though their rebates are always mail-in only i do register each one online to get a confirmation/tracking # (and use their form for the rebate itself).

On that form, it states the following info, and they also have a # you can call to get further info as well to confirm what you are looking for (888-859-6995):

Rebates: This mail-in rebate offer is valid only with purchases between April 6th, 2017 and April 30th, 2017 by an end user
customer on Remington Core-Lokt Ammunition, American Clay & Field, UMC P&R, and Premier STS Target Loads.
Eligible Participants: To qualify for this rebate, only the actual purchaser of the qualifying product may participate. End user must
keep copies of all materials sent. Materials received become the property of Remington and will not be returned. Please allow 8-10
weeks for receipt of rebate. Remington is not responsible for lost, late, incomplete, damaged or misdirected mail. Use of multiple
addresses to obtain multiple rebate requests is fraudulent and could result in federal prosecution under the U.S. Mail Fraud
statutes.
Restrictions: Limit 105 rebates per qualifying purchase. Limit 105 rebates, 272.5 dollars per household. Valid while supplies last
for purchases made in the 50 United States. Promotion is void where prohibited or restricted by law. Not valid with any other
rebate offer. Rebates to clubs and associations are not allowed. Excludes items won or purchased at or for fundraising banquets
or similar events. No rain checks.