CZ 452 Benchrest Customisation Part 1 Sear Collate/ sleeve Trigger Spring The trigger has been using the Eric Brooks trigger kit. I had this trigger kit already on the rifle but I managed to get time to lower the trigger pull to about 1lb. The kit can be obtained from Eric Brooks directly at his new web address at http://www.cz452.com/ It is relatively easy to install and he supplies online instructions you can follow easily. There is a safety warning, so be aware of this. The kit comes with four springs and two collate like sleeves for the trigger and sear respectively. You can choose the weight of trigger pull by combining the springs with the two thicknesses of collate. As my rifle is meant for Benchrest I went for one of the lower trigger pulls. When set it comes out very clean and crisp with little or no creep in the trigger pull. Eric also does hex action screws, inch pound torque screwdrivers cleaning rod guides (which I hope to try out) and a host of other CZ goodies. The website is well worth a look. I bought new hex action screws a while ago to ensure I get accurate torque each time I disassemble the rifle, using a set torque screwdriver fixed at 20lb f in, which is a common setting for the CZ rifle with barrel lug. More can be found on torque settings on Eric Brooks website. To achieve consistent accuracy with your rifle it is well worth reading. Alternatively you can get the trigger kit from Roger Francis at South Yorkshire Shooting who imports Erics products directly at; http://www.rimfiremagic.co.uk/ . I think most of the CZ rifles he sells go out with this trigger kit already installed Set screw I also made a set screw to try out for the barrel lug on the varmint. This retains the lug in a fixed position so it does not move. (Do be careful when tightening this as with lighter/ thinner barrels it could distort the barrel and rifling. It does not need to be too tight. If unsure leave it.) The CZ 452 does differ in design from one model to another, some actions having a barrel lug with a retaining bolt, plus one action screw. Others, like the American, have two action screws. The Varmint model has the former design and there is much debate over the usefulness of the barrel lug, (some throw it away just relying on the one action screw). Having read a bit about bedding I believe the barrel lug works well, as it acts like a basic pillar bed on the barrel. If you read the article at http://riflestocks.tripod.com/ things make sense as the barrel should be bedded in some way up to the balance point of the action and barrel. The barrel lug does this in part. There are various articles on the web and rimfire central on this theme and it is worth taking a look before you start overhauling your rifle. You need to decide for yourself what method you will use. After talking to Eric Brooks, who is the US guru for CZ rimfire rifles, I did a bit of reflection. I asked if the barrel lug should be removed. Although he does not favour the barrel lug design, as it can give rise to inconsistent reassembly, he recommends setting it in the way described. However, do experiment with the torque applied when setting the action and screws back in place. (Remember CZ usually set the action screws between 20 and 24 f in). Bedding the action into the stock is part of this process and I will get around to that when the stock arrives. I have some parts ready for this which I will deal with in a later article. Next I hope to get the bolt jewelled, as I have been experimenting with patterns over the last month. (I did manage to prepare the bolt by polishing to a near mirror sheen). Before/ After It is time now to bite the bullet, not literally, and get on with it. Bill Shehane has started to make my stock, so I hope this will be with me in next month to six weeks. Once that is with me I can finished the lacquer on the wood and begin bedding the rifle. His stocks can be found at; http://www.scopeusout.com/ I also hope to get the extension of the bolt arm started, but we will see how long the above takes me. Part 2 Quite a few things have spurred me on with the next part of the project. Not least the arrival of the Shehane Tracker stock, which is a thing to behold. Anyway more of that at another time. I will have to wait to bed the action and finish the stock as I am still waiting for parts to convert the CZ to single shot only. (The part is from the Walther KK100 target rifle, which uses the same receiver as the CZ 452). The bolt jewelling went well, all be it the pattern turned out slightly different to what I wanted. Instead of going into details here about how it is done, the following website has ample instruction. http://www272.pair.com/stevewag/jb/jb.html I suggest using a very abrasive compound on steel, about 120 grit. For a finer finish like mine 400 to 600 grit. It depends what you want? The Brownells brushes shown in the web article can be bought from any hardware shop, including B&Q, for between £2.50 and £4. With the bolt suitably polished and cleaned the next part for the equation was the make an extended bolt arm. Two reasons for this; One, the CZ bolt knob is very close to the wood work and hard to grip from a bench position. It does not protrude out for an easy grip. Two, I wanted more leverage when working the bolt, to try and reduce movement between shots. Firstly the original knob has to be removed. Do look at the amount of metal you are leaving yourself to put a thread on the metal that is left. The part of the arm that is left will vary from rifle to rifle, but the smallest diameter on mine was 5mm, which is ample to turn a thread. (It actually varied from 7mm to 5mm, thus some filing was necessary to form a round of 5mm. If you wish you could build up the metal to 7mm by using a mig welder, but protect the rest of the bolt from splatter if you take this route). The new bolt knob has been turned from aircraft grade aluminium, as I love this metal as it gives a great finish. The design is similar to some Italian ones I have seen and liked in the past. Both bolt knob and arm had 5mm threads turned using a tap and die; the knob whilst still on the lathe to ensure a straight thread was cut. When all cutting has been done, finishing the bolt arm and knob with silicon carbide cloth is a must to get a fine finish. The steel arm needs 200 to 400 grit to accept new bluing, whilst the aluminium needs 600 to 800 grit. After bluing the steel both are then married together using a thread lock adhesive; I used the medium strength adhesive just in case I want to change at a later date. After all polishing and finishing I was very happy with this part of the conversion. The handle is now about 115 degrees from the vertical , giving a much better grip and access to work the bolt. Lastly, for this session, I decided to adapt a BSA Martini trigger shoe to give a better feel to the CZ trigger. The original is hard to feel at times and I wanted something better. The shoe was shaped to fit the profile of the CZ trigger better, using an epoxy putty to mould the shape of the trigger to the shoe. The putty is very strong and takes the shape of both easily. This was them reduced and finished with a sparing amount of aluminium black. (This was also used on the bolt arm extension). Aluminium black is best sealed using clear enamel, acrylic varnish or gun stock oil. Next time I hope to report on the stock or the new trigger guard I want to make. So far can I say many thanks to Bill Shehane for an excellent product, Eric Brooks for his support and not least Vince who has answered all my questions and best of all made me think. Part 3 At the time of writing most of the furniture for the new rifle is now done. I have a few bits to finish off, but these are minor and next stage is the final one of bedding the rifle and fitting everything together. However, let’s get back to how far I have come thus far! One of the things I have found, like most, is when you get good service keep going back to the place you get it. Try as I might to get one part for the rifle refit, a new single shot shell plate, I could not. I forgot that a local supplier I use a lot did business with Walther. Why Walther when I am developing a CZ 452? Well the Walther KK100 prone rifle uses the same receiver as the CZ 452.