IIRC, the locking lugs on the 788 were at the rear of the bolt, making for a "springy" bolt and stretched cases with max loads....
Ahh, google is my friend:
http://www.charm.net/~kmarsh/788.html
That should help....
"The achilles heel of the Model 788 is the combination of the rear-locking bolt, brazed-on bolt handle, and high pressure cartridges with standard head sizes. When a fired cartridge gets wedged in the chamber, the bolt handle is leaned on until it breaks off. While this issue affects primarily reloaders, benchresters and other experimenters, a broken bolt in the field can ruin a hunt.
If you have a small head size (.222Rem, .223Rem) 788, or one of the rimmed 788's (.44Mag, .30-30) this issue is less likely to affect you. However, even these rifles are not good choices to explore max reloads with.
The late Gale McMillan set us rec.gunners straight when he explained how bolt compression and case length growth with high pressure loads doomed the 788 to a short stay at the benchrest line.
The rear locking bolt compresses, allows the case to stretch. This leads to short case life and possible case head seperation (for reloaded cases). Stuart Otteson's The Bolt Action Rifle: A Design Analysis bears this out, calculating a .001" compression per thousand pounds of bolt thrust. Since a full-strength .308 Winchester cartridge has as much as 6,000 pounds of bolt thrust, handloaders can see the problem here."