Most definitive way to determine scope failure

[jimh406]

I got the scope back from Leupold with no repairs required. While it was at Leupold for warranty evaluation I purchased and mounted a Burris XTR II and got the same results. 200gr Bergers, 200 accubonds, 180 accubonds, 180 bondstrike, 181 hammers,166 hammers,175 LRX, and 175 Terminal ascent are the loads I tried in this rifle. The 180's had a few decent group sizes, just not where I was aiming, and not consistent patterns. Two different scopes, three different mounts, multiple shooters, a plethora of different ammunition. The only logical conclusion is that it was the rifle. I really wanted to sell the rifle but I doubt it'd sell after disclosing why I'm selling it. Add in the cosmetic blemishes and I'd be lucky to get 500 bucks for it.
I shipped it to a reputable gunsmith for a complete teardown.

Thanks for the update.

 

[Wind Gypsy]

Interested to see what the gunsmith says.. Was rifle bedded? No barrel contact anywhere?

 

[millerkiller77]

Interested to see what the gunsmith says.. Was rifle bedded? No barrel contact anywhere?

I was told it was bedded so tight that it was not advised to remove it from the stock because it would be difficult. As far as barrel contact, it passed the "dollar bill test" , so no I don't believe that is the culprit.

 

[perma]

I was told it was bedded so tight that it was not advised to remove it from the stock because it would be difficult. As far as barrel contact, it passed the "dollar bill test" , so no I don't believe that is the culprit.

I never knew there was such a thing as a too tightly bedded gun.

 

[cahunter805]

I never knew there was such a thing as a too tightly bedded gun.

If you bed the lug without any clearance it’s pretty tight. You usually need an action puller tool to lift it straight out or they won’t come out easily at all. You also run the risk of chipping/damaging the bedding if it isn’t pulled straight up.

 

[yakimanoob]

I never knew there was such a thing as a too tightly bedded gun.

This immediately smacks of a craftsman making up some rule when what they really mean is "if you take this apart I'm off the hook".

 

[Cornbread]

Any chance you can swap another scope off another gun? Probably not the answer you want to hear but that makes it as black and white as it can be.

I recently sighted in a Mark V and had similar groups. Soft point bullets were the culprit, my gun didn’t like it. Switched to polymer tips and all was okay. I assume the 70 rounds had non soft points as well?

I'd also take that, what you think, defective scope and shoot it on another rifle. Yep, it's a pain in the ass, but that will isolate it even more.

 

[Cornbread]

I could swap it with another scope I guess. I've already invested over $600 into 3 different scope mounts for this gun and now the reciever is tapped for larger diameter screw, so I'm kinda committed to sticking with a 34mm tube. That's going to limit me on optics options

All 70 rounds were the Norma tipped Bond Strike long range. I picked up 26 boxes of the same lot number dedicated to this rifle since they shot well out of 3 other rifles in the same caliber and make for excellent brass to reload.

Just becasue that ammo shoots good out of one rifle doesn't mean it will shoot well in another. I start fresh with every rifle.

 

[Cornbread]

American Rifle Company M-Brace mount torqued to 55 in-lbs , per the manufacturers instructions.

Leupold suggests 25-28 inch lbs!! Dont use what the rings manufacturer says. Use the scope manufacturer.

 

[perma]

Leupold suggests 25-28 inch lbs!! Dont use what the rings manufacturer says. Use the scope manufacturer.

I learned this yesterday too. My parallax wouldn’t adjust, called vortex and they told me I overtorqued my rings. Dropped it lower and the parallax adjustment worked.

 

[Cornbread]

I learned this yesterday too. My parallax wouldn’t adjust, called vortex and they told me I overtorqued my rings. Dropped it lower and the parallax adjustment worked.

Desert Dog did a youtube video on scope installation. I think this guy is pretty knowledgable. I'm not as anal as he is, but as far as torqueing the rings, he was dead on. I recently went through a problem I had with a Browning BAR Safari. Though it might be the scope; a zeiss conquest4. Changed to another zeiss I had. Moved the "bad scope" to a new rifle I had and the new rifle shot 3/4" groups. Not the scope. New scope on the BAR Safari, and the rifle continued to shoot 5-6" groups. Im taking the rifle to Montana with me and dropping it off at a Browning authorized service center on the way. The rifle was shooting 13/16" group with Hornady Outfitter ammo. It's a .338 win mag. Then I used it in a Lead Sled. That damn sled loosened the butt stock, and may have damaged the rifle. It has only very sporadically shot a decent group. It ain't the barrel cause I cleaned it thoroughly with copper solvent. This gunsmith is known for having 2 top-quality smiths. F'ing pisses me off. but the rifle is worthless unless I find out what the problem is.

 

[brockel]

I learned this yesterday too. My parallax wouldn’t adjust, called vortex and they told me I overtorqued my rings. Dropped it lower and the parallax adjustment worked.

That’s a go to vortex excuse for every situation. I had a turret literally spin off. They told me my rings were torqued to much

 

[perma]

That’s a go to vortex excuse for every situation. I had a turret literally spin off. They told me my rings were torqued to much

Not to derail this thread, I do hear a lot of similar complaints like that. I’ve had dozens of their scopes, have 4 of their binos and a spotter, never had an issue with any of them.

 

[Cornbread]

That’s a go to vortex excuse for every situation. I had a turret literally spin off. They told me my rings were torqued to much

Zeiss torq specs are even lower. Zeiss says to torq the rings to 20-22 "/lbs. It is critical to have one of the torq wrenches. Fortunately my buddy down the road has one.

 

[Wind Gypsy]

Leupold suggests 25-28 inch lbs!! Dont use what the rings manufacturer says. Use the scope manufacturer.

There is more to it than that. A number of things in the configuration of rings and the associated hardware impact the ring clamping force that corresponds with a given screw torque amount. In the case of ARC rings, it's a single screw that creates the entire clamping force for a ring and not at all the same as a typical 4 screw horizontally split ring set up. Size and thread pitch on the hardware also impacts the the clamping force for a given screw torque value.

 

[Cornbread]

I was told it was bedded so tight that it was not advised to remove it from the stock because it would be difficult. As far as barrel contact, it passed the "dollar bill test" , so no I don't believe that is the culprit.

Is it a factory ruger M77?

 

[millerkiller77]

Is it a factory ruger M77?

No. It is a custom built rifle on a stainless Winchester M70 receiver.