The cap was mounted towards the contact gap from the gun (prolonged to sort a "nipple") and ignited by the influence from the gun's "hammer". (The hammer is approximately the same as the cock located on flintlocks apart from that it does not clamp onto anything at all.) In the https://tituskthth.blogprodesign.com/38173592/a-simple-key-for-sig-saeur-handguns-unveiled