Mount Burris Signature Tactical rings: TRG22/S&B PMII 5-25

[Topdogpippin]

Burris signature tactical rings fitting to TRG22/S&B PMII 5-25
I saw these pop up in eBay and did a bit of background on them before I bid, the attractive part being the start price of £20 and the fact that having paid a lot of money for the scope new, I normally buy s/h, I had fitted a pair of very good quality steel rings that mic'd up at 32mm,as many will know this is not ideal as the S&B tube is 34mm. They fitted fine, did not pinch the tube, and dialled in with little problem. The rub was that ,despite them being 20 moa rings, there was still another 28moa of elevation adjustment left after zeroing, so not really getting the best from the scopes' spec. Now, the likelihood and the opportunity of getting to use or having to dial in that 'lost' 28moa Is going to be rare but the OCD clicked in and the gadget need!

The principle behind these rings is that the mount heights (these are the 'low' version) are both the same base to bottom of ring but they have inserts which clamp inside the ring which allow either 0,5,10,20,25,30,40 moa of adjustment. It does this by utilising elliptical interior insets of 0 moa x2 and +\-5 moa +\-10 moa and +/- 20 moa of which there are two sets. The extra range is achieved by combining say a -20moa ring at the bottom of the front ring and a +20moa at the top (they MUST be used in matching pairs +/-) and say a +10 at the bottom of the rear ring matched of course by the paired -10 at the top, this maintains concentricity and gives a total of 30moa, hope that is clear, if not they are well covered off on the web.

So, to try and get at my elusive 20mm I decided to buy the rings as, even if the adjustment principle was unusable, they are well manufactured by a reputable name and the inserts, which are plastic, would be kind to the tube. In the end nobody else bid on them so I got them for £20, bargain, I hope!

Having read a bit more the first thing I did was to mic the inserts as I had read that some sets had gone out with the shims mis marked, these were fine. Now let me say, THESE ARE FIDDLY, the other thing to bear in mind that if the rings are not set equally to the horizontal axis of the ring they will of course act as a collimator therefore affecting adjustment on the horizontal axis I.e. Windage. I went through the standard scope mounting procedure to get the eye relief right and initially set it up with the 20moa inserts in the front ring, - at the bottom + at the top and the 5moa at the back + at the bottom and -at the top this should have given me roughly the missing 28moa. At this time the ring distance between centres was 4 inches. The distance between the illumination adjuster and the bell to the objective lens on this scope is quite limited with, of course, the reticle housing in between. Using this setting and using a laser bore scope this still did not give me full access to the adjustment range leaving a missing 10 moa. So I disassembled all over again and put the 20moa adjusters in the rear again +20 at the bottom and -20 at the top so the reverse of the front inserts and this should be 40 moa total. After reassembly I was still missing 5moa! Again reference to the wonder of the web and the instructions that came with the scope I again disassembled the rings and moved the rings closer together, now 3.50 inches apart and BINGO! Dialling the scope down to the bottom stop I only had to come up 1moa, 4 clicks on this scope, to match the laser dot and then set the zero stop in the turret. Now you know why I say FIDDLY.

As as yet I have not shot the rifle and we are away on holiday soon so I will post my finding from the range. The fly in this might be the effect of the inserts on the windage setting which only seem to be 4moa off the original setting but if I want to centralise the windage adjustment and see where the poa is then and adjust the eclipse of the inserts then this will affect the elevation as at the moment, relative to the vertical axis, I have maximised the down angle, this obviously changes if the inserts are rotated to adjust for the horizontal axis.

I hope you find this post of interest, or at least an advice that unless you have a few hours to spare and reasonable degree of patience these may not be for you!

[ovenpaa]

I will be interested to hear how the laser indicated POI varies from the actual POI at your chosen zero. I use a laser all the time here and zero at 10m which is the length of the workshop, I have tested with many known zero rifles as well and have a good feeling for where it should point for our local 25m or 100m zero. One thing I can add is it is seldom within 100mm/4"

[Topdogpippin]

Hi again Ovenpaa, Will let you know. It really is, as you well know, just a guide, and I did it from my gun room across the hall into the furthest room which is about 18mtrs. A high tech answer to bore sighting but I normally move the laser through 90 deg four times to get an idea of the 'average' of the indicated poi and then adjust the scope accordingly. The club's range for full bore is 50 Yds so I normally drop a couple on a marker in the sand back stop and then move to a zeroing target of my own designs so I t is good and safe enoughto be on target when taken to one of the MoD ranges we use.

[Topdogpippin]

Hi all, a quick update on the range experience using the Burris Signature adjustable rings detail of the whole rig in the foregoing posts.

From the indoor efforts with the laser bore tool I took the setup to my club range and got a good zero on our indoor 50yd tunnel and it was only 2 or 3 moa out on the windage so I adjusted for that and re set the marked zero. Elevation again was 2-3 moa so dialled that in and did the same with the elevation and zero stop.

I have had two trips to the range first 300 and 600. This proved very frustrating as, unbeknown to me one of the club youngster (15) was marking my target. There were six of us shooting and the two shooters to my right were using CSR's with open sights and the feed back I was getting turned out to be reflecting their rounds down not mine. I ended up going to maximum adjustment right and then undoing the adjuster re setting it to "0" and based on the feed back went max again. As we were rapidly running out of time, a 25min detail aaarggh, I held over the full width of the reticle and bingo, straight on target, he had been calling me the wrong way!!

On returning home or took the windage knob off and counted stop to stop, 250 1/4 moa clicks total, so from one stop I counted back 125 clicks and waited for are turn to the 50yd tunnel. This proved, again, only to be 3 moa out which I adjusted for.

Next trip was to my favourite MoD range in Somerset and we shot 100, 200 & 300. This gave the set up and me a better off than straight in at 300 and no pressure as we had plenty of time and experienced shooters/markers. To my relief the gun was spot on for windage so I don't have to adjust the eclipsed inserts and can now leave it alone and shoot it. I haven't had a chance, or kit, to chrono my current load which is PPU cases loaded with 43.5g of VN140 under 155g SMK FMJBT (usual caveats apply to personal load data, this is not a recommendation!) using a generic ballistic table as a guide the round was impacting nearly 1moa higher than the table guide. Now my confidence with the set up has grown I will take the time to log a comparative impact chart and draw up another stock mounted ready guide which is my preferred method, a bit ol' skool as they say but I can't be asked mucking around with tablets and glasses etc. when a quick glance gets me on the target so easily.

So, I would recommend these rings, the rings themselves are well made and constructed and the flexibility the inserts allow would work for a variety of scope/gun/rail combinations to maximise the adjustment on your particular scope. Obviously much more relevant for LR shooting than any kind of sensible stalking or varmintimg ranges unless using small calibres or reduced velocity loads.

[ovenpaa]

We had a chap at one of the clubs I was a member of who used to get tired so marking became sporadic after a while, usually afternoons. I asked home why he was no longer marking and he replied they were in the black so good enough...