Any gunsmiths recommended to work on these? Cowboy shooters crowd .It is an older straight stock pre-crossbolt safety model in 45-70.Don't have the tools/knowhow to do it myself nor want Gravel to change out any parts made by Remington.Lifter is not raising the next shell even when roughly cycled.From the shoulder it's no go but if you bring the gun down it works better.I'm sure it just needs tweaking /polishing as machining marks abound.Cuts 1/2 " groups at 100 yards with either 300gr HP or 350gr FN handloads and a 4x Leupold...I'm aware of the Marlin website......Harold