Davidson base alignment/bedding gizmo

[AlNyhus]

When the late Stan Ware was tutoring me on machine operation, one of his first first 'assignments' for me was to make scope ring risers for our Pandas and Kodiaks....this was before tall Davidson style dovetail rings were generally available.

"I don't want to hear anything out of you, Nyhus. That Bridgeport is the only sound I want to hear."

The set screws in the top snug it into position on the top of the rail. We used LocTite sleeve retainer on the angles and between the top of the rail and the bottom of the riser...ended up being a great system. Eventually, we both transitioned to higher rings after they became available.

I was bedding some Davidson bases at Stan's one day on a 700, using my riser as a way to line up the bases and keep them at the same height when snugging the screws down and compressing the bedding. Leaving the riser on when the bedding cures also maintains the alignment and height between the bases as the epoxy cures. Stan looked over my shoulder and said "You know, Nyhus, you're not as dumb as you look. That's a good thing."

I whittled these Davidson style bases up yesterday for this Mack Brothers action and bedded them using it. It's become one of those simple gizmos that gets used a lot...can't imagine how many sets of bases it's been used on. It also works great for troubleshooting base alignment. It helped me identify an issue on a vintage Wichita 1375 action last seaon.

Made me smile thinking of Stan.

Good shootin' -Al

 

[LVLAaron]

Al, you have all the cool widgets.

 

[3Sigma]

Good idea.

Quick question... could you use a lapping bar and rings to keep the same alignment? I doubt it is as precise...

I've only done two piece bases a few times, and struggled with alignment on both a M70 and 700, the former using Talley one piece rings, the latter weaver style bases.

I used a ring lapping bar to hold the bases while the bedding cured. The Talley rings were then lapped and bedded to the scope, the M700 used Burris Signature rings, so that step wasn't needed.

 

[AlNyhus]

Good idea.

Quick question... could you use a lapping bar and rings to keep the same alignment? I doubt it is as precise...

I've only done two piece bases a few times, and struggled with alignment on both a M70 and 700, the former using Talley one piece rings, the latter weaver style bases.

I used a ring lapping bar to hold the bases while the bedding cured. The Talley rings were then lapped and bedded to the scope, the M700 used Burris Signature rings, so that step wasn't needed.

Yes...a lapping bar is a good way to keep bases aligned when bedding. -Al

 

[boltfluter]

Al,
Are you just lightly torquing the bases down to the action? Or? The 1375 was a great action, I refuse to believe you found a problem with one! Lol.
Paul

 

[rangertim]

Stan was a Great Guy, and a True Gunsmith !!!

 

[AlNyhus]

Al,
Are you just lightly torquing the bases down to the action? Or? The 1375 was a great action, I refuse to believe you found a problem with one! Lol.
Paul

Paul, you don't want to end up with a paper thin layer of bedding on the bases. I just sort of go by feel on the base screws...if the bases and receiver are a good fit when I pre fit them, a light snug on the screws is the most I do. This jig makes the Davidson bases easy as you just slide it back and forth when your snugging the screws to keep them aligned and at the same height.

The late Dan Hackett designed and sold a tool called the 'Base Align' that does the same thing for both Davidson and Picatinny bases. It's a really slick tool. Very few people realized the genius of it, though. I've got some Picatinny two pieces bases to bed shortly and will grab some pics of it in use.

The Wichita's woes were caused by previous owners attempts to modify it. After a lot of work on the ignition and cocking piece, it now shoots very well with 22 lbs of spring pressure rather than the factory 32 lb setup. The scope bases were just another thing that was wonky...off height and cocked on the receiver.

Good shootin' -Al

 

[RGRobinett]

Paul, you don't want to end up with a paper thin layer of bedding on the bases. I just sort of go by feel on the base screws...if the bases and receiver are a good fit when I pre fit them, a light snug on the screws is the most I do. This jig makes the Davidson bases easy as you just slide it back and forth when your snugging the screws to keep them aligned and at the same height.

The late Dan Hackett designed and sold a tool called the 'Base Align' that does the same thing for both Davidson and Picatinny bases. It's a really slick tool. Very few people realized the genius of it, though. I've got some Picatinny two pieces bases to bed shortly and will grab some pics of it in use.

The Wichita's woes were caused by previous owners attempts to modify it. After a lot of work on the ignition and cocking piece, it now shoots very well with 22 lbs of spring pressure rather than the factory 32 lb setup. The scope bases were just another thing that was wonky...off height and cocked on the receiver.

Good shootin' -Al

Ya beat me to mentioning Dan's gizmo - Dan was grossly misunderstood and brimming with knowledge. RG

 

[butchlambert]

Ya beat me to mentioning Dan's gizmo - Dan was grossly misunderstood and brimming with knowledge. RG

Randy, we have differing opinions of Dan. I guess I misunderstood him.

 

[WSnyder]

The late Dan Hackett designed and sold a tool called the 'Base Align' that does the same thing for both Davidson and Picatinny bases. It's a really slick tool. Very few people realized the genius of it, though. I've got some Picatinny two pieces bases to bed shortly and will grab some pics of it in use.

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[AlNyhus]

I might recognize that picture.....

 

[WSnyder]

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View attachment 1431947

For some reason it won’t let me edit the original post. The original links are dead after the BRC update awhile back so I’m updating the links here.

Bedding bases

This is a simple thing you can do to insure maximum contact between the bases and receiver and make sure the bases are aligned longitudinally. Normally, I use the excellent Base Align, designed by the late Dan Hackett. But for this, I'll do it old school since few have this tool. I...

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Scope ring lapping and bedding

Lapped and bedded the scope rings on my Sako project: Leupold rings installed: Closer view of the ridges that Leupold puts in their rings. They actually do a pretty good job: What I use for a compound. Ring bottoms have the compound applied: My home made lapping bar is a...

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