260 Rem - Please Help...it won't shoot the heavies

[buckbrush]

Hello,

I have a 260 Rem with an 8-twist 25” barrel in a light Palma contour. I had the rifle built to shoot 140 class bullets. So far I have not been able to get the 140 A-max under 1” with any consistency. I’ve tried about every combination of H4350 and seating depth I can think of and none of it seems to make a difference on group size. There isn’t any stringing or anything, they are just all big triangular 3-shot groups.

I recently tried some 123 A-maxes and H4350 and the groups were worse…close to 2”. This rifle will shoot 95 v-maxes and 100 A-maxes very well but I really want to go with the heavy bullets. All testing has been done at 100 yards.

Here are some additional load details:
LC “88” brass, necked down with flash holes deburred. Brass has been trimmed and annealed.
CCI200 primers
Seating depths from -0.015” to 0.060”
H4350 powder charges from 41.0 – 45.0 grains. Anything over 44.0 is pretty hot with heavy bolt lift.

Barrel is not fouling. Rifle was professionally built. Any advice is welcome.

Thank you.

 

[jcampbellsmith]

I would look to the brass first. I've shot the 260 Rem since '99. I initially reloaded with my once fired Remington brass from factory ammo. Then I got some 260 Rem Nosler brass and have had some good results with that and 123 gr A-Max. Attached target was shot with N160, Nosler brass and 123 gr A-Max.

http://www.thestalkingdirectory.co.uk/gallery/member-galleries/p2948-remington-700-sa-in-260-rem.html

I've also got some 260 Rem Lapua brass in the cupboard for when I work my way through what I've got.

Starting afresh today I would just use Lapua brass. I don't have a 140 gr A-Max load at the minute, but I've had good results with 140 gr A-Max in the past. I have been practicing with 142 SMKs recently and they have gone well. My twist is 1:8.5.

Good luck.

JCS

 

[MTETM]

Check and make sure you don't have a doughnut at the neck shoulder junction... The long 123's and 140 would likely run into it where the shorter bullets wouldn't.

Good Luck

 

[trailrider121]

I tried H4350 with 130 vld and it would group well at 100 yards, but when I stretched it out to 550 yards it shot MOA,vertical was bad too. So I switched powders per recommendation, and went with 39grs IMR4064. I got sub moa groups or better and vertical was around 3/4". Speed was a little slower, but that's fine.I was told Varget works well to, if you can find some. Try either Varget or IMR4064 and see what happens.
Also H4831SC works well too!

 

[Jet]

Have you eliminated the rifle/scope not being the cause? Loose action screws, loose scope mounts, crown damaged, etc? If so, try some different brass--Lapua preferably

Use Fed 210M or 210 primers

Try SIE 142 HPBT, Lap Scenars 139, or one of the Berger 140 gr bullets.

Also, try loading down a bit more. I have found 40.7 grains of H4350 to work well pushing the above bullets in numerous rifles chambered in 260.

Good luck

Jet

 

[kelbro]

Try H4831. Worked for me with 140 AMaxes.

 

[BigDMT]

Gun probably doesnt like H4350. Simple as that.

You have so many variables left to try with different powders and primers that theres no way you can conclude that your gun "wont shoot the heavies". You havent even scratched the surcface with the load testing you've done.

Get your hands on some Reloader 17 and I'll bet you find that accuracy really quick. And the speed too.

 

[Lapua40X]

What's your neck tension?

 

[brian427cobra]

I would verify the twist first, light weight pills shoot good but the heavies don't indicates to me your barrel is not a 8 twist.

 

[mytwo60]

You should be able to shoot sub MOA with just about any new brass. Go with the basics first before injecting variables into your loads. Like why are you even annealing brass at this early stage?

Are you even full length sizing your brass?

 

[masterblaster1]

Did you try shooting it with factory bullets? I have a new custom built 260 waiting to be shot tomorrow, 8 twist Rock barrel in m24 contour, I bought 140 and 123 grain bullets to ensure the gun works right before I start doing my own load development.. I got the bullets from Southwest Ammo, they make some nice bullets for accurate shooting.

 

[Steel Mover]

Not knowing how your gun was setup in the build it is nigh impossible to diagnose a problem.
But you did not mention your brass setup process. So, as the 260 is capable of .1 then the brass setup must be capable of .1 also. I use 120 SMKs in my five 260s and get .1 in each, at 3,200 + fps with a very low, single digit ES and SD. But I use H-414which requires a bit of work to get right. If you did not use 243 brass to make 260 brass you might have some issues with varying case neck thickness.
I started with the 6.5x08 before there was a 260, so developed my process and loads before….

 

[6MMsteve]

did you buy the barrel new, replacement barrel if so r u sure of the twist, make sure you start close or just in the lands, and try some re23 or n160

 

[Lone Hunter]

Thread is from 2013. Hope he got it figured out.

 

[paw]

Drop powder charge

 

[Skedaddle Shooter]

Thread is from 2013. Hope he got it figured out.

If not he is a very patient guy

 

[Zero333]

Get better brass (Lapua) and use H-4831sc with 140+ gr bullets.

 

[284winner]

I found when H4350 won't shoot in the .260, the H4831sc will. Try 44.0-46.0 grain of H4831sc( if you can find it) under that 140 Amax

 

[deadidarren]

I started at 47.5 of 4831sc in a lap case with a cci250 with BERGER 144 LRHT and it only gave me 2738fps no pressure .
Also one thing you could do is drop your 44 grain load 121 1/2 grains Jam 0.010 to 0.015 in the lands it's where my barrel loves to be