WASHINGTON (AP) -- The Senate Judiciary Committee postponed its work Thursday on writing bills curbing guns, probably until next week.

The committee is considering Democratic-sponsored bills that would ban assault weapons, strengthen federal laws against illegal gun trafficking, provide money for school safety improvements and expand the requirement for background checks for gun purchasers.

Such delays are common for the committee, which often grants them to give senators more time to work on legislation. As the panel began discussing the measures Thursday, top Republican Sen. Charles Grassley of Iowa said he had questions about the constitutionality and cost of some of the measures and said senators needed more time to trying working out differences.

The postponement will also prolong the period of time that Sens. Charles Schumer, D-N.Y., and Tom Coburn, R-Okla., have to try crafting a compromise on requiring background checks for nearly all gun purchases. Talks between the two have been stuck over Coburn's opposition to a requirement that records be kept of private sales between individuals.

Recalling a plea by wounded former Rep. Gabrielle Giffords, D-Ariz., that lawmakers take action to curb guns, Commmittee Chairman Patrick Leahy, D-Vt., said, "I agree that we must act, and today is the next step in that process."

Leahy assured Sen. Dianne Feinstein, D-Calif., that she would get a vote on her bill banning assault weapons and high capacity ammunition magazines. That measure, in particular, has drawn strong Republican opposition and been treated warily by some moderate Democrats, and it faces long odds for congressional approval.