You have two issues that need addressing:

a. The 4.5kg weight limit (including scope and glove) for LSR
b. the 500g minimum trigger weight for LSR

(NSRA Rules 8.3.3.1-2)

Most of the standard 10m rifles weigh around 4.2-4.4kg and that would leave you pretty tight for the scope and glove. 10m trigger weights are typically below 100g, so trying to shoot with a 500g trigger is a significant disadvantage. Now you could of course adjust the trigger for different disciplines and take bits off to lighten the rifle for LSR. Clearly neither would be satisfactory. To try to use a single rifle for both disciplines could end up like trying to play football with a rugby ball.

Rutty