Many forms of smallbore rifle competition require that the rifle meet certain maximum weight limits . . . or have trigger pulls that do not fall below a certain minimum weight.     There's nothing worse than arriving at a tournament all ready to shoot, and then finding out your rifle is too heavy, or the trigger pull is not heavy enough . . . Result ?     Disqualification . . . before you've even fired a single round !

So . . . why not have your very own deadweight checking equipment so that this is not going to happen to you.    There are certified official trigger deadweights available on the market, along with exotic and expensive weighing scales.    But, with a little thought, you can put together a convenient package that will do the job for less than $30.

The most expensive part will be the purchase of one of the inexpensive electronic digital scales available at most fishing gear stores.    I have used the Rappala scale from Wally World in conjunction with a simple "looped cord" sling for many years . . . it has proven fairly reliable and reasonably accurate in weight indication.    Typical pricing for these units is in the $20 to $25 range.     I verify its' accuracy for checking the 7.5# CMP weight limit with my own deadweight checker - (Ref. Picture below !)     

The 7.5# deadweight is made up from three 2.5# 'lifting' weights bolted together with a threaded eyebolt, two penny washers and a locknut.    Now, obviously this all adds up to more than 7.5# . . . check its' weight with your Digital scale.     Let's assume it now weighs 8# according to the scale readout.    So - we're somewhere about 0.5# too heavy.     Doing a little simple arithmetic, we divide that excess weight by the approximate density of the cast iron used in the weights . . . 0.284# /cu.in.     The answer . . . 1.76 cubic inches of weight material needs to be removed !

How to do it ?    Well, let's say we use a regular 1/2" drill bit and drill holes in the weights.    A 1/2"hole will remove 0.5 x 05 x 0.7854 =  0.2 cubic inches of material per inch drilled.     So we need to drill approximately 1.76 / 0.2  =  8.8 inches of 1/2" hole in the weights.    Now , the stack of bolted weights is only about 1-1/2" thick, so maybe drill four holes all the way through, equally spaced around the centre . . . that should remove about 1.2 cubic inches of cast iron weighing some 0.34# .

Now re-weigh the assembly and see how close to the desired 7.5# you have come.    Remember you don't yet know how accurate the new scales are, so you don't want to take off too much weight yet.    Make a note of the weight and get in the car and take a short trip !    Where ?    Well I head off the mountain and down to our local "friendly U.S. Post Office" and ask the gal at the counter to please weigh the blob of weights and eyebolt on her certified scales . . . smile as you ask ! Now, if you're a handsome old "Sean Connery look-alike" like me, she then tells you the exact weight in pounds and fractions of an ounce . . . Bingo !    Now drive home and figure out exactly how many more holes have to be drilled - and to what exact depth - to arrive at a final weight for the assembly of 7.5#.     Go drill the holes !    To finish up I suggest going back to the Post Office and sweet talking that gal into re-weighing the assembly.    If exactly correct, mark the weight on the assembly and you're finished.    The odds are however it'll be slightly too light or too heavy.     Make the final correction for the exact weight by marginal drilling of one of the last set of holes . . . or by adding additional washers under the nut on the eyebolt.

Now weigh the check weight assembly on your digital scale.    This will give you a fair idea of any inaccuracies in the scale at the limit weight so that you can make the necessary mental adjustments when weighing actual rifles.

Now let's move on to the trigger pull check weights.    For these . . . I have two of them, a 2# and a 3# deadweight . . . you'll need a 2' length of 3/16" diameter steel rod, a suitable dumbell or flat 2.5# lifting weight, a #10-24 nut and a few 3/16 steel washers.    The picture above gives a pretty good idea of what to do.     I use the flat weight for 3# checking and a cut-down dumbbell for the 2# checks.    First put a right angle bend at one end of the rod about 2 to 3 inches from the end . . . then put a double joggle bend in the opposite end of the rod so that the axis of the remaining free end of the rod is located about midway along the original end hook.    This joggle must be about 14 to 15 inches down from the hooked end in order to clear the butt-plate of the rifle being checked.     Thread this end of the rod with a #10-24 die for about an inch or so.

Referring to the picture above for location, drill and tap the end or edge of the weight with a #10-24 threaded hole.    Screw a nut on the threaded rod, and then screw the rod into the weght.    Now check the total weight using your new relationship with the Post Office gal.    Adjust the final weight by drilling the weight or adding washers or other suitable small weights to get the test weight exact.    A little flourish that makes the rig look more "official" is to slide a small piece of 3/16" bore plastic tubing over the hook end . . . don't forget to include this in the final weight !

To use the trigger pull weights, cock the rifle and hold it vertically by the barrel.    Now place the check weight hook over the centre of the trigger with the deadweight resting on the ground.    Now lift steadily and gently !     If the trigger will lift the weight off the ground without releasing the cocked sear then the trigger is "legal" for that specific minimum weight limit.    A light touch of a finger of your free hand on the top of the hook while lifted will tell you whether you need to do a little more adjustment to "lighten" the trigger/sear arrangement.     Or conversely . . . !