The Oregon Supreme Court ordered changes Wednesday to the ballot title of an initiative that would ban the sale of many semiautomatic guns and high-capacity ammunition magazines in the state.

It's a setback for the Portland-area clergy behind Initiative Petition 43, who have just over a week to gather the 88,184 signatures necessary to get it on the November ballot. The signature deadline is July 6, and they cannot begin gathering signatures until the ballot title is finalized.

In an opinion issued Wednesday morning, the court said Attorney General Ellen Rosenblum must revise the summary of the initiative that would be put before voters in November.

Several gun rights and hunting groups appealed to the Oregon Supreme Court to modify the ballot title, saying the use of such terms as "assault weapons" and "large capacity magazines" is misleading.

The ballot title now reads: "Prohibits 'Assault Weapons' (Defined), 'Large Capacity Magazines' (Defined), Unless Registered With State Police. Criminal Penalties."

The court agreed with the gun rights and hunting groups that "assault weapons" is an imprecise term that could be interpreted in different ways and that the attorney general's reference to the definition within the full text of Initiative Petition 43 was not adequate to explain the effect.

Chief Justice Thomas Balmer wrote: "We conclude that the (ballot title) caption could accurately state that the proposed measure would criminalize the possession and transfer of many semiautomatic weapons, as well as magazines holding over 10 rounds."

The ban would apply to certain semiautomatic rifles and pistols capable of accommodating detachable magazines and have other military-style features, such as a collapsible stock or grenade launcher, plus some semiautomatic shotguns. Military and law enforcement employees who are required to carry firearms would be exempt, as would retailers and manufacturers who supply those agencies.

Initiative Petition 43 would allow existing owners of such weapons to keep them if they passed a criminal background check and registered with the Oregon State Police in order to keep the firearms.

The court said the attorney general's office must also make clear that the exception would apply only to weapons people owned at the time the initiative would take effect.

One of the initiative's chief petitioners, Rabbi Michael Cahana of Congregation Beth Israel, declined to comment Wednesday on the outlook for the initiative. Supporters of the initiative, who call their campaign "Lift Every Voice," are planning a press conference on Thursday morning.

On its Facebook page, the group shared inspirational quotes and urged supporters to remain optimistic.

-- Hillary Borrud

503-294-4034; @hborrud