Slug Ballistic ???
11-14-2004, 05:55 PM
#1
Nontypical Buck
Thread Starter
Join Date: Feb 2003
Location: SW Michigan
Posts: 1,906
Slug Ballistic ???
With years of scientific training, I'm a bit befuddled about some information I have attained.
I have been playing with my slug gun, of which I recently topped with a scope. Therefore, I decided this afternoon to try out different brands of 2 3/4 inch slugs again, to see if I could get better groups with better optics. I had sighted in with open sights using just the Federals, as recommended by the techs at Ithaca.
What I found, is that out of my Ithaca 12 gauge, Federal Barnes Expanders in either .75 or 1 oz drastically outperformed Brennekes, Lightfield EXPs, or Remington Copper Solids. And I mean drastically !
With the Federals I was shooting bullet holes 2.5 inches high at 25 yards, 1 inch groups ~ 1inch high at 50, and 2 shots at 100 yards were a 2 inch group -0.5 inches low (sorry guys, ran out of rounds [&:] ). The 0.75 oz slugs outperformed the 1 oz., as I suspected they might from my previous shooting experiences with open sights.
The Rems were actually second best, with 4 inch groups a little low, and the lightfields were, and get this, approximately 16 inch groups all over the place. With the results I obtained from my gun, obviously it prefers a lighter load (all the other slugs were at least 1.0, the EXPs are 1.25 oz.).
So I went to Federal, and looked at the ballistics for the 0.75 & 1 oz. slugs, as I decided I would use the ballistics to decide the round because they were pretty even in accuracy and precision. This is the info provided by Federal (with open sights 1.5" above bore; scope will change accordingly):
distance: 25 50 75 100 125
0.75 vel: 1810 1720 1640 1560 1480
0.75 ft#: 2370 2140 1940 1755 1585
1.0 vel: 1380 1320 1260 1210 1160
1.0 ft#: 1860 1695 1545 1420 1310
Now I'm pretty good with physics, so I expected without looking at the ballistics that even though the velocity would be slightly reduced, the extra 0.25 oz of weight would provide more or equal the foot pounds and obviously a slightly larger entrance/exit wound. However, these rounds are not even close, and re-examining my papers I found that the 0.75 grouped even tighter than the 1.0 ouncers.
But with my results from this gun, coupled with the ballistics above, then the following questions need examination...
1) Why shoot a heavier slug? A lighter slug (at least Federal) carries more velocity and more torque, hence better shocking power. A lighter slug also induces less recoil.
2) What are the disadvantages to a lighter slug? From my results, in this gun, there are none. From the ballistics from Federal, there are also none. Flatter trajectory, more power with a slightly smaller hole (probably 4mm total)...
Looking for some answers on this one...
I have been playing with my slug gun, of which I recently topped with a scope. Therefore, I decided this afternoon to try out different brands of 2 3/4 inch slugs again, to see if I could get better groups with better optics. I had sighted in with open sights using just the Federals, as recommended by the techs at Ithaca.
What I found, is that out of my Ithaca 12 gauge, Federal Barnes Expanders in either .75 or 1 oz drastically outperformed Brennekes, Lightfield EXPs, or Remington Copper Solids. And I mean drastically !
With the Federals I was shooting bullet holes 2.5 inches high at 25 yards, 1 inch groups ~ 1inch high at 50, and 2 shots at 100 yards were a 2 inch group -0.5 inches low (sorry guys, ran out of rounds [&:] ). The 0.75 oz slugs outperformed the 1 oz., as I suspected they might from my previous shooting experiences with open sights.
The Rems were actually second best, with 4 inch groups a little low, and the lightfields were, and get this, approximately 16 inch groups all over the place. With the results I obtained from my gun, obviously it prefers a lighter load (all the other slugs were at least 1.0, the EXPs are 1.25 oz.).
So I went to Federal, and looked at the ballistics for the 0.75 & 1 oz. slugs, as I decided I would use the ballistics to decide the round because they were pretty even in accuracy and precision. This is the info provided by Federal (with open sights 1.5" above bore; scope will change accordingly):
distance: 25 50 75 100 125
0.75 vel: 1810 1720 1640 1560 1480
0.75 ft#: 2370 2140 1940 1755 1585
1.0 vel: 1380 1320 1260 1210 1160
1.0 ft#: 1860 1695 1545 1420 1310
Now I'm pretty good with physics, so I expected without looking at the ballistics that even though the velocity would be slightly reduced, the extra 0.25 oz of weight would provide more or equal the foot pounds and obviously a slightly larger entrance/exit wound. However, these rounds are not even close, and re-examining my papers I found that the 0.75 grouped even tighter than the 1.0 ouncers.
But with my results from this gun, coupled with the ballistics above, then the following questions need examination...
1) Why shoot a heavier slug? A lighter slug (at least Federal) carries more velocity and more torque, hence better shocking power. A lighter slug also induces less recoil.
2) What are the disadvantages to a lighter slug? From my results, in this gun, there are none. From the ballistics from Federal, there are also none. Flatter trajectory, more power with a slightly smaller hole (probably 4mm total)...
Looking for some answers on this one...
11-14-2004, 06:57 PM
#3
Nontypical Buck
Thread Starter
Join Date: Feb 2003
Location: SW Michigan
Posts: 1,906
RE: Slug Ballistic ???
Bowhunter,
I'm not looking for justification about the slugs through my Ithaca. I didn't clean the barrel after the Federals, and had fired off 2 boxes, so some fouling could have altered the shots.
I'm more bewildered at the ballistics of the same slug with different weights, and what the advantage/disadvantage is to shooting a lighter/heavier slug.
My Dad, who was a sniper in the military, always stated that a smaller projectile would have greater accuracy in the hands of most people, but I didn't realize that it would carry true to 0.25 oz difference in the same brand/type of shotgun slug...
I'm not looking for justification about the slugs through my Ithaca. I didn't clean the barrel after the Federals, and had fired off 2 boxes, so some fouling could have altered the shots.
I'm more bewildered at the ballistics of the same slug with different weights, and what the advantage/disadvantage is to shooting a lighter/heavier slug.
My Dad, who was a sniper in the military, always stated that a smaller projectile would have greater accuracy in the hands of most people, but I didn't realize that it would carry true to 0.25 oz difference in the same brand/type of shotgun slug...
