I have the Traditionns Nitrofire with the 1:24 twist. I really like the concept, but it does come at a price. The firesticks are expensive, but if you look in the classified section of Gunbroker.com you can find some deals if you buy in bulk. I use the 100 g firesticks.
At the range, I have shot many different bullets and found that the Hornady Bore Dirvers (290 g or the 340 g ELD) are the most accurate rounds with the Hornady 300 g SST a distant 3rd. Here are some random comments:
1. I am not fond of the trigger as it has a lot of creep. Once you get used to the creep and learn that you can slowly pull the trigger back and stop when you get some resistance and then pull the remaining way - you will get much better groups. It takes getting used to but once you learn how to handle the trigger creep - it is not that bad.
2. I regularly get 1.5" groups at 100 yards with the Hornady BoreDrivers.
3. I employ a chronograph and get a 200 fps drop in muzzle velocity after 3 or 4 shots due to plastic fouling. After a good brush cleaning, the velocity comes back. I purchased a 50 cal boresnake and use it after ever shot and that does the trick.
4. I get a muzzle velocity of 1818 fps with the 100 g firestick and the 290 g BoreDriver. I get 1764 fps with the 340 g BoreDriver. If your shots are 125 yds or less, the 290 g BoreDriver is best. If you will have shots > 125 yds - use the 340 g BoreDriver ELD-X.
5. I also find that the gun shots better after one fouling shot. I hate wasting a firestick, but the gun simply shoots better with a fouled barrel. Shoot one firestick with no bullet to foul the barrel.
6. Sighting your gun in at 100 yds, here is what you should get:
290 g BoreDrivere: 100 yd , 0; 125 yd, -2.1"; 150 yd, -5.6"; 175 yds, -10.7"
340 g BoreDriver ELD-X: 100 yd, 0"; 125 yd, -1.7"; 150 yd, -4.3"; 175 yd, -8"; 200 yds-12.7"
I really do not see the big advantage of the Nitrobolt as it appears to be more difficult to clean using a boresnake. If the Nitrobolt came in a 45 cal I would be interested as you can still get the Honady BoreDriver bullets in 45 cal. The 45 cal will get you more velocity and distance along with shooting a little flatter (higher bullet coeff.).