BSA R10 MK2 John Bowkett Blueprint Tuned .177 Air Rifles

MORE PHOTOS TO COME.

This is the most accurate well ballanced air rifle I've ever shot. My much loved BSA R10 MK2 JOHN BOWKETT BLUEPRINT TUNED is a thing of beauty. I'm selling because I don't get time to go use it much. Please read below of work done.

Included in the sale - the gun in walnut finish, bag, 2 scopes, bipod, 7ltr divers bottle, 1 mag, sling, buddy bottle o-rings, infrared torch and pellets. Everything you need to get you started. If I've missed anything, please refer to the photos.. you will get everything that I've documented in the photos.

So here it goes..

Pellet probe nose modified for smoother operation through magazine.

Oversize holding down bolt to secure the breechblock correctly onto the hammer/valve assembly and strengthen the scope rail.

Breech end of barrel sharp edges removed and polished for smoother feeding.

Smooth airflow into barrel from transfer port. Transfer port also modified for similar reasons.

Muzzle of barrel recess crowned and shoulder cut to 90 degrees with rifling to correctly line up a silencer when fitted.

Hammer tube honed and all contact surfaces in its slots smoothed out.

Steel hammer core machined to alter weight.

One off spring guide made from a synthetic material to a size to precisely fit the individual spring to be used in my R10.

Hammer spring adjuster cup fitted with bearing ring. Sharp edges of steel sear rod removed and rod polished in contact area where it latches onto trigger is honed for smoother pull.

Exhaust valve seat recut and knock-off valve modified for different return spring.

This spring is then fitted with a damper sleeve.

Secondary reservoir dimensions altered to suit 12ft/lbs use.

Buddy bottle valve seat recut to correct dimensions and valve shuttle modified to work as it was originally meant to and sealing at all pressure levels. A rather special red long life O ring is fitted!

Probe on socket where buddy bottle screws in is set to correct length so that valve does not open before it should and damage O ring seal.

Inlet valve assembly modified to increase seal surface area making it more robust and less susceptible to leaks.

Valve between high and low pressure parts of the regulator block replaced with one that works correctly avoiding any velocity curve over the shot string caused by the lowering of pressure in the buddy bottle.

The regulator works itself is binned and JB's “non-mechanical” regulator fitted. This does not contain any helical springs or spring cup washers making for a faster and more consistent regulator response.

The use of lightweight material for the piston speeds up the regulator reaction to pressure drop further which removes the need for restrictors in the system. These tend to clog up if a rifle is not used on a regular basis.

The regulator pressure setting is then matched to the individual rifle.

The bore of the aluminium regulator block where it seals on part 38 is honed for a better seal than provided by an untreated extrusion which can leave leak causing “tracks” during manufacture.

All sear surfaces in the trigger unit are honed. The trigger blade assembly pivot pin reamed out and an oversize roller fitted to smooth operation and remove any sideways wobble.

The springs inside the trigger unit are replaced to give a lighter second stage while maintaining safety. The whole unit is then set up to give a very acceptable trigger with minimum of creep before releasing.

JB bolt modification.

A non-removable carbon fibre reflex silencer shroud is made as a one-off for my individual rifle. UK made tube is used. It features an internal backflow bush combined with an air stripper and my special baffle system.