Target Sports

GALLERY RIFLE: MARLIN LEVER ACTION PART TWO

Created on 26th May 2009

A basic tune-up by GWYN ROBERTS

LAST MONTH we stripped out Marlin's action parts; cleaned and inspected them for marks showing high spots plus any burrs; and adjusted the ejector to make the action lighter and smoother in operation. Now we continue work on the other components to achieve a slick, reliable rifle suitable for competition use.

To work in conjunction with the ejector the next step was to deburr and polish the slot that moves over it, along with the top and bottom surfaces of the bolt. I then used some very fine wet and dry sandpaper wrapped around a small flat file to lightly smooth inside the recess where the lever locates. I bevelled the edges of the holes containing the various pins slightly with a sharp blade to eliminate any binding, and then used a fine rubber block to smooth over a few burrs on the small lug that rides over the top of the hammer. Great care should be taken to ensure the height of the block is not reduced, as this will render it impossible to reset the hammer during cycling. The firing pin parts were also removed and the hole they belong in was lightly stoned to reduce internal friction, which will also help improve primer ignition. I did not alter the bolt face or the firing pin hole from which it protrudes, as this is an area that should only ever be modified by a competent gunsmith. Installing a one-piece firing pin will actually slightly reduce the closing force of the lever, as the locking block has to push the rear pin upwards against a small spring to align them both in order for the rifle to fire. The locking block also had quite a few rough surfaces, and particular attention was given to the sides where it rises and falls inside the frame.

Modifying the hammer and hammer spring will also substantially reduce the effort required to rack the bolt back and, if done properly, will provide a very smooth action that should help you shoot better on the range. Starting with the hammer, the first thing that I did was remove the burrs from one side of the hammer where it had been binding against the frame slightly. I then de-burred the edges of the strut that the spring fits over, along with the hammer screw and the hole that it locates in, and finished off with some light stoning around the arc of the hammer as it had quite a rough finish on it. I then polished up these areas and put the rifle back together again ready for the next step, which was to re-profile the hammer.

The most important thing to do before you start removing any metal from this part is to cycle the bolt slowly rearwards and watch exactly what happens to the hammer during the operation. As the bolt moves back the lower edge contacts the face of the hammer and starts to rotate it through its arc. You will then notice that the small lug on the bottom of the bolt then takes over and continues to ride over the top of the hammer. At this point listen carefully and stop moving the lever as soon as you hear the sear engaging. You will be able to see exactly how much excess material on the nose of the hammer can be removed safely. I then simply used a marker pen to draw a line level with the lug at the sear engagement point, and marked out a profile just above this point to give a ‘softer' arc line that could be followed on my bench grinder. Light pressure against the wheel and moving in a constant rolling motion will give the best results on a wheel. However, access to a flat-edged belt sander would give an even better result as the hammer could be laid flat against it instead of it having to be held ‘square' by hand. Once the hammer nose had been polished up, I put it back into the rifle and again went slowly through the cocking action to see if it needed more material removed. As it happened everything was fine.

The common sense approach for anyone doing this for the first time would be to mark out and remove a small amount of metal, polish it, refit it back into the action and then test the results. Then simply repeat the process, re-marking and making slight adjustments to the area to be profiled. Although it may take quite a few attempts to get it just right, remember that removing metal is easy but adding or replacing metal is not, so do be sure to only remove a very small amount each time.

Combined with this re-profiling I changed the standard hammer spring to one resembling a Ruger 10/22 piece I had lying around in my toolbox. It just means I have to use Federal primers to ensure reliable ignition, but that's all I've ever used anyway so no change there! As well as helping to achieve a very slick action this also decreases the trigger pull weight dramatically, as it reduces the holding pressure on the sear. It's well worth trying different springs you may have to hand or can obtain readily, and testing them on the range, as you can always cut them to length or simply add a small washer at each end until you get perfect reliability. You can, of course, just buy one of several ‘performance kits' now available - but careful selection of your own spring could produce the same result at a lower cost!

For anyone not familiar with handloading for competition use, Federal primers are the choice of most competitors simply because they are very reliable and are a little more sensitive than most. This makes them well-suited to use in guns with a ‘tuned' (which usually means lightened) hammer blow or firing pin strike for improved cycling and trigger pull. Remember that ‘light strikes' cost time and points, so there is no point taking things to the extremes where misfires due to insufficient hit on the primer become likely. Light but reliable is the balance we are looking for.

Cartridge carrier

Moving on to the carrier (or lifter, as it's sometimes referred to), all I did with this part was de-burr the pivot hole (and screw) and the two flats either side and also, very lightly, on the side holding the plunger where the lever makes contact. It is crucial that no metal is removed from the nose of the carrier as this will cause major jamming problems, and although the cradle that the cartridge sits on was slightly burred I also left that alone, as removing too much metal from this area will cause feeding problems. All that was required then was a quick polish up on the buffing wheel.

The next job was to remove the plunger from the lever; polish the V-shaped end that locks over the pin in the frame; and replace the small spring inside it with a weaker one sourced from an old pen. The standard spring holds the plunger under quite a bit of tension. Finding a suitable replacement (or taking coils off the old one) takes a bit of time and effort to get the lever to stay closed properly, but is worth it in the end. The lever on this rifle had some quite large scrape marks either side of the plunger housing, where it has caught on the inside of the frame when closing the action. Running it over some fine wet and dry sandpaper placed on a flat bench soon sorted out the problem, though. The last thing to do was relieve some of the tension on the trigger block safety spring, by placing a flat-ended screwdriver under the looped end and prying it up slightly so that the lever would close more readily and with reduced effort. The relevant parts were then oiled up and the rifle put back together and function-tested. The action certainly felt a lot smoother cycling through some dummy rounds, and the trigger pull weight was considerably lighter with the new spring installed. All that's left now is to find some small washers (to pack out the spring if required) and test-fire it at the range to check for reliable primer ignition. It's important to let the newly worked-on parts settle and to fire plenty of rounds through the action before entering your next competition. This will ensure all is working as it should, and allow you the opportunity to get the best from the improvements you have made.