rampant wrote:Hi All,
Doing my head in with trying to calculate the most appropriate scope base for my Ruger 22LR. It will be for precision only and intend on dabbling with some ELR (out to ~300m optimistically) so I feel I need to maximise my scopes range of available elevation.
Ruger has 30MOA rail built-in, scope is a 1-8x24 with 100MOA elevation.
I've read that total cant/tilt shouldn't exceed half the scopes elevation (50MOA) otherwise you can't zero at 100M. However I expect to be zeroing (and shooting) at 50M. Does that mean the total cant/tilt should be even less than half the scopes elevation?
When I throw the ammo through Hornady's BC it reckons I'd need 59.2MOA adjustment to get out to 300M
Based on the above it seems I should get a 0MOA scope base?
rampant wrote:@bladeracer did you replace the stock 30MOA rail on your RPR with a 0MOA one?
Biscuits wrote:Are you sure your scope has 100 MoA of elevation? as it is a 1-8x24, I assume it has a 1-inch tube.100 MoA of elevation adjustment is a lot for a scope with a 1 inch tube.
Personally I would set a 50 meter/yard zero. You will find that for a (far) zero at 50, you will have a near zero at about 25. So you have an exact zero at 50 and something pretty close to zero at 25. Find a rail or rings so that you have about 10% of your total travel below the zero and 90% above the zero. Or 20/80% if you don't like that extreme. Scopes sometimes don't track accurately at the limit of their travel, that is why you don't want to have a zero at the limit of travel.
Once you go beyond 300m, you need a lot of additional elevation for a bit of extra distance.
You can use the Burris Signature rings to get a bit more elevation, but still that will only take you so far past 300. To go much further, you will need some serious elevation, you will need either an adjustable base, a March scope which is a couple of months pay for most people or a Charlie Tarac prism. Your life will be much more simple if you limit yourself to 300m.
I'll second the recommendation above for RWS R100. I don't get along with Eley ammo though. The R100 will be coming out the end about 100fps faster than any other match grade ammo I can think of.
bladeracer wrote:Actually, I hear a lot that you only get big elevation from a fat tube, but I haven't found that to be correct. It's more about magnification. My 35mm 10-40x56 only has 42-minutes total, my 25mm 4.5-18x40's have 105-minutes. When the maximum zoom is high you need to physically move the internals a long way. If maximum zoom is only 8-power, I would expect heaps of adjustment, but due to the lower magnification they often drop the precision of adjustment back to half- or full-minute clicks.
Biscuits wrote:bladeracer wrote:Actually, I hear a lot that you only get big elevation from a fat tube, but I haven't found that to be correct. It's more about magnification. My 35mm 10-40x56 only has 42-minutes total, my 25mm 4.5-18x40's have 105-minutes. When the maximum zoom is high you need to physically move the internals a long way. If maximum zoom is only 8-power, I would expect heaps of adjustment, but due to the lower magnification they often drop the precision of adjustment back to half- or full-minute clicks.
Yes, I was thinking that this may be due to the scope being low power. The erector assembly inside the scope will still need to move by the same angle, so I assume the length of the erector assembly is shorter in a low power scope so that it can move a greater angle in a smaller tube, without a clash. I don't have any low power scopes, so I've never investigated further.
I don't think I would be a fan of a 100m zero. I only need about 1.4 milliradian of elevation to go from a 50 yard (the range I zero at is in yards) zero to get to 100. Remember with a 50 zero, you get an approximate 25 near zero when the bullet is on the up trajectory. Giving up a 25/50 zero, which is where you will do a lot of your work, seems like a lot to give up to get only a bit of extra elevation on your scope.
The furthest I have gone with a 22LR is 450 metres and I had to holdover into the solid black line/unmarked part of the reticle. I'd need to check my logbook but from memory it was about 26 milliradian of elevation. I'm planning on buying either a Coldshot or WR Precision elevating base to push it further.
Biscuits wrote:^ Always interested to hear what long range 22 rimfire shooters are doing, bladeracer. Is you adjustable scope base an Era Tac?
I considered that, but it ties me to a particular scope tube diameter. In my case, my 22 has a 30mm tube scope, whereas all my others are 34mm tubes. I'm reluctant to cough up for an expensive base which ties me to a (relative to the other scopes) a lower cost scope. Hence my thought on getting a Coldshot or WR precision base, which goes on the picatinny rail and under the existing rings. It will mean that my cheek rest is too low, but I can put something temporary to fix that. Hopefully if I only put this on when I am doing ELR, the zero won't change much when I take the scope on and off. I've only used R100 for ELR rimfire. I must try CCI Velocitor and see if what you lose on it being non-match ammo, you gain on higher velocity.
Biscuits wrote:^ I'm leaning towards one of the expensive adjustable bases as the scope on my 22 only has 15 milirad of available elevation and I could also use the base on a centerfire with more recoil. The total elevation travel on my 22 scope is about 29 milirad, even if I put in a more highly canted rail, so this won't take me much past 450m where I used I previously used 26 milirad total elevation, achieved using holdover. Also I don't have a workshop
I'll be going to Sydney mid-November and plan to pick up one of these adjustable bases, which are made in Australia, $795:
https://watersrifleman.com/elr-steel/
From what I have seen of the design, it should be slightly harder to adjust but slightly more rigid than the US made Cold Shot base, which is a similar price:
https://heritage-arms.com/product-categ ... ope-bases/
I have a trip to a 2000 metre range in Scotland next April. If it works out, this base could do double duty on my 6.5 Creedmoor which I predict will run out of elevation at about 1800 metres.
One thing I have found, is that the ballistic calculator firing solution only works if you put your own BC in based on past DOPE, the BC number on the box/website doesn't give the right results.
Biscuits wrote:Will be interesting to see how the 22LR goes at 500+ metres. 450m impacts on the target seemed to be moderately repeatable, esp given that I was holding over into an unmarked part of the reticle... or actually what I was doing was picking a ground feature well above the target and aiming at that with the lowest hash mark in my reticle, to hit the target which was another 6 milirad below the ground feature.
Will see how the 6.5CM goes at 1600-2000m. I'm wondering if it will be similar to when my 308 goes long range, for a 308. My ballistic calculator says the 308 is subsonic at about 950 metres. It is quite accurate to about 1000m. The furthest I have shot the 308 is around 1300 metres and for the same aim point, same environmentals, the impacts can be anywhere in a cone about 3 MoA across. 6.5CM could be similar, just further out. Obv you need to be very accurate with your rangefinding as the bullet is dropping maybe 3cm per metre at extended range, so a few metres out on your ranging equals a miss on the target.
This was my 22 on my 450m day; though for the 450m target I fired it prone.
Biscuits wrote:Spotting impacts is tricky; you really need sand or dirt around the target so you can spot a miss. And paint on the target to get a bit of spray of paint for hits. Wet grass would just end up being throwing lead downrange and almost relying on luck.
Brexit has really messed up U.K. shooters shooting in continental Europe. Before there was a European Firearms Pass… a Europe wide licence on top of your home licence. Now that is gone for U.K. shooters, so if you want to drive to Italy, you need to get a visitor permit not just for Italy but all the countries you go through on the way. You can’t fly, because you can only take 5kg of ammo by air, including the container weight.