DPMS .260 first 3 loads

[704]

wet and cold range day today.
My upper arrived in the mail I cleaned it, mounted a scope and headed to the range

loads
1. 140 grain Nosler accubond 5 shot group .464
2. 140 grain Berger VLD 5 shot 1.039
3. 130 Berger VLD 5 shot (only counted 4-called the 5th) .484
testing 100 yards
powder 4831 SC
all loads were 46 grains and COAL was to barely fit in the magazine
needless to say I am happy with the starting loads.

gun is DPMS 24 in upper 1-8.5 twist, geissele trigger




still need to paint the upper to match

 

[threejones]

Nice stick. I've had a 260 AR in mind for a while. What's your total loaded weight?

 

[704]

14 pounds

 

[LouBoyd]

There's something odd here. I also have a DPMS LR-260. Since some time ago when I worked up loads for it I've considered the 140 Berger to be too long to be practical to use in that cartridge and rifle combination.

I checked further and see that Berger advertises two 140 grain 6.5mm VLD bullets, the 26401 for target, and the 26504 for hunting. Both have the same BC's and length. I don't know if they differ or it's just marketing. I just ran a Quickload simulation with 46 grains of H4831SC which indicates (from the given information) that a seating depth under 2.9" will be over SAAMI max pressure. 2.9" won't fit the DPMS magazine.

My memory is that I didn't use that bullet because it's shank-boattail junction would be inside the neck shoulder junction when seated to a depth which would fit the DPMS magazine. I do use the 26401 bullet with good results with other cartridges and rifles which don't have a magazine or throat limitation.

I'm only saying I wouldn't use that load in my LR-260 without further investigation.

 

[704]

yep I am using Nosler accubond not VLDS now

 

[Nimrodmar10]

I just ran a Quickload simulation with 46 grains of H4831SC which indicates (from the given information) that a seating depth under 2.9" will be over SAAMI max pressure. 2.9" won't fit the DPMS magazine.

My memory is that I didn't use that bullet because it's shank-boattail junction would be inside the neck shoulder junction when seated to a depth which would fit the DPMS magazine. I do use the 26401 bullet with good results with other cartridges and rifles which don't have a magazine or throat limitation.

Lou
I understand your line of thinking. Until recently I would have agreed. I bought a Remington 700 SPS in 7 STW. The case length on this case is 2.850" and the SAMMI max length is only 3.60". In my new rifle I can only stretch this out by about .02" and still fit the magazine. Still pretty short. Waaay too short to seat the Berger 180 gr. VLD Hunting bullets I want to shoot in this gun out to the lands, where they like to be seated. But the Berger Reloading Manual showed some pretty impressive numbers with this bullet seated to this length so I decided to give it a try. The neck is .2783". This bullet is 1.524" long. That's .496" of bullet extending into the case body. No way it will shoot, right? Wrong. I'm pushing the bullets at almost 3000 fps and they're shooting in the .3s. So don't write a bullet off just because it's long.
Could I get more speed out of the STW if I could use this case space for powder? Yeah, but since this is a hunting rifle, I want it to be a repeater.

 

[704]

I will tell you all 3 loads including the VLDS were all Crush fit and none of them showed any sign of pressure, primers were good and cases as well

 

[slm9s]

My LR260 upper shoots much better than it should also. I'm using 123 amax's and use the rifle for my tactical competition rifle and it does very well.