Author Topic: Looking for your expert opinions (Read 366 times)

cpobb · « **on:** January 12, 2006, 11:08:18 AM »

I do not consider my self a handloader (although I do occasionally reload ammo in quantity via my brothers dillon press), and I need some advice from ballistic experts. I am considering having a winchester model 70 in .270 win. cut down to 16.5 or perhaps 18" to make a compact deer rifle. I am planning to put it in a Choate folding sniper stock. My question is how severely will this effect the accuracy, energy and bullet drop of factory ammo? Say 130 gr. btsp for instance. My absolute maximum shooting distance with this rifle would be 200 yds. with common distances around 100 yds or less. Thanks for your input.

jcunclejoe · « **Reply #1 on:** January 12, 2006, 12:24:27 PM »

If the shortening and recrowning is done properly, your barrel should be more consistently accurate under most all conditions. Shortening a barrel increases it's relative stiffness and can really make them humm. You will probably lose about 30 to 50 fps per inch it is shortened. At the distances you are talking about shooting the critters will never know the difference in velocity and you won't notice much difference in drop either. As for energy the 270 has plenty to overcome any loss.
Just sight it in 2 to 2 1/2 inches high at 100 and you'll be able to aim right where you want to hit and be no more than 3" high or 3" low out to about 250 yards.
Good luck and enjoy.
Joe

cheatermk3 · « **Reply #2 on:** January 12, 2006, 07:33:41 PM »

This may not matter to you, but that short of a barrel (16.5") shooting that much powder will most likely mean a heck of a lot of muzzle flash.

Like enough to burn the paint off of the hood of your new truck (Thanks a bunch, steve...).

cpobb · « **Reply #3 on:** January 13, 2006, 04:18:45 AM »

Thanks for the info Joe. That is just what I was hoping to hear. And Cheater.....how'd you know I got a new truck?

I'll be sure to keep my muzzle away from combustables like those dry autumn leaves. Thanks guys.

jhalcott · « **Reply #4 on:** January 13, 2006, 06:27:12 AM »

Range Velocity Energy Moment Elev Wind Lead Slope Time
(yards) (ft/sec) (ft-lbs) (lb-sec) (inches) (inches) (inches) (in/yd) (sec)
0 2605.9 1960.2 1.50 --- --- --- --- 0.000
25 2552.9 1881.2 1.47 -0.61 0.05 0.0 +0.029 0.029
50 2499.4 1803.2 1.44 -0.05 0.22 0.0 +0.016 0.059
75 2446.7 1727.9 1.41 +0.15 0.49 0.0 +0.001 0.089
100 2394.6 1655.1 1.38 -0.00 0.88 0.0 -0.013 0.120
125 2343.2 1584.8 1.35 -0.54 1.39 0.0 -0.029 0.152
150 2292.5 1517.0 1.32 -1.47 2.02 0.0 -0.045 0.184
175 2242.5 1451.5 1.29 -2.81 2.78 0.0 -0.062 0.217
200 2192.9 1388.1 1.27 -4.58 3.67 0.0 -0.080 0.251