Hey Mate,
there are a couple of things that i can notice… in one of the earlier images, the left elbow looks like it has an un-natural bend in it, like “Banana Elbow” if u have ever herd that expression. It means that it almost bends in a flat crease… perhaps u could try puffing out that area a little…
In terms of your pose, Remember Shilouette counts for alot in a good pose. Also i think the gun is too small, thats why he kinda looks forced, perhaps increase the size of it a little, also gives him more to hold on to… ( but then again i know nothin about guns n their size ) lol
if he’s not looking down the “Sight” then maybe lower his arms alittle and make more of a relaxed pose, if not, then bring the arms up more horizontal.
lol i sound like an animator…
maybe cause thats the other half of my job lol… anyway nice first try mate… keep it up…
The above it jus my opinion. 