There has been a lot of discussion, and excitement, about the new ELDX bullets on this forum, and for some good reasons. I recently shot some of the best groups ever with the 143's in my 6.5 SS which measured in the .0's. (.014" to be exact). Having said that, this forum is about sharing info which is beneficial to others, so we need to share the bad with the good.
I recently measured some 143's at .2642"-.2643" which CAN be a good thing for accuracy if the throat/bore combination happens to be loose enough. For MANY factory barrels, accuracy will likely be better than a bullet which measures .2640, which is what the bore SHOULD be. The down side is, if you happen to have a bore like my 6.5 L A Sherman which is on the tight side, this can cause pressure issues even before normal velocity is reached (and it has)!
Here is another case in point: A customer is building a 6.5 SS custom with a lot of high dollar components and wants to shoot the 143 ELDX. (based largely on the excellent results I had). He ordered several hundred of the 143's and they measured, like mine, 2 to 3 tenths oversize. So here is the problem! Most throats are .0005" over bore size and SOME competitive shooters like to run them even tighter than that. If the throat is only .0005" over bore size and the bullet is .0003" over already, you only have .0001" clearance per side in the throat area. THIS IS NOT ENOUGH and can quickly cause pressure spikes. Now, if you want to shoot these bullets, you need another reamer, or at least a throater, which will open it up. This is a burden, and an expense for gunsmiths, and most of the time it would not even be caught. The customer would receive the rifle and it might shoot another brand just fine but they would have issues with the over sized bullet. Guess who would normally get the blame? Most people don't measure all their bullets, and they shouldn't have to.
The customer who is building the 6.5 SS, which I eluded to above, will have a choice to make. He can have his chamber throated oversize to accommodate the bullets he has, and hope the next batch is the same, or he can chamber with a std. throat and shoot something else. Because all these issues were surfacing, he called Hornady and talked to someone named Doug in their bullet dept. Doug told him that these bullets were "WELL" within spec. I decided to call Hornady myself this a.m. and specifically asked for Doug, but got someone named Preston. He was helpful in that he looked up the Hornady "spec" sheet for the 143's and found that tolerance was .0002"-.0003" which made them BARELY meeting spec! What happens if the next batch is .0003" UNDER bore size but still is within spec? I think you can see the dilemma from a builders, and a customers standpoint.
I recently purchased some 175's for my 7SS so I went to the shop and measured them. They were at .2839, or .0001" under size which is far more normal for most bullets.
There is at least one barrel manufacturer that regularly makes barrels with the bore on the tight side. This is likely to gain a little accuracy edge because they want the bullet to fit the bore tightly. The downside is you usually loose velocity, and have to load a little lighter to keep pressure down. Imagine if you get one of these barrels, AND a bullet that is FAT!
Again, I am not posting this to give Hornady a bad name. I will likely shoot the 143's in my SS because they shoot VERY well and I like the way they expand, coupled with the high b.c.
Everyone can decide for themselves which way they want to go, but just be forewarned of the downside.........Rich
I just noticed the "y" in my "alert" title, but don't know how to edit it out, so deal with it
