Long Range Hunting Online Magazine


Go Back   Long Range Hunting Online Magazine > Rifles, Reloading, Optics, Equipment > Rifles, Bullets, Barrels & Ballistics

Rifles, Bullets, Barrels & Ballistics Applied Ballistics


Reply

Nosler Accubond Long Range problem

 
LinkBack Thread Tools Display Modes
  #120  
Old 09-11-2013, 03:39 PM
Silver Member
 
Join Date: Jan 2013
Location: Maple Valley, Washington
Posts: 458
Re: Nosler Accubond Long Range problem

Well, I tried something a little off the track. See what you think of this. I posted a target below. I think it illustrates the problem I have been having with the 270 WSM using the 150 grain Nosler Accubond Long Range bullets even though I shot the target with a different rifle and ABLR bullet.

The target was shot with a Savage 7mm WSM using the 7mm 150 grain ABLR bullet (first cousin to the bullet in question). That rifle has a 4-groove Brux barrel attached and as the target shows has some issues with these bullets however it is not near as bad as the factory barrel on the 270 WSM. All loads were H4831SC fired at 200 yards.

Shots in group number 1 averaged 2,871 fps which used a low stress load of 63.0 grains and group size was decent at 1.156.

Loads for group number 2 were bumped up 1 grain to 64.0 grains of H4831SC which resulted in an increase in average velocity of 64 fps to 2,935 fps. Group size of 0.734 indicates good barrel timing the bullet is leaving the barrel at a favorable time (low barrel distortion and movement).

Loads for group number 3 were bumped up another grain to 65.0 grains with average velocity up another 56 fps to 2,991 fps and is just starting to get into trouble with 1 flyer opening the group to 1.781.

Loads for group number 4 were bumped up another grain to 66.0 grains with average velocity was up only 27 fps but nevertheless over the magic 3,000 fps to 3,018 fps and things hit the fan with a group of 4.093. There are some bad barrel/bullet interactions going on.

These ABLRs act more like Bergers than Accubonds when shot with a load that is out of tune with the rifle which means that they can shoot really bad. I dont recall the original Accubonds every doing that.

In my factory barreled 270 WSM I think the same thing is going on as with the 7mm WSM but the 270 WSM, for whatever reason, amplifies the effect by a factor of about 5 which results in bullets that go clear off the paper. I may have to reevaluate my original thought that this has to be a bullet problem. The bullets may be more sensitive than Im used to seeing but Im beginning to think that they are just what Nosler intended to make.

I think Kirby may have been right in his initial assessment this is most likely a problem with barrel harmonics and not with the bullet.

Having said that, Im still interested to see what the high velocity and expansion test results show. Im betting the ABLRs hold up well but from what Ive seen so far they dont always act nice and friendly like the original Accubonds.
Attached Thumbnails - Click to View Larger
Nosler Accubond Long Range problem-7mm-wsm-150-ablr-h4831sc-001.jpg  
Reply With Quote
  #121  
Old 09-11-2013, 04:06 PM
Platinum Member
 
Join Date: May 2008
Location: South of Canada and North of Wyoming
Posts: 5,953
Re: Nosler Accubond Long Range problem

A picture is worth a thousand words. I would say you have a rifle/barrel problem.

Making a pressure point on the fore end might tighten up those groups a little but you not likely see precision groups and you will probably find inconsistencies in various environmental conditions.

My guess is that the problem lies in the barrel(s), the bedding, the fit/torque of barrel to receiver or a combination thereof.

I'm guessing that Roy is going to shoot some nice small groups.
__________________
- Mark

You will never know how much it has cost my generation to preserve your freedom. I hope you make good use of it.
~ John Quincy Adams
Reply With Quote
  #122  
Old 09-11-2013, 04:08 PM
Platinum Member
 
Join Date: Apr 2005
Location: Alaska
Posts: 3,512
Re: Nosler Accubond Long Range problem

Am I missing something? Similar problem in three different barrels and two different rifles. I'm asking myself how can the problem not be with this bullet? 3000 fps is commonly exceeded with 150 grain bullets in .284 caliber cartridges.
Reply With Quote
  #123  
Old 09-11-2013, 04:15 PM
Platinum Member
 
Join Date: Nov 2008
Location: SW Montana
Posts: 4,562
Re: Nosler Accubond Long Range problem

The only time I've seen a Savage model 12 with a varmint contour barrel in 270 WSM blow bullets all over the place was when I had the bedding break out at the back rh corner torquing the action and after the throat just crapped out and it would not shoot Bergers any more. Even with a worn out barrel it still pushes a 150 Ballistic tip well over 3000fps, heck my newer barrels push a 175 Matrix 3000fps, your not even tapping the potential of the WSM.
__________________
"Pain is weakness leaving your body"
Reply With Quote
  #124  
Old 09-11-2013, 04:29 PM
Platinum Member
 
Join Date: May 2008
Location: South of Canada and North of Wyoming
Posts: 5,953
Re: Nosler Accubond Long Range problem

Quote:
Originally Posted by phorwath View Post
Am I missing something? Similar problem in three different barrels and two different rifles. I'm asking myself how can the problem not be with this bullet? 3000 fps is commonly exceeded with 150 grain bullets in .284 caliber cartridges.
No, but I am I completely glossed over the 7mm WSM. So, yeah..... it could be the bullets or maybe both rifles having bedding issues????

Really scratching my head.... Roy, hurry up and shoot those boolits!!!
__________________
- Mark

You will never know how much it has cost my generation to preserve your freedom. I hope you make good use of it.
~ John Quincy Adams
Reply With Quote
  #125  
Old 09-11-2013, 07:06 PM
Platinum Member
 
Join Date: Dec 2009
Location: Redmond Or.
Posts: 2,527
Re: Nosler Accubond Long Range problem

Engineering101,
Have you tried a different powder at all?
I wonder if you could get similar or higher velocity with lower pressure from a different burn rate powder?
I'm dying to get my hands on a chrono & blast away with RL-22 to see what they do.
Maybe better, maybe worse. We'll find out, but I'm surely confused by these results.

I gotta go use the search function, but I'm almost positive I've read a thread or two about guys pushing the 30 cal 210 ABLR to or past 3100 with a RUM case I think, but still with good accuracy.
Gotta go look still so don't quote me on it.
I'm real curious to see Roy's results, & Rich's "professional autopsy". They should reveal Alot.
Doubt we'll see it tomorrow unless Roy bites the mailman like a dog tearing them out of his hands, to get em loaded up in time to shoot too.
__________________
"Its not Rocket Surgery.....'
GOD,GUNS,&GUTTS MADE AMERICA, LETS KEEP ALL 3!winmag

"I have No idea why that cop made me ride in the back seat, when I Clearly called Shotgun!"
Reply With Quote
  #126  
Old 09-11-2013, 07:32 PM
Silver Member
 
Join Date: Jan 2013
Location: Maple Valley, Washington
Posts: 458
Re: Nosler Accubond Long Range problem

winmag,

Yeah, I've tried some Magnum, IMR7828SSC and some RL-17. In fact I was just sitting here thinking that I should shake up the barrel timing with some oddball powder that you normally would not use like say RL-33 or, going the other way, maybe some Varget. Just cram the case full or RL-33 and see what happens. Likely wouldn't be near fast enough but I've used that trick before and it can work.
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes



All times are GMT -5. The time now is 06:47 AM.


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