Not raining on the 338 Allen Magnums parade at all. There is a very good reason why I also offer a 338 Allen Xpress which is another form of the 338 Lapua AI. For 90% of the hunting and shooting situations out there, the 338 Allen Xpress or 338 Lapua AI would be far more practical then the 338 Allen Magnum.
That is why I build my 338 AX rifles 10 to 1 compared to the 338 Allen Magnum and thats why I also talk potential 338 Allen Magnum customers out of that round into a more ALL AROUND chambering 10 to 1.
That said, if your looking at shear performance and your looking for a legit +1000 yard rifle that will do its work in the 1000 to 2000 yard range, there is no comparision between the 338 Allen Magnum and the lesser 338 magnums.
You say you will get 3200 fps with a 29" barrel length, not looking to start a fight here but you will not without EXTREME chamber pressures. The problem with the 338 Lapua parent case is that its so strong that it hides most pressure issues. If you ever loosen a primer pocket on a 338 Lapua cases your WAY over pressured. In a 30" barrel length you should see 3000-3050 fps with comfortable pressures in the 65 to 68,000 psi range.
If you want to proven this to yourself, get some Norma made 338 Lapua cases and try your load in those cases. These cases will have the primer pockets loosen in that 65-68K PSI range whereas the Lapua brand cases will take you WELL into the mid 70K range with tight primer pockets.
Again, not trying to start a fight but I would bet there are not alot of guys out there that have not run the Lapua case any harder then I have or as much as I have developing the loads for my 277 Allen Magnum, 7mm Allen Magnum, 300 Allen Xpress, 338 Allen Xpress and 375 Allen Xpress.
Even your 3100 fps expectations are a bit on the high side. RC barrels can run on the faster end of barrels so you may see 3100 fps but 3200 fps is certainly WAY over what you SHOULD be getting with that case capacity.
When you consider that the standard 338 Edge gets you 2850-2900 fps with a 30" barrel length, 3000-3050 fps with slightly more case capacity out of the 338 Allen Xpress or 338 Lapua Improved is still very impressive. Just don't like to see guys trying to make these rounds into something they are not. They are impressive in their own rights, just need to keep them in the safe ranges of chamber pressure so everyone is happy.
Back to the 338 AM. WHen you consider the wear you will put on your barrel fireforming brass, things do not look QUITE so perfect for the 338 Lapua AI. It should get you close to 2000 rounds down the barrel before you need a new one installed but some of that will be used up in fireforming.
The 338 AM will get you into the 1000 round class if you take good care of your barrel and do not overheat it and keep shooting.
If you want a high volume shooter, in my opinion, the 338 Lapua or the 338 Allen Xpress or 338 Edge are much better choices then the 338 Lapua AI simply because either you do not have to fireform brass or formed brass is available so there is no need to fireform. All are great chamberings but none come close to the shear performance of the 338 Allen Magnum or any other CHEY TAC based wildcats.
If you ever had a chance to shoot the two side by side in canyon country at long range in conditions that you could not read dead on the money, the 338 Allen Magnum makes it dramatically easier to hit small, precise targets at longer ranges then any smaller 338 caliber magnum chambering. On paper it has a 200 to 400 fps advantage but in the real world it seems like MUCH more then that when bullets are being send down range.
Again, its a VERY specialized weapon system. I talk more guys out of them then what I build for customers. But there are situations and there are hunters that have hunting situations where they fit in perfectly and for those, there is no comparision to smaller 338 magnums.
So for all around use, your correct but your numbers are exaggerated quite abit over what you SHOULD be expecting from your rifle. Again, not looking to pick a fight, just telling you what over a decade of load development with the 338 Lapua, 338 Edge, 338 Allen Xpress, 338 Kahn, 338 Raptor and 338 Allen Magnum has told me with dozens of examples of each to develope loads in and record data.
3200 fps is not practical in a 29" barrel length with a 338 Lapua AI with pressures under 70K PSI, even if you have a 4.250" OAL in your ammo. 3100 fps would be on the VERY top end of what you should be getting with that combo.
Good shooting and your right, you have a great round that will cover 95% of all shooting and hunting needed, Course in the rifle your building, its not exactly a portable weapon system anyway so it would have to be put up head to head with the very best long range weapon systems available. In that comparision, it truely comes down to what your hunting, how far you will be shooting and what conditions will you be shooting in.
Nearly everyone that I build a 338 Allen Magnum for has a lesser intensity rifle or several of them that they use for their high volume shooter and only use the 338 Allen Magnum for specialized situations which is how it should be. YOu do not drive your 1000 horsepower dragster to the supermarket every sunday to get groceries, well most of us don't!!!
No flame intended in any way, just offering my experience with loading ALOT of rifles and chamberings in this class over the years.