20 Gauge Sabot Trajectory

[nachosgrande]

In a predicament. I'm out of town and the only local range is 25 yards long. I just got a new Savage 220 shotgun and need to sight it in before a hunt on Monday. I'm using 260 grain Remington Accutips (2 3/4 inch) and am curious how high or low it will be at 50, 100, 150, 200, etc yards. Thanks.

 

[docsleepy]

Need some more information. Are you using a scope ? Or Iron sights? How high above the barrel?


Take that information the weight of to the bullet, and it's velocity enter all that into one of the calculators at JBMballistics.com. Set the zero at 25 yards, and see where it goes.

If you can give me the answer to the above questions, I can fill it in for you.

 

[docsleepy]

The "how high above the Centerline of the barrel " is the most important piece of information.

 

[nachosgrande]

Thanks for the quick response. It's a Nikon Prostaff 3-9x40 and it uses low mounts.

 

[Tom Held]

info on the remington sabots

found this article, might help you:



"...In 20 gauge, the PRA20 is the 1850 fps 2-3/4 inch shell, the PRA20M is the 1900 fps three inch shell. Your rifled slug gun won't get near these velocities, nor will your rifled slug gun achieve any manufacturer's published velocities. The reason is, the standard test barrels for 20 gauge are 30 inches long, a barrel length no one I know wants in a slug gun and no manufacturer offers. With the Savage 220's 22 inch barrel for example, you'll be getting 1725 fps or so.

Sighted in two inches high at 80 yards, the Remington Accutips net you about a 160 yard maximum point blank range (+/- 3")...."

 

[Texan Scott]

Ran the numbers, assuming 1.5" reticle above bore axis and velocity 1800-1900fps.
Oddly enough, your zeros fall right at 25 and 100 yds. Sight in dead on at 25yds, and you should be GTG for 100 yds.

 

[Naybor]

Man, that 220 must be some shotgun!!! Hope yours is the "F" model!

This article makes me want one.

http://www.shootingtimes.com/2010/09/23/longgun_reviews_st_spadvart_201007/

Also you need to check out www.shootingtimes.com. A wonderful gun related site.

 

[AI&P Tactical]

Thanks for the post of that Neybor - I have been preaching the 20 ga as a slug gun for years and that review gave me some information I did not know.

To the OP. You can get that information for that exact load from the Remington Web site. The balistic charts are there.

 

[nachosgrande]

Thanks for the help everyone, gives me more than enough to go on.

 

[nachosgrande]

I spoke too soon. I can't seem to find the ballistic coefficient for the accutip slug. Anyone have any idea where I might find that info?

 

[AI&P Tactical]

On the Remington home page www.remington.com Click on "News and Resources" a drop box appears and click on "ballistic Calulator" When that page comes up scroll down till you see the Program that you down load. Once you have that down loaded read the Tutorial as there are a lot of features in this new program and you can find all the Remington ammo.

 

[docsleepy]

http://www.outdooroutfitters.com/remington-ammunition-PRA450B1.aspx

I'm betting the 260grain slug is the same one used in their 450 Bushmaster product. If this is correct, then the BC is .144

If the scope is indeed 1.5 inches above barrel centerline [my cantilevered Mossberg 500 measures 1 5/8" so 1.5" might be a tiny bit on the high side, but very reasonable--the Savage 220 will need a base anyway] , and the muzzle velocity 1700 fps, then plugging those numbers into the ballistic computer at www.jbmballistics.com yields:


Calculated Table
Range Drop Drop Windage Windage Velocity Mach Energy Time Lead Lead
(yd) (in) (MOA) (in) (MOA) (ft/s) (none) (ft•lbs) (s) (in) (MOA)
0 -1.5 *** 0.0 *** 1716.2 1.537 1700.1 0.000 0.0 ***
20 0.0 0.0 0.2 0.9 1620.9 1.452 1516.5 0.036 6.3 30.2
40 1.0 2.3 0.7 1.7 1530.3 1.371 1351.7 0.074 13.0 31.1
60 1.3 2.1 1.7 2.7 1444.9 1.294 1205.1 0.114 20.1 32.1
80 1.1 1.3 3.0 3.6 1365.3 1.223 1075.9 0.157 27.7 33.0
100 0.0 0.0 4.8 4.6 1292.0 1.157 963.6 0.202 35.6 34.0
120 -1.8 -1.5 7.1 5.6 1225.8 1.098 867.3 0.250 44.0 35.0
140 -4.6 -3.2 9.8 6.7 1167.3 1.046 786.5 0.300 52.8 36.0



which agrees with what an earlier poster calculated. I think the geometry of the scope and the low BC are the most important factors. Given that a deer has a pretty large vitals package, this shouldn't be difficult to make work with a 20-yard zero.

 

[docsleepy]

Hmmm...actually you wanted a 25 yard target, not a 20. Dunno where I got 20. I ran the numbers again for a 25 yard zero:

Calculated Table
Range Drop Drop Windage Windage Velocity Mach Energy Time Lead Lead
(yd) (in) (MOA) (in) (MOA) (ft/s) (none) (ft•lbs) (s) (in) (MOA)
0 -1.5 *** 0.0 *** 1716.2 1.537 1700.1 0.000 0.0 ***
25 0.0 0.0 0.3 1.1 1597.8 1.431 1473.6 0.045 8.0 30.5
50 0.6 1.2 1.2 2.2 1486.9 1.332 1276.2 0.094 16.5 31.6
75 0.3 0.4 2.7 3.4 1384.6 1.240 1106.6 0.146 25.7 32.8
100 -1.2 -1.1 4.8 4.6 1292.0 1.157 963.6 0.202 35.6 34.0
125 -3.9 -3.0 7.7 5.9 1210.4 1.084 845.7 0.262 46.2 35.3
150 -8.2 -5.2 11.3 7.2 1141.0 1.022 751.5 0.326 57.4 36.6


Still reasonable.

 

[nachosgrande]

Thanks Doc, just what I was looking for.