I have seen several instances where people were depending on a gun/ammo combination that didn't work. Fortunately, none found out the hard way.
That is the reason I always tell anyone who intends to use a semi-auto for serious purposes to make sure it will fire at least consecutive 200 rounds with the carry magazine and carry ammunition, no malfunctions. Revolvers are less likely to have problems, but should be checked out also.
One guy I know practiced with cheap ammo and had no problems, but saved the expensive stuff for carry. When I finally persuaded him to fire some of the super (and super costly) ammo, he got four failures to feed out of a magazine. So saving money could actually be costly, in a way you might not like.