First the info: Reloaded 30rds of the 6.5 using Lyman 47th ed. book start load of 39gr of IMR 4320 w/140gr bullet. Approx 15 out of first 30 rds seemed to show hi-pressure (bolt hard to open first 30 sec after firing, bright spots on base) Factory rds shot OK. Purchased go/no gauge...bolt closed.
Questions 1. Could above problem be due to excessive head space? 2. What about damage to rifle? Note: Not shooting till I find out.

whisler,

Lyman loads are way too hot for some calibers, if you look at their test gun data, you'll see they used a .266 bore gun, so I guess their loads are ok only if the gun is .266 (but I wouldn't do that)

Here's a cross reference between two reloading manuals-

Lynman 47th : 6.5X55, 140 grn, IMR 4320

start 39.0 - 43.0 max

Speer 13 : 6.5x55, 140 grn, IMR 4320

start 36.5 - 40.5 max (lower 1 grain if loading for military surplus rifles)

If you are loading for a m96 then according to Speers manual you are "starting" pretty close to maximum of 39.5 grn--back off a little, and it's good to have several manuals for check.

Another thing to consider. The Carl Gustaff rifles have a sl;ightly different head space than the Obrendorffs. I found with my Gustaff that if I fire formed the brass with easy loads I could crank them up to hot with no problem. If I full sized the brass (Hornady die) I would perferate primers at moderate loads. After that experiance I pulled a couple dozen bullets, fire formed with 120 rem and 43 grains of RL22. Now I can load that brass back up to previous levels. Another solutiion would be to have the barrel set back to tighten the head space. I did that with a sporterized gustaff and it now is nearly identical to my obendorff. Onc you sort out the problem this gun will drive tacks. I commonly get .5 moa with Hornady hunting bullets.

Did you diassemble the bolt before checking the headspace? If not you cnnot "feel" if things tightened up even a little on the no-go gauge. Put one layer of masking tape on the no-go gauge and check again, this will give you close to the field gauge, with a stripped bolt. If it closes on this with NO resistance, you have excessive headspace and need to have it corrected. The handloads that you fired are exhibiting classic signs of TOO hot of a load, as suggested you need to back off on the powder charge- IMR 4320 is famous for pressure variations from lot to lot, and with the powder you have it sounds like you are about 2 grains over maximum.

Stripped bolt down, some light resistance when closing bolt on go/nogo gauge. Added masking tape, would not close. Answers that question. THANKS! Better info on this site than I get from others.....