As Rusty stated, most I've seen have the emitter in a correct size tube centered in the "barrel." One joker even tried running his as IFA, that got shot down pretty quickly via
self policing at the Danville battlefield. Figure a Sturmtiger is no different than a Hummel or Sherman 105 on the field. Sure the Hummel and 105 were more easily used in a direct fire scenario but not much is realistic when it comes to IR battling anyways.