What is "converted guns"

Convert \Con*vert"\, v. t. [imp. & p. p. Converted; p. pr. & vb. n. Converting.] [L. convertere, -versum; con- + vertere to turn: cf. F. convertir. See Verse.]

1. To cause to turn; to turn. [Obs.]

   O, which way shall I first convert myself?
   --B. Jonson.

2. To change or turn from one state or condition to another; to alter in form, substance, or quality; to transform; to transmute; as, to convert water into ice.

   If the whole atmosphere were converted into water.
   --T. Burnet.

   That still lessens The sorrow, and converts it nigh to joy.
   --Milton.

3. To change or turn from one belief or course to another, as from one religion to another or from one party or sect to another.

   No attempt was made to convert the Moslems.
   --Prescott.

4. To produce the spiritual change called conversion in (any one); to turn from a bad life to a good one; to change the heart and moral character of (any one) from the controlling power of sin to that of holiness.

   He which converteth the sinner from the error of his way shall save a soul from death.
   --Lames v. 20.

5. To apply to any use by a diversion from the proper or intended use; to appropriate dishonestly or illegally.

   When a bystander took a coin to get it changed, and converted it, [it was] held no larceny.
   --Cooley.

6. To exchange for some specified equivalent; as, to convert goods into money.

7. (Logic) To change (one proposition) into another, so that what was the subject of the first becomes the predicate of the second.

8. To turn into another language; to translate. [Obs.]

   Which story . . . Catullus more elegantly converted.
   --B. Jonson.

   Converted guns, cast-iron guns lined with wrought-iron or steel tubes.
   --Farrow.

   Converting furnace (Steel Manuf.), a furnace in which wrought iron is converted into steel by cementation.

   Syn: To change; turn; transmute; appropriate.