24hourcampfire.com
Previous Thread
Next Thread
Print Thread
Hop To
Page 1 of 3 1 2 3
115 Partitions .525 Ogive #15983233 04/11/21
Joined: Apr 2003
Posts: 6,083
southtexas Offline OP
Campfire Tracker
OP Offline
Campfire Tracker
Joined: Apr 2003
Posts: 6,083
Anyone have clue what the BC is for these bullets on sale at SPS? TIA

BP-B2

Re: 115 Partitions .525 Ogive [Re: southtexas] #15983490 04/11/21
Joined: Jan 2010
Posts: 709
K
knivesforme Online Content
Campfire Regular
Online Content
Campfire Regular
K
Joined: Jan 2010
Posts: 709
If you look on the sale page it should say, if I remember correctly. Wrong again but I came up with a photo of the box that says. 0.389.

Last edited by knivesforme; 04/11/21.

If your a leftist, whatever Donald Trump says or does, that pisses you off rest assured, I am a Happy Camper!
Re: 115 Partitions .525 Ogive [Re: southtexas] #15983557 04/11/21
Joined: Jul 2001
Posts: 52,169
M
Mule Deer Online Content
Campfire Oracle
Online Content
Campfire Oracle
M
Joined: Jul 2001
Posts: 52,169
The .389 BC is listed for their standard 115 Partition, and it doubt it's that high for the shorter-ogive version, which the SPS ad says "are Overruns of an OEM Partition bullet made by Nosler. Designed to provide a shorter COAL in cartridges such as the 257 Roberts, these have a shorter ogive curve and a slightly more rounded profile than the standard Nosler 25 Cal 115gr partition."
:


“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck
Re: 115 Partitions .525 Ogive [Re: southtexas] #15983659 04/11/21
Joined: Jan 2008
Posts: 12,171
mjbgalt Online Content
Campfire 'Bwana
Online Content
Campfire 'Bwana
Joined: Jan 2008
Posts: 12,171
I intend to ignore the listed BC and drive them as fast as the weatherby will allow, thus cheating physics like all the guys who say their 270 "is still rising" at 400 yards lol

Re: 115 Partitions .525 Ogive [Re: mjbgalt] #15983711 04/11/21
Joined: Jul 2001
Posts: 52,169
M
Mule Deer Online Content
Campfire Oracle
Online Content
Campfire Oracle
M
Joined: Jul 2001
Posts: 52,169
The BC won't matter much with that combo--but also won't matter much in a .257 Roberts at "normal" ranges.


“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck
IC-A

Re: 115 Partitions .525 Ogive [Re: southtexas] #15983801 04/11/21
Joined: Dec 2014
Posts: 1,931
G
GSPfan Online Content
Campfire Ranger
Online Content
Campfire Ranger
G
Joined: Dec 2014
Posts: 1,931
I've loaded some for my Roberts and a 250 Savage. Just need to get to the range and see how they do.

Re: 115 Partitions .525 Ogive [Re: southtexas] #15983954 04/11/21
Joined: Jun 2001
Posts: 1,145
Puddle Offline
Campfire Regular
Offline
Campfire Regular
Joined: Jun 2001
Posts: 1,145
I loaded up a bunch of them just for grins for my Roberts using H4350 for a MV [email protected] 3000 fps. They grouped fine - well under an inch, but then every handload groups fine in that rifle.

I just plan on using them for field practice and save the 110 gr. NABs for hunting.

Re: 115 Partitions .525 Ogive [Re: southtexas] #15984090 04/11/21
Joined: Sep 2015
Posts: 849
G
Goosey Offline
Campfire Regular
Offline
Campfire Regular
G
Joined: Sep 2015
Posts: 849
Originally Posted by southtexas
Anyone have clue what the BC is for these bullets on sale at SPS? TIA


[Linked Image from i.imgur.com]

I would use 0.340 for the 0.525" ogive version on the left. The regular on the right is 0.389

Last edited by Goosey; 04/11/21.
Re: 115 Partitions .525 Ogive [Re: southtexas] #15984178 04/11/21
Joined: Apr 2003
Posts: 6,083
southtexas Offline OP
Campfire Tracker
OP Offline
Campfire Tracker
Joined: Apr 2003
Posts: 6,083
Thanks, that looks reasonable. How did you arrive at that number?

Re: 115 Partitions .525 Ogive [Re: southtexas] #15984240 04/11/21
Joined: Sep 2015
Posts: 849
G
Goosey Offline
Campfire Regular
Offline
Campfire Regular
G
Joined: Sep 2015
Posts: 849
Originally Posted by southtexas
Thanks, that looks reasonable. How did you arrive at that number?


Did some comparing to similar bullets, the 115 TSX is .320, the discontinued 117 Sierra flat base is .351 (Applied Ballistics #s). The TSX .527" ogive and the Sierra .506".

Last edited by Goosey; 04/11/21.
IC-B

Re: 115 Partitions .525 Ogive [Re: southtexas] #15985104 04/11/21
Joined: Jun 2019
Posts: 891
T
TRexF16 Online Content
Campfire Regular
Online Content
Campfire Regular
T
Joined: Jun 2019
Posts: 891
So glad to see this thread. I have bought up a bunch of these myself, even before I knew about the "Roberts" statement (it wasn't on the SPS site when they first marketed these) but they looked perfect for the Roberts to me. and maybe good in my .25-06 too. I have always shot the 100 TSX in the Roberts, and the "regular" 115 Partition in the 25-06. Mule Deer inspired me to buy some 100 TTSX for the Roberts, but I have not yet used them, and then I saw these .525 ogives for cheap on SPS and loaded up on them too. I also have not yet loaded any of them.
If anybody has further educated input on the BC (or even better...tested data), as well as any loads for any of the .25's it could be used in, please share them here.
This thread could turn into a really handy reference for all those who have bought these from SPS.

Thanks to the contributors,
Rex

Re: 115 Partitions .525 Ogive [Re: southtexas] #15985288 04/11/21
Joined: Jul 2001
Posts: 52,169
M
Mule Deer Online Content
Campfire Oracle
Online Content
Campfire Oracle
M
Joined: Jul 2001
Posts: 52,169
TRex,

How far do you anticipate shooting them at game?

With all the attention placed on BC these days, due to "long-range hunting," many folks don't realize that there's very little difference in trajectory and wind-drift out to 400 yards between two spitzers of pretty widely differeing BCs.

A good example is the .270 and .308 Winchesters. Both are capable of just about exactly the same muzzle velocity with the same-weight bullets--and despite the higher BCs of .270 bullets of the same make/style, the difference in drop and wind-drift at 400 yards is around two inches.

Which is why I suggested earlier that unless somebody is shooting beyond "normal" ranges with the short-ogive 115 .25 Partition a lower BC won't make any practical difference.


“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck
Re: 115 Partitions .525 Ogive [Re: Mule Deer] #15985304 04/11/21
Joined: Nov 2002
Posts: 23,960
E
EdM Offline
Campfire Kahuna
Offline
Campfire Kahuna
E
Joined: Nov 2002
Posts: 23,960
Originally Posted by Mule Deer
TRex,

How far do you anticipate shooting them at game?

With all the attention placed on BC these days, due to "long-range hunting," many folks don't realize that there's very little difference in trajectory and wind-drift out to 400 yards between two spitzers of pretty widely differeing BCs.

A good example is the .270 and .308 Winchesters. Both are capable of just about exactly the same muzzle velocity with the same-weight bullets--and despite the higher BCs of .270 bullets of the same make/style, the difference in drop and wind-drift at 400 yards is around two inches.

Which is why I suggested earlier that unless somebody is shooting beyond "normal" ranges with the short-ogive 115 .25 Partition a lower BC won't make any practical difference.


Spot on. This whole BC trip has, well, been a trip...


Conduct is the best proof of character.
Re: 115 Partitions .525 Ogive [Re: southtexas] #15993491 04/14/21
Joined: Jun 2019
Posts: 891
T
TRexF16 Online Content
Campfire Regular
Online Content
Campfire Regular
T
Joined: Jun 2019
Posts: 891
Mule Deer and EdM,
Good points, and understood. It's just the looneyism in me interested in having a good number to play around with.
In order to calculate accurately enough to show the very good comparison points y'all just made above, wouldn't you need valid BC numbers to input to run the trajectory numbers? Or just shoot side by side but my regular shooting range only runs to 200.

And to answer MD's first question - yes, 400 yards would be about the limit I think I'd shoot my 722 to with these bullets and conditions would have to be good. I think its furthest kill since I've owned it has been 415 yards, but that was by my buddy after I loaned it to him when the "goats" were holding way out in a frying pan flat and his rifle choice that day had been an iron-sighted M1886 45-70, but the weather was making him inclined to go ahead and "make some meat." I've had quite a few kills beyond 300 with that old Roberts but none past 400 myself. And all of those were with a 4X Leupold compact. If I'd had one of those fancy dialing Hubble space telescopes I might have done different, but I just never felt the need.

400 yards is also about the limit I have killed anything with the "normal" 115 NPT in my 25-06 - the furthest with it was 416 paces, back before we had laser range finders.

Still hoping to see some others' range results with this bullet. I've not yet taken them out.

Cheers and thanks again to all,
Rex

Re: 115 Partitions .525 Ogive [Re: TRexF16] #15993953 04/14/21
Joined: Jul 2001
Posts: 52,169
M
Mule Deer Online Content
Campfire Oracle
Online Content
Campfire Oracle
M
Joined: Jul 2001
Posts: 52,169
No, you don't need "valid BC numbers" to kill big game at 400 yards--which was the point of my previous post.

Other "inputs" easily make as much or more difference, including height of the reticle over the bore, altitude and temperature. I know this from shooting quite a bit beyond 100-200 yards with various rifles.


“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck
Re: 115 Partitions .525 Ogive [Re: southtexas] #15994033 04/14/21
Joined: Nov 2002
Posts: 23,960
E
EdM Offline
Campfire Kahuna
Offline
Campfire Kahuna
E
Joined: Nov 2002
Posts: 23,960
John,

I get that this is your job just like oil was mine. We can both dive deeply into our work. Very deeply...


Conduct is the best proof of character.
Re: 115 Partitions .525 Ogive [Re: EdM] #15994332 04/14/21
Joined: Jul 2001
Posts: 52,169
M
Mule Deer Online Content
Campfire Oracle
Online Content
Campfire Oracle
M
Joined: Jul 2001
Posts: 52,169
Ed,

Yep! If you're a professional, that's what you do.

One of my early role-models in my business was Charley Waterman, who published under the by-line Charles F. Waterman. He explained things simply, yet evocatively, about hunting, hunting guns and fishing (which I also wrote about for many years). He once wrote (very entertainingly) about falling asleep at night while reading a professional journal about bluegill biology--or something like that. He said most of his readers wouldn't find it very interesting--but he did, and simplified it for them.

I am pretty damn sure you did a great job of passing along (and adequately compressing) what you know to the people who worked for you. That's what professionals do, because that's what we care about.



“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck
Re: 115 Partitions .525 Ogive [Re: southtexas] #15994396 04/14/21
Joined: May 2005
Posts: 10,164
S
shootinurse Offline
Campfire 'Bwana
Offline
Campfire 'Bwana
S
Joined: May 2005
Posts: 10,164
I picked up 200 of these bullets. Not that i needed them but, well, why not. No concern over BC, as I sight all my rifles about 1.5" high at 100yds, and they all mange to hit about the center of the pig silhouette at 300 meters with a top of the back hold.



Gun control...schemed by tyrants and supported by fools.
Re: 115 Partitions .525 Ogive [Re: Mule Deer] #15994587 04/14/21
Joined: Jun 2019
Posts: 891
T
TRexF16 Online Content
Campfire Regular
Online Content
Campfire Regular
T
Joined: Jun 2019
Posts: 891
Originally Posted by Mule Deer
No, you don't need "valid BC numbers" to kill big game at 400 yards--which was the point of my previous post.

Other "inputs" easily make as much or more difference, including height of the reticle over the bore, altitude and temperature. I know this from shooting quite a bit beyond 100-200 yards with various rifles.


John, I respect you - well - about as much as it is possible to respect a man, having bought most all your books, read every magazine article of yours I've ever found, and learned so much from you over the years. So please just bear with me a bit on this, and don't go crushing the curiosity you have done a lot to inspire:
I know you don't need "valid BC numbers" to kill game at 400 yards (and you know that is not what I wrote above). I have done so, with and without valid BC numbers. But you presented a specific example comparing the flight path of the .270 Win and .308 Win, concluding their wind drift and trajectory are within 2" at 400 yards. There are two ways to draw this conclusion. The first is actual shooting of 400 yard groups, but we are now talking about a difference of only 1/2 MOA between the centroid of two groups, which for many of us is within the "noise level" of our shooting skill, and of course we would need both rifles to be very accurate to even be able to discern the centroid differences. The second way would be to run the numbers in a ballistics program. The former method has the referenced limitations. The latter requires valid ballistics coefficients as an input variable (along with the others you mentioned, but we must assume those variables are held constant in any reasonable comparison).

That's all I said.

It is perfectly OK for me and others to be curious about the BC of this particular bullet, and that curiosity does not warrant beratement, especially not from a man who has been such an incredible mentor and monumentally contributing mind to the body of knowledge that we only half-jokingly refer to as Rifle Looneyism.
Being curious about the BC of this bullet has nothing to do with whether or not I understand that particular parameter's contribution to killing game at reasonable hunting ranges is trivial. Knowing things like that is FUN, and adds to the enjoyment of our passion.
For the record, I understand that the BC difference between the .525 ogive 115 grain .257 Nosler Partition and that of its "parent" bullet is trivial to killing game effectively within 400 yards. But I would much rather know what that BC difference is than to remain ignorant of it. And there's nothing wrong with that.

I am also very interested in how this bullet performs for others here on this thread, and since it's kind of a one-off bullet, thought this would be a nice place to post those results. When I get a chance to run it in my Roberts I'll share what I learn too.

Most Respectfully,
Rex

Re: 115 Partitions .525 Ogive [Re: TRexF16] #15995274 04/15/21
Joined: Jul 2001
Posts: 52,169
M
Mule Deer Online Content
Campfire Oracle
Online Content
Campfire Oracle
M
Joined: Jul 2001
Posts: 52,169
Rex,

Sorry that I offended you.

You can actually come up with a pretty good idea of functional BC out to 300-400 yards by chronographing a handload both at the muzzle (or 10 feet in front of it, depending on the chronograph) and then again at 100 yards (or 100 yards, plus 10 feet, then comparing the velocity loss to other bullets with different BCs. Probably the best way is to use a ballistic program, adjusting the BC input until the velocities match your results.

This is pretty much how many companies come up with closer-range BCs, because it's close enough for shooting at what many hunters consider "normal" hunting ranges. It's not valid for longer ranges, because BC isn't the written-in-stone number many shooters believe, but certainly would work well enough at the distances you mention.


“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck
Page 1 of 3 1 2 3

Moderated by  RickBin, SYSOP 

RR1b
Who's Online Now
578 registered members (160user, 1beaver_shooter, 16penny, 10gaugeman, 10gaugemag, 10ring1, 73 invisible), 1,909 guests, and 1,057 spiders.
Key: Admin, Global Mod, Mod
RR2/3










Fish & Game Departments | Solunar Tables | Mission Statement | Privacy Policy | Contact Us | DMCA
Hunting | Fishing | Camping | Backpacking | Reloading | Campfire Forums | Gear Shop
Copyright © 2000-2020 24hourcampfire.com, Inc. All Rights Reserved.
 
Powered by UBB.threads™ PHP Forum Software 7.7.3
(Release build 20190728)
PHP: 7.3.28 Page Time: 0.059s Queries: 15 (0.004s) Memory: 0.8807 MB (Peak: 1.0441 MB) Data Comp: Zlib Server Time: 2021-05-15 00:01:04 UTC
Valid HTML 5 and Valid CSS