Not entirely true.I actually owned an accumark in 30-378 for a short time.When they were first announced,I managed to get my name on the top of the order listofa local dealerand my gun was one of the first in Alberta.Howeverbefore I got to fire it,the dealer called me and asked if I would consider selling it for a profit.I looked at the gun andthe cost of brass,compared it to the price of a custom rifle,compared the ballistics to that of the 300ultramag,and I sold the rifle for a very healthy profit.I had a custom 300ultramag built for the price that I sold the accumark for and comparing the two the differences are:
1)the 30-378 has noticeable more recoil
2)the 30-378 factory loads produce about 70fps more than my handloads
3)my 300ultramag is considerably more accurate
4)the fit and finish is much better on my rifle.The action on the accumark was not centered in the stock properly so the gap was larger on one side of the barrel than the other.
5)whether using factory loads or factory loads,the 300ultramag brass or loads are much lower priced.

In the end.I am happy to have sold the 30-378.