Jessica Davis (Alisha Boe) shows off her father's Glock 19 to Bryce Walker (Justin Prentice) and pressures him into handling it in "Tape 5, Side B" (S1E10). She says it's a Glock 19 and it's her "favorite gun" and that it "holds 15 rounds" which she is correct about, but since the show takes place in California, 15-round mags are officially illegal due to California's strict laws regarding so-called "high-capacity" magazines.
In season 1's finale "Tape 7, Side A" (S1E13), Tyler Down (Devin Druid) adjusts his cache of illegally purchased firearms, ammunition, and homemade pipe bombs. Note: in "Tape 6, Side B" (S1E12), Tyler illegally purchased a handgun covered with a cloth (heavily implied to be the Kimber Ultra Raptor) and it is mentioned that it "has a bit of a kick". Since it is not clearly shown enough for an ID, it's not in one of entries above.
Error creating thumbnail: File missingTyler's cache in Season 1's finale "Tape 7, Side A" (S1E13). The following guns are seen: the aforementioned Kimber Ultra Raptor, Walther PPK (which appears to be the same prop shown in Jessica's father's gun safe), Intratec TEC-9, Beretta Cx4 Storm, sawed-off Remington 870, homemade pipe bombs, and Federal American Eagle branded .45 ACP ammunition along with Remington ammunition in an unknown rifle caliber, although none of the firearms seen in this cache chamber rifle ammunition. Note the filled-in hammer on the Kimber, meaning it's a rubber prop and the other guns appear to be rubber and/or airsoft replicas.