richbug
05-16-2008, 09:25 AM
I recently embarked on an attempt to shoot cast bullets in one of my FAL's as a cost saving measure.
My requirements of the load:
1. 4 MOA or less
2. cycle the action on the same gas setting that I use for jacketed
3. have enough power to reach out and touch something, IE knock over a heavy steel target at 200 yards plus
4. feed from the magazine
I picked the Lee 200 grain bullet, this will allow for lower velocity to keep from leading, while having enough mass to hit with authority at longer ranges. Also it has a shape which will feed from the magazine with little deformation.
The alloy I used was 1 part linotype to 2 parts 8BHN recovered range lead. Air dropped, BHN about 15. Hornady gas checks, bullet sized to .309", lubed with white label BAC lube. Bullets were visibly inspected, but not weighed.
I selected H4831 to start with, this might seem like an inappropriate powder for 308, but its slow burn rate gives a more gradual acceleration of the bullet(no stripped rifling), and adequate port pressure to cycle the rifle on its regular gas setting. All charges were thrown through a Lee measure, only the first couple were weighed on a scale, no trickling here(I'd guess I was withing .1 gr plus or minus on all).
I varied seating depth some, at full mag length it required the POGO to get a live round back out of the chamber. I settled on a length that just started to engrave the rifling on the bullet.
Brass was some pulled down TW-65 military brass with the original primers in place.
Test rifle: Dans grade 3 IMBEL kit, on a PAC Imbel receiver that I built myself. This rifle has shown uncanny accuracy with everything run through it. 2 MOA or better on 70's Indian. Iron sights.
All tests fired form magazine, sand bag under forearm, no rear rest, Iron sights, shooter had been flashed by an arc welder a few hours earlier, vision a little fuzzy. All groups 10 shots or more. All fired pretty rapidly, under 1 minute for 10 shots. I used a 6:00 hold on a 2" black square for center hits.
35 grains Cycled the rifle, but wouldn't lock back on an empty mag, lots of unburned powder in the bore.
- not suitable, no accuracy test done
36 grains, Cycled rifle locked back most of the time, lots of unburned powder,
-not suitable, no accuracy test done.
37, cycle properly, Lock back on empty, some unburned powder, brass all went about 5 feet
Accuracy 3.5" at 50 yards
38 grains Ran fine, little unburned powder, brass went 6 feet,
Accuracy 3.25" at 50 yards
39 grains Ran fine, virtually no unburned powder, Brass about 8 feet
Accuracy 1.54" at 50 yards "MONEY LOAD"
40 grains Ran fine, No unburned powder, Brass about 10 feet.
Accuracy 2.3" at 50, includes a couple flyers otherwise, 1.5"
41 grains, Ran fine, brass 12 feet, No unburned powder, SMOKEY(just a little too fast). Accuracy 2.5" at 50, 5 into under 1"
The brass was not damaged by the rifle in any way. None of the primers show any pressure.
I fired 25 rounds of the 39 grain load at the 8" 200 yard gong, all were hits using a slightly above center hold. Based on the return time from the sound of the hits I would estimate 2000-2100 FPS with this load.
Conclusion, While not the accuracy of my 6.7 cent Indian from a few years back I am pleased with the 39 and 40 grain loads(sadly even with free lead this costs more too). Unfortunately I used all my TW brass and primers in the test, so I can't repeat it exactly. I plan to dedicate a batch of LC match brass to this quest, and play with different primers. I would expect similar results from any other extruded powders in the same burn rate, 3100, Data 86, IMR4831, RE19 etc
I expect I could do better by weighing my bullets and charges. A rear rest would probably help.
Primer 1.8 cents, Gas check 1.8 cents, 8.5 cents for propellant. Still pretty cheap.
My requirements of the load:
1. 4 MOA or less
2. cycle the action on the same gas setting that I use for jacketed
3. have enough power to reach out and touch something, IE knock over a heavy steel target at 200 yards plus
4. feed from the magazine
I picked the Lee 200 grain bullet, this will allow for lower velocity to keep from leading, while having enough mass to hit with authority at longer ranges. Also it has a shape which will feed from the magazine with little deformation.
The alloy I used was 1 part linotype to 2 parts 8BHN recovered range lead. Air dropped, BHN about 15. Hornady gas checks, bullet sized to .309", lubed with white label BAC lube. Bullets were visibly inspected, but not weighed.
I selected H4831 to start with, this might seem like an inappropriate powder for 308, but its slow burn rate gives a more gradual acceleration of the bullet(no stripped rifling), and adequate port pressure to cycle the rifle on its regular gas setting. All charges were thrown through a Lee measure, only the first couple were weighed on a scale, no trickling here(I'd guess I was withing .1 gr plus or minus on all).
I varied seating depth some, at full mag length it required the POGO to get a live round back out of the chamber. I settled on a length that just started to engrave the rifling on the bullet.
Brass was some pulled down TW-65 military brass with the original primers in place.
Test rifle: Dans grade 3 IMBEL kit, on a PAC Imbel receiver that I built myself. This rifle has shown uncanny accuracy with everything run through it. 2 MOA or better on 70's Indian. Iron sights.
All tests fired form magazine, sand bag under forearm, no rear rest, Iron sights, shooter had been flashed by an arc welder a few hours earlier, vision a little fuzzy. All groups 10 shots or more. All fired pretty rapidly, under 1 minute for 10 shots. I used a 6:00 hold on a 2" black square for center hits.
35 grains Cycled the rifle, but wouldn't lock back on an empty mag, lots of unburned powder in the bore.
- not suitable, no accuracy test done
36 grains, Cycled rifle locked back most of the time, lots of unburned powder,
-not suitable, no accuracy test done.
37, cycle properly, Lock back on empty, some unburned powder, brass all went about 5 feet
Accuracy 3.5" at 50 yards
38 grains Ran fine, little unburned powder, brass went 6 feet,
Accuracy 3.25" at 50 yards
39 grains Ran fine, virtually no unburned powder, Brass about 8 feet
Accuracy 1.54" at 50 yards "MONEY LOAD"
40 grains Ran fine, No unburned powder, Brass about 10 feet.
Accuracy 2.3" at 50, includes a couple flyers otherwise, 1.5"
41 grains, Ran fine, brass 12 feet, No unburned powder, SMOKEY(just a little too fast). Accuracy 2.5" at 50, 5 into under 1"
The brass was not damaged by the rifle in any way. None of the primers show any pressure.
I fired 25 rounds of the 39 grain load at the 8" 200 yard gong, all were hits using a slightly above center hold. Based on the return time from the sound of the hits I would estimate 2000-2100 FPS with this load.
Conclusion, While not the accuracy of my 6.7 cent Indian from a few years back I am pleased with the 39 and 40 grain loads(sadly even with free lead this costs more too). Unfortunately I used all my TW brass and primers in the test, so I can't repeat it exactly. I plan to dedicate a batch of LC match brass to this quest, and play with different primers. I would expect similar results from any other extruded powders in the same burn rate, 3100, Data 86, IMR4831, RE19 etc
I expect I could do better by weighing my bullets and charges. A rear rest would probably help.
Primer 1.8 cents, Gas check 1.8 cents, 8.5 cents for propellant. Still pretty cheap.