nralifer
Well-Known Member
Ouch!! Guess it worked? Looks good to me
Badlands Precision Bullets thread - From BC to terminal ballistics
- Thread starter codyadams
- Start date
Help Support Long Range Hunting Forum
nralifer
Well-Known Member
Well guys and gals, as promised, did some testing on or new 150 gr .277 SBD2 bullet using a borrowed rifle 6.8 Western with a 3" short action and Winchester brass derived from a box of factory loads using a 162gr Copper Impact bullet. As the photo shows, my loaded round OAL was 3.000" so that I could have a jump of 0.025". The OAL of the factory load was 2.88". This discrepancy illustrates my point of using 3.2" long actions for these new short fatter magnums to allow mag feeding while capitalizing on the use of high BC bullets. I was able to measure BC on both the new 150 gr SBD2 and the Winchester Copper impact bullet using the Lab Radar. Had to hurry as a winter storm was due to come in soon.
The stats on the SBD2 are as follows:
1) Bullet length: 1.635"
2) Boat tail 0.277"
3) Ogive approx 0.877"
4) G1 BC 0.710
5) G7 BC 0.350
Saw a rather wide velocity node using 57-60 gr of StaBall6.5 with group measuring 0.5-0.6MOA @ 100 yds with final MV at 60 gr SB6.5 of 3080 fps from 24" 1:7 twist Preferred carbon wrapped barrel with Paradigm carbon wrapping courtesy of Matt Kranz who graciously made one of his superb light weight hunting rifles available to me to test with. No pressure signs noted.
Photos show the .277 SBD2 150 gr bullet, and the OAL of the load tested along with the factory 6.8 Western loaded by Winchester using their 162 gr Copper Impact bullet (OAL 2.88"). I was able to also measure the G1 BC of their bullet at 0.566, which agreed with the stated G1BC on the ammo box. I used their brass resized as that was my only source.
The stats on the SBD2 are as follows:
1) Bullet length: 1.635"
2) Boat tail 0.277"
3) Ogive approx 0.877"
4) G1 BC 0.710
5) G7 BC 0.350
Saw a rather wide velocity node using 57-60 gr of StaBall6.5 with group measuring 0.5-0.6MOA @ 100 yds with final MV at 60 gr SB6.5 of 3080 fps from 24" 1:7 twist Preferred carbon wrapped barrel with Paradigm carbon wrapping courtesy of Matt Kranz who graciously made one of his superb light weight hunting rifles available to me to test with. No pressure signs noted.
Photos show the .277 SBD2 150 gr bullet, and the OAL of the load tested along with the factory 6.8 Western loaded by Winchester using their 162 gr Copper Impact bullet (OAL 2.88"). I was able to also measure the G1 BC of their bullet at 0.566, which agreed with the stated G1BC on the ammo box. I used their brass resized as that was my only source.
Attachments
Gstew1930
Well-Known Member
didnt even twitch lolOuch!! Guess it worked? Looks good to me
With the 150 the .277 may have the best lineup of BD2s under 30 cal. The 140gr is still a spectacular combo of speed and BC, and the 150gr is competitive with the best of the 7s and 6.5s. Now I just need to burn out my factory 1-10 twist barrel.
Bghunter338
Well-Known Member
I agree with you. I can't wait. These guys going 3200-3300 is going to be wicked.
akmtnhnt
Well-Known Member
I ran the numbers vs the 140 in my 2.950 limited mag and the lower velocity due to eating even more powder, the difference is irrelevant at hunting distances, even in wind drift, and wind drift isn't appreciably better until 1000y or so.
However with a short mag in a long action, they'd be awesome.
@nralifer have you looked at making a 170gr 284 bullet with an even higher BC?
nralifer
Well-Known Member
We probably should. It likely would be a long bullet needing a 1:7 twist but with short magnum cases and 3.2" length actions, it should work. Have to see what BC we would get to see if the increase is worth it. I'll get back to you. Good thought.
Last edited:
nralifer
Well-Known Member
Getting 2950 fps doesn't sound unreasonable to me.
akmtnhnt
Well-Known Member
Ya in a 7saum or 7wsm or one of the shermans I bet it'd be awesome in a defiance or tikka. Same with the 150gr 270 in a 270wsm or 6.8W in either of those actions.
Hoping for 3k really
Was able to get up to 3090 at 71g of N560 before seeing a heavy bolt lift and mild ejector swipe (no primer flattening). Will drop back down to 69-70 and find a good load. Cant wait to take this on my elk hunt next fall!
Gstew1930
Well-Known Member
What barrel length?
26"
