Long story short, bottled my first batch after a long hiatus. Aiming for 1 gallon (~11 bottles) and ended up with 9 bottles.
Carbed for 1 gallon (~30g Turbinado) aiming for 3.2 volumes. Reverse engineering the calc shows that for 0.78 gallons (~9 bottles) with 30g Turbinado I’m anticipating 3.7 volumes. I used bottling yeast as well (~1/2 g).
I used recycled Westmalle bottles:
I’ve carbed similarly before but was much closer to anticipated bottle yield and did not use bottling yeast.
I’d be surprised if you had any problems at 3.7 volumes in those bottles. I’ve done 3.5 for hefes in regular long necks before, and while I wouldn’t do it again, I didn’t have any issues, either.
Here in BFE, Hermiston, OR, the local constabulary has me listed as a carb-head (hop head too, but that’s slightly different) so take that into consideration when I say: [there’s no such thing as “overcarbed”].
I accidentally carbed to 4.5 volumes in some old natty boh bombers. They survived just fine, so I’d imagine you’re fine. There was enough pressure for the caps to dome over though.
You will have no worries whatsoever with using those bottles. They are very strong and will easily handle the 3.7-4 vol you have especially if kept cold.
ive routinely done 3.8ish target in my bombers for hefe. first time i bagged them and put in box… since then never have. no issues at all that i’ve experienced-not even swollen caps.
I now have one bottle left (out of 9) and the beer was definitely carbed on the high side.
I had a few gushers in the beginning but it now displays a pretty large foam stand when poured. Nice foam. Flavor is a bit off due to a slight mishap with rising temperature but all in all it turned out very drinkable. I am going to save the last one for my next brew day.