Tuesday, February 18, 2014

Boresighting perils...

So, on Facebook somebody asks about sighting in their first scoped Bambi-zapper. Several people chime in with boresighting advice and dial-in tips and tricks. One guy points out in an aside that
"If the rifle is used you might want to mechanical zero the scope. Misaligned mounting and someone putting clicks on it can leave you little adjustment in one direction or t'other."
...which reminded me of a tale...

'Way back in the Fall of Aught-One, I ordered a handy little Ruger No.1 RSI in .243 Win from Davidson's and purchased a used Leupold fixed 12x scope for it from a coworker. (Yes, current me laughs at old me's choice of optics, too; that thing wanted a fixed four or low-power variable glass, not a lunar observatory.)

He offered to mount and boresight the scope for me, which was nice. As I left to run some errands and fetch lunch, he had my little rifle in the cradle on the counter and was breaking out the scope ring lapping kit. When I returned to the shop, the lapping kit was as yet unused and he was spinning a ring reamer and standing in a disturbing amount of metal shavings from the scope rings.

"What's up?" I asked, cleverly.

"Here," he said, plopping the Loopie glass in the rings and tightening them down, "Look through there at the collimator and see if you can tell."

Sure enough, the crosshairs were 'way over at the edge of the grid on the old-style ground glass boresighter, and the adjustment screw was pretty much all out of clicks in the opposite direction. This was not good.

After a bit more grinding, it was apparent that we were going to run out of scope ring before we got the thing dialed in, and the base was, in fact, unusable. (We were fast on the draw like that.)

The rings on a No.1 are mounted on a little quarter-rib, which is secured to the barrel with screws fore and aft. My co-worker began to loosen the forward screws and, when he got down to, like, the last the last half-turn on the second one, the front of the sight base torqued to the side off the barrel, pulling the screw free with what my mind insists on remembering as a *ping* but which was more likely a *click*.

With the quarter-rib off the gun and the upper scope-mounting surface held level, it was obvious to the naked eye that the two "feet", the mating areas at the front and rear on the bottom of the quarter rib where it sat on the barrel, weren't machined anything remotely like concentric. In other words, while the "rib" part of the quarter rib was nice and straight, the feet were askew, and tightening both feet down flush to the gun twisted the formerly-straight rib like a piece of rotini.

"I don't have to worry about that!" says the Cletus in the back, at this point in the tale, "I only buy nice guns!" Hey, this was on a rifle that had an MSRP of something like seven or eight bills even back then, right? You could have darn near bought two Remington Wally World specials for what this thing cost.

Ruger handled it well though; we called them and they sent a fresh quarter rib and a set of rings gratis, without even a core charge. I still have the cattywhampus quarter rib someplace, I guess. I think we pitched the rings.


Erich505 said...

Great read; thanks.

og said...

That is a massive screwup. Was it a "Real" #1? Red recoil pad? Do you still have it? Sounds like a sweet rifle.

For that to happen while the old man was alive is really bad.

Robert said...

Makes me consider that someone at the factory had to assemble it that way, and didn't reject the parts in the first place.

Gewehr98 said...

Details, Tam! What about the fate of the nice #1? Keep the warped rib, but not the rifle?

Tam said...


"That is a massive screwup. Was it a "Real" #1? Red recoil pad? Do you still have it? Sounds like a sweet rifle.

For that to happen while the old man was alive is really bad.

I dunno, I'm no scholar of Rugers in general or No.1s in particular. It was whatever came if you called Davidson's back in late '01 and ordered a No.1 RSI in .243. I sold it back in late '07 before I moved up here; one of the few firearms I sometimes wish I hadn't.

What killed me is that the quarter rib is finished before being attached to the gun. You'd know better than I how much hands-on is involved in getting that part on there, but in the interest of not messing up the bluing, I'd assume it's attached manually. Even if the guy didn't notice that the feet on the rib were off-center to one another with his eye (and it was visible to the naked eye with no gauges required) you'd think he'd have noticed when it took a drift punch with a cheater bar to get the holes lined up enough to get the first mounting screw started.

og said...

Old Rugers with red buttpads are supposed to be the carefully hand fitted ones. It is an old gun-bubba trick to take a "new" ruger and put a red buttpad on it to sell it to the uncautious. Some people think the red pad guns were forged while the others cast, but I'm pretty sure they investment cast them all.

Yeah, all of that stuff was supposed to be handfitted, even if only to be able to say it was handfitted. Old Bill would have roared had he heard of that screwup, it was his baby. IN 01 it would probably have been "new" production

jdunmyer said...

I know a fella who is a pretty good basement gunsmith who is quite competent in Ruger #1s, he can make 'em shoot.

He also claims that most rifles are somewhat pitiful in regards to scope base mounting to bore alignment. His favorite rings are adjustable, from (Mullet, Mallet, I forget) so he can zero the scope adjustments to begin with.

I put a set of those rings on my Savage .17HMR because the scope adjustments were way off to one side otherwise.

Tam said...

When we got the new quarter rib on the gun, during the final dial-in of the scope, the thing put three out of three factory Federal gold box Nosler BTs into a little over an inch.

I'm sure that five or ten rounds, or a less-than-leisurely rate of fire, would have opened the group up dramatically, but everyone who fired it agreed that it was one of Ruger's better efforts in the No. 1 accuracy department, especially for an International.

Hat Trick said...

Your quarter rib must have been made by the same guy who cut the rear sight dovetail on a Mk II Target that I found used at our local gunsmith's back in '01. The dovetail was cut so that the rear sight was tipped so that the left ear was just a hair lower. Didn't notice until I started shooting it. My gunsmith made it right for no charge. Required recutting the dovetail and shimming under the sight base but it worked like a charm.

Matthew said...

I got quoted on VFTP! And -without- derision!

And they said I'd never amount to anything without that degree. ;)

Sport Pilot said...

Great article Tam, I enjoyed it and to a degree went through the same grief with a #1 in 45/70 with its wandering zero following the first shot from a cold barrel. Yes Og, it was a red butt pad model. Other #1's in 7mm Mag & 30/06 were fantastic. Still we learn as we do and some of us remember to pass along the know how. good for you.

Anonymous said...

I have a #1 in 22-250 and it is amazingly accurate, I think I am the weakest part of the system. Three shot cloverleafs at 100yds are possible with a custom handload using Nosler varmint bullets.

Seller's remorse is a terrible thing when it comes to guns or motorcycles. That's why I'm buying another gunsafe rather than selling some off to make room.

By the way, out of curiosity I googled 'how old is my Ruger #1'. Ruger.com has a chart that will tell you the year of production of your #1.


Tam said...

"Seller's remorse is a terrible thing when it comes to guns or motorcycles. That's why I'm buying another gunsafe rather than selling some off to make room. "

I have no idea how many guns I've sold. Probably a couple hundred at least.

Old NFO said...

Great post, and don't feel bad, you're NOT the only one that has been bit by that particular problem... It's NOT just Rugers... sigh

Matt G said...

I remember hunting whitetail in Georgia with you with that No. 1, Tam. When the moonscope you had on it was too high a magnification, you took it off and used the open sights. When we put you on the Cherry Tree stand, you said, "Hey, I've got Return To Zero" mounts!" and put it back on. That was a pretty slick little rig. :)

Will said...

When I was 16, my boss offered to get his machinist friend to fix my single shot Rem to mount a skinny Japanese scope. This rifle was made before they came out with the .22 scope slots in receivers.

Rifle came back with a machined block mounted to it with the slots cut in the side. Can't remember if I was shooting it in my cellar, or doing some sort of Mk1 Mod0 visual bore-sighting. Not even close.
Took it back to work, and it showed up a week later. Lined up ok, and used it for years.

Lost the scope, and had the same alignment problem with a new scope. Turns out the machinist modified the scope base to match his screwed up rib block. Thrilled, I was...

Roger said...

To see the wide range of scope mounting mishaps, one should spend some time a large public range like I work at. Backwards, 90 degrees off, 4" too far to the rear, loose mounts, loose screws buggered up screws, backwards 10 & 20 moa bases, crooked mounts, canted mounts, scopes mounted an inch & quarter too high and on and on.

Retired Spook said...

I've had a No.1B for many years, a 1978 production .30-06. Won't shoot for beans with factory ammo (which is why I got it cheap), but load 180 gr. BTSPs over just-a-bit-too-much H-4895, and it will do little tiny cloverleafs for days.

The rear scope ring needs a 0.010 shim under it to keep the scope in the adjustable range. And for the love of all that's holy, don't overtighten the fore-end screw!