Long Range Hunting Online Magazine


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

Long Range Hunting & Shooting Nightforce Optics


Reply

Accubond LR Comparison and G7 BC Test

 
LinkBack Thread Tools Display Modes
  #1  
Old 06-09-2013, 04:52 PM
Gold Member
 
Join Date: Feb 2013
Location: Central MT
Posts: 755
Accubond LR Comparison and G7 BC Test

A hunting companion called me last week inquiring if I had any luck locating the Long Range AccuBonds (LRAB) for his 7 Rem Mag he recently purchased. "Not yet," I informed him. He has portrayed several times not being comfortable hunting with what he called "exploding" bullets. With the new line of LRABs advertised, he was quite interested in their performance. I informed him I had recently acquired two boxes of the 30 Cal 210 LRAB’s and would be willing to test a few around 1000 yards with the results used to help him with his decision on a direction for a bullet to use in this new rifle. I also was not willing to invest more than 40 total rounds during tests to save barrel life on my rifle.

With the name Long Range, an appropriate starting point for testing would be with bullet consistency and evaluating the advertised G7 ballistics coefficient. I used the Berger 230 Grain Hybrid Tactical OTM with an advertised G7 BC of .368 for comparison to the LRAB advertised G7 BC of .366.
Accubond LR Comparison and G7 BC Test-lrab-berger-bc.jpg

Accubond LR Comparison and G7 BC Test-bullet-comparison.jpg

Pictured left to right for visual comparison are the 30 cal Berger 230gr Hybrid OTM, 30 cal Nosler 210gr LRAB, 338cal Berger 300gr Hybrid OTM, and 338 cal Nosler 300gr AccuBond.


I decided to evaluate the LRAB with comparison to the Berger OTM in four areas:
1. Base to Comparator length.
2. Weight.
3. Short range precision to include muzzle velocity variation.
4. Computer generated G7 BC drop results tested at ranges near 1000 yards specifically for the LRAB. I have shot the OTM’s for the past few years and have confidence in their advertised G1 and G7 BC’s.

Base to Comparator Length and Weight
Accubond LR Comparison and G7 BC Test-testing-equipment.jpg

Twenty bullets each were randomly selected, measured, weighed and placed back into their box. Sorting was not conducted. Length was measured using a Sinclair bullet sorting stand and quick sorting comparator. Weight was measured using a Sartorius M-prove scale.


Berger OTM
Average Weight - 230.07 grains
SD .091 grains
Average base to comparator length - .789"
SD .00074"

LRAB
Average Weight - 210.31 grains
SD .221 grains
Average base to comparator length - .766"
SD .00078"

Short Range Precision (Group Size in MOA) and Muzzle Velocity Variation
Accubond LR Comparison and G7 BC Test-range.jpg

Three shot groups were taken with each bullet at 100, 200 and 300 yards. Average group size was measured in MOA. An Oehler M-35p chronograph measured the muzzle velocity of each shot. The rifle used during testing was an accurized Remington 700 LA fitted with a 30" Lilja 1-10" twist barrel chambered with a SAAMI reamer in 300 RUM and skim bedded in an HS Precision stock. A Nightforce 8-32X56 NXS scope with NP-R1 reticle topped the rifle and finished with a Sinclair bipod. Rounds were loaded three grains below estimated MAX charge with an OAL of 3.660" thus allowing just enough room for clearance in the magazine. Free bore was approaching 170 thousandths of an inch for each. Keep in mind load development was not conducted and results could have varied by conducting load development. I was more interested with the muzzle velocity standard deviation results considering the LRAB was not as precise in bullet weight as the Berger’s.
 
Berger
Average three shot MOA .64
Average Muzzle Velocity 2960 ft/s, SD 15 ft/s

LRAB
Average three shot MOA .96
Average Muzzle Velocity 3136 ft/s, SD 11 ft/s

LRAB G7 BC

Ten additional LRAB’s were loaded using an estimated MAX charge and zeroed. The four shot average zero muzzle velocity was 3222 ft/s.

The next morning a target was set up at 960 yards. Adjustments were made for wind and spin drift. Three shots were taken using the advertised G7 BC of .366 utilizing my ballistics engine. The group measured 18" low and 9" in size. Accubond LR Comparison and G7 BC Test-1095-yards.jpg
Note the vertical.

The target was then placed at 1095 yards for my last three shots. The first shot hit low just missing the target. I adjusted up 2.25 MOA and fired my last two rounds. The two shot group measured 12" low and was 11" in size. Accubond LR Comparison and G7 BC Test-960-yards.jpg
Note the vertical.

The advertised LRAB G7 BC of .366 is significantly above a corrected G7 BC required for my particular firing solution for the ranges noted above.

Of particular interest is the vertical displacement of the two groups. While two groups do not support near enough data to draw any form of validity, the results look promising. Both LRAB groups additionally measured approximately the same average MOA as in the short range testing while under slight wind and mirage changes (less than 3 MPH). The vertical displacement appears promising. I would consider the LRAB of having the potential of being a formidable long range hunting bullet compared to their current AccuBond design with further tested G7 BC validation and hand load development.
__________________
Shoot CONFIDENT, Shoot SMART, Shoot STRAIGHT
Reply With Quote
  #2  
Old 06-09-2013, 05:09 PM
Platinum Member
 
Join Date: Feb 2007
Location: Townsend, Montana.
Posts: 7,934
Re: Accubond LR Comparison and G7 BC Test

Quote:
Originally Posted by MMERSS View Post
The advertised LRAB G7 BC of .366 is significantly above a corrected G7 BC required for my particular firing solution for the ranges noted above.
So what did you need to use for a G7 BC to get your dial ups to come out for these two distances for the LRAB 210?

Thanks and good work.

Jeff
__________________
Reply With Quote
  #3  
Old 06-09-2013, 05:17 PM
Platinum Member
 
Join Date: Jan 2003
Location: The rifle range, or archery range or behind the computer in Alaska
Posts: 3,586
Re: Accubond LR Comparison and G7 BC Test

Nice job. Can I ask what your zero was and atmospheric conditions were?
__________________
__________________
Long range shooting is a process that ends with a result. Once you start to focus on the result (how bad your last shot was, how big the group is going to be, what your buck will score, what your match score is, what place you are in...) then you loose the capacity to focus on the process.
Reply With Quote
  #4  
Old 06-09-2013, 05:42 PM
Gold Member
 
Join Date: Feb 2013
Location: Central MT
Posts: 755
Re: Accubond LR Comparison and G7 BC Test

Quote:
Originally Posted by Broz View Post
So what did you need to use for a G7 BC to get your dial ups to come out for these two distances for the LRAB 210?

Thanks and good work.

Jeff
Sorry typo,

G7 BC corrected to .321 for solution.
__________________
Shoot CONFIDENT, Shoot SMART, Shoot STRAIGHT

Last edited by MMERSS; 06-09-2013 at 06:23 PM. Reason: Typo
Reply With Quote
  #5  
Old 06-09-2013, 07:13 PM
Gold Member
 
Join Date: Feb 2013
Location: Central MT
Posts: 755
Re: Accubond LR Comparison and G7 BC Test

Quote:
Originally Posted by Michael Eichele View Post
Nice job. Can I ask what your zero was and atmospheric conditions were?
Michael,

I suppose you could say I established a zero 18" low at 960 yards with a DA of 5600. I don't take much validity with my first zero while shooting only a few rounds with groups measuring close to 1 MOA. In either case both ranges produced low shots using the advertised .366 G7 BC. Additional groups at various ranges need to be conducted to accurately predict the BC needed for a solution for my particular rifle and ammo combo. On the positive side, the LRAB's appear to be holding MVV and verticle well!
__________________
Shoot CONFIDENT, Shoot SMART, Shoot STRAIGHT
Reply With Quote
  #6  
Old 06-09-2013, 07:25 PM
Platinum Member
 
Join Date: Nov 2008
Location: SW Montana
Posts: 4,550
Re: Accubond LR Comparison and G7 BC Test

Nice work, thanks for doing it!! It looks like in this case the ALR may have similar ballistics to the Berger 210, it will be interesting to see how long range accuracy holds out over time!
__________________
High Fence, Low Fence, Stuck in the Fence, if I can Tag it and Eat it, it's Hunting!

"Pain is weakness leaving your body"
Reply With Quote
  #7  
Old 06-09-2013, 07:33 PM
Platinum Member
 
Join Date: Jan 2009
Location: Rochester, NY
Posts: 1,483
Re: Accubond LR Comparison and G7 BC Test

Good work.

Thanks for taking the time to put a pencil to this first shoot.
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes



All times are GMT -5. The time now is 01:53 AM.


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