I know a guide here who also said he has seen some 7mmRM pass through shots on elk that resulted in the elk running off. Whenever I hear a story like this, two questions come to mind. Shot placement and bullet performance. On the first question, when it comes to guides, their clients will probably fall into one of two categories. One client will be a very proficient marksman and hunter and the other has no business being in the field with a rifle. I have personally "guided" a handfull of friends and associates hunting antelope, deer and elk and have experienced both situations. I had to put down a deer and an antelope with follow up shots, while they were running off, after they were both shot with poorly placed shots with a 7mm RM and 30.06, with a friend and an associate. Both gut shot. In another case, a deer hit the ground when shot and when we got to the other side of the coulee, where it was, it had gotten up and departed. We tracked it for a couple of miles and lost the blood trail and also lost the deer. This was with a 30.06 at about 200 yds.
I find this to be a very interesting subject, because of the range of results one may experience or hear. In one case, maybe a DRT elk from a .243 and another, a lost elk with no blood trail from a 7mm RM. In the case of the guy you were hunting with, did you actually see the impact of the bullet? A lot of guys will completely loose their bearings when confronted with the kill shot, especially if it's the animal of a life time. My old taxidermist told me that he has seen numerous antlers and horns with bullet holes through them. I looked at him in amazment and disbelief, and he said yup, guys will get fixated on the horns and shoot. A couple of years ago, I actually saw a huge Rocky Mtn Bighorn ram that scored 195, that the guy had just shot a couple of days earlier, and it had a bullet hole in the horns.
Speaking of bighorn rams and bullet performance. I also shot a B&C ram (back in 89) with the same rifle and load that I shot my large bull with. The immediate results were a little different. I shot the ram at about 150-200 yds right through the middle of the rib cage and saw him shudder and stumble forward a couple of steps and then he just stood there while his two friends trotted off into the badlands of the Missouri Breaks. I chambered another round, aimed and fired again. Nothing happened - he continued to stand there. I chambered and fired a third time and again, there was no movement or sign that he had been hit. I chambered my fourth and final round and put the cross hairs on the back. He shuddered and swayed and tipped over. When I climbed up to him, I saw that he was a very large animal with massive horns - I'm guessing well over 300 lbs. He scored 185. When I got him home (in 2 parts) and skinned him out. I found three entrance holes in the middle of his rib cage that could be covered with a silver dollar and three nickel to quarter sized exit holes that formed about a 2-3 inch group and the fourth shot through the top of the back bone. The ram was dead with the first shot but didn't know it. The first bullet (160 Partition) performed well creating a good wound channel. In the case of my point blank shot on the big bull, I'm guessung the front end of the bullet came completely apart resulting in some shrapnel wounds and destruction. I didn't really bother checking for bullet performance. It was almost dark, so I just field dressed it, went home, got my father-in-law the next morning, went back and he cut it up while I packed it out, so I never even saw the exit hole.
In the comparison between a 7mm and 338, the 338 will certainly be a better killer, but the difference in wound channel isn't all that much. If we assume the same construction of bullet and say a 2.5 increase in frontal area from expansion, the 7mm will create roughly a .71" diameter wound channel to the .845 diameter wound channel of a .338.
You have a lot more personal experience in the killing of elk than I, but my question is, how many elk have you seen run off to excessive distances and then actually recovered with both lungs shot through with a well performing, properly expanded bullet? Maybe I'm wrong (and that is always a possibility no matter how remote
), but I just do not not see an elk running off more than a couple of hundered yds with a .7" hole through both lungs. And if the bullet performs properly, it will certainly leave an exit hole large enough for a good blood trail, assuming good shot placement.
So my theory is that when an animal runs off and is not found due to lack of blood trail, is that either the shot was poorly placed and/or the bullet did not perform well, creating a large wound channel and exit hole. Maybe I'm wrong.