215gr Berger Hybrid in the 308Win

MontanaMarine

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Joined
Dec 4, 2001
Messages
348
Location
Canyon Ferry, MT
Broz gave me a few of the 215gr Berger Hybrids to test in the 308. Here's the results from the range.

Load:
Berger 215gr Hybrid, moly'd
Win brass
CCI 200
RL-17, 49.0gr (START LOWER FOR SAFETY)
OAL 3.10"

308215Berger_zps700a8e3a.jpg



Environmentals: 30F, 25.5 Hg, wind 2-7mph from 3 o'clock, 4500' elevation.

Rifles:
Rem 700 308 varmint, 1/12 twist, 20.5", HTG, MK4 3.5-10x40.
CopyofPC210012_zps33fdd94d.jpg


Rem 700 308 varmint, 1/12 twist, 26", A5, Super Sniper 16X.
CopyofPC210015_zpsaf14e2c7.jpg


I had 20 bullets. Ended up shooting five over the chrono, and fifteen at 100 yard target, three groups of five.

Chrony F1 results at 30 feet from muzzle:

20.5" - 2508, error, 2503

26" - 2602, 2605

The error was followed by a low battery indicator (I think from the cool temp). I had to warm up the 9V battery in my pocket then reset the chrono and shoot through it quickly.

Accuracy:

First group, 20.5" rig, five shots were 2" horizontal, and .5" vertical. All holes looked like good stability. The horizontal spread is probably my form being a little ganked up, bipod too low. But hey, I shot it, so I'll own it.

Second group, 20.5" rig, five shots in a round pattern .84" wide by .86" tall, .96" furthest center to center. That's a solid sub-moa. I had elevated the bipod and tightened up my position.

Third group, 26" rig, five shots in a fairly round group, one called flyer high. Group .30" wide by 1.1" tall. Minus the called flyer the remaining four went into .30" wide by .58" tall. That shows potential for consistent .5 moa accuracy.

PC210002_zpsdb1d3a07.jpg


That was all twenty shots. I had hoped to take it out to 1200 yards or so with five rounds, but my first five-round group was so schitty I decided to unphuck myself and try again.

I'm still shooting the 208 AMax as my go-to bullet. But since Broz handed me 20 of these 215s to try out, I wanted to document and share my findings.

For S&G, here's a traj table for the 215 out to a mile, with a MV of 2600 fps, el 4500':
Code:
Gunsite altitude : 4500 ft.
 Bullet           : .308, 215 gr, Berger Hybrid
 Ballistic Coefficient(s) (G1): [email protected]>0 fps;
-------------------------------------------------------------------------------------
 Range  Velo Time of  Energy   Path    Deflection    Total  Sight correction  Target
        city  flight            to    at crosswind    drop   for setting new   lead
                                LOS    of 10.0 Mph             zero range     20 fps
-------------------------------------------------------------------------------------
·Yards   fps     s    ft.lbs.   in.    in.     MOA     in.   Clicks     MOA     yds ·
-------------------------------------------------------------------------------------
|    0  2600  0.0000   3227    -1.9    0.0   -----     0.0   ------    -----    0.00
X  100  2491  0.1177   2963     0.0    0.4    0.38     2.6      0.0     0.00    0.78
|  200  2385  0.2397   2715    -3.7    1.6    0.75    10.8     +5.1    +1.74    1.60
|  300  2282  0.3684   2485   -13.5    3.9    1.25    25.1    +12.5    +4.29    2.46
|  400  2181  0.5036   2270   -30.1    7.4    1.77    46.2    +20.9    +7.19    3.36
|  500  2082  0.6447   2070   -54.0   11.9    2.28    74.6    +30.0   +10.32    4.30
|  600  1986  0.7912   1883   -85.6   17.4    2.77   110.7    +39.6   +13.63    5.27
|  700  1892  0.9437   1709  -125.5   23.9    3.27   155.1    +49.8   +17.12    6.29
|  800  1802  1.1069   1550  -176.0   32.4    3.86   210.1    +61.1   +21.01    7.38
|  900  1715  1.2797   1405  -238.0   42.5    4.50   276.5    +73.4   +25.25    8.53
| 1000  1632  1.4609   1271  -311.9   54.0    5.16   354.9    +86.6   +29.79    9.74
| 1100  1551  1.6498   1149  -398.4   67.0    5.81   445.8   +100.5   +34.58   11.00
| 1200  1474  1.8458   1038  -497.8   81.2    6.46   549.7   +115.1   +39.61   12.31
| 1300  1401  2.0538    938  -614.3   97.5    7.16   670.7   +131.2   +45.12   13.69
| 1400  1334  2.2743    850  -750.2  116.0    7.91   811.2   +148.7   +51.17   15.16
| 1500  1272  2.5048    772  -905.5  136.2    8.67   971.0   +167.6   +57.64   16.70
| 1600  1214  2.7456    704 -1082.2  158.3    9.45  1152.1   +187.7   +64.58   18.30
| 1700  1163  2.9984    646 -1284.1  182.5   10.25  1358.5   +209.6   +72.12   19.99
| 1760  1135  3.1549    615 -1417.4  197.9   10.73  1494.5   +223.5   +76.89   21.03
 

Broz

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Messages
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Location
Townsend, Montana.
Shane great report.

So did you see any velocity gain over the 208's?

Since this was just a load em and shoot em test do you think you could do some load development and get them to a solid 1/2 moa from the 26" rifle?

I think they look pretty pretty good for the first test load with no development. And I am impressed they shot this well from a 12 twist too. Looks like they liked the longer tube rifle could so they might be asking for velocity. Could you push the load some more or do you feel you are close to max?

Thanks for the report.

Jeff
 

MontanaMarine

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Joined
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Messages
348
Location
Canyon Ferry, MT
Jeff, Actually I saw a loss in velocity as compared to the 208s. The moly'd 208 over 49gr RL17 usually gets about 2675 fps in the 26" rifle, and 2575 fps in the 20.5" rifle.

I know you saw gains in velocity, and I do not doubt it. There are a lot of different dynamics going on in different case volumes and different powders. H1000 in the 300 WinMag, and RL17 in the 308Win are a good ways apart from each other in volume and burn rate.

The 49gr charge left visible flattening on my primers, although there was not a hint of ejector swipe, nor stiffness in bolt lift. Considering the 30F temps, I would not want to bump up the powder charge any higher. In 70-90F weather, I suspect velocity would be more in the 2650 fps range.

I was very pleased wit the accuracy from the 26" rig. I suspect playing with seating depth could yield pretty consistent .5 moa accuracy.

I'll likely buy a box of the 215s myself, to continue with some long range tests.

Shane
 

Broz

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Messages
8,638
Location
Townsend, Montana.
I was very pleased wit the accuracy from the 26" rig. I suspect playing with seating depth could yield pretty consistent .5 moa accuracy.

I'll likely buy a box of the 215s myself, to continue with some long range tests.

Shane

That would be cool, the accuracy I see with them at distance is pretty sweet.

Thanks
Jeff
 

angus-5024

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Jan 22, 2008
Messages
1,145
I wonder if the 1-12 twist could be the reason for the larger groups out of the 20.5" tube, as they dont have as long to stabilize in the tube.
 

MontanaMarine

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Joined
Dec 4, 2001
Messages
348
Location
Canyon Ferry, MT
I wonder if the 1-12 twist could be the reason for the larger groups out of the 20.5" tube, as they dont have as long to stabilize in the tube.

Stability has to be right at the edge, and I would think ther lower velocity of the 20.5" tube is likely a factor. I figure at 2600 fps in the 26" tube it is getting about 4% more RPM.

I ran the numbers through the stability calculator on the JBM website, they are definitely at the bottom end of the 'marginal' category.

2500fps/30F/25.5Hg - 1.029

2600fps/30F/25.5Hg - 1.042
 

liltank

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Nov 3, 2008
Messages
4,178
Location
Central Pennsylvania
Stability has to be right at the edge, and I would think ther lower velocity of the 20.5" tube is likely a factor. I figure at 2600 fps in the 26" tube it is getting about 4% more RPM.

I ran the numbers through the stability calculator on the JBM website, they are definitely at the bottom end of the 'marginal' category.

2500fps/30F/25.5Hg - 1.029

2600fps/30F/25.5Hg - 1.042
I didn't expect those numbers at all.
 
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