Savage 110 & EGW picatinny mounting problems?

[TonyBen]

I got a new EGW Picatinny scope base for my Savage 110 long action flat back receiver yesterday.

For some reason, when I trial fit the rail one of the screws did not want to come out and the head began to strip. I figured I might as well just comitt and snugged the rest of the screws down and I installed the rings. I got the rings lapped (kokopelli lapping and alignment kit). So last night I was stweing over what to do. I had to get the damn screw out and managed to get it out this morning after a good night's sleep. I got a new set of screws on order from EGW.

This morning, I decided to install just the rear screws and see how the front end looked. That's when I noticed there was about a .030" gap between the rail and the receiver. I can spring it like a diving board. i'm guessing I'll have to either bed it or settle for it being slightly tweaked when snug. I already got the rings lapped in that condition anyway. The good news is that it only took a few minutes to lap the rings and they were nearly perfectly aligned from the start. After a couple of minutes of lapping, alignment was dead on.

I can probably bed or shim the front or stone the back to fit the scope perfectly and I am willing to do that if I have to. If it comes to getting a replacement base, I'm willing to go with a different type of base. I really don't want a 2 piece and prefer a one-piece. I take it people may prefer round base Savages to avoid these kind of fitting issues? At this point I don't know if the mount is out of spec or the receiver. It's from the mid-80's.

When I installed the Kokopelli alignment bars, the long rod that tells you if the scope is in line with the bore indicated that there's a slight angle to the right in relation to the barrel. It's not gross, but it's there. When I look over the top of the barrel, the alignment rod is angled to the right but doesn't overhang the barrel.

Since it's a picatinny base, I can't adjust the yaw of the base so I guess I'll have to settle for the misalignment. Any comments or suggestions on this one? The ring alignment bars line up perfectly.

I'd like to do it right the first time instead of doing it over a second time.

[geargrinder]

Throw those crappy EGW screws as far away as possible. Get some new quality screws and bed the base with the epoxy/bedding compound of your choice.

[TonyBen]

Here's the gap I was seeing. I measured .018" with a feeler gauge on the side and I added some shim stock in the front. I ended up having to add a .005" shim to the front and rear and somehow everything founds it's happy place. I'm guessing I didn't need that much shim under the front because it's rounded which must have multiplied the effect of the shim. I put .015" worth of shims at first and the rear was WAAAAAYYYYYY high after snugging down the front screws. I kept subtracting .005" until I only had one .005" shim under the front which gave me a perfect .005" gap at the rear so I threw a .005" shim under the rear so now the mount is stress free.

I'm going to avoid a permanent bedding solution since I don't really know if I'm going to stick with this mount in the long run.

http://i1205.photobucket.com/albums/bb423/tonyben3/DSCN1845.jpg

http://i1205.photobucket.com/albums/bb423/tonyben3/DSCN1847.jpg

http://i1205.photobucket.com/albums/bb423/tonyben3/DSCN1849.jpg

My ring alignment is still good to go...
http://i1205.photobucket.com/albums/bb423/tonyben3/DSCN1854.jpg

Here's the slight offset in barrel alignment (don't let the shadow on the ground fool you). I can't correct this unless I get some different rings with windage adjustment. I think it will do for now but the real test will be at the range.

http://i1205.photobucket.com/albums/bb423/tonyben3/DSCN1860.jpg

I also levelled the action in a vise later and checked the level of the scope mount. It has a slight twist to it. The center of the base is level but if I slide the level to the front, the bubble shifts just slightly to one direction but the bubble is still within the center marks. If I slide it to the rear, the bubble shifts the other direction and is off center in the opposite direction as the front but again, still within the center marks.

God, I wish I was a machinist...

[earl39]

Here's the gap I was seeing. I measured .018" with a feeler gauge on the side and I added some shim stock in the front. I ended up having to add a .005" shim to the front and rear and somehow everything founds it's happy place. I'm guessing I didn't need that much shim under the front because it's rounded which must have multiplied the effect of the shim. I put .015" worth of shims at first and the rear was WAAAAAYYYYYY high after snugging down the front screws. I kept subtracting .005" until I only had one .005" shim under the front which gave me a perfect .005" gap at the rear so I threw a .005" shim under the rear so now the mount is stress free.
Is it just my math or is anyone else confused now? With a .005 shim in the front and a .005 shim in the back and it is a perfect fit sounds like all you really needed to do was lap the base in just a little.




Here's the slight offset in barrel alignment (don't let the shadow on the ground fool you). I can't correct this unless I get some different rings with windage adjustment. I think it will do for now but the real test will be at the range.

http://i1205.photobucket.com/albums/bb423/tonyben3/DSCN1860.jpg

I also levelled the action in a vise later and checked the level of the scope mount. It has a slight twist to it. The center of the base is level but if I slide the level to the front, the bubble shifts just slightly to one direction but the bubble is still within the center marks. If I slide it to the rear, the bubble shifts the other direction and is off center in the opposite direction as the front but again, still within the center marks.


Make sure your indicator rod is not bent by rotating it. If it is bent the offset will change as the rod is rotated. If that checks out turn your ring bases around 180 degrees. That should move your offset to the other direction if it is the rings. If not it is the base or the receiver. If it does change then turn the rear ring back around 180 degrees and check again with your indicator and it should move back toward center.

Gary

[TonyBen]

I was confused too. My thinking was that if I added shims to the front and snugged down the front screws, then the rear should lay flat against the receiver but it didn't work that way. I have never lapped a scope base before. I was considering just stoning the rear down to bring the front down (maybe the lapping you are talking about). I am new to mounting scope bases on bolt guns. I normally shoot iron sights with M14 clones. I may be doing things the hard way but it is also able to be undone if I make a mistake.


I will try the advice on changing the rings around.

Thanks,
Tony.

[geargrinder]

The bedding doesn't have to be permanent. Put a release agent on the action and the base. You just need the epoxy to take up the space between, no bonding needed.

[TonyBen]

The bedding doesn't have to be permanent. Put a release agent on the action and the base. You just need the epoxy to take up the space between, no bonding needed.


Thanks. I'll try it.

Tony.