243 in Long Action - does anyone make a mag filler

[xdHammar]

I have a Magpul Hunter 700 Stock in Long Action (rifle was originally a 30-06) and put a 243 Winchester barrel on it. The 243 is shorter and it feeds ok but there is a lot of extra room in the mag (AICS) so the rounds can slide forward. Does anyone know of a solution that would better fit the 243 rounds in the long action? Here are some of the solutions I am looking for.

• Long action mag that has some sort of filler in it so that it holds short action round better?
• Short action magazine that fits into the long action mag well?
• Adapter sleeve or something that would go on the short action mag to allow it to fit into a long action mag well?

If any knows of a solution of a good solution I would appreciate it.

Thanks!