Not being a double rifle owner I will guess from a distance

The perception of so so accuracy. Big bores are a bit different in that area. People are usually looking for less, their testing is not as extensive as with small bores and 1.5" group from a 458 looks nice....from a 243 it looks like a pattern.

Price is obviously a very big issue. However, with bolt actions, once you hit 375 H&H and above you do not need to get real serious before the dollars start to mount up...and of course cost of components.

So the gap in price (including components) is not so great between something like a Searcy and a big bore bolt gun as there is to the small bore.

Lastly, people just seem prepared to pay more for a big bore.

Mike