Shifting Point of Impact

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Wally Whitetail

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Hi all. I'm new here. I've been a long time lurker but this is my first post. I'm from MN. Just started hunting deer last year and bought my first centerfire rifle about 6 months ago. It's a Winchester M70 Featherweight with a stainless barrel chambered in .308. I did a bedding job on it by following a guide by GunBlue490 on youtube because I was getting decent groups with several types of ammo, but not great (nothing sub MOA). The bedding job went well as far as I could tell. I work with epoxies professionally, so I felt confident that I could do the work in a competent manner, and the results look great.

My issue now, though, is that I'm experiencing strange groups at the range, where I'll put two shots very close together and the third will be 2-3 inches away. I have several groups where that "flyer" is in the same direction about the same distance, but sometimes it goes back and forth, 2 here and 2 there, but there is a definite disconnect between what I'm seeing in the scope and what I'm seeing on the target. I'm a lifelong shooter and I have pretty solid trigger control, and I've shot enough with this setup to confidently say there is a pattern here that exists independently of my human error. Now the other relevant bit of info is that I'm shooting primarily solid copper bullets. The ammo that I'm seeing these groups with is Barnes VOR-TX 150g TTSX. I've shot a lot of this, as well as the 130g ammo of the same variety.

My question is this: should I suspect my bedding job is the culprit, or is it more likely to be copper fouling that I need to use a copper solvent on? Until now I've only used standard mineral spirit based cleaners like no.9 (as per the advice of GunBlue490 again, who claims solvents are a bad idea and that the copper only smooths the bore and doesn't require solvent removal).

Thanks for your input. Let me know if I've left out any necessary info.


WW

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A mag-base dial indicator is the means to determine if your bedding job is good, or merely looks good.
 
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Yow, lots in here.

Wally Whitetail said:
. . . my first centerfire rifle about 6 months ago. . . I'm a lifelong shooter and I have pretty solid trigger control,
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Can't have it both ways. The split groups could be you, but maybe not. Sounds to me like bad bedding, but I have ~1k rifle rounds off the bench each year, so I know what my own technique produces.

Wally Whitetail said:
. . . should I suspect my bedding job is the culprit,. . .
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If the split groups started after bedding, then. . . yes.

Wally Whitetail said:
. . . per the advice of GunBlue490 again, who claims solvents are a bad idea and that the copper only smooths the bore and doesn't require solvent removal. . .
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Horsehockey. Time for some new youtube channels, and equal (large) measures of copper solvent and patience to decopper the bore. I like ProShot Copper Solvent IV and Montana Copper Killer.
 
edwardware said:
Horsehockey. Time for some new youtube channels, and equal (large) measures of copper solvent and patience to decopper the bore. I like ProShot Copper Solvent IV and Montana Copper Killer.
Click to expand...

There are plenty of us who don’t push out copper. I only push copper during barrel break in, then use a carbon only solvent for the rest of the barrel life, with the only exception being if groups open up suddenly. Breaking in is meant to lap bore, so we push carbon out then, and the rest of the barrel’s, there’s copper fouled into the remaining voids. Folks can criticize it all they want, but after years of being a “bare steel” barrel cleaner, then trying it myself with a couple barrels, I won’t waste time pushing copper out with every cleaning ever again. Copper fouling, at least, certainly is not a cause for double grouping.
 
For the OP:

Here’s what I have observed regarding “double grouping” rifles:

1) Most likely - it’s not really double grouping. If it double groups for 5 rounds, shoot 10. More often than not, you’ll get a round group, no longer double groups. Everyone wants to think it means something when two holes touch each other, but if you shoot enough rounds at a single POI, almost all of them will touch, eventually. A gap in the middle of a 5 shot group is usually simply a matter of not firing enough rounds to have closed it in.

2) Rifle Mechanical issues - bad bedding, loose optic mount/base, loose action screw, etc. a mag based dial indicator and a torque wrench are easy means to troubleshoot and eliminate mechanical issues.

3) Thermal expansion (specific mechanical issue) - guys shoot a 5 shot group, starting with a cool barrel, they group well at first, the barrel starts to walk, but they finish the group before it continues stringing.

4) Probably REALLY the most likely - Shooter/support mechanical issues. If you’re not supporting the rifle in exactly the same way each shot, or viewing through the scope in exactly the same way, you can’t expect the rifle to shoot in exactly the same way.
 
Varminterror, how would one check a bedding job with a mag-based dial indicator?

edwardware, why so snarky? I can indeed "have it both ways." My shooting experience was with pistols, shotguns and rimfire rifles. This rifle is my first deer rifle. The guy on YouTube you are casually dismissing is an expert gunsmith with a laundry list of qualifications. Maybe check him out sometime. I'm open to ideas other than his of course. That's why I'm here. But you seem like a pretty closed-minded individual to me, and that doesn't usually go hand-in-hand with a lot of wisdom.
 
Don't blow off @Varminterror #4! Stock weld, sight alignment, and trigger pull move the bullet a surprising amount. Just shoot Smallbore prone and find out!. I have bedded one M70 Featherweight and that rifle is extremely sensitive to how the trigger breaks, how the thing sits on the front rest. Featherweights are not in any sense of the word, target rifles. They are light weight because people don't like carrying heavy rifles into the woods.

As an aside, NRA Across the Course rifle shooters used to pork up their NM AR15's with lead weights, because they are so twitchy to shoot off hand. I think my NMAR15 weighed 15 pounds, and hauling that on my shoulder, in its case, down to Vaile Range was a shoulder killer!

I do want to ask, did you free float the barrel? Bedding the action is great, but if that barrel has any contact with the stock, all sorts of weird things are going to show up on target.
 
I had something along those lines once and found the scope was bad. Just one idea out of a laundry list of possibilities
 
Wally Whitetail said:
Varminterror, how would one check a bedding job with a mag-based dial indicator?
Click to expand...

Mount the mag base to the barrel, indicating on the tip of the forend (dealer’s choice on the front of the tip or bottom side, remembering to load the dial before zeroing, for negative movement). Loosen the rear screw, observe the indicator. Replace. Loosen the front, observe the indicator. Replace. Push, press, and pull on the barrel, and observe that the indicator does or does not return to zero/reference.
 
1. I'm assuming you're not reloading your own ammo. If you're using factory ammo, I'm not too surprised you're not getting sub MOA groups since in many rifles that won't happen unless you're lucky. Before you assume the bedding job is bad I would shoot the ammo that gave you decent groups before the bedding job if you haven't already done so.

2. As other(s) have noted above, in a three shot group, the legendary "flyer" means nothing. The best group I ever shot was a three shot one holer out of a rifle that wouldn't consistently do better than 2 to 2.5 inch groups. I hate the term "flyer," by the way (sorry guys).

3. I detest Hoppes No.9 but it's your rifle; use it if you want to. To get copper out I use Wipe-Out (either the foam or the Patch-Out) with the Accelerator and generally only use patches and no brushes. In the rare event I use a brush, it's either brass or nylon. After the copper is out, the barrel gets a coat of Prolix, then a dry patch and it's put away. I have not put oil in a bore in years. I don't put anything steel down a bore unless it's nylon coated. The rods are generally fiberglass except for the 17 caliber ones that I don't think come in fiberglass. After cleaning, some barrels shoot better after a couple of fouling shots and some don't.

4. I've only had one rifle that was sensitive to heat expansion; actually a Blaser 243 Winchester over 20 gauge shotgun combo gun. The first two shots are fantastic but the third is just a little off; still well under 1 MOA though. It's possible that's your problem but I doubt it.

5. You don't say what kind of scope you're using. Some brands are better than others and if it's one of the higher power ones, there can be a parallax issue. This probably isn't the problem though. Just for fun check the scope mounts to be sure they're not even slightly loose.
 
I'd be looking at the scope, but before getting on that, shoot your group again, but let the rifle cool completely between shots. The featherweights can be sensitive to heat.

You also didn't mention the make of scope. You pretty much get what you pay for in an optic. While a Schmidt and Bender isn't called for in most average applications, a cheapo will cause lots of weird problems and break when you need it most.
 
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