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View Full Version : mil spec picatinny rail & weaver base



powers
02-07-2011, 03:58 PM
Anyone know differences between thes two?

wolf gray
02-07-2011, 04:18 PM
The grooves on a picatinny rail are deeper/wider than on a weaver base. I have a IOR Valdada scope that came with rings that will fit a picatinny rail but are too big for the weaver grooves. That's when I learned the difference.

Best,
Dan Batko

"Where are we going and why am I in this basket?"

pbike
02-07-2011, 11:50 PM
Picatinny goes back a ways... 1913. Somewhere, I'm sure someone will correct me... the idea got lost in the translation and out came the weaver "Cross Slot bases" the problem with the Weaver types is that from base to base, rifle to rifle the pitch, (consistancy of the cross slots) is not standard. The depth and thickness of the picatinny slots are consistant so a scope that is mounted on one picatinny rail can be removced and put on another rail, on another rifle. Weaver types don't do that. Odds are the slot will be in another place, just forward or just aft of where you need it. For that reason alone WEAVERS SUCK! And it's why Picatinny's cost more, they're better. Here is a link to what you need to know about Picatinny. http://biggerhammer.net/picatinny/

Paul

Dans40X
02-08-2011, 01:43 AM
1913 pic rail cross slot spacing ctr/ctr(.394") is standardized & is different than Weaver cross slot spacing(varies between various manufacturers).
Hence the reason scope ring spacing from one will not interchange to the other or vice versa.

MilGunsmith
02-08-2011, 07:00 AM
The Picatiiny rail was designed in the office next to my shop, it was done in the 1980's (the 1913 is just a design number) and is a variation on the Weaver and ARMS bases. The big thing was to create a uniform spacing and a numbering system so that an optic or other device could be mounted anywhere and be repeatable.

powers
02-08-2011, 09:47 AM
Is the angle of the bases the same so that weaver rings are compatible?

Greg Culpepper
02-08-2011, 10:22 AM
Yes. The angles are the same.

Jdh
02-08-2011, 11:10 AM
Wonder why they used 10mm spacing?

pbike
02-08-2011, 11:57 AM
Glen Seekins, from Seekins precision is who clued me in on the details of Picatinny rail. His bases and rings (some of the best I've ever had) are true picatinny spec, others are not. The problem arises when you try to put a ring of Picatinny standard on a base that's not, The slot in the base won't accept the lug under the ring. The reverse of that Picatinny base with weaver ring, is a sloppy bolt running through a slot, this could allow the scope to slide for or aft. Either case is not good. I have three Slug guns for deer hunting and a muzzle loader for deer hunting here. They all have picatinny bases, this way I can swap the Leupold 2-7x scopes between the guns if needed, I also can easily remove the scope and replace it when cleaning the muzzle loader. even the newest greatest muzzle loader are still a chore to get as clean as I like them.

Paul

pbike
02-08-2011, 11:59 AM
Wonder why they used 10mm spacing?

?? because they didn't want to use 11mm?

Larry Elliott
02-09-2011, 10:48 PM
Wonder why they used 10mm spacing?

The Picatinny system is military, and our military has been using the metric system since the late '50's or early '60's which is why the 7.62x51 NATO and 5.56x45 NATO are metric. A 10 mm spacing is more rational than any other spacing since it allows enough strength and freedom of location of optics, or.... That last is just my assumption mind you, but if I were to design something like this in the metric system it'd have a 10 mm spacing.

alinwa
02-09-2011, 11:11 PM
using the metric system isn't communist

John Kielly
02-09-2011, 11:27 PM
I wouldn't mind betting that the Picatinny system exists for the same reason that the military used the 7.62x51 NATO and 5.56x45 NATO - that similar devices were patent protected & therefore subject to premium cost for use.

Jdh
02-10-2011, 10:06 AM
My apologies, I should have thought a little more about it before wondering out loud about the choice of metric spacing. It only makes sense especially for NATO use.

I have no problem using the metric system but the English system is not communist either.

MilGunsmith
02-10-2011, 11:33 AM
According to one of the enginneers on the project, the 10mm spacinc is due to the Elcan Machine Gun Optic original picked for use on the M240B machinegun. It has two recoil lugs on it, the 10mm is a an even division of the distance between them. This allows it to be positioned anywhere along the rail.

Greg Culpepper
02-11-2011, 08:47 AM
using the metric system isn't communist
If we were supposed to use the metric system God would have given us ten fingers and toes....wait a sec.......nevermind.

Larry Elliott
02-11-2011, 04:33 PM
I have no problem using the metric system but the English system is not communist either.


BUT it's the Imperial System, which offends the delicate sensitivities of many.... :D