In my earlier posting, I said that I intended to load some lead bullets in .30 Rem, and also some very heavy jacketed bullets (220 grain). I just finished shooting them today, in my 1950 Model 81 and will share my results.
I. Lead bullets - I purchased some 165 grain flat nose lead bullets from Missouri Bullet Company. They are plain base, not gas check, but are sold for hunting use in the .30-30. They are fairly hard, 17 Brinnell. My goal was to find a load that would function reliably in the Model 81 and provide fair accuracy. Alas, it was not to be. I loaded 5 rounds of each variation for velocity and grouping tests. Loading data was not entirely random, as the loads selected came from an amalgamation of Lyman reloading data and also Quickload software. Shooting was done using 5-shot groups from a bench rest and sandbags at 50 yards, using my Chrony chronograph. My sights were the factory M81 open sights. Loads were all held at an OAL of 2.52-2.53" (SAAMI maximum). Bullets were lightly crimped into the crimping groove. In none of these loads did pressure seem high, as there was no hint of primer flattening or cratering around the firing pin depression.
1. 11 grains of Unique. 5 shot average muzzle velocity (actually at about 6 feet) was 1578 ft/sec, with SD of 21 ft/sec. This load would not function the action. I did not shoot this load for grouping, only velocity.
2. 19 grains of 2400. Average muzzle velocity was 1944 ft/sec, with SD of 51 ft/sec. This load functioned the action satisfactorily. Four shots went into a 6.5" group, while the fifth shot went somewhere else, as I couldn't find it.
3. 17 grains of 2400. Average muzzle velocity was 1796 ft/sec, with SD of 22 ft/sec. This load would not function the action. Grouping was terrible, over 12"
4. 12 grains of Herco. Average muzzle velocity was 1837 ft/sec, with a SD of 11 ft/sec. This load would not function the action. Grouping was over 12"
5. 14 grains of H240 (this is an obsolete Hogdon propellant, somewhere in performance between Blue Dot and 2400). Average velocity was 1665 ft/sec with SD of 7 ft/sec. This load would not function the action. Grouping was 10-5/8"
6. 25 grains of Accurate Arms (AA) 2230. Average velocity was 1838 ft/sec, with SD of 111 ft/sec (yes, 111). This load functioned the action satisfactorily. Grouping was over 12".
7. 25 grains of AA 2460. Average velocity was 1859 ft/sec with SD of 29 ft/sec. This load functioned the action satisfactorily. Grouping was over 12"
8. 23 grains of AA 2015. Average velocity was 1778 ft/sec with SD of 19 ft/sec. This load functioned the action satisfactorily. Grouping was over 12"
9. 26 grains of H4198. Average velocity was 2089 ft/sec, with SD of 45 ft/sec. This load functioned the action satisfactorily. Grouping was over 12"
Conclusion: This experiment resulted in lead bullet velocities ranging from 1578 ft/sec to 2089 ft/sec. To get reliable functioning, a velocity minimum of about 1900 ft/sec is required. No load tested had satisfactory grouping qualities, good only for making noise on New Years eve or maybe shooting cattle in the head at a slaughterhouse. Gas check lead bullets might perform better, but I don't know. My previous experience with GC'd lead .30 bullets many years ago in a .30-'06 didn't work out well in the grouping department either. I don't think the poor grouping performance has anything to do with my barrel condition, as it is pristine. Lower velocities might improve grouping, but that turns the Model 81 into a straight pull bolt action repeater.
II. 220 grain RN FMJ bullets. I have a good supply of .30 caliber 220 grain RN FMJ military bullets which I believe were used in the .30-40 Krag or maybe the .30-'03 Springfield. They mike 0.307" in diameter. My main concern with the 220 grain bullet was stability in the 1:12" rifling twist rate of the Model 81. My calculations indicated that stability was right on the borderline at expected velocities (a bit of useful information - long bullets require a tighter rifling twist to keep them going point forward than do shorter ones). As no loading data is available for such heavy bullets in the .30 Remington or the .30-30, I used my Quickload software to come up with a modest load. Quickload said that I could go as high as 26 grains of IMR 3031 without exceeding the maximum chamber pressure. I had no IMR 3031, but I do have Hercules HiVel #2, which is balistically very similar. Therefore I made two 5-round cartridge sets, one with 22 grains of HiVel #2 and one with 23 grains. OAL was kept at 2.52-2.53". This required seating the bullet very deeply. Even so, there was plenty of room in the case for the powder without compressing it (Quickload calculates that also).
Results for the 220 grain FMJ loads:
1. 22 grains of HV#2. Average velocity was 1436 ft/sec, with SD of 25 ft/sec. This load functioned the action satisfactorily. Three shots went point first into a 1.25" group (50 yards), while the other two shots were 2" apart but about 4" to the lower left of the first group. These two bullet holes were elongated, indicating bullet yawing, therefore instability.
2. 23 grains of HV#2. Average velocity was 1508 ft/sec with a SD of 21 ft/sec. This load functioned the action satisfactorily. All bullets went point first into a 2-7/8" group that was mainly horizontal. There was no evidence of yawing from the appearance of the bullet holes. Not too bad, better than I have been able to get with 150 grain jacketed RN bullets in the Model 81, which was about 3.5".
Conclusion: The 220 grain bullets performed better in the .30 Remington than my expectations. It seems that increasing the velocity slightly by one additional grain of HiVel#2 may have prevented yawing, at least at 50 yards. There is, I think, room for improvement in velocity (and stability) by increasing the propellant charge a little more while remaining within safe working pressures. Again, there were no indications of excessive pressures from observation of the fired primers. Also, recoil wasn't at all objectionable. If you need to use your Model 8/81 on elephant and cape buffalo, this is a good load to start with.
My standard disclaimer: I don't recommend your duplicating any of these loads and they are presented for entertainment purposes only.
Posts about the Model 81~Woodsmaster~
2 posts • Page 1 of 1
Thanks for the write up! I cast and shoot far more CB's than jacketed. Mostly in large caliber single shot rifles like the Remington roller and Sharps using black powder. So any rifle I shoot will sooner or later see some cast slugs. Your work with the .30 Rem M81 will come in handy when I get to trying out cast in mine. At some point I plan on trying it. Right now just to get out hunting with it this next fall I am going with the old standard 150 grain Hornady RN jacketed pill.