Very low spoiler notice Typical average Isekai story, light hearted with decent ideas but plague by typical tropes that are over-used and a lack of tension or real challenge. As someone who does enjoy airsoft and real guns, I tried giving it a read to see how this typical isekai will go. The isekai part is poorly established at the beginning. He just can go to the other dimension at will and go back home. All his BB guns turn to real one in that isekai fantasy world with unlimited ammo. He instantly acquire the typical sword women Rena as a partner for his adventures. So there is noreal relationship building, it just happens instantly.
What I find bothersome is the poor knowledge the author has on weapons and over glorified them. The main protagonist use most of the time non-lethal bullet aka rubber bullet.
Which is technically very slow projectile and low range compare to the more lethal ones.
But when fighting bigger entities, his choice of weapon is left to be desire. The damage they do is over the top exaggerated.
The combat in the story is very low stake since it's very light hearted. Because the author doesn't establish what type of weapons the MC has, he can pull anything at will and justification.
Daisuke never find himself in a real life threatening situation and never take any situation seriously but more like an entertaining discovery and curiosity with what is happening despite him being in danger.

If you feel like reading a simple gun fantasy isekai with no stakes at play. Feel free to give it a try.