John,
I had Talleys on an 84M with a 6x Leupo and both the front and rear cracked. I know Brad beds his Talleys, mine were not. I replaced the Talleys with Leupo DD and a 3-9x Chicken. Couldn't zero my scope at 100y and discovered the DD cracked. This happened with just a handful of rounds.
I'm using Warne steel bases on my 84M now with Maxima rings and the 3-9x Chicken. Only 60-70 rounds so far but no cracks. The rifle is shooting one big hole at 100y and roughly 1-moa at 490y and 670y, just today. Perhaps I over-torqued the Talleys and DD, or should have bedded the Talleys but so far I dig the steel bases. All of them fit the receiver great with no visible gaps but I'm not a fan of that trough running down the middle of the Talleys or the thin metal on the DD. That said, my first set of Warne bases had a defect and I took them to Warne in person for a replacement. Fella at Warne said they are extruded steel.
I'm pretty sure that the Nightfarce UL rings will fit the Warne base slots as their lug is narrow. I called NF and they said they would not fit weaver-bases but did confirm my suspicion that the lug is narrow enough to fit the Warne slot. But... I've never tried to install them. Other 1913 rings like Seekins absolutely will not fit due to the wider lug. If you've got access to a mill, you could open the slot on the Warne bases.
Or check-out the Kimber 1913 bases. I wish they had the slot offset on the front base or offered an extended front base.
Jason
