Mr. Tedman,
May I apologize for my less-than-impressive last posting. I was in a rush and wanted to respond. A bad combination. Please allow me to elaborate on what I was trying to say.
While on the surface a 30-30 Improved seems like a great idea with its increased velocity for little monetary outlay, there are some important things to consider that put some tarnish on the idea. Firstly there is the question of pressure. The 30-30 is an old case that isn't nearly as strong as newer cartridges. When the case is "improved," that weaker brass is stretched much farther than intended. Now for exterior ballistics to approach the .307 or .308 Winchester, interior ballistics must also be similar. That means working pressure in the area of 52,000 CUP or more, a 37% increase over the SAAMI specification for the 30-30.
Let's not forget that this increased pressure is the reason for the "Big Bore" modifications to the Model 94. So you now have a combination of overtaxed brass in an action never intended for such working pressure. If I may quote the following relevent passage from Speer's Reloading Manual No. 13, p. 263: "We are occasionally asked if the 30-30 can be loaded to higher velocities in a modern bolt action like the Remington Model 788. The answer is NO! (Speer's emphasis) The 30-30 case is an old design with relatively thin walls. Attempting to load "hotter" would risk a dangerous case failure."
Secondly I believe 150 grain bullets at 2700 fps is highly optimistic, let alone coming within 5% of the .308 Winchester as indicated by Gary Reeder. That would be quite impressive considering some .308/150 loads can touch 2900 fps from 22" barrels! Marshall is right when he says a 30-30 Imp is more like a 300 Savage. Even then I would hazard it to be a best case scenario.
Finally even if such a round could push 150's to 2700 fps, the exterior ballistics of required flat nose bullets versus the .308's spitzers lose the gained velocity beyond 200 yards. Using Speer's 150 FN and flatbase spitzers for comparison, we see that if both start at an equal 2700 fps the theoretical 30-30 Imp is down quite a bit (2065 vs. 2250) at just 200 yards compared to a modestly-loaded .308. By 300 yards the gap has grown to just under 300 fps. If the .308 is loaded with boattails and/or to its full potential, the rift is greater still by a significant margin. So what is to be gained in the field? Killing power is only marginally increased past 150 or so yards. Trajectory is somewhat flatter but nothing to write home about.To take advantage of each would require more practical accuracy than I've seen in any Winchester 94.
I think that if you have a 30-30 you should enjoy it for what it is and what it represents. A wonderful, historic development in small arms technology that is at its best as a deer rifle under 200 yards. There is absolutely nothing wrong with that. The majority of game are taken closer still, so you really won't be hindered much at all while hunting. But if you need or want 200+ yard capability in a lever action, I honestly believe you'd be far better off with a real .308 Winchester in a Browning BLR or Savage 99 than some hot rodded 30 WCF that may be on the verge of seizing or blowing up.
