Let’s face it, the Masterpiece Arms (MPA) chassis looks cool. Unfortunately, they have some not so cool engineering. Since the oversized vertical grip is advertised as something that can be shaped, I am not lumping it into the bad engineering. Fact is, I like that I can shave down the grip. My gripe with the MPA, in this case the Competition chassis, is entirely at the back.
If you are part of the crowd that does not like, or does not want to pay for a folding chassis, this post is for you.
To their credit, MPA elected to make the cheek rest and butt pad adjustable. Both make use of a thumb wheel. While the wheel allows adjustment, set screws are used to keep things firmly in place once adjusted. I have read several posts where there are complaints about having to use the set screws. Truth is, I have never used them and really don’t know why anyone bothers. Short of sliding the chassis on its side for a decent length, it is pretty difficult to imagine the wheels being forced to inadvertently turn far enough to make a big difference in adjustment.
Having the thumb wheels is where the good engineering stops and the bad kicks in. In both cases (cheek and butt pad) the wheel has a detent ball that is backed by a spring and set screw. While it seems reasonable to assemble things this way, using a steel ball that spins against the end of a steel spring is a really bad idea. The spring end has sharp edges that stop the ball, in turn locking up the wheel. And when I say locking it up I mean go grab a mallet and give it a few whacks to get it turning again.
MPA, if you are listening, steel body ball plungers are a real thing for a reason!
I am guessing the real fix for this is shell out the money for a correct size plunger. Assuming the right size exists they will probably run around $25 – $30 for a pack of 5. You only need 2, but I have never run across them lose so for me I am guessing it would be a 5 pack.
The DIY fix is to take a Dremel to the end of the spring and round it out so the ball has a smooth place to ride. It may take a bit of trial and error, but it can be done. I have 3 MPA’s and ended up doing the mod to all of them. The first one only lasted for a few weeks before it started binding again. A little more attention to detail seems to have fixed it for good. I did the second and third chassis together after the second one started binding as well.
The next head scratcher is the adjustable cheek rest. I am guessing MPA neglected to attempt sticking a bore guide into the action with a non-folding chassis else they would have surely done something different. We know there is no way they knew about it being impossible to do and not fixed the problem, right?
Yes, you have to remove the cheek rest on a non-folding chassis to clean your rifle with the aid of a bore guide. Simply, the bore guide will not make it past the rest even when it is at its lowest position.
At first glance this may not be a big deal. However, once you consider that shooters already complain about having to use the set screws, says they don’t like having the rest move once it is in place. This calls the entire design into question. Secondly, remember the detent problem? Running the rest up and down to clean during cleaning is when they locked up on me. Lastly, the wheel floats without the rest in place so it’s prone to moving around without the rest. When it moves, the steel ball and spring jump ship.
The butt pad has a similar problem if, like me, you run them in an elevate position. When the pad is raised you must remove it, or at least get it clear of the frame so you can tilt it, to get a rod down the barrel. Undoing the rest can quickly result in another lost ball and spring.
While I don’t have a good way around having to remove components to clean the barrel, I did find that a couple of plugs solve the problem of having the wheels shift out of place. Between modifying the springs and using the plugs, getting the chassis ready for cleaning is a reasonably quick process that I can live with.