I've looked & looked, but can not find the published BC (ballistic coefficient) of the cast Lee 310 boolit. Trying to do some trajectory predictions and need that info.
725
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I've looked & looked, but can not find the published BC (ballistic coefficient) of the cast Lee 310 boolit. Trying to do some trajectory predictions and need that info.
725
Sight the gun in dead on at 100 yards, you will add 6MOA for 150 and 12 MOA for 200. This is with the boolit at @1600 fps. May vary slightly but this is close.
Don't know what the exact BC is for that boolit, however on a round like this that is really done at 150 yards, the only really effective way to plot trajectory is thru shooting at different distances. Hard to predict as the trajectory is so steep that slight variables make big changes.
If you start at 100 yards and sight the rifle dead on, then shoot at 150 and then 200 using the original elevation offsets you will see exactly what the trajectory is. In this particular case there just isn't that much to be learned. I included 200 yards simply because I shoot Short Range Silhouette with my Marlin 1894CB with a 24" bbl. and the elevation offsets I gave above are what I use in the matches.
Those matches are shot at 50,100,150,and 200 meters. I am at "Mechanical Zero" for 50 and 100 meters. and then up 6MOA for 150 and another 6 (12 total) for 200 meters. That is all the usable range the gun and .44 magnum cartridge have with any boolit. Sure you might be able to hit something farther out but the boolit is dropping like a stone beyond 200.
If you aren't using a Lyman 66 Rear Sight on your gun (assuming it is a levergun of some type) it will be difficult to adjust your sight easily and predictably for the different elevation changes. It will also be hard to get those adjustments to repeat.
The Steel Lyman Sights repeat exactly everytime (well worth the extra money off Ebay) and thus it is easy to make elevation adjustments during a match and return to "Mechanical Zero" after the match, so you just start over at the same place next time. There is also a stop screw that you use once you have established MZ so that all you have to do is push in the slide release button, run the elevation slide down to the stop and release the button and you are right back where you started.
With a Skinner or XS Rear Sight you would still just sight in at 100 yards but you'll have to hold over for longer shots as these sights are more about Hunting type shooting as opposed to Range type shooting. They are pretty much a set and forget type of sight.
On most open sights with stepped wedges for elevation changes, the steps are generally placed at 50 yard intervals using a specific type of ammo. They are usually right on with that ammo, and have been for 150 years. This is the way they did it, and what surprises me is that more people aren't aware of that fact. It only takes a second to slide the wedge up a notch or two.
Back in the day if you had an 1873 or 1892 Winchester or 1894 Marlin in say .44-40 there was only two or three types of ammo available, and they were pretty much exactly alike, so the sights were calibrated accordingly. If you reloaded, those rounds were generally loaded to duplicate factory ammo. IE; 40 gr of Black Powder and a 200gr boolit.
They actually worked pretty well as long as you understood what you needed to do for longer range shots. Most people just held over a target as needed and thus the fact that the sights were actually adjustable got forgotten. All of the gun makers and the Military actually had all of this stuff figured out to a gnats rear end, and a well trained and educated shooter knew about it as well. Shots out to fairly long distances were made with iron sights routinely,,,
Because that's all they had to work with!
Hope some of this helps. I find shooting with iron sights to be the most enjoyable.
Old eyes just have to learn to focus on the Front Sight, nothing else matters.
Randy
According to a 2016 Lee catalog, the BC for that bullet is .218
.218 according to lyman cast bullets #4. Awesome bullet!
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I have a PB copy from Accurate.Attachment 204390
Thank you so much. Answered my question. ..........and yes, awesome.
My favorite .44 boolit....so far.
Now to try it in the T/C Contender. It's good in the rifle.
Your results in the rifle will be very similar to what I described above.
Randy