can anyone confirm the bc of the sierra 155 palma?

dylan_b · 12-23-2009, 04:02 PM

i noticed the the old 155 palma from sierra has been updated and now has a advertised b.c. of .504 can anyone confirm how close the real world b.c. is?

Scott Gags · 12-23-2009, 06:49 PM

This link should answer your question. It looks like around .417 G1 BC. Brian is very well respected I would accept his findings without reservation.

http://www.appliedballisticsllc.com/...ALMAbullet.pdf

dylan_b · 12-23-2009, 08:26 PM

Quote:

Originally Posted by Scott Gags

This link should answer your question. It looks like around .417 G1 BC. Brian is very well respected I would accept his findings without reservation.

http://www.appliedballisticsllc.com/...ALMAbullet.pdf

that is for the old 155, the newer one is the bullet that caught my interest. the article written by mr. litz seems to be on the older palma because he states the bullets as being 1.131 long, the newer ones are 1.219 long. although i find it odd because the old ones were advertised at being 1.119? the newer ones are like i said advertised at .504 and in the article mr.litz states that at the time the advertised bc was .437 and .450 at over 2600

http://accurateshooter.wordpress.com...-palma-bullet/

dylan_b · 12-23-2009, 08:35 PM

on second thought i think that article might be the answer without actualy testing them. the bullets were about 4.57% less then advertised so that means the new 155 should be .481

thndrchiken · 12-24-2009, 05:13 AM

Per Sierra's website:
.504 @ 2700 fps and above
.470 between 1800 and 2700 fps
.430 between 1500 and 1800 fps
.380 @ 1500 fps and below

Ridge Runner · 12-24-2009, 06:03 AM

the published BC's of bullets almost are never dead on for most people. Its just what they get the day they test them, under the conditions they test them, and I've heard some are corrected for sea-level.
I've had 1 bullet that the makers published BC was "spot on" that was a 6.5 dia. 139 gr scenar. some that weren't close under my shooting conditions that I can recall from memory were
Nosler 160 gr. accubond published at .531, to make my charts match my actual trajectory I run a BC of .62 in exbal
Berger 140 vld's published at .64, to make my charts match what I'm shooting I use a .7 BC.
About all you can do is buy a box and test them.
RR