Long Range Hunting Online Magazine


Go Back   Long Range Hunting Online Magazine > Rifles, Reloading, Optics, Equipment > Reloading

Reloading Techniques For Reloading


Reply

Velocity not making sense.

 
LinkBack Thread Tools Display Modes
  #1  
Old 10-27-2012, 02:32 PM
Silver Member
 
Join Date: Feb 2012
Posts: 181
Velocity not making sense.

Loading ammo for my .243 Winchester, I've been trying a bunch of different bullets. Several different kinds shoot sub-MOA, some shoot under half-MOA, some can't make 2 MOA.

But that isn't my problem, my problem is that I can't find a load that gives both good external ballistics/terminal performance AND accuracy. For example- 70 grain Nosler Ballistic Tips pushed to 3400 FPS over a 40 grain charge of Varget give me all the flat trajectory and terminal oomph that I could ask for, but accuracy is JUST below MOA.
On the other hand, 69 grain Berger High BC FBs can only be pushed to MAX 3100 FPS with 41 grains of Varget, but they shoot close to 1/4 MOA.
Ditto the 85gr Sierra HPBTs. Max charge of Varget- topping out at 2950 FPS- very close to 1/4 MOA, but dropping like rocks past 250 yards.

I don't understand why I can push 70 grain bullets at 3400 easy, but 69 grain bullets (with an extra grain of Varget behind them) only do 3100 max.

There isn't THAT much extra bearing surface on the Bergers over the Noslers.
Reply With Quote
  #2  
Old 10-27-2012, 03:18 PM
Gold Member
 
Join Date: Feb 2005
Posts: 564
Re: Velocity not making sense.

When chronograph data doesn't make sense, 9 out of 10 times it's the chronograph... lighting issues... maybe too close to the muzzle and you're getting powder blow thru...

Your speed on the 70 grain Noslers is about right. The accuracy load is 42 grains of Varget, per Nosler--and it works... so you might dial it up a bit, so long as you're using Winchester brass.

Dan
Reply With Quote
  #3  
Old 10-27-2012, 10:44 PM
Silver Member
 
Join Date: Feb 2012
Posts: 181
Re: Velocity not making sense.

Well, I might just try loading up a few more 70 grain BTs with 42 grains then. I only loaded to 41 because my Lee loading manual states that as a "Do not exceed" load.

My chronograph is about 8 feet from muzzle, so it shouldn't be powder blow-through, although stranger things have happened. I guess I'll have more testing to do yet.
Reply With Quote
  #4  
Old 10-27-2012, 11:13 PM
Platinum Member
 
Join Date: Apr 2012
Location: The cold part of Montana
Posts: 1,390
Re: Velocity not making sense.

If you want the best of both worlds your probably want to try a slower powder, Ramshot hunter shows the highest velocities for 243 with a 69gr Berger, the second thing you'll want to do is try different seating depths, third is try different primers. Some times you can just assemble components and get what your looking for but it generally doesn't happen that way.

You did stop at with a charge that was listed in your reference material as being max and that's the smart thing to do. But there's a lot of different powders, bullets cases, and primers. carefully finding the combination that gives you what your looking for with out going in to the "I'm trying to blow my gun up" area is load development, and it can be a lot of fun and pretty satisfying.

So keep researching, buy manuals, and books, keep visiting places like this and ask lots of questions. there's a massive amount of information easily available now than what there was when I started reloading.
__________________
Keep in mind the animals we shoot for food and display are not bullet proof. Contrary to popular belief, they bleed and die just like they did a hundred years ago. Being competent with a given rifle is far more important than impressive ballistics and poor shootability. High velocity misses never put a steak in the freezer.

Joe
Reply With Quote
  #5  
Old 10-28-2012, 07:52 AM
Silver Member
 
Join Date: Apr 2007
Location: Fort Morgan, Colorado
Posts: 327
Re: Velocity not making sense.

Just one point of correction in thought on this subject. More bearing surface with similar or same weight bullets increases pressure over less bearing surface bullets, and therefore velocity should increase similarly with the increase in pressure. Sometimes the bullets that give the best muzzle velocity, because of the longer bearing surface, don't have the highest BC and lose velocity quicker.

BTW, I wil take more accuracy over smaller gains in velocity every time.
__________________
Dennis
Reply With Quote
  #6  
Old 10-28-2012, 08:25 AM
Platinum Member
 
Join Date: Apr 2012
Location: The cold part of Montana
Posts: 1,390
Re: Velocity not making sense.

Quote:
Originally Posted by Gunpoor View Post
Just one point of correction in thought on this subject. More bearing surface with similar or same weight bullets increases pressure over less bearing surface bullets, and therefore velocity should increase similarly with the increase in pressure. Sometimes the bullets that give the best muzzle velocity, because of the longer bearing surface, don't have the highest BC and lose velocity quicker.

BTW, I wil take more accuracy over smaller gains in velocity every time.
Not necessarily, Before Berger announced the Classic Hunter (they where still calling it the SAAMI Hybrid) I emailed Walt asking about reloading them Vs. the VLD. What could I expect to see, pressure differences ect. he said the only difference I should notice is slightly less velocity due to the longer bearing length.

Seems that like many other things with reloading and shooting, there isn't a really much of a hard fast answer, just best fit answers (maybe, could be, who knows, try it and see). The things about the bullet that can effect vel being of the same weight, are jacket material, jacket thickness, bearing length, composition.
__________________
Keep in mind the animals we shoot for food and display are not bullet proof. Contrary to popular belief, they bleed and die just like they did a hundred years ago. Being competent with a given rifle is far more important than impressive ballistics and poor shootability. High velocity misses never put a steak in the freezer.

Joe
Reply With Quote
  #7  
Old 10-28-2012, 09:06 AM
Platinum Member
 
Join Date: Feb 2011
Location: Cincinnati, Ohio
Posts: 1,903
Re: Velocity not making sense.

Just shoot the Bergers and dont worry about it!
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes


Similar Threads for: Velocity not making sense.
Thread Thread Starter Forum Replies Last Post
Talk some sense into me! 3fingervic Long Range Hunting & Shooting 13 08-11-2011 02:25 PM
.222 What is a common sense range or this caliber???? stoneman2 Long Range Hunting & Shooting 1 08-09-2010 03:41 PM
bought a rifle that doesn't make sense backyardsniper Rifles, Bullets, Barrels and Ballistics 8 06-06-2010 12:01 PM
Does this make sense to you? bryceh12321 Rifles, Bullets, Barrels and Ballistics 2 04-10-2009 11:39 PM
Not Makin any sense !!!!!! uncleB General Discussion 26 05-22-2008 01:50 PM


All times are GMT -5. The time now is 05:38 AM.


Powered by vBulletin ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Management Powered by vBadvanced CMPS
All content ©2010-2014 Long Range Hunting, LLC