"The problem is that even the strongest 3D-printable thermoplastic currently available for the FDM process (Ultem 9085) doesn't even have half the tensile strength needed to withstand the 24,000 psi maximum allowed chamber pressure of the .22LR round as defined by SAAMI (the Sporting Arms and Manufacturer's Institute).
As such, yes, a 100 percent 3D-printed gun made on a RepRap could certainly go "bang," but even with a barrel of large enough diameter to keep it from exploding, there would be so much deformation in the bore that most of the available energy would be sapped by gas leakage around the projectile (to say nothing of the utter lack of accuracy). In the end, you'd have a smoking, charred crater left for a barrel bore after the single shot."
http://news.cnet.com/8301-11386_3-57499326-76/you-dont-bring-a-3d-printer-to-a-gun-fight-yet/

dostrel ar-15 komp. zbrane je cez 3km (3500+ metrov), to, co spominas je ucinny dostrel na bodovy ciel (point target).
sice neporovnatelne, ale vz.58 (ina raz ako ar-15 komp. zbran, ktoru "tlacili" na tej tlaciarni a ina dlzka hlavne, ktora je pre max. dostrel rozhodujuca) ma ucinny dostrel 600m na bodovy ciel a max. dostrel je cca 2800m a po celej dlzke je smrtiaci.

kazdopadne "amatersky zbrojar" nepotebuje ziadnu 3d tlaciaren, staci mu hornbach, baumax ci iny dodavatel a dielnicka s nastrojmi pre rucne a strojove opracovanie kovov ;)