Scope rails & QR mounts

[Brushy]

Looking to abuse the collective wisdom further......

 

I have 2 x Tikka T3s. One is a .308 (running 155g amax) and one in 300 WM (using 208 amax). I have an S&B PM 2 and I'd like to run this on both rifles using some good quality QR mounts.

 

So here's the question:

 

If I buy 2 x picatiny rails with the same cant (20-30 MOA) could I run the same scope on both rifles with minimal POI shift? Furthermore, does anyone have any experience of the on/off repeat-ability in return to zero? Finally, how different are my POIs likely to be between the 300 and the 308. Both run chassis systems so there should be no influence from stock - barrel interactions

 

Thanks in advance,

Brushy

[jcampbellsmith]

It depends is the short answer. You are only going to really find out by doing it. One option would be to get a selection of rails so that you can try and select two good rails and return the rest?

 

Regards

 

JCS

[Brushy]

Hi JCS,

 

Thanks for the prompt reply. I had suspected that it might be a 'suck it and see' case.

Recommendations for a good 34mm QR rings (or one peice mount)?

[Laurie]

With a good quality rail and mounts you can remove and replace the scope with minimal zero shift - but obtaining a near zero windage shift usually needs a torque wrench to be employed (if 13mm nuts, the Tier One setscrews or similar). The better lever operated mounts (ie the type that don't allow variable thumb tightening, rather are side mounted, cam over, and hinged at one end seem to manage this feat too.)

 

So far as using one scope on two rifles go, you'd almost certainly end up with two different zero settings. In theory, you can zero the scope for one rifle, and assuming we're talking a target or tactical type scope with easy to read and zero-set turrets, set both elevation and windage turrets to their zero setting; then redo the exercise for rifle #2 and note the new turret settings for whatever distance you're zeroing at - eg plus or minus a minute or two of elevation and whatever numbers of minutes, a fraction of a minute if you're lucky, left or right windage.

 

If you mainly adjust the scope for elevation for distance and aim off for windage, it can work. If you click windage a lot, it's a recipe for disaster and confusion. The KISS principle is definitely a good one to follow for scope mounting and setting.

[terryh]

Brushy,

 

you do not say if your PM2 is SFP or FFP?

 

If It is FFP then switching between rifles you can adjust once and leave be, then use the mildots for windage.

 

For elevation you could have a second wrap put on the turret for the 2nd cartridge - just do not get the two mixed up?

 

Terry

[gbal]

Brushy,as I understand the question-same scope moved from 308/155 g and 300WM 208g loads,will POI be close....well, err...not very,as Laurie. Could they be brought closer....well,maybe-it's all about BC/MV 'fiddling' in particular rifles-

assuming return to zero scope on/off in both....and how close do you have to be...?

Since you give no MV data,here is the nearest I can get with reliable data (not someones wish full extrapolations)-there isn't a lot on the 208 Amax BC .65 in 300WM.

 

 

30amaxBC.435 MV2750;200 0/3.2;300 8.3/7.4;400 24/14;500 49/23; 600 84/34;800196/66; 1K383/112

 

30WM Nos200.588 2800;2006/2.2;3007.3/5;400 21/9.5;500 42/15;600 71/23;800 157/43;1k 293/72

 

200-1k yards,drop /drift inches in 10mph wind.

 

Sorry there is no data on 208 Amax.

Can the two sets be brought together...suck it and see seems optimistic-there will have to be turret twiddling,though if two zero sets are possible,it might be workable.... with some velocity fiddling too-or BCs etc-a recipe for compromised,though....and MV varies with temp etc etc....and drops/drifts are simply not linear in either (any) cartridge,let alone coincident in two different multi variable loads.

If you only shoot largish targets at moderate range,maybe-but then you won't need 300WM?

Switch barrel shooters might be able to hold out more optimism/experience?but eg 800y: 196/66 and 157/43.....hardly close.

 

gbal

[DW58]

I have a quick detach Picatinny mount on my T3 and have swapped it from rifle to rifle (between us my son and I have 3 T3 rifles).

 

I use an Innomount - perfect return to zero every time - available from https://www.optics-trade.eu/uk

[Brushy]

Hi chaps,

 

Thanks for the replies so far. The scope is a ffp so I could aim off for windage on the second rifle.

 

General question, if i were to a purchase a good quality unimount (I.e not QD) and torque it down to the same torque each time,would the return to zero be expected?

[Laurie]

Unimount? Yes I have three scopes on Tier One Unimounts and I attach and demount them to their respective rifles for each day out. I found use of a torque screwdriver essential to obtain consistent windage zeros, but reattaching this way sees any inconsistency under a half-MOA - if there is any at all.

[Brushy]

Great stuff - thanks for the info Laurie.

[Scrumbag]

Folks, what do we think are the best QD rings?

 

Thinking of having a target and a hunting scope for the 7x64.

 

Scrummy

[Laurie]

Tier One (Evo Leisure in Heckmondwike) must be near the top of the tree - it makes both paired and Unimount models for Picatinny rail mounting. There are the expensive US 'tactical' mounts - Badger Ordnance, Leupold M4s and suchlike. Ken Farrell (American) mounts are very good.

 

I used to use Burris Xtreme Tacticals on several rifles and they were available at very good prices from Ebay suppliers and worked very well. However, my last pair was disastrous - barely fitted the rail and gave a huge windage change on each refitting. The change from earlier purchases was on the packaging and the bases ....... 'Made in China'.

 

I've used Brownells' tactical mounts recently and have been pleased with them - I needed a 'super-high' 30mm set and this was one of the few available in the form and were cheaper than Leupold M4s (which were also shown as unavailable in that height anyway at the time).

 

For finger tightened mounts, German Recknagel (from Alan Rhone) and Weaver QRW are good, but I prefer to be able to tighten mounts up with a torque wrench. Recknagel does tactical mounts too with odd delta-shape nuts and supplied matching socket/bar tool at a fairly good price. I think it does a dedicated torque wrench too (like Leupold), but that's an extra cost.