Long Range Hunting Online Magazine


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

Reloading Techniques For Reloading


Reply

Cooper arms 280 ackley velocity

 
LinkBack Thread Tools Display Modes
  #1  
Old 12-13-2011, 07:46 PM
Junior Member
 
Join Date: Mar 2010
Posts: 8
Cooper arms 280 ackley velocity

Hello all
Recently I have come up with a load giving me good accuracy.... 3/8-1/2 MOA out of my Cooper arms .280 AI excalibur. The barrel is 24 inches. Nosler advertises MAX 62.5 grains of H4831 giving 3179 FPS and Hodgdon shows MAX 62.0 grains of H4831 at 3012 FPS. My currently load is 62.1 grains of H4831, Nosler brass and F210 primers. My last range session I chronograph my load at a disappointing 2840 FPS........ not even close to 3000 FPS. Has anybody had a similar experience with H4831? I chose H4831 for temperature stability, however I am considering RL 22 for the extra speed. Any thoughts??
Thanks
Reply With Quote
  #2  
Old 12-13-2011, 10:42 PM
Bronze Member
 
Join Date: Apr 2009
Posts: 49
Re: Cooper arms 280 ackley velocity

Quote:
Originally Posted by goatliver View Post
Hello all
Recently I have come up with a load giving me good accuracy.... 3/8-1/2 MOA out of my Cooper arms .280 AI excalibur. The barrel is 24 inches. Nosler advertises MAX 62.5 grains of H4831 giving 3179 FPS and Hodgdon shows MAX 62.0 grains of H4831 at 3012 FPS. My currently load is 62.1 grains of H4831, Nosler brass and F210 primers. My last range session I chronograph my load at a disappointing 2840 FPS........ not even close to 3000 FPS. Has anybody had a similar experience with H4831? I chose H4831 for temperature stability, however I am considering RL 22 for the extra speed. Any thoughts??
Thanks
Believe it or not you chose the right powder. What weight bullet are you shooting? I shoot 140 grain Nosler accubonds. I shoot 59 grains and then jump up to 62 grains. My best accuracy is with 59 grains and I get 3/8" groups at 100 yds. The group opens up a little as I increase the powder then tightens back up at 62 grains. I get almost 2900 fps at 59 grains and then 3100 plus at 62 grains. The velocity is less than RL 22 but the temp sensitivity was driving me crazy! I got tired of my point of impact moving from season to season with RL 22. I was getting over 3200 fps but the inconsistent groups were not worth the velocity. I love using H4831sc because I know where my bullet is going to go. I can do without 100 fps for the accuracy.
Reply With Quote
  #3  
Old 12-13-2011, 10:49 PM
Gold Member
 
Join Date: Dec 2001
Posts: 795
Re: Cooper arms 280 ackley velocity

I would chronograph the load again also the test barrel is a Wiseman 1/19 twist 26" long. We have one 280AI with 25" long Kreiger barrel using Nolser load for the 150gr with H-4831sc we get little better than max published velocity (3000fps) at 1gr under max.

I had a factory Rem 280 with 24" long barrel I was going to use that action as donor for another 280AI want to have build. Alliant site has some loads for the 280 max 53gr/R-17 with 145 Speer @ 2968fps. I started at 50gr with 145gr Speer @ 2656fps max of 53gr @ 2904fps.

You could have problems with the chronograph if you have another rifle that you shot over it before use that to check it with. If that check you might want to call Cooper see what they say before spend lot on more powder etc.

Wish I could help more
Reply With Quote
  #4  
Old 12-13-2011, 11:03 PM
Silver Member
 
Join Date: Dec 2005
Posts: 124
Re: Cooper arms 280 ackley velocity

Quote:
Originally Posted by goatliver View Post
Hello all
Recently I have come up with a load giving me good accuracy.... 3/8-1/2 MOA out of my Cooper arms .280 AI excalibur. The barrel is 24 inches. Nosler advertises MAX 62.5 grains of H4831 giving 3179 FPS and Hodgdon shows MAX 62.0 grains of H4831 at 3012 FPS. My currently load is 62.1 grains of H4831, Nosler brass and F210 primers. My last range session I chronograph my load at a disappointing 2840 FPS........ not even close to 3000 FPS. Has anybody had a similar experience with H4831? I chose H4831 for temperature stability, however I am considering RL 22 for the extra speed. Any thoughts??
Thanks
You have not mentioned bullet weight I use H- 4831 with 140 grain bullets in my 280 which is not the AI version and IMR-7828 with 160's. You have not mentioned if you are seeing any pressure signs with your current load so perhaps you could work up a bit to see if speed increases with your combo and then tweak for group size. I am getting 2820 with 160 Ab's over 7828 in my standard 280 but this rifle has a really fast barrel and I wish all my rifles were as easy to work up as this one has been. In the standard case for me Rl-22 was a wee bit faster than H-4831 but not even close to group size. Do not rule out RL-19 either if 4831 is not working for you I have had this powder turn a pig into a princess on a couple of ocasions right before I wrapped the rifle around a tree.

Best of luck
Reply With Quote
  #5  
Old 12-14-2011, 01:27 AM
Silver Member
 
Join Date: Nov 2008
Location: New Zealand
Posts: 104
Re: Cooper arms 280 ackley velocity

I'v had the same rifle/cal with a 23" barrel for a couple of years,for the 140-160gr bullets N560 gave best velocity,but like RL22 was a bit temp sensitive.I use N165 now as its better with the 160gr weights.As has been said do not trust your crony unless its an ohler or maybe a CED 2 with ir screens.With the shooting chronys Iv seen 100fps spreads with nothing more than a change in light conditions.The 140 gr TTSX I run at 3100 and 162 amax at 2920 av.both validated at range.
Reply With Quote
  #6  
Old 12-14-2011, 10:51 AM
Silver Member
 
Join Date: Apr 2008
Posts: 185
Re: Cooper arms 280 ackley velocity

I shoot the 280AI as well and have found a load of 63.5 grains of Retumbo with a Berger 168 grain Hunting VLD is right at 3,000 and 1 ragged hole. I have a 26" Pac-Nor barrel and a blue printed and squared Rem. 700 action in a HS precision stock. I have found this combo to be excellent in all weather conditions from 12-90+ degrees. There was a writer named Bob Milek that had some pretty hot loads for the 280Rem. as this was one of his favorite calibers . He has passed some years ago and I have lost the article he published these loads in but if you could find them they may be of help.
Reply With Quote
  #7  
Old 12-14-2011, 04:21 PM
Junior Member
 
Join Date: Mar 2010
Posts: 8
Re: Cooper arms 280 ackley velocity

Thanks for you inputs guys. The bullet in question is a 140 gr Nosler AB. My chrono set up is a CED 2 Not the IR version. I am just surprised at 62 grains of H4831 i am not getting at least 3000 FPS. I will also switch back to the original Primer (WLR) which I haven't had the opportunity to chronograph.
Regards
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes


Similar Threads for: Cooper arms 280 ackley velocity
Thread Thread Starter Forum Replies Last Post
Cooper Arms 6.5x284 300barnes Guns For Sale 2 04-13-2011 08:01 PM
cooper arms southtexashunter Rifles, Bullets, Barrels & Ballistics 14 01-02-2011 06:51 PM
cooper arms phoenix krake22 Long Range Hunting & Shooting 1 03-06-2010 01:19 PM
Correspondence to Cooper Arms MontanaRifleman Politics Of Hunting And Guns (NOT General Politics) 12 11-14-2008 08:47 PM
Tactical Bases for Cooper Arms??? lerch General Discussion 0 08-20-2006 06:05 PM


All times are GMT -5. The time now is 01:05 PM.


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