooting from hand. Those groups were not of concern. I already had suspicions about the scope, but if it's wiggling out of zero that badly, how could a single group be so good? Is this perhaps an effect of a heated barrel? And if so, then how come it happened suddenly and not gradually? It could be switching from the Federal ammo to Remington, but that's a BIG difference and I didn't see any such difference the previous session. Are the tolerances on the 742 SO bad that this is a potential problem? If so, I'm dumping right away this rifle that I can't trust to hit reliably in the woods. As you can see, I'm really unsettled about this and grasping at anything. I'm hoping that someone with more experience than I will be able to see what I'm missing.

Thanks for any advice, and for reading to the end of this tome.

 

[JohnKSa]

1. Get enough of ONE kind of ammo to do the WHOLE job. By ONE kind of ammo, I mean ALL the boxes exactly the same. Not just the same bullet weight, not just the same brand, but exactly the same in every respect. By the WHOLE job, I mean sighting in, AND for hunting this season.

By switching ammo around, you are never going to get the job done. I've seen different types of ammo using the same bullet weights give over a foot difference in point of impact and a tremendous difference in group sizes.

2. Ditch the scope entirely and see if the gun is shooting good groups with the iron sights. If it's not then either you or the gun is having problems--you should have another shooter test it. If it shoots good for him then you need to practice more. If it won't shoot good for him then it needs some expert attention. If it shoots good then you need to check the scope mount.

3. The scope mount should be rock solid. Pick up the rifle by the scope and give it a little shake. NOTHING should move or give even a tiny bit.

4. If the mount is good then the scope is toast. Get a new scope, and don't be afraid to spend a little money. Sometimes you get lucky with a cheap scope but more often then not you will pay in mental anguish what you save in dollars. The bitterness of low quality lingers long after the sweetness of low price is forgotton.

A couple more tips.

When sighting in, shoot from a rest. Use something relatively soft like a rolled up towel to rest the forearm of the rifle on. DO NOT allow anything to touch the barrel.

 

[C.R.Sam]

1....Scope.

2....What John said.

Sam

 

[rugerfreak]

Yup---dump the cheap scope and get a good one.

 

[Coronach]

I'll just add this:

Don't get too frustrated.

I once sighted out my AR-15 at Falconer's place. Yes, you read that right. Sighted out. Turns out my dad got suckered in by the siren call of the big ole dial on the A2 rear sight and gave it a twirl. I had sighted in at 25 yards and knew I should at least be on paper at range...but I wasn't. So, I proceeded to dial the front sight until I ran out of elevation adjustment....and was still barely on paper.



I took it home, wondering exactly what had gone wrong, and belatedly noted the rear setting. I hadn't even considered checking it, because I knew that I hadn't touched it.

I'm not sure who I was more POed at...my dad for fiddling, or me for not checking something so brain dead simple.

You know, its like feeling a draft and never even considering its because you're not wearing pants.

Mike

 

[C.R.Sam]

I got suckered into sighting OUT.
Wanted to check old but new to me 10-22.
Gonna be a smart alec and do a max three shot zero.
Put one downrange...25yds.
Hole appeared 10 Oclock, 4".
Anchored gun on x ring and dialed scope to the hole.
Second shot 4 Oclock, 4".
What the.....?
Looked through spotting scope and had a hole centered in X ring.

Partner had put the 10 Oclock hole in my target sometime during my first shot.

Anchored gun again and pulled scope to the 4 Oclock hole.
Fired third shot and got a barely X.
Quit while less behind.
Tweaked at partner and really ticked at myself for not payin attention.

Sam

 

[DMK]

Partner had put the 10 Oclock hole in my target sometime during my first shot.

That's just mean!

 

[critter]

Also, please be aware that the Rem 742 MAY NOT shoot the same type group NOR the same zero COLD vs WARM vs HOT!

 

[Jaywalker]

What JohnKSA said - a really excellent troubleshooting (pardon the pun) check.

I'll only add that I also had a 742 with a wandering zero and I also suspected the trigger actuator, but that turned out not to be the case. I had purchased it used due to its fine condition, but it turned out to need the muzzle recrowned. The previous owner had also kept it "really clean," but since the only way to clean the bore was from the muzzle end, had apparently scraped the rifling near the crown a bit with his cleaning rod.

I also removed his Weaver "See-Through" mount in favor of something sturdier (and nicer).

When you do buy new mounts and rings (they are critical, and you didn't really address this part in your story), you'll need to follow the installation instructions, even when they don't seem to make any sense. There is typically a reason for the instructions, but the manufacturers don't always explain the reasons for their demands. (Millet's Angle Lock, for instance, say to tighten the "left" side completely then back them out two turns, install, then tighten from the "right" side. This was silly; they were interchangeable, so there was no "left" side, so I ignored it at first. I finally realized that the "left" side was shorthand for either side, and the "two turns back out" on one side merely served to align the rings to the mount, minimizing the number of scope clicks necessary for zero. Thus, there was reason to their instructions, just that it was unexplained.)

Jaywalker

 

[standingbear]

try 1 ammo grain weight..1 only with the scope.your problem sounds like a damaged scope or stripped threads on the scope rings.could be that your flinching,it makes a huge difference downrange.also if your tucking your arm right next to the stock.pulse can throw off the accuracy too.try iron sights first.your groups should be at leaast on the paper all the time if your doing your part.if the groups are still all over the place,id suspect something wrong with the stock or the barrel.if your groups are in on paper with the iron sights and youre doing your part and it still does it with the scope on-its the scope or the rings/bases.cheap scopes arent always a bad thing,i have a 50 dollar tasco 6-24x on my varmiter and its held zero since day one.if the mounts and/ or bases arent staying tight,you can put a 700 dollar scope on it and it wouldnt help.try the iron sights first then go from there.

 

[boing]

...suckered in by the siren call of the big ole dial on the A2 rear sight

It's like a big, red button that says "Don't Push".

 

[Steve Smith]

It's like a big, red button that says "Don't Push".

Well, that of course depends on who you are!


Campergeek, I suspect the scope too. Shoot that thing at 25 yards to start.

 

[Hutch]

Y'also gotta let that barrel cool between shots. Don't know if your range allows it, but getting out a .22 and knocking empty shotgun shells around for 3-4 minutes between shots seems to help kill the time.