Remington 700 barrel nut rig from either Arrowhead or Hankins about a 15 minute build ,pull the barrel off your 700 action screw the new barrel on, headspace the module ready to go several times I've put rifles together and been shooting them 2 hours later. There are other options, like the Omega and Woodman arms. The 45-70 CVA conversions are very practical for beginning smokeless too. You really have a lot of options just about any bolt action rifle could be made into a smokeless muzzleloader. The 700 ml will require a gunsmith most likely and a rebuilt Bolt the 700 short action or even a 700 long action just needs a new Barrel,, I've been thinking about building one on a 98 Mauser just because I love Mausers and I've had a couple of mini howa actions that really turned out very well,, they were originally 6.5 grendels Hankins cut me some modules with a PPC both face and I put the guns together and headed down the road. All smokeless rigs of course shoot all the sub powders and black horn well,,,,, what has welded me and grounded me to smokeless rifles is just this one aspect ,,,accuracy,, I maintain a 45 smokeless rifle built right is consistently one of the most accurate rifles on planet Earth