105 amax

I'm working on a new project. Its a shorter barreled rifle. I was wondering if anyone knows at what velocity the amax stops expanding?

As velocity decreases, so does expansion. Most bullets need about 2000-2200 fps to have some expansion. As velocity increases, so will the expansion. So, there's not really an answer. I would plan to keep the velocity above 2500 fps for some expansion, for hunting speeds.

Ok. I was thinking the amax may have been more fragile then that.

Try it and see!

What caliber are you planning to run, and how short a barrel?

I have a 243 with a 26" barrel. Im going ti shorten it or rebarrel to something else. I'm really wanting a 16 or 18" barrel. I think I'm going to have to rebarrel to a larger cal. I'm just want to be able to reach 409 yards for deer and pigs. Running the numbers, the 243 would be borderline. It would have around 1800 fps and 800 ft-lbs.

I know 3000 fps is attainable in a 24" barrel in a 243 Win with a 105 grain. If you went to 18", you will lose about 150 fps, so that puts you at a muzzle velocity of about ~2850 fps. Looking at the drop data, 300 yards and in should get you decent performance. With good shot placement, I think you will be fine at 400 yards with a 105 A-max. Shot placement is key. If you can be proficient at 400, then you will be fine.

If you wanted to try a different bullet, like an 87 grain Berger VLD-H, that will get you a little more muzzle velocity and the VLD's are easier to open up at lower speeds. 3150 fps is doable, so 3000 fps in an 18" barrel.

105 A-max
Range Velocity Energy Elev Wind
(yards) (ft/sec) (ft-lbs) (inches) (inches)
0 2850 1893.7 --- ---
100 2667.5 1658.9 0 0.63
200 2491 1446.6 -3.4 2.59
300 2321 1255.9 -12.4 6.03
400 2157.8 1085.5 -27.88 11.11
500 2002 934.4 -50.83 17.99

87 VLD
Range Velocity Energy Elev
(yards) (ft/sec) (ft-lbs) (moa)
0 3000 1738.5 ---
100 2785.3 1498.6 0
200 2578.2 1284 -1.43
300 2379.3 1093.6 -3.57
400 2189.4 925.9 -6.12
500 2009.1 779.7 -9.03

Also, what's your barrel twist?

I can live with that performance. I was thinking ii would lose more velocity then that. Just need to find someone to cut the barrel for me.

1-9.25 Its working oornthe amax now but it may not once I cut it.

Go for it. I've killed more stuff with A-maxes than anything else. They make a fine hunting bullet for certain tasks. I wouldn't go far on elk or mulies, but they'll pleasantly surprise you on whitetail, hogs, and coyotes.

I'm going try it. I've got better stuff for elk, if I ever get a chance. I'll use the worlds best long range round, the mighty 257 wby.

Now you done went off the rails.

With a 1:9.25" twist @ 2850 fps, it shows a 1.13 stability factor, where a 1.4 or more is best. The BC is reduced by about 11% due to lack of stability. It may shoot decent, but the lower stability will increase the drag.

I think I'll order a 1 in 8 from McGowan or blackhole.