I do not think you have mentioned what bullet weight you are using? If your using 140-142 gr bullets, your velocity is not all that bad. My 6.5-06 AI will get 3050 fps in a 26" barrel with the 140 gr A-Max. Your longer barrel will get you more but loaded head to head, I have always found the AI rounds to run within 50 to 75 fps of the Gibbs.
You may just have a slow barrel.... It happens.
As far as you loosening the primer pockets on forming with corn meal. Are your primer pockets loose when you seat a new primer after fireforming? If they are not, OBVIOUSLY, you are not loosening your primer pockets using this forming method.
It is true you never want to run pressures high enough with corn meal to see any change in primer fit but you know this the instant you reseat a primer. If they are tight, you are not doing anything wrong.
Anyway, let us know what bullet weights your using and that will help determine if you have a real problem or not.
To say every rifle chambered for the 6.5 Gibbs will take 62 grains of powder is hard to believe with the variations in barrels, bullets, case volumes and powders.
I think velocity claims get us into alot of trouble. There was a time that the 257 STW was claimed as a 4100 fps round with the 100 gr barnes bullets in a 28" barrel. Most of this "crap" was started by a smith by the name of Ferguson down in Texas I believe.
For years he stood by his claims even though even his customers could not get these levels of velocity without ruining cases on the first firing.
Finally, just this winter I got a call from one of his X customers that said he finally got him to admit that he can easily reach this level of performacne but cases only last one firing. And that he loaded his personal rifle to the 3800-3900 fps range for longer case life.
Again, if your using a 140 gr clas bullet, you are not doing to bad for this chambering despite what many smiths may tell you. Your case necks may be to snug and that will cause pressure spikes but other then that, listen to your rifle, it will tell you when pressures are to high. I have found on many occasion you get much more meaningful information from listening to your rifle then others that offer opinions on your rifle!!!
Allen Precision Shooting
Home of the Allen Magnum, Allen Xpress and Allen Tactical Wildcats and the Painkiller Muzzle brakes.
yeah kirby I'm shooting the 140's, I know with the h1000 I can get decent velocity (3200 fps), but I have to go 4 gr over published max. just trying to figure out that if he's so sure 62 gr of re 22 will work then it must not be a hot load, but 61 gr fireformed with my method will be deprimed when you eject the case. If I go above 3100 with any of the optimal powders (imr 4831, re22, imr 7828, h4831) then the cases are junk after 1 firing.
guess what I'm trying to figure out is what would fireforming with a bullet change vs. the COW method, does it thin the necks opposed to using cow?
I belive my old P.O Ackley loading manual says to use 20grns of Unique for fire forming the 6.5-06 AI
Iv'e tried lots of differnt loadings for fire forming brass and never seen one loosen a primer pocket. Not saying it wount.
It sounds like you either have a tight bbl or the necks are a bit snug.
I don't know if I ever asked you but what brass are you using?
I do agree with Ray that if your necks are .015" then they should be fine, but who knows. Turn them and fire form a few with the H4831 then fireform a couple without neck turning and see if it makes a difference.
using rem brass as per rays instructions, I dug out the cases which ray sent with the dies and the necks are .012"
but all mine are .015" even the 50 win brass that I have fireformed.
personaly I can't believe that fireforming with unique/cow/tp is harming the pockets, the shoulders look like a weatherby radious so there isn't alot of pressure there.
Ray told me to trash all my cow ff'd cases and buy new ones, just trying to figure out if the cases can be salvaged, thinking about getting some nosler brass if I can get the thing straightened out.