I've been taking a long hard look at this 1920s .250-3000 take-down I picked up. I've read a bit about these developing slop in the barrel threads from people playing around with the takedown feature too much etc. But looking at this one and how it's made, I think the problem is much more likely to be barrel whip when firing gradually "working" the barrel and receiver against each other and enlarging the threads and perhaps the receiver ring, at least where it overhangs the receiver walls.
With the inherent weakness of the barrel locking mechanism which relies on forcing that V shaped lug up into the corresponding slot in the barrel and the receiver, this system was less than ideal from the get go IMO. This barrel now has to be overturned maybe 2-3° before it is hand-tight.
If the barrel shoulder was enlarged out to the edge of the receiver face, and even better, if the receiver face was not so heavily beveled on the corner and had a larger surface, the flexing from barrel whip would have been a lot better handled I suspect. Those of course were the days before high-speed photography, so not as much was known about what happens when a rifle is fired and recoils.
The receiver ring is 1.24" dia. and the barrel is 1.025" on this one. I'm guessing the barrel threads were .895" dia. when new. The barrel shoulder bearing against the front face of the receiver is only about .055" wide! I notice that the shiny contact areas on this one are only around the outside edge of the barrel shoulder and the matching surface on the front face of the receiver. That could indicate that the shoulder on the barrel was cut slightly proud on the outside to make that area contact the receiver first (which might not be a bad idea) or it could just mean that as the barrel whips when the rifle is fired, the outside edges naturally take more force and wear more; I dunno!
It's surprising how much the barrel can be moved side to side as it is screwed into the receiver, even almost right up to the shoulder. Unless the barrel was inserted and removed thousands of times with no lubrication, I just don't see people playing with it being a factor in the slop that has developed.
If you take a digital vernier and measure around the receiver ring just behind the front face it varies from 1.226" when measuring from 10:00 to 4:00 to 1.240" at 9:00 to 3:00, to back to 1.235" at 8:00 to 2:00! In other words, the barrel ring is now ovoid by as much as 14 thou, at the outside face. (Assuming the outside surfaces are consistent, which they appear to be, within reason) No wonder there's slop! [Edited: Ignore this part - I noticed there are two slight flats on the receiver ring that explain those differences. Besides, the barrel whipping vertically would tend to make the ring ovoid vertically, not horizontally]
If you hold a steel machinist's 6" rule against the sides of the receiver ring at 9:00 and 3:00, it is obvious that either the ring was not machined parallel originally or the sides have started to flare outwards.
This is probably due to that slot cut right through the outer 3/8" of the receiver ring for the locking lug on the forend. Not such a hot idea...
There is actually only a pretty thin web of steel at the bottom of the threads holding the two sides of the receiver ring together. You can see this clearly if you take out the magazine mechanism.
Not to take anything away from Mr. Savage who came up with a hell of clever design, but I think if the barrel shoulder had been made as large as possible and if the receiver ring was made thicker by continuing the plane of the receiver side walls right over the top, (about .30 thou thicker than present) the threads and barrel ring would be less inclined to develop slop like they do.
Going to have some fun reworking this one sometime.