I have short action Model 788 rifle. The caliber is 6mm Remington. I'll add a new custom barrel to it and I have made a few choice of short action calibers. (284 Win, 308 or 300WSM/SAUM). 6mm Rem case head is .472", 284 Win: .473" but 300WSM case head is .535". Is it possible to replace the bolt head to a bigger head that will fit .535" case? or do I need M 700 standard bolt action to fit Model 788 action? I'm aware that I may have problem with the one-row magazine. I may have to accept a single shot rifle unless any good gunsmith can work on it.(repeating magazine).
-DG

I'm not sure about the 788 but the Rem 700 bolt face can be opened up to take the magnum size case...need to fit a new extractor...usually Sako or clone.

No fear<
Although it would be possible to open up the face of the 788 bolt to take the magnum size brass and use it as a single shot I couldn't reccommend it.
Although the 788 withit's rear lock up has little difficulty with standard cases such as the 308 the increased bolt thrust of the WSM could creat a problem with this action.
I would recommend staying with any cartridge based on 308 brass. Regards, Bill.

I own 4 788's in various calibers, and aside from the thrust issue in converting to 300 WSM, the other problem will be feeding. 788 magazines don't take kindly to wildcats or rounds they wern't designed for. Small changes (improved versions of existing cases etc) will usually work, but 284 Win cases, WSM or the SAUM's from Rem. won't feed. You might be able to use one of the rimmed case mags, but they're hard to find, and you'll still be modifying the mag to feed. Good luck.