230 A-Tip in .300 Norma Magnum Improved -- Load Help?

[wjplohman]

You won’t reach 3000 meters with any sort of consistent accuracy. I’d put a cap at 2,000 meters or you’re just wasting time and ammo.

Best send a text to Jeff Medline. He has not obviously been informed of that yet

 

[shoot4fun]

While on a recent prairie dog safari in Wyoming I took a little time to shoot my 300 NMIMP 35˚. I have very few rounds on the rifle and few of them were chrongraphed but decided to see if I could get one still at at least one mile. I had run Berger Ballistics charts with fair guesses and what little data I had for both Berger factory 300NM ammo with the 215 Hybrids and my Lapua 300NM formed to the IMP version before hand and hoped by using approximate environmental and altitude numbers I could be close quickly.
I fired twelve total rounds between the factory and handholds with winds crossing right to left at about 10-15MPH. Target was placed just over 1 mile distant (the guide's Leica RF bino's registered at 1486 yards but we wound up having to range from that point to a location just over 315 yards farther away. The two directly above the black dot in center are factory ammo with 16.2 mrad elevation and the two larger hits are the IMP loaded with same bullets. Those only needed 14.6 mrad to reach the target. After my twelve rounds the guide shot two more IMP rounds, one striking at the base of the target.
Target is 11" wide. I'll come back and add the load data, as I don't have it in front of me right now but the powder was IMR7977.
I really wish I had a spot closer to be ale to do this more often.

 

[shoot4fun]

I did have some loaded with the 230 A-Tips as well but after seeing what the 215 Hybrid is capable of I did even try the A-Tip.

 

[wjplohman]

I'm getting ready to try 230 Atips with retumbó. Rifle is a .300 Norma Magnum Improved (NMI) with 34" barrel 8.5 twist. Just wondering if anyone has tried something similar. I'm really interested in how this bullet performs going through the transition zone as I'm looking to reach out to close to 3000 meters. From previous bullet experience with this rifle I'm expecting to get around 3150 fps out of it
or will be looking for a node around that range

So to follow up.
I'm running about 91 gr of retumbó with a velocity of 3173. barrel twist of 8.5 so getting spin of 269,000. Have yet to lose one. Accuracy has been fine, I'm holding under 0.5 moa at 500 meters (560 yards)
With only about 0.3 moa of vertical. Will have better info after this coming weekend but to me they seem fine. Running just over 0.100 of jump but allowing a tolerance of 0.003 of runout on loaded rounds

 

[shoot4fun]

I have a 1 in 9 twist barrel 28" in length. I am going to do some testing on the 230 A-Tip and Retumbo myself.
Thanks for this info!

 

[HotRod6mm]

The 300 Win Mag was the popular prone match cartidge before the 6.5 .284 came on the scene. Recoil without better ballistics was major reason for change.

That money’s already spent, in all I must have 65k A-Tips mainly in 4 calibers/weights and I’m happy to have them, despite challenges. This was a read of the 230’s from a while back.

It’s a little more complicated than Lapua mag won’t work. With the 250 A-Tip having come out, there is literally no .338 match bullet with its BC, and the .338 LM can not only not compete in BC, but it was actually hard pressed to challenge the 195 EOL in a Suam even before that, I’ll say that even a .284 with 195’s shot inside it. I have used it (none blow up, but I feel silly adding a ring to a 7’s hold). I’d be shooting 300 grain bullets with a lower BC, slower. It would be counterproductive.

If I were making 250 grain 30 cal bullets, I would anticipate that the Win Mag to be at the smaller end of what they will be shot with, and it’s actually probably the smallest cartridge feasible right there with their own 300 PRC. We do have to keep in mind that the absolute highest BC combination on the line recently was one extremely rare blow up away from winning the LR national match last year. It’s going to happen. Wasn’t long ago everyone swore by their .284’s, and now, they don’t.

I do realize that my twist rate isn’t needed for 230’s but it’s only a bit faster than the 8.5 minimum for 250’s, and I had them made for the 250’s.

Here’s the thing about the 230’s they don’t actually have a much higher BC than the 190’s, but the 250’s do, by a lot. And I think they may be the smallest shooting until the 110 A-Tip, which is an extremely good bullet.

That’s legit!