Interesting to me

[sewwhat89]

I have been trying to decide what my first custom rifle will be, and have settled in on the 6mm BR. KISS for me with this one, and a long life is a must. In playing with the ballistics on this round, this is what I discovered.

300 SAUM 178gr AMAX 100 yd zero

1000 yds

elevation/wind drift
28.1 MOA/ 7.4 MOA

6mm BR 95 gr Berger VLD 100 yd zero

28.1 MOA/ 7.4 MOA

They end up with almost exact balliztics on paper. The difference is 0.4 inches in elevation and 0.2 inches in wind deflection at 1k.

This seems immpossible to me, but I haven't shot past 500m to verify on paper this to be the case. Are my numbers flawed?

 

[sewwhat89]

Regardless of bullet size or diameter, the variables affecting trajectory are BC and velocity.

I guess I am a little slow, but this was my ground-breaking discovery of this week. /ubbthreads/images/graemlins/grin.gif

 

[Centre Punch]

sewwhat,
Excellent choice of calibre you wont be dissapointed.
Long barrel life is a massive plus for this round, thats why it is so popular with the 1000yd benchrest boys and F-class shooters.

Nothing wrong with your figures, in fact i am suprised that the 6mm 95 Berger VLD did not return better results, having a 524 BC as apposed to a 495 BC for the 175 A-max.
Bullets of the same BC will track the same trajectory if launched at the same velocity, regardless of diameter.
i was also going to say weight but im sure that the weight of a bullet is relative to its BC.

Ian.

"I meant to shoot the pike but the duck got in the way"

 

[Guest]

long life.. you mean long barrel life?
what are you velocities for both rounds

the 6mmBR is a fantastic round and arguably one of the most accurate...

if you plan on hunting with this though... nothing bigger than deer at long range and without velocities I'm not sure how long of a range the 6br has

the 175 smk and the 7mm are at 26 MOA at 1K

jury is still out on barrel life...

 

[sewwhat89]

I'll use the BR on white-tails in East TX, but body size here is much less than UT and MT way. AVERAGE mature bucks in my neck of the woods range about 150 on the hoof. In managed/high fence leases I have worked on, 5.5+ yo bucks weigh upwards of 220 and one tipped the scales at 287 lbs. He was a bruiser, 8 pt. 126 BC, 32" neck!!! That is huge for East TX! (Neck not rack!)

The gun would NOT be used until after I filled my buck tag, and thus would be used to take 100lb doe as far as my eyes could see them. . . and pigs . . . crows . . . yotes . . . unlucky squirrels . . . armadillos . . . rabbits . . . Pepsi cans . . . you get the picture.

 

[sewwhat89]

[ QUOTE ]

the 175 smk and the 7mm are at 26 MOA at 1K


[/ QUOTE ]

Is this from a 100 yd zero?

My 300 SAUM 175 smk 220 yd zero is 26 MOA @ 1k. 28 MOA from 100 yd zero.

 

[sewwhat89]

[ QUOTE ]
in fact i am suprised that the 6mm 95 Berger VLD did not return better results, having a 524 BC as apposed to a 495 BC for the 175 A-max.

Ian.[ QUOTE ]


I calculated the bc of the AMAX at .525 in my rifle based on drop charts out to 500m.