I have a ton of lapua 155 grain mega tip bullets .I wanted to try them in my 260 .I have reloader 17,19 and 22 ,25 .These bullets are awesome accurate and knock the heck out of stuff.

I'd go with a stiff charge of RL 19....

I've had some fast velocity, with a 160 hornady RN and a stiff charge of H 380....

I can't help you with the Alliant powders but can tell you that the 160 gr Hornady RN shoots very well in the 260 Rem with H 4831 sc, IMR 7828 ssc and IMR 4350. Have only tried the 155 gr Lapua in my 264 WM, need to try them in the 260 sometime soon.

John how fast?

I would think IMR 7828 or H1000 would be excellent choices of your choices I would try reloader 22. There is very little data out there as the space in the case is displaced by the bullet to much.

The 140 NPT data for reloader 19 starts at 41 with a max of 45 its construction is not totally different from the mega lapua a little shorter. Starting at 40 would seem appropriate. Watch out in higher temps with RL19 I had a bad experience with it one summer with a full charge in my 30-06.

Good luck and shoot straight.

Bob

I ran the the 155 Mega in QL, reference points are 2.800" OAL and 100% fill, 22" barrel and QL recommended the following powders in order:

RL17 - 2666
RL26 - 2665
Ramshot - 2644
H414 - 2638
W760 - 2638

There are quite a few powders not typically found in the US mixed in with the above five.

Hodgdon has lots of data for 160-grain bullets, all with slow powders. Velocities range from ~ 2500-2600 fps. QL is a mathematical model, not data. I'd start with powders like RL-19, RL-23 or RL-25.


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Not the same bullet, but in a Tikka .260 the 156 Norma Oryx shoots very well with 42.5 grains of Norma MRP, which is the same powder as RL-22. Velocity is a little over 2600 fps from a 22" barrel.

What version of QL are you using?


RL 25 at 100% fill will get you ~2400 fps at 40K psi even though the 260 is a 60K psi cartridge...good advice.

I had good luck with these bullets in my 264 win mag.I shot clover leafs at 100 yards and just above am inch at 300 yards.I shot two pronghorns at 350 yards flipped them dead off their feet .I will try reloader 17 and 22 first starting at 40 grains .The 155 grain lapua has a BC of .377 and is made for moose in Sweden .

I even used them in my 6.5 jap with good results .That was my kids rifle before I got the 260 Remington.I have only used necked down 308 brass in my 260 so far .I like the 26 win mag but it kicks way to hard for kids .I like the 260 way better than the 243 Winchester also .These 155 grain lapua bullets should make it hit way harder than The 140 grain bullets .

Awesome shot dead center from first shot and made a 3/4 inch group with two in same hole at 100 yards.It was my starting load of 40.5 grains of r19.I had to seat the bullet very deep but still a little bit if powder room left .These 155 grain lapua mega tip bullets are awesome.I shot a gallon jug of water at 100 yards ripped it apart !