I have a Remington 700 Custom Shop, 416 Rem. Mag. that came with open sights. In order to sight in with factory sights, the rear sight was setting 3/16 inch to the right. I thought it was an instillation/alignment problem so I installed a set of NECG sights. Same problem.
To get the rear sight center I had to machine and tilt the front sight 1.5% and offset the bead .050. This worked but looks like s--t. I won't give it back to the customer like it is.

The scope sights in perfect and the adjustment is just a few clicks off center. I have checked barrel crown and bore for irregularities. I have checked barrel for straightness. I have not pulled the barrel and checked the receiver face or lug for misalignment but it looks good.

What am I overlooking?
Thanks

James

quote:

Originally posted by J Bennett:
I have a Remington 700 Custom Shop, 416 Rem. Mag. that came with open sights. In order to sight in with factory sights, the rear sight was setting 3/16 inch to the right. I thought it was an instillation/alignment problem so I installed a set of NECG sights. Same problem.
To get the rear sight center I had to machine and tilt the front sight 1.5% and offset the bead .050. This worked but looks like s--t. I won't give it back to the customer like it is.

The scope sights in perfect and the adjustment is just a few clicks off center. I have checked barrel crown and bore for irregularities. I have checked barrel for straightness. I have not pulled the barrel and checked the receiver face or lug for misalignment but it looks good.

What am I overlooking?
Thanks

James

First, is there forend pressure on the barrel? Uneven pressure or contact between the barrel and forend will effectively move your point of impact. How did you check the alignment of the sights? How did you check the barrel for straightness?With both sights mounted to the barrel, it won't matter if the receiver face is a little out of whack. As a last resort you might run the barrel slowly in the lathe and watch the crown. Sometimes (rarely) they look good by sight, but when you actually watch one spinning, you could lose your balance.

You might want to use the milling machine to check the sight alignment. Square the bore, front and back, to the table, locate and zero the center of the barrel at the muzzle and then move the table to check the rear. That should tell you something. But I would check for stock and barrel contact first.

quote:

Originally posted by J Bennett:
What am I overlooking?
Thanks

James

Perhaps the front sight is not on straight.

Barrel has a small contact point in center/front of forend. I don't think that is it as the barrel is .875 at the muzzle.
Crown was re cut with a piloted cutter.
Barrel straightness was only checked visually and by spinning in lathe.
Sights were installed in milling machine centered on OD of barrel.
I have attached a couple of pictures of sight alignment. One, front scope base and rear sight base and the other of the front and rear sights.

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James

Lets try these photos again.

Anyone else with an idea? Thanks

James

Pull the barrel and place it between centers and see how bad she flops. If the barrel is straight, the sights are centered, the crown is square to the bore and there is no excess pressure on the left side of the barrel, then maybe the bullet is spinning too fast.

Seriously, assemble the gun in the stock with the scope. Center the cross hairs to your bore sighter. Without removing the bore sighter, pull the barreled action from the stock and have a look at where the cross hairs are. If they haven't moved then maybe get someone else to shoot the gun to see where it's hitting for them. Without the gun here, I'm at a loss.

FWIW, using the scope base to gauge the level of barrel mounted sights might not always be such a good idea. Sometimes the scope base holes are out of whack with the rest of the gun. The fact that the scope works fine doesn't tell what irons will do. It doesn't take much of a misalignment to cause a complete miss at 100 yards.

Sounds like the front site wasn't installed TDC. The two options is to find out how much it is off by and lathe back the shoulder and tenon appropriately then re-headspace to get it to line up correctly. Or better yet (as it takes far less time), remove the front site, get a banded front site and solder it (or loctite) into place.

John

Thanks Malm & John

I'm at a loss to. Over 30 years of installing sights and this one has me stumped. I have had this problem on muzzle loaders with off center bores not being indexed but not a modern rifle.

There is no shift in cross hair alignment in or out of stock. Barrel spins straight within a few thousandths. Owner has shot rifle with same point of impact. Levels were used to indicate that I had rotated the front base counterclockwise 1.5%. I even checked alignment with my Forester jig.

I am going to start over and install an oversize recoil lug. This will let me straighten the barrel shank and receiver face.I will install a new banded front sight and reposition the rear. If this doesn't work I will try something different.

James

quote:

Originally posted by J Bennett:
I am going to start over and install an oversize recoil lug. This will let me straighten the barrel shank and receiver face.I will install a new banded front sight and reposition the rear. If this doesn't work I will try something different.

James

I would almost doubt the problem lies in the barrel receiver joint. You said the scope only required a few clicks to center which tells me that the barrel connection is square enough to hold the scope in alignment with the muzzle. I think you will find the problem lies somewhere between the barrel, the sights and maybe even the pressure point. But good luck!

Have you checked the alinment useing a different front sight or compared the difference ( if any ) useing severel different front sights?

Doug

Good point but both the factory and replacement sights were same point of impact.

James

James,

I don't know if this will help you or not, but do you have a laser boresighter you can chamber to possibly help you visualize where the goofiness is coming into play?

You could even use a bit of modelling clay to shape up a front sight, to help you see if there is any way possible a front sight can be configured.

I know it sounds drastic, but you might try cutting an inch off the barrel and recrowning. I have seen a barrel that was straight as an arrow on the outside and the crown looked acceptable but the bore was as crooked as a politician. You could even try cutting just a half-inch at a time.

Gentlemen

Thank you all for your suggestions.

I found the problem this evening and John gets the Gold Star.
I started today by removing the barrel. I looked at everything again,it looked good. Put barrel in lathe on centers, about .010 run out,looked good. Next indicated muzzle and chamber separately. Turned on lathe and you would not believe how bad out of center the bore was. No correcting this one short of re-barreling. I can not believe this barrel could have been run through the custom shop. The inside has to be warped .100. While spinning the bore looks like a 30 caliber.

Thanks again, live and learn.

James

I'm glad you found it. Save that barrel to show customers...or send it to me so I can. Without an example to show people, few will believe it.