shifting zero

[bamaranger]

I took 7 rifles to the 100 yd range yesterday and verified zero on all of them. Each year I rotate a few rifles in and out of the mix that I intend to hunt for our 2-1/2 month whitetail season. As rifles come out of "vacation" I check the zero. Interestingly, every one of the rifles with a zero shift wore a wood stock. None of the rifles exhibiting a zero shift had dramatic POI change, say 2 MOA at worst. I was aware of not to accept a "cold/wet" bore shot as true zero. Most needed a slight bump of both windage and elevation, mostly windage. My old Rem 700 ADL / .270, not hunted in two seasons, was nearly 2 MOA high. Grandad's vintage M88 Win in .308, not shot in about 10 years, was impacting right about 1.5 MOA but would have killed a deer well beyond the distances I normally shoot.

Of the three rifles that held their zero, two of those wore synthetic stocks . Surprisingly, an old Mossberg 800M (mannlicher style stock) in .243 plunked three rounds into the same spot where it shot to three seasons ago, bang on. I would have expected it to shift. The Ruger .44 carbine was problematic as always. An ammo change with the Ruger Predator in .308 necessitated some elevation change but was expected. None of the rifles that were "off" have been mishandled but had been hunted a full season at some point previously, then cleaned and put up. All have decent Leupold (1 Burris) scopes and quality rings and mounts.

The point of all this.......on the surface it might appear that a synthetic stocked rifle MIGHT hold zero a bit better over time but best practice is to verify your zeros before you hunt. We all know this, but I was reminded of it again yesterday.

 

[tangolima]

Synthetic stock is indeed more stable. Are the wood stocked rifles glass bedded and/or free floating? It is supposed to help.

All and all, people are trying to separate the wood from the gun metal, as wood is not that great, although it is pretty to look at.

-TL

Sent from my SM-N960U using Tapatalk

 

[bamaranger]

wood

No bedding or free floating, all the stocks OEM.

Years ago I put a credit card shim on the forearm tip of the M88, which largely solved its tendency to shift vertically year to year. The little Ruger .44, which I really like for the type of treestand hunting I mostly do, was stringing vertically. That could be my ammo, or a bedding problem (or both) as the hooked breech and barrel band up front are all that hold the barreled action to the stock. The M700 has the typical bump in the barrel channel at the tip of the forend. The guy that ran that piece of walnut through the stock machine must have been asleep, as it's the prettiest piece of walnut I own and likely belonged on a better grade of rifle. The M700 was the surprise, it typically does not shift, but this year (after a season on vacation) it was 2 MOA high.

One would have thought the full length Mannlicher styled Moss 800M would have shifted....all that stock/barrel contact, but it printed where I wanted it.

I have an old magazine article, forwarded by a member here, on how to bed the .44, I just have never followed up with the work. I should load about a dozen .44 test rounds up with an eye to precision....I may have loaded the .44's on my progressive press.

 

[rc]

I think it's a good practice to sight in your gun and confirm zero with the ammo you intend to use from one season to the next. Bumps in the safe, humidity changes, temperature variation and even how you hold the gun can all affect your guns sight in.

 

[jmr40]

If the climate is stable where you live, and if you don't travel far to hunt MOST wood stocked rifles will usually be close enough. I say MOST, because not all stocks and rifles are the same. Some can be pretty stable; others will shift POI quite a bit. But what you observed is common.

A lot of people only think of a wood stock having issues when hunting in rain. But as the seasons change, temperature, altitude, and humidity change anything made of wood will expand and contract. You can zero a wood stocked rifle in August, leave it in the safe and POI can change by November. It's always been that way, but years ago rifles weren't accurate enough to notice.

I put a Brown Precision stock on my Remington 700 in 1983 and haven't hunted with a wood stocked bolt rifle since. I have had some bolt guns with wood stocks and all of my lever guns have them. But if I'm serious about hunting I take a synthetic stocked bolt rifle.

I've traveled to Colorado and New Mexico a few times to hunt. I live at about 900' elevation; temps can be in the 80's with 80% humidity here at home in October. It's a 24 hour drive to Colorado where I may be hunting at 9000' in 20 degree weather and 20% humidity. Chances are very good a wood stocked rifle will be off with those changes. Maybe not enough to cause a miss, but maybe it will be enough.

 

[Paul B.]

I've never had much trouble with changes in POI, what I have had was more or less minor. But most of my rifles had glass bedded and free floated barrels. I have three Remington M700 and they've proved to be quite stable. However, every wood stocked Ruger I have can and do literally change POI every day. It was a pain when I hunted my #1s. based in roughly 25 Ruger rifles I have worked with, not one rifle had shown any signs of sealed wood on the interior portion of the gun. Not a one. Just hat appears to be a light coating of stain.

On an elk hunt in the John Day area of Oregon ai was hunting with a Ruger #1 in .300 Win. Mag. Rifle was extremely accurate with the 200 gr. Speer Hot Core. Halfway up a mountain I got caught in a bad rainstorm with very high winds. The rifle and I were totally soaked. I got back to camp, changed clothes and dried my rifle as best I could. A few days later my hunting partner and I stopped off at a ranch in Nevada to hunt a few pheasants with friends. I had a Nevada license and tag so took the .300 along and spotted a coyote running off with a pheasant. My host said shoot that dog, and I fired several shot, never hitting the yote. Took bit of a razzing as I'd bragged on how accurate thar rifle was. No one saw where the bullets hitting. A few days after arriving home in Tucson, I took the .300 to the range. The bullets were hitting right at the top of the berm, almost six feet high. Guess I was lucky as the stock and forearm had swollen up badly. I removed the wood and stored it in my shed. It gets pretty hot in the summer and I've recorded temps as high as 130 degrees. Long story short once a year I'd put the wood on the gun, take it to the range nd see where it was hitting. It took six years before it was within a couple of inches where it should be. Reassembled the gun and stuck it in the safe. About six or seven months I test it once more with no change i POI. Got it properly resighted once more and use it and my other Rugers as fair weather guns only.
Paul B.