My 300WM Match barrel came with the fitted Pic rail but at the time I didn’t have much in the way of Pic mounts so I took it off…. to reveal an extra locating stud set into the top of the chamber to position and and set the rail. The barrel also came with the standard inlets for the Saddlemount and the mount will sit over the stud without interference.
Standard Saddlemounts can be used without a problem on the LRS2’s
For Picatinny/weaver, historically there was a seller called zruncho(Bojan Soyanov) on eBay for the Bulgarian Gunstar Blaser mounts but I’ve just looked and not found him….. however Gunstar might post to the U.K.?
This is the link to the long rail I use on mine …it should be noted there is an element of flex but I’ve learned to keep my free hand off the scope when taking a shot…
L = 200 mm; ВН = 13,7 mm; М = 0,194 кg; Брой канали – 17; Корпус (монобаза) и заключване – 100% термообработена стомана;
gunstarmount.com
With the .243 barrel….. I shoot right-handed but having a lh bolt made sense on this rifle so the action could be cycled without shifting body weight, losing grip and control of the rifle whilst maintaining the sight picture……credit for that to
@schmidtman who I bought the rifle off in the first place.

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With the “Hubble” fitted, high mounts with the additional 5mm risers……
Also shows my diy narrow cheekpiece cut out of an old Remi700 stock with the Blaser riser plate, a couple of bolts to position it and expanding foam to hold it together. I made this as the original cheekpiece is way too ‘fat’ for me….and, once adjusted latitudinally, I couldn’t swap sides without laying my head on it… not conducive to accuracy and left-handed shooting.
View attachment 379888
Cheers,
Fizz