6.5 x 284 slow bullet ?

[skinny pedal]

So i made some loads for my 6.5x284 . I have a savage LRH . i loaded 140 grain berger vld's with 59 grains of retumbo and lapua brass . I shot it through my chrono in the shop tonight expecting around 2950 give or take but i ended up with an average of 2550 fps ??? oh and i loaded them .075 off the lands as i read works the best with the bergers ... so my question is why am i only getting an average of 2550 fps with this load.
thanks in advance for some info.

 

[Wyliecoyote]

That's a huge jump despite what Berger says about vld's. I shoot a 260 and .020 off is the ticket. I'm only getting 2650 fps but it is stupid accurate. How long is your barrel?

 

[Greyfox]

So i made some loads for my 6.5x284 . I have a savage LRH . i loaded 140 grain berger vld's with 59 grains of retumbo and lapua brass . I shot it through my chrono in the shop tonight expecting around 2950 give or take but i ended up with an average of 2550 fps ??? oh and i loaded them .075 off the lands as i read works the best with the bergers ... so my question is why am i only getting an average of 2550 fps with this load.
thanks in advance for some info.

Most likely a bad chrono reading. Yes, you should be 2950-2975. Powder scale ok?

 

[deathwobble]

A friend of mine is using around 46 grs of h4350 in a 28inch barrel and 140vld hybrids 5k off the gun and getting around 2940 or so Retumbo sounds a little slow I would try a faster powder some 4350 or maybe some 4831sc

 

[ShootnMathews]

I can't believe it's really shooting that slow. I'd check your scale, and the chronograph. And make sure you are shooting straight through the chrono. Even a slight angle of pass through drastically changes readout speeds.

Also. How long is your barrel??

 

[Nimrodmar10]

At 59 grains of Retumbo you're only going to get about 3 loadings out of your Lapua brass before the primer pockets get loose. Back it down to about 57.5 grs.

And buy a new chronograph.

 

[BrentM]

I can't add much except shoot it for confirmed drop. Zero, then shoot at 500 or something like that for a group and calculated actual drop from the zero.

How far are you from the chrono? need to be around 12 feet for the 284 I think.

LRH has a 24" barrel plus the brake. Not sure if that does anything for speed since it is not a rifled portion of the barrel. However, unless the powder is bad, the primers are bad, the scales are bad, and/or the chrono is bad there is no way that speed is correct. Even with low loads of 4350 and 4831 my speeds were solidly in the 2750 to 2850 range. With 59 retumbo my primers would be flat and speeds around 3030 fps. 24" barrel.

 

[skinny pedal]

thanks for the info . i did double check the scales and the powder is new and primers . i think i will try another chrono and see what that does. it just didnt make sense to me so i figured someone would be able to help .

 

[BrentM]

Can you shoot for drop? If you do and don't hav the program to run the numbers several of us do. We just need elevation, baro, and temp. If you zero at 200 and shoot 500 without making adjustments your bullet will drop x inches. This is the number we need to figure out speed. With 57.5 retumbo you should see 34-36 inches of drop, FOR EXAMPLE. Without the known conditions this is just a range. I am right around 33.8 to 34.3 for the area I am hunting right now.

 

[skinny pedal]

I am going to the east side of the state this weekend to do some shooting and will collect the data and will report back when i get home.
thanks