Rear bolt baffle

I just bought a used 116 flat back 270. I noticed a strange gap on the bolt between the bolt handle and the rear of the receiver and figured out that is where the rear baffle would normally be. First off, why would someone remove this? And second, does anyone know where to get a replacement? I can call Savage tomorrow but wonder if they support parts for the older flat back guns.

Brownells sells them.

i tried brownells and I dont see where they distinguish between a round and flat receiver.

Me neither, but I ordered one and they sent me a flat rear.