I've used a Dillon 550B since 1985, 45-70 is one of the calibers I loaded. Both Black and smokeless powders. It's an excellent machine.

Seriously look also at the Hornady press. It's cheaper and of equal quality. Unfortunatly I don't own one of these.

If there is a local gun club handy perhaps someone there has these machines and could help you decide/let you load on them. I've done so for several folks in my club.

Jeff

I would also agree the Dillon is a good progressive. It’s long moved down the road, but my 450, which is basically a 550 without removable die heads, did fine. 

I use smaller turret presses for other things, but I have looked at the Redding T7 on and off, because I can keep all the dies basically set and just swap out turrets. It’s slower than a progressive but a decent turret press moves along pretty quickly. 

I prefer to use hand primer seaters, not press mounted, but the Dillon primer feed and seating is good. Best of luck with it.

The smokeless powders I use for BPCR don't meter well in anything but a B&M using a tube so never considered a progressive...  You got me thinking about the length of the Hornady though, checking it with a 45-120 case I had handy there is still room to load a 485 gr. Postell - so it would be long enough.   
In another discipline, a different era, I used the Hornady progressive a considerable amount, with some tweaking the primer feed seemed to work better on it than my peer's Dillon's.   Not in that big of a hurry to run and gun anymore... wonder when that happened?

I have loaded lots of 45-70 on the Lee progressive press, but I do it "semi-progressive".  I run the cases through the press twice. The shell plate has five stations.   The first time around,  I size and bell the case.  Also in the press is a powder checking die and bullet seating die which are not actually used the first time around. As each case comes off the press I immediately prime it in a small Lee bench mounted press with the Lee Priming device. After the batch of cases is sized, belled and primed  I remove the size die and put in the powder charging die. The second time around, I seat the bullet in the last station, then using the RCBS Chargemaster digital scale, I charge the case with powder, run it through the case belling station again, then the powder checking die. The next station is empty but I used a wooden dowel with a red end marked to indicate a double charge, as a "belt and suspender" double check of the powder charge. The next station is the bullet seating die. So on the second run through the press, I load the powder, and while doing so I watch the powder checking die to make sure all is well. After the powder is dumped I stick the dowel in the empty station to double check the powder charge. The "empty" station is one which has a case in it but no die. Keep in mind that as I am describing this there is a cartridge case in each station of the press . 
To summarize, the first time around I size and do the priming in a separate press right after the case comes off the progressive press. I can visually see the primer before it seats to make sure it is right side up and I can check to make sure its properly seated when I remove it from the priming press, which you cannot do with a fully progressive press. This makes the first time through relatively fool proof. On the second trip through the press,  the main thing is to make sure they each have one and only one powder charge, which is checked by the powder checking die, ( which I watch as I dump the powder) and the dowel.  If you want to skip the dowel you could add a factory crimp die if you want. The send trip through the press is also relatively fool proof. When running the press fully progressive, a messed up primer really ruins your speed and sets you back because you then have to pull the bullet, remove the primer and start all over. This procedure can be used with any progressive, but the Lee is the only one I have ever tried or needed. I hope you find this useful.
Joe S

Looked at the various progressive presses, decided they might be good for producing vast quantities of pistol ammunition.
So when my old rockchucker started getting sloppy I went with the Redding t7. Load stuff as small as the 32 HR to as big as the 45 2 7/8.

GT you missed a fun match at Cheyenne a couple of weeks back, and you left out the matches in Alliance on your list.

Glenn,
This takes the topic the OP started a little off subject and we should probably start a new thread but I'm not going to yet so please bear with us Retreever.   
I appreciate those that still live and compete in the BP bubble, and even more so those that are starting and venture into the world of BP.  The majority of the group locally I began this discipline with have gotten away from this sport entirely, some passed, some wrinkle their nose at the thought of the effort they use to put into it, a few - yeah sure yeah, but never show.  This group was a very active 40 to 50 strong, I miss not having those folks to shoot and meet with on a weekends notice.   
One of my passions beside building a rifle, developing an accurate load and jerking the trigger is introducing someone new to the discipline.  And then have them stay with it for a while.  I take considerable time out of my normal 80 hour week, one semester a year and add another 10-15 hours to my schedule to teach folks in our community how to build a high wall from one of Rodney castings.  The majority of these folks have little to no interest in casting bullets, let alone playing with BP, but they've found that with the smokeless loads we develop, purchased cast bullets, we come close to how that rifle performed originally - and they get hooked when they sit down behind cross sticks at 800 yards, using a tang sight, they ring the buff target.  Now if they decide to venture off in to BP at that point, that's a bonus.  My group is growing again, nearly back to where it was when I started...  Some of the ages of these are 20 year old's...   tell me how many of your organizations see this?

Don,   
I didn't mention Alliance, Forsyth, Carpenter or Sentinel Butte either, must of slipped my mind.  I saw your score with the new rifle, congrats!  Looked like Jack was in fine form too!  I see Dick is talking about one last 22 match for the season, we have a group of 7-8 wanting to go to the Fall Big Hill so that'll probably be my last for the year.  I let the majority, the youngsters call the shoot destination that August weekend, they chose LG/BG at Big Hill, had a 20+ year old newbie shoot it for her first time, another hook set!   .

Greg      
   

I like BP & have used it 50 years but

Like Gregs our club does not require black powder, lot more shooters than if we did. I  dealt with NRA competition department when I was both HP & SB Match Director. They were OK not great. Guys running NRA rule matches from our club now say the Competition department is lightly staffed due cuts. For sure they are not promoting the Sport. 

Wish we had a proactive well funded single competition organization. Other hand leaving it to the clubs like ASSRA works pretty good.

On presses simple turret, dies set up permanently is my solution. Have 3. Single shot rifle I decap on a dedicated die  after tumbling. Then neck size, expand with a M die, last seat. That’s 4 dies don’t think the progressives will do that. 

Anyhow shooting single Shots 38/55 & 32/40 about 200 per month. Another 200 + between 25/20 & 30/30 Lever actions . Add a few 38/40 & other Revolver cartridges, 500 odd cartridges split 4 + calibers not the sort of runs that favor progressives   500 all same Caliber less complex die set up probably favor progressives . 

My routine others may handle different 

Boats