Ken ferrell rings

Does anybody by any chance have a set of ken ferrell low ring they want to part with? I am having a heck of a time sighting in my rifle and I think lower ring might help me.

30mm? 1"?

I'll check to see if I have a set of "Low" Farrell rings at the house when I get back there, but meantime, that's not your problem unless something in the assembly is defective.

Ring height should be selected to keep the scope as low as possible w/o touching anything. This enables a proper cheek weld. Ring height has absolutely NOTHING to do with getting zeroed and there is another, yet unidentified issue that is causing your problem.

What is the actual symptom?

Can't dial out the error?

Big groups/erratic impacts?

Is the scope tube touching anything except the rings?

Is everything tight?

30mm. If you have a set that would be AWESOME! I am scoping my polytech m305 using a sadlak alum mount. The glass is a nikon x1000 "50mm bell" on vortex pro low rings which are .90 in height. I lapped the rings and made sure they were aligned and tight.
My issue is I cant get the crosshairs to line up without maxing out my elevation. I adjusted the mount the best I could to drop the front to gain some moa but it was still not enough. At this point I decided to use the penny method to see if I could use lower rings. I got to 2 pennies a stack before i came really close to touching anything. Using my sitelite sl500 bore laser to get my point of impact I laid my scope on the pennies and adjusted the elevation to get on level with the laser. Doing this I was able to get the cross hairs on target with 1 full rotation left on the turret " 4 1/2 turns from top to bottom". Not ideal but atleast I'm not maxed out.
Now I am looking for the lowest 30mm mounts possible which I am finding out is really difficult. I found some vortex hunters at .75 height but I did not feel comfortable using them. While searching the internet I discovered ken ferrell rings which are the lowest at .73 and also had great reviews, and here I am now. I am terrible at explaining things so if anything does not make sense please let me know.

hchon3 said:

30mm. If you have a set that would be AWESOME!

Click to expand...

Sorry, 6 pairs of tactical rings in the box and nothing in 'low' that isn't mounted on something.

I am scoping my polytech m305 using a sadlak alum mount. The glass is a nikon x1000 "50mm bell" on vortex pro low rings which are .90 in height. I lapped the rings and made sure they were aligned and tight.

Click to expand...

Sounds good so far...

My issue is I cant get the crosshairs to line up without maxing out my elevation. I adjusted the mount the best I could to drop the front to gain some moa but it was still not enough. At this point I decided to use the penny method to see if I could use lower rings. I got to 2 pennies a stack before i came really close to touching anything. Using my sitelite sl500 bore laser to get my point of impact I laid my scope on the pennies and adjusted the elevation to get on level with the laser. Doing this I was able to get the cross hairs on target with 1 full rotation left on the turret " 4 1/2 turns from top to bottom". Not ideal but atleast I'm not maxed out.

Click to expand...

It sounds like you've done a pretty good job on it thus far, except that laying the scope on the pennies, vs cradled in the rings, doesn't seem to be a viable method.

It sounds like you are losing the "parallism" we need between the scope axis and bore axis and not getting good data. It is one thing to use the pennies as a thickness 'feeler gauge' to determine if the mounted scope can be made lower, but quite another to try to use any sort of shimming device to determine zero capability. It sure sounds to me like something isn't straight. The scope base you've installed seems to be of reasonable quality, but I often wonder how a SA M1A can be $1,500 and a Polytech can be $500 without sacrificing something someplace.

If your "x1000 scope" is the 4-16x model, it has 90 moa internal adjustment, which means that, in a perfect world, you have available 45 up and 45 down. Something has to pretty crooked to not be able to zero with over 45 inches of adjustment at 100 yards....

I would look into the mount interface with the receiver and see that the mount is lying tightly against the receiver at all contact points and nothing is being sprung as you tighten the hardware. Maybe a shim can be solidly applied at the rear end of the base to bring impact up...

Now I am looking for the lowest 30mm mounts possible which I am finding out is really difficult. I found some vortex hunters at .75 height but I did not feel comfortable using them. While searching the internet I discovered ken ferrell rings which are the lowest at .73 and also had great reviews, and here I am now. I am terrible at explaining things so if anything does not make sense please let me know.

Click to expand...

Ken Farrell products are top notch, and I understand your line of reasoning, but you will not buy yourself anything by simply lowering the rings. If you have a set of higher rings on hand, you could swap them out and prove this to yourself.

There is an angular relationship between the bore and the scope base that must be modified to change your elevation adjustment range. This is the nature of a 20 minute base - we modify the bore/base angle to provide more elevation capability for the scope before running out of elevation.

If you go from extra high rings, say 1-1/2 inches off the top of the rail, to a low ring that places the scope a half inch off the rail, you have done nothing to modify the bore/base angle. If you could zero, then swap rings, you zero MIGHT move the same distance as the ring height difference. It will not make the difference between being able to zero with your scope at mid-range and not being able to correct elevation at all.

In short, if you can find lower rings, they should make the rifle more comfortable to shoot by bringing the scope down closer to the iron sight height the stock was designed for, but they will not solve this problem.

You will need to modify the angular relationship between the bore and base in order to change the elevation adjustment range to get within your scope's adjustment range - ring height does not address this.

Burris 'Pos-Align' rings have bushings that are eccentric and allow one to make the angular adjustment you really need. https://www.opticsplanet.com/burris-signature-pos-align-offset-insert-kits-individual-inserts.html

I have installed a dozen or so sets of these rings and they have worked well.

ETA: It occurs to me that some bases are true Picatinny rails while others are "Weaver style" and while the rings may seem to interchange, the crossbolt sizes are different. It may be that your base has Weaver width slots and your rings have Picatinny crossbolt diameters, which would prevent firmly seating the rings on the base. Make sure your rings are properly mated to the base and sit firmly down on top of the rail. There should be a small amount of fore/aft play between the base slots and the rings' crossbolts.

Dang that sucks. I triple check the mount to make sure everything was tight and good to go. The scope is brand new and 6-24x50. I am new to scoping a rifle so my knowledge base is limited, but I think I understand what your saying. It sounds like you know what you are doing, do you mind taking a look at my rifle and seeing it it my mount or my rifle? Even if the mount height doesnt matter I will still go with the lower rings

Is that mount adjustable at all or is it locked in place and the receiver determines how square it is?

The 6-24x version only has about 30 minutes each way, but that is still a lot of adjustment to not be able to dial it to zero.

Very sorry, but I'm retired from teaching and not working on rifles any more, so I won't be able to look at your rifle with you. Are you located near any gunsmith Industry Partners that could take a look at it for you? Check the industry partner forum here at MD Shooters and see who is close.

Hopefully you can isolate the issue yourself.

One thing to note, is that if your scope had to be adjusted near its end of travel in windage, the elevation will be limited and not what is published. This means your elevation issue could be made worse by lateral misalignment. Think of the effect on headroom if walking through an arched doorway near center or near the side...To check this, you would max out your elevation as if trying to zero, then you would make sure the windage turrets are centered, then go back and check if the elevation will come up further once they are.

I would definitely check crossbolt clearance, because the crossbolts can seem tight and still not be properly seated if you have the Weaver rail x Picatinny crossbolt diameter issue. When the rings are loosened on the rail, they should be able to slide back and forth slightly (0.050"+/-) and when tightened, they should be pressed toward the front of the rail slots so they don't move under recoil.

My bet is that the mount isn't sitting tightly/squarely on the receiver, either with respect to elevation or both windage & elevation. With the scope/rings removed, the mount screws removed and the mount loose in your hand, does it lie tightly on the rifle where it should? No rocking? How about once you install only the side screw? Still sits tight/flat against the receiver? Is the top screw in alignment? Is the block in the clip slot, that receives the other mounting screw, properly installed and pinned? If you install the top screw, does the mount lie in the correct position to get the side screw started? We are looking to see if something has to flex to align and/or if it's rocking on a high spot.

Barrel angle can be a problem and it is always possible the barrel axis isn't concentric & parallel with the bolt axis. Will it zero with iron sights in such a way that the sights can still be referenced to "0" when it's dead-on at 100 yards? (In other words, will it zero w/o cranking the sight up to 500-1,000 yards?) If it won't zero with irons, then the barrel is bent, the barrel angle is off or the bedding/hardware is pulling down on the barrel.

Understood, I will try to trouble shoot it myself but if i cant get it I can go to charles maloney.
The windage is off a tad bit. With the mount on the rifle I am able to look down the rail of the mount and line up my irons, but i do notice the irons will be closer to the right side more than the left. I will adjust both the windage and elevation to where they are neutral and double check where the retical ends up in relation to the boresite.
I never really paid much attention to the crossbolt of the rings when mounted on my mount. I didnt think that would really affect my elevation issue, but I will run that check to see if I do have any significant amount of play.
As far as the mount goes I am in leaning in the same direction as you are. I watched videos and followed the direction exactly as they were written when I first mounted the sadlak mount. I also checked my reciever to see if I was in spec according to the directions and the video I watch. Going off the measurement I got my receiver does not fall in spec for the sadlak mount. I called the sadlak tech support and the gentleman i talked to said that I should still be ok and he recommended that I use diffrent rings. But to answer your questions the mount does seem to fit tight with all hardware off, loose, and tight. The cartridge clip key does line up with the mount and the screw goes in with no issues. The front screw is not off to the right or left of the reciever. With everything level and securely mounted my scope is just to far off my point of impact and it seems like no matter how much I mess with the mount I cant get it to close that gap.
The barrel is something I am somewhat comfortable with. I had mr maloney a well know M1 garand and m14 gunsmith install a new barrel, bolt, and bed my rifle, but I will double check that as well.
Unfortunately my range will be closed for a week or two so I can not test fire my rifle with any changes I made. So I now have more time to tinker with it.

hchon3 said:

Understood, I will try to trouble shoot it myself but if i cant get it I can go to charles maloney.

Click to expand...

The windage is off a tad bit. With the mount on the rifle I am able to look down the rail of the mount and line up my irons, but i do notice the irons will be closer to the right side more than the left. I will adjust both the windage and elevation to where they are neutral and double check where the retical ends up in relation to the boresite.

Click to expand...

If you can readily see the error, it must be fairly large. I will be interested to hear what you find.

I never really paid much attention to the crossbolt of the rings when mounted on my mount. I didnt think that would really affect my elevation issue, but I will run that check to see if I do have any significant amount of play.

Click to expand...

The crossbolt problem is that if the slots on the mount are narrow, ala` 'Weaver', the crossbolts on the rings must also be designated 'Weaver'. To further compound this issue, not all manufacturers seem to recognize or care about this distinction. "If it has military looking slots, it's a Picatinny, blah blah...". Note the technical drawings at this link:https://en.wikipedia.org/wiki/Picatinny_rail

'Picatinny' crossbolts are of slightly larger diameter than Weaver crossbolts and must be used with a true Picatinny rail or the rings will not sit flat on the rail.

When a Weaver rail receives Picatinny crossbolts, they do not drop completely into the slot because the diameter will not allow it. When the crossbolt nuts are tightened, the crossbolt jams into the leading edges of the mount slot and they both may not jam in exactly the same distance, leading to an unexpected slope. Meantime, it will seem tight.

When a Picatinny rail receives Picatinny crossbolts, there is a small amount of play, as described in my post above. This is because the true Picatinny rails have slots that are slightly larger than true Picatinny crossbolts, The ring should be able to slide back and forth on the rail as the crossbolt travels that small amount of slot clearance.

As far as the mount goes I am in leaning in the same direction as you are. I watched videos and followed the direction exactly as they were written when I first mounted the sadlak mount. I also checked my reciever to see if I was in spec according to the directions and the video I watch. Going off the measurement I got my receiver does not fall in spec for the sadlak mount. I called the sadlak tech support and the gentleman i talked to said that I should still be ok and he recommended that I use diffrent rings. But to answer your questions the mount does seem to fit tight with all hardware off, loose, and tight. The cartridge clip key does line up with the mount and the screw goes in with no issues. The front screw is not off to the right or left of the reciever. With everything level and securely mounted my scope is just to far off my point of impact and it seems like no matter how much I mess with the mount I cant get it to close that gap.
The barrel is something I am somewhat comfortable with. I had mr maloney a well know M1 garand and m14 gunsmith install a new barrel, bolt, and bed my rifle, but I will double check that as well.

Click to expand...

It would seem that your tolerances are stacking. The mount maker says "it should be OK", with the unsaid inference/assumption being that everything else is right as well. While your gunsmith may be highly skilled and well regarded, if the bore for the barrel tenon into the receiver is not straight, there is a definite limit to how far he can go to correct it. His perspective: "It should be OK...", since it was probably OK before, and probably still would be if you only used your irons, but if the receiver's external tolerances are violated in a contributing direction, you may not be able to zero. AND, all this assumes the mount is perfect...which of course it is, LOL.

As an aside, if the mount maker said to use different (lower) rings, he doesn't fully understand the difference between the (very small) change in distance between two parallel axes and the effect of changing of the mount slope relative to the bore and its influence on elevation.

Unfortunately my range will be closed for a week or two so I can not test fire my rifle with any changes I made. So I now have more time to tinker with it.

Click to expand...

You might consider bedding the mount with Steel-Bed or Marine-Tex (apply release agent/wax to both mount and receiver). If the mounting holes are slightly enlarged, you can develop some play in the mount, tilt it forward (down in front and/or up in back to shift point of impact upward) and just glass it in place.

While I'm getting old and surely don't have much patience with gimmicks, those Burris rings I linked above work fine and WILL solve your problem.

Finally, and FWIW, I scoped my own GI stocked precision M1A, first with 4.5-14x, then a 3.5-10x, and decided to get rid of the scope set-up entirely and just run irons. The scope wasn't intuitive to use like the irons, even with a correctly adjusted cheek riser, and I realized I had taken a naturally pointing, easy to use rifle and ruined the feel and handling. With the long sight radius and relatively fine sights, the M1A can work well at longer range with irons.