Reloading Meplat Trimmers
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- Last updated: 23/08/2021
I have touched on this precision rifle reloading kit as an aid to improving ammunition and now I have done an in-depth study. The way a bullet traverses the air on its way to a target potential accuracy. The ballistic coefficient (BC) is one thing but having a uniform tip/ Meplat on the bullet is also important.
Excluding polymer tipped projectiles, if you look at some bullets, you will often notice how the closure of the copper jacket does not always come to a uniform circumference. On the whole, this is not really an issue at normal ranges, however, as distances increase, shooters strive for as much precision and less variance as possible. Hence trimming or uniforming the forward section of the bullet has become quite popular. It is very easy to do and extends the bullets aerodynamic stability.
I have used the Sinclair Meplat trimmer on bullets to uniform their profile. It can be used not only for your reloads but can also trim up any factory loaded ammunition too. It retails between £80- £100 depending on the retailer.
I like the tool as it’s very compact and lightweight, weighing only 175-grams. It can easily be mounted to a reloading bench or wood block for ‘in the field’adjustments on the fly.
The tool consists of three major parts. The black anodised support stand has a single screw hole, which is used to fix it to a bench, and an Allen screw at the top for securing a calibre specific, cylindrical aluminium housing. This has a calibre hole at one end and the cutter at the other.
The cutter is hand crank only and is not designed for powered use, which is sensible as you need a delicate touch to achieve precision. It is manufactured from hardened steel and shows a spiral twin cutting face that revolves easily in the housing. There is a small orifice on top of this housing for oil if desired.
The handle/crank arm is made of aluminium and can be removed by loosening a single grub screw. This allows the cutter to be swapped out for a different sized one if required. A small, black, free revolving handle allows a delicate touch to the cut as it progresses.
Operating the tool is very simple and it is most stable when screwed to a bench.
Alternatively, you can use a small G-clamp instead. At the top of the housing is a large window, which allows you to clearly see the cutter and the bullet during the trimming process. There are two methods of setting up the trimmer, either works fine and comes down to personal preference.
The first method is thus. Using a 3/32 Allen key, loosen the set screw on the crank handle that holds it to the cutter shaft. Next, insert a bullet into the housing end, tip first, until it engages and stops on the taper. Whilst holding the bullet in this position, slide the cutter up until it touches the bullet meplat. Now, set a small distance between the housing and the crank handle on the cutter by inserting a spacer, then re-tighten the crank handle screw. This gives you your cutting depth as the cutter crank handle will contact the housing spacer and stop cutting. This means you can specify the trim depth that you want.
The alternate set-up procedure is the same, to begin with. Start by loosening the crank handle and then insert a bullet until the taper is engaged. Again, keep pressure on the bullet to stop it from moving and look for a set screw located on the rear of the crank handle. While holding the cutter against the bullet tip, screw this set screw clockwise until it contacts the cutter housing. Now add a further ¼ turn to push the crank away from the housing body. This approximately equates to a 0.008” (8 thou) cut.
Once set up you can begin to trim some bullets. It’s best to press firmly but squarely on the base of the bullet and slowly rotate the cutter arm crank handle. As the cutter engages the tip of the bullet, you will find that the projectile will try to wobble and move. This is normal as the cutter begins to trim the even part of the meplat, and it actually shows the tip needs cutting! When the cutting depth is reached, relax the pressure and remove the bullet. If it sticks on its taper in the calibre specific hole, then nudge it out through the inspection slot.
Usually, you will trim off about 0.005” (five thou) from the top of the bullet tip, but it depends on how bad the closure is. You can also custom turn down a head to make a more open hollow point, as some bullets have a larger than seen cavity behind the tip. This can be exploited by opening it up to allow even better expansion. I am thinking of subsonic centrefire loads here!
Obviously, there is a small downside to what effectively is flattening off the meplat area, as the streamlined nature of the projectile will decrease. In reality, it’s only about a 2% reduction in quoted (BC) values anyway. Good luck if you can judge that type of trajectory difference when out shooting. I would much prefer knowing all my bullet meplats are as consistent as possible and adjust elevation accordingly.
It’s a small tool that makes a big difference and really does not take much time to use, especially when you think of the benefits. If you are keen on exploiting the best possible accuracy from your factory or reloaded ammunition then a meplat trimmer from Sinclair, Montour County Rifles (MCR) or Whidden won’t disappoint.
Norman Clark Gunsmiths - www.normanclarkgunsmith.com
Brownells UK - www.brownells.co.uk
1967SPUD - www.1967spud.com