I am going to work up some new loads with two Barnes bullets for my 404 Jeffery: the 400 grain TSX and 400 grain Banded Solid. I will be using VihtaVuori N150 propellant. If my goal is to obtain the same impact point at say 100 yards my intuition tells me that the solid will have to leave the muzzle faster, since it doesn't have the same BC. Is this correct? Is it always the case?

My own exp. tells me the harmonics plays more into it than the BC. The Barnes 400gr mono is quite a bit longer than the 400gr Woodleigh or 380gr NF. I run the 400gr Barnes @ 2150fps & the 380grNFs @ 2250fps, 400gr Wood. softs @ 2200fps. The solids land about 1" lower than the softs @ 100yds. Close enough for me, as the solids are for close & personal to me.

In theory if the muzzle was in exactly the same spot when both left the barrel the solid would be .8" lower at 100yds.

That said depending on the barrel harmonics the solid might actual print higher. Basically it is a crap shoot.

I would develop the load for the primary bullet and then play with trying to get the other to print close at your expected shooting range.

I tried to do the same thing with my 375 H&H using the Barnes 300 grain TSX and 300 grain banded solids.

For some weird reason the solids all shot 2-3" left of the TSX bullets, some loads higher on the target and some lower but always to the left.

I've bought some 270 grain banded solids to try also but haven't had a chance to shoot them yet.

quote:

Originally posted by Fjold:
I tried to do the same thing with my 375 H&H using the Barnes 300 grain TSX and 300 grain banded solids.

For some weird reason the solids all shot 2-3" left of the TSX bullets, some loads higher on the target and some lower but always to the left.

I've bought some 270 grain banded solids to try also but haven't had a chance to shoot them yet.

Remember that harmonics affects quite a few different vibrational nodes. You guys are focusing in the up-down. There is a L-R vibration, a front-back (due to stretching) and a rotational (due to torque.) I think the last two are pretty neglibible.

I recall a link to an article about the vibrational harmonics. The barrel travels in a "Figure 8" pattern. I used to have a bookmark to it, but can't seem to find it now.

Not only that but the bullet yaw will be different. I'm guessing that the idea of the original post was to get the loads working pretty much the same in order to bypass learning two trajectories, using the same hold over/off points. It might work ok for shots in the neighborhood of 100 yards but probably not well much further out.

I've seen a lot of folks with computer generated trajectory information printed out and taped on the stock. That seems like it might be a better bet.

Try it and see Wink. I used the same loads for TSX and Banded Solids in my 9.3x62, and they shot close enough to the same POI, that I was not going to bother adjusting the load.

Like Fred, I consider the solids primarily for close range work. So I sight in for the TSX and live with perhaps 1" different POI for the solids.

- mike

I have done this with a 416/404

400gr Trophy Bond Solid 75gr IMR 4320 210M 2330fps

400gr Horn encp solid 75g 4320 WLMR primer 2289fps

400 Partition 75gr 4320 WLMR 2349fps

350 Speer Sptz 74gr Varget 2156fps Accurate & same point of aim as 200yds.

This should get you close. Kudude

quote:

Originally posted by Fjold:
I tried to do the same thing with my 375 H&H using the Barnes 300 grain TSX and 300 grain banded solids.

For some weird reason the solids all shot 2-3" left of the TSX bullets, some loads higher on the target and some lower but always to the left.

I loaded some ammo for a friend's Winchester M70 with Vihta N140, the 300 grain solids shoot 3 cm lower than the 300 grain TSX. He adjusted his scope 4 cm high at 100 m for the TSX so the solid is practically right on at that distance, this was a happy coincidence.