What a surprise that I did this topic. I've got a few that are popular/well known and/or iconic/seen in the series. Seeing as to how Pratt's character is ex-military, I'd imagine some cool weapons would be in it.

Sniper Rifle

Barrett M82A1

My personal all time favourite rifle, the Barrett M82A1 is a .50 BMG, 10 round semi automatic anti material (meaning it was meant to shoot vehicles, not people) that is accurate at over a mile.

Shotgun

SPAS 12

My all time favourite weapon, this Italian shotgun was made badass by Bob Peck in 1993 when it was used in Jurassic Park. 8 round semi automatic and pump with a top folding stock (with the hook in later variants) make this shotgun pretty cool.

Assault Rifle

M4 Carbine

Along with the SPAS 12, this weapon was seen in Muldoon's armoury in the 1993 Jurassic Park film. It is a 30 round, fully automatic .223 that is the same as most other American made assault rifles.

Other

M72 LAW

The M72 LAW was used by Robert Muldoon in the Jurassic Park novel, and using tranquilizer rounds, brought down the T-Rex. It is a military rocket lainches, but may be outdated compared to newer rocket and grenade launchers.