I don't consider the 30/30 cartridge a speed demon in a lever action. I conducted a series of tests attempting to find the best accuracy with a 170 Hornady.
IMR 4064 was a good powder, I tested a number, including AA4350 and AA2700 hoping to find a combination of accuracy and velocity. N135 gave me the best overall accuracy at or around 2100 fps.
I am of the opinion that these lever action rifles will shoot their best accuracy at or around 2100 fps with a 170. Low velocities, higher velocities, resulted in blown groups. Such as I encountered in the AA2520 series of tests. I believe the best accuracy comes from powders with low velocity standard deviations. These lever action rifles are complicated structures, lots of things hanging off the barrel, all with different vibrational modes, and my Marlin only shot well in a limited pressure/velocity range.
I am not going to publish my AA5744 data, but I got 2163 fps and blown groups. I believe I was exceeding, by a good margin, published data. It is my recollection recoil was stout, the rifle lever unlocked itself on recoil, and accuracy was poor.
I recommend trying IMR 4064 and N135 with your 170's, see what happens at factory velocities. If your lever action shoots ten shot groups less than three inches at 100 yards, that is very good for these things. I am certain a number of people will claim half MOA with three shot groups, but I would like to see some ten shot groups, as I am of the opinion, three shots is not a sufficiently large population to substantiate accuracy claims. It is more likely that tight three shot groups are just statistical aberrations, especially out of lever actions. I tested my Marlin at 100 yards and I got what I got.
In a front locking bolt rifle, there is no reason to stay within the low pressures of ammunition manufactured for these rear locking lever actions. Pressure levels for the 30/30 are based on the assumption the ammunition will be used in these weak lever rifles and pressures are appropriate for the actions.
I would not make the assumption that ammunition is downloaded for old rifles, though old rifles would be made out of plain carbon steels, I think this design is springy and weak, and I don't recommend exceeding factory pressures even in a modern 30/30 lever action. Maybe the M99 Savage is stronger, but, still, this cartridge is not a speed demon no matter what rifle it is fired in.
Code:
Marlin M336 microgroove barrel
170 gr Hornady FBFP 31.0 grs AA2520 wtd lot 9595 W/W cases CCI200 OAL 2.545"
10 Jan 2014 T = 51 °F
Ave Vel = 1852
Std Dev = 41
ES = 55
High = 1864
Low = 1809
N = 5
170 gr Hornady FBFP 31.5 grs AA2520 wtd lot 9595 W/W cases CCI200 OAL 2.545"
10 Jan 2014 T = 51 °F
Ave Vel = 1873
Std Dev = 40
ES = 68
High = 1883
Low = 1815
N = 5
170 gr Hornady FBFP 33.0 grs AA2520 wtd lot 9595 W/W cases CCI200 OAL 2.550"
14 Jan 2014 T = 50 °F
Ave Vel = 1986
Std Dev = 25
ES = 58
High = 2014
Low = 1956
N = 5
Last three shots good group
170 gr Hornady FBFP 34.0 grs AA2520 wtd lot 9595 W/W cases CCI200 OAL 2.550"
14 Jan 2014 T = 50 °F
Ave Vel = 2115
Std Dev = 35
ES = 87
High = 2143
Low = 2056
N = 5
Good group, best of series
170 gr Hornady FBFP 34.0 grs AA2520 wtd lot 9595 W/W cases CCI200 OAL 2.550"
7 Feb 2014 T = 40 °F
Ave Vel = 2117
Std Dev = 24
ES = 78
High = 2148
Low = 2070
N = 10
170 gr Hornady FBFP 35.0 grs AA2520 wtd lot 9595 W/W cases CCI200 OAL 2.550"
14 Jan 2014 T = 50 °F
Ave Vel = 2223
Std Dev = 24
ES = 53
High = 2250
Low = 2197
N = 5
poor group, easy extraction
170 gr Hornady FBFP 31.5 grs IMR4064 wtd lot 2449 W/W cases CCI200 OAL 2.545"
14 Jan 2014 T = 50 °F
Ave Vel = 1802
Std Dev = 12
ES = 24
High = 1812
Low = 1788
N = 3
poor group
170 gr Hornady FBFP 34.0 grs IMR4064 wtd lot 2449 W/W cases CCI200 OAL 2.550"
1 Feb 2014 T = 58 °F
Ave Vel = 2031
Std Dev = 20
ES = 50
High = 2064
Low = 2014
N = 5
group 2.6 X 2.0
170 gr Hornady FBFP 35.0 grs IMR4064 wtd lot 2449 W/W cases CCI200 OAL 2.550"
1 Feb 2014 T = 58 °F
Ave Vel = 2104
Std Dev = 30
ES = 68
High = 2122
Low = 2054
N = 5
group size 2.6 X 2.0"
170 gr Hornady FBFP 35.5 grs IMR4064 wtd lot 2449 W/W cases CCI200 OAL 2.550"
7 Feb 2014 T = 40 °F
Ave Vel = 2103
Std Dev = 20
ES = 64
High = 2128
Low = 2064
N = 10
group size eight shots 3 3/8" X 1 7/8
170 gr Hornady FBFP 36.0 grs IMR4064 wtd lot 2449 W/W cases CCI200 OAL 2.550"
7 Feb 2014 T = 40 °F
Ave Vel = 2135
Std Dev = 21
ES = 67
High = 2180
Low = 2113
N = 10
group size 2 3/8" X 2 1/2"