You need a metal rod (brass, aluminum, or polished steel) near enough to be a slip fit in the bore.
(Think hardware store metal rack.)
But, if you have a .38 / .357 bore, and only can find 5/16" (.3125") rod?
Or a .45 and can only find 3/8" (.375")
Wrap tape strips around the rod until it is a slip fit and centered in the bore.
The problem with cleaning rods is they are always too small, and never center on a pointed bullet nose.
And the threaded joints expand and seize into the barrel when you apply a hammer too them!
The problem with wood dowels is they always have lengthwise grain pattern.
When they split, they become two wedges, driven side by side and wedged tighter then heck.
(Or, the end grain split wedged beside the stuck bullet.)
And there is no good way to get them out that won't ruin the barrel.
This is a 3/8" wood dowel rod pounded on a little, the hit once against a pointed bullet.
Get that wedged in a barrel beside a stuck bullet tip and you will have
The Mother of All Bore Obstructions to try and get out!!
View attachment 216237
Of course, the ultimate Squib removal is, don't have one in the first place.
If you are shooting a centerfire caliber and want .22 RF recoil?
You should be shooting a .22 RF!!
rc