Long Range Hunting Online Magazine


Go Back   Long Range Hunting Online Magazine > Hunting > Long Range Hunting & Shooting

Long Range Hunting & Shooting Nightforce Optics


Reply

Why is the 25-06 slower then the 30-06 with the same Bullet weight?

 
LinkBack Thread Tools Display Modes
  #1  
Old 08-23-2011, 10:43 PM
Silver Member
 
Join Date: Jul 2011
Location: Nebraska for now...
Posts: 217
Why is the 25-06 slower then the 30-06 with the same Bullet weight?

So i was looking through my reloading manual today. and with the 110 or 115 Gr bullet weights, the 25-06 has about 200 FPS slower speed then the 30-06. and about 100 FPS then the 270....i found this VERY odd, seeing how it's the same case. My question is does the smaller opening restrict how much velocity you can get due to pressures? also, the 30-06 was tested with a 24 inch barrel, and the 25-06 and 270 a 26". any insight would be great. i just built a custom 25-06 for out to 600 yards. Thank you.
Nimrod
Reply With Quote
  #2  
Old 08-23-2011, 11:27 PM
Gold Member
 
Join Date: Jan 2011
Location: Northern Utah
Posts: 834
Re: Why is the 25-06 slower then the 30-06 with the same Bullet weight?

The difference in velocity does have to do with pressures. A 115 grain bullet in a 25 caliber is going to be lots longer and have much more bearing surface that produces friction than a 115 grain bullet from a 30 caliber. The more friction that is created causes higher pressures and does not allow you to achieve the same velocities with the same weight bullets in your example.

That being said, the 25 caliber bullet will have a much higher BC and should fly much better at longer ranges than the 115 grain 30 caliber bullet.
Reply With Quote
  #3  
Old 08-24-2011, 02:26 AM
Silver Member
 
Join Date: Mar 2011
Location: Brusly, LA
Posts: 162
Re: Why is the 25-06 slower then the 30-06 with the same Bullet weight?

Same reason all larger calibers beat smaller calibars on the same case. Ex: 338-08 vs 308.
__________________
To teach those that don't know, To remind those that do Know, To correct those that think they know.
-Helio Gracie
Reply With Quote
  #4  
Old 08-24-2011, 05:47 AM
Silver Member
 
Join Date: May 2008
Location: NEW ZEALAND
Posts: 208
Re: Why is the 25-06 slower then the 30-06 with the same Bullet weight?

My understanding on this matter is, in leymans terms.

Its to do with the surface area on the back of the bullet, the more surface area there is for the energy(the bang) to push on, ie the larger diameter bullet receives more energy than the smaller one, so goes faster.

Make sense?

Im no rocket scientist, but thats how I understand it works.

Im more than likely wrong, and apoligise for confusing you if I am.
Until someone confirms Im right, or on the right track,dont take it as gospel truth, I failed Science,Phyics school in general
Reply With Quote
  #5  
Old 08-24-2011, 07:46 AM
Platinum Member
 
Join Date: Jan 2004
Location: Blackfoot, Idaho
Posts: 8,093
Re: Why is the 25-06 slower then the 30-06 with the same Bullet weight?

Quote:
Originally Posted by 300WSMMAD View Post
Its to do with the surface area on the back of the bullet, the more surface area there is for the energy(the bang) to push on, ie the larger diameter bullet receives more energy than the smaller one, so goes faster.

Make sense?
Your understanding won't lead anyone astray.

Start with the '06 then the 280, 270, 6.5 and 25-06 and pick the same weight bullet in each caliber loaded to the same velocity. As you go down in caliber it will take less powder to achieve the same velocity, correct?

As the bore gets smaller barrel volume decreases (expansion ratio) and bearing surface increases (bullet friction) plus the affects of the smaller surface of the bullet base.

There's probably a very long equation that explains the stuff, but I'm with the common sense approach. It is what it is, and I can live with it
__________________
I may be the slowest guy on the mountain . . . . but . . . . I'm on the mountain!
Reply With Quote
  #6  
Old 08-24-2011, 03:38 PM
Silver Member
 
Join Date: Jul 2011
Location: Nebraska for now...
Posts: 217
Re: Why is the 25-06 slower then the 30-06 with the same Bullet weight?

Thank you for the explination. I was really hoping to be able to push the 115 to 3200-3250, but it looks like i'll have to be dancing around the 3050-3100 range. I still think i wanna shoot the 115. It might be the 110 would be the best balance between velocity and BC. i've got a 26" shillen barrel on a tikka action. What kinda Velocity should i see with the 115?
Nimrod
Reply With Quote
  #7  
Old 08-24-2011, 04:52 PM
Platinum Member
 
Join Date: Jan 2004
Location: Blackfoot, Idaho
Posts: 8,093
Re: Why is the 25-06 slower then the 30-06 with the same Bullet weight?

Shoot the highest bc bullet that your rifle likes best.

Don't be concerned about MV but get as much as you accurately can, then forget about it and go to engaging targets i.e., meat in the freezer.

The higher bc will make for more consistent accuracy in wind. The drop chart will remain constant, along with accuracy. That's all you need.

A few FPS doesn't mean squat to the target engaged. Hitting it does!
__________________
I may be the slowest guy on the mountain . . . . but . . . . I'm on the mountain!
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes


Similar Threads for: Why is the 25-06 slower then the 30-06 with the same Bullet weight?
Thread Thread Starter Forum Replies Last Post
.243 bullet weight 100 or 110 gr. chris matthews Rifles, Bullets, Barrels and Ballistics 15 09-30-2011 03:02 PM
300 RUM Bullet weight? jackin brass Long Range Hunting & Shooting 10 08-28-2011 05:11 PM
What bullet weight would you run deerhunterjj Reloading 2 05-22-2011 01:49 AM
Bullet Weight For 22-150 Micheal326 Varmint Hunting 15 11-12-2008 10:19 PM
.243 bullet weight rtv900 Rifles, Bullets, Barrels and Ballistics 5 10-06-2008 07:58 AM

Current Poll
Do you archery hunt for elk?
YES - 32.82%
85 Votes
NO - 49.42%
128 Votes
Not yet, but I plan to. - 17.76%
46 Votes
Total Votes: 259
You may not vote on this poll.

All times are GMT -5. The time now is 10:09 PM.


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