After some research I found that the Remington 783 uses the same Bolt head as the Marlin X7.
Since I just happen to also have a 783 in 7mm Rem Mag, I did a quick check, and they look the same, so I tried it in the XL7, slid right in, closed, and the bolt handle even lined up.
I know the head is wrong for a 270, but it does confirm the general function.
I just picked up a bolt for a 270/30-06 out of a 783.
I also know about head spacing, but good idea to warn people.