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14-11-2023, 15:46 #11
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14-11-2023, 19:25 #12
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- Oct 2012
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- Noord van die biltong gordyn.
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- 57
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Re: Scope base or picatinny - overthinking it again?
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14-11-2023, 20:24 #13
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- Oct 2022
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- 50
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Re: Scope base or picatinny - overthinking it again?
Heat treatment may be part of the problem, but the design is such that any fore-and-aft force is reacted on two very small areas where the OD of the "stud" contacts the inner flat surface of the slot in the ring, and the friction force generated by the four grub screws. Similar to a high-heeled shoe, this creates extreme localized stresses.
AR, alignment was very carefully checked. It was also a very easy action to mount to, entirely cylindrical on the top half. I am still convinced that the design is marginal for heavy scopes.
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14-11-2023, 20:52 #14
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- Oct 2012
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- Noord van die biltong gordyn.
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- 57
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Re: Scope base or picatinny - overthinking it again?
I tend to agree on the heavy scope issue. I have made bases that take 3 or 4 Lynx type rings on hard-kicking rifles with relatively heavy scopes, for the exact reason. That was all that was available back then. Nowadays, I would use a wider ring on a picanini rail to hold a heavy scope. Fortunately they are available now.
I do not agree on "the friction force generated by the four grub screws". The grub screws act against a tapered part of the stud, pulling the ring down and the stud up, just like a screw would do. The retention force is quite positive and the system is solid. The ring's fore- and aft movement is also stopped by the heads of the studs bumping against the inner surfaces of the holes in the rings. No friction involved, as that would definitely allow slippage under recoil, much like the rings clamped to the dovetail on a spring-powdered air rifle tend to creep under recoil.
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15-11-2023, 08:01 #15
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- Oct 2022
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- 50
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- 359
Re: Scope base or picatinny - overthinking it again?
The friction force is not so much between the grub-screws and the studs, but between the bottom surfaces of the rings and the top surfaces of the bases, generated by the "pulling force" you describe.How much force that is, I don't know. But it's there and contributing. As you say, the primary mechanism is the contact between the stud OD and the inner face of the ring. But because the ring is round and the non-tapered section of the stud is quite short, that contact area is very small. The system is great for getting the scope on straight, and terrible for absorbing recoil forces.In those days, I didn't have the equipment (and probably not the skill) to make my own bases. If I had, I would have made bases to take Warne rings (which I had actually bought for that very purpose but which are still lying in a box even now).
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15-11-2023, 20:39 #16
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- Oct 2012
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- Noord van die biltong gordyn.
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- 57
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- 9,093
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15-11-2023, 21:21 #17
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- Dec 2010
- Location
- Boland
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- 8,008
Re: Scope base or picatinny - overthinking it again?
This has drifted from the OP, so I won't feel bad digressing further: lots of discussion about the stud bases, to the point where I get the idea they were only option in the days of yore...
However, no-one mentioned plain Weaver bases and I'm wondering why? My Musgrave Vrystaat still has the Weaver bases my dad put on when he bought it new in 1972. When I wanted a more modern scope on it, I could fit brand new Warne rings on it without an issue. I had to swing one of them (the front one iirc) through 180deg to reposition the recoil slot but that was it. Since I've had the rifle it has always shot at or slightly better than 1MOA, so those 51y old Weaver bases are still going strong. If I couldn't mount my scope directly to the action (all hail BRNO/CZ ) and chose not to have a Pic rail fitted (for all the good reasons mentioned by others), I'd far rather have the Weaver bases than the stud bases. Or am I missing some advantage of the stud bases?
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15-11-2023, 23:03 #18
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- May 2010
- Location
- Right next to the pot that needs stirring.
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- 46
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- 2,166
Re: Scope base or picatinny - overthinking it again?
Only advantage of the stud bases (might be a disadvantage for some that don't follow correct mounting procedures) is that alignment can be slightly adjusted left to right.
I have Lynx stud bases and rings on 3 of my rifles for many years and use without problems.... 30-06, 44 mag, 6,5 x 55
Had an issue with the 30-06 after years of use of developing bad groups. New scope did not sort it. New stock improved it to 95 % of what it was. Now this thread is having me getting strange thoughts about maybe the rest of the problem is with the stud bases as the flyers really seem to be scope problems, but it is not as I have changed scopes to test it. Scope adjustments not doing as they are supposed to do (moving POI to another area than the "clicks" adjusted should move it) always tell me it is scope related. Might be mounting related, but the movement is so minute I cannot feel or see it, but hard kicking 30-06 loads migh move something?
Another "new year" project to work on the 30-06 again.
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16-11-2023, 21:49 #19
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- Oct 2012
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- Noord van die biltong gordyn.
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- 57
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- 9,093
Re: Scope base or picatinny - overthinking it again?
There was time in the late eighties and early nineties, when we had limited options in scope mounting systems. A few of the options then were:
1. Weaver bases and rings. These were made from fairly soft aluminium and were easily knocked out of zero. The 1916 picatinny rail is based on the weaver base.
2. Lynx/Tasco rings and bases with the stud. Made of steel and laterally adjustable. This was handy at a time when many actions were drilled and tapped slightly skew. These rings and bases were available for most of the rifles on the market at the time and often the only viable option.
3. Rings for dovetailed actions, mostly steel. Sako made their own brand and other brands also made suitable rings or bases to fit.
4. EAW (Ernst Appel Werke) bases and rings. They made various steel mounts and rings, all very sturdy. Some were of the QD type and would usually return to zero. They were pretty pricey and usually reserved for the more expensive rifles like Steyr Mannlicher, Sauer etc.
5. Redfield made mounts where the front ring would go into a rotary dovetail (very secure) and the rear ring would be clamped between the heads of 2 opposing screws. This was intended to allow some lateral adjustability, and was very weak. These were not often seen in SA at the time.
Now we have a much better selection available. It is interesting to now which systems lasted and which faded away.
The Lynx stud system is still popular and made by 2 local manufacturers.
The Weaver system evolved into the very versatile Picatinny rail, and is available in both steel and aluminium. It has also become the new standard for "tactical" and sports shooting style rifles. The guys who make the Lynx stud type systems also make these now.
Dovetail-top actions are still popular, with CZ, Sako and Tikka being prominent examples. Most of them are also drilled and tapped to allow some other base (usually picatinny) to be mounted on top. Talk about versatility.
A new trend is for actions to be made with integral picatinny rails on top, machined from a single piece of steel. The downside is a lack of adjustability, especially if you may want an angled base.
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19-11-2023, 21:41 #20
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- Mar 2010
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- 2,213
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