The H&R barrel can be reamed and threaded for a choke sleeve.
I have tried a number of different barrels on my Model 088,none of them would quite lock up.I fitted a 20 ga and another 12 ga. barrel to my action by stoning the locking ramp on the barrels.
I have lined 2 H&R shotguns converting them to rifles.The first one was chambered in .32 S&W,I later rechambered it to a .38 Spl. necked to .32 caliber.I used .30 M1 loading data for it.This barrel was later rechambered to a .357 Mag.case necked to .32 caliber,some of my loads were probably
approaching 40,000 lbs.I never had any problems with either the gun or ammo.
I presently have a Model 088 with a barrel sleeved to .30 caliber,it is chambered to the .30 HLS CHEAPSKATE.The chamber is cut with the .30-06 reamer to a depth of 1.635,the rim recess is cut .062 deep,.520 dia.
Cases are formed from .445 Supermag. trimmed to 1.625 using a shortened 30-06 fl die.Case capacity is almost the same as the 7.62x39
and I use that data for loading.
I have never experienced any problems with this gun or cartridge ,so who knows what pressures the H&R 088 will actually contain?
WC