BC has my 308 beating my friend's 7 Rem mag

[AZShooter]

I finally got around to trying some 215 berger match bullets in my 22" barreled 308. It is actually a 30BR/308. I used my 30 BR reamer and went in an additional 1/2". Think of it as a 308 improved. 30 degree shoulder with less body taper. I just couldn't see spending the money on a 308 reamer.....

I doubt there is much difference in case capacity between this altered case and a regular 308.

I used 46.5 gr of RL-17. The 215 is going 2533 fps very accurately. It is a single shot proposition with bullet engaging the lands .010."

My friend is getting 2949 fps with a 160 accubond with his 7 Rem mag. I was doing some comparisons of the two and was very surprised at what I discovered.

I crunched two charts with JBM for 4000 ft etc where we hunt coues wt. I admit the 7 mag shoots flatter, BUT from 50 yds and on the 308 pulls away in energy and with less wind drift.


308 drift velocity energy
100 0.4 2440.0 2841.8
200 1.6 2348.9 2633.5
300 3.7 2259.7 2437.4
400 6.7 2172.7 2253.2
500 10.6 2087.6 2080.2
600 15.6 2004.5 1917.9

7RM drift velocity energy
100 0.5 2808.1 2801.0
200 1.9 2665.9 2524.5
300 4.3 2527.6 2269.4
400 7.9 2393.3 2034.7
500 12.8 2263.2 1819.5
600 18.9 2137.5 1622.9

The next thing I did was to look up Broz's thread on the performance of the 215 on elk, deer, and antelope.

http://www.longrangehunting.com/forums/newthread.php?do=newthread&f=28

He lists the velocities along with very detailed pictures of the bullet's performance. The 308 is not much compared to the 300 win mag BUT it would work quite well based on Broz's documentation. The 308's velocities vs the 300 win mag cuts its useful distances in half but I think it could be called upon to perform well on antelope or deer out to 750 yds and elk at closer ranges.

I was surprised at this data and wanted to share.

 

[Tare]

I run 230otm in my .308 for long range, they are best for wind even at slow speeds. 215s were about equal but not 100% stabilized(10 twist) and not mag length loadable.

I did a big comparison on another site, my 230 loads vs. 140gr 6.5cm loads from the same barrel length. The difference is small.

 

[MudRunner2005]

Your friend's 7mm RemMag is running a little slow...

That said, I've been shooting the 210/215's out of my .308 Win for years, and they are the best shooting load I have (1/8-1/4 MOA average). And it has a 5R 11.25" twist 24" barrel. And I'm only at ~250' ASL. The ballistics are astounding, when you consider how slow that bullet leaves the muzzle, but it holds a very solid trajectory. This is why I've always been a big proponent of the heavy-for-caliber bullets.

 

[Canadian Bushman]

My last 308 barrel was running the 215's comfortably out of the mag at 2640fps.

With rl-17 i ran it up to a max load of 49gns and a mv of 2730.

With a fast barrel, the 215's can really wake up a 308.

My newest barrel is much slower. Aprx 2490-2500. It maxed out just under 2600 but shot terribly there.

You will also find out that the 215's expand at unusually low velocities for that type od bullet. I have data saying i got them to open as low as 1600, but i dont specifically remember the test, so i cant be certain of the hows and whys.

 

[Tare]

I should clarify, according to stability calculators, the 215hybrids are not 100% stabilized from my 10twist, they shoot just fine but according to Litz, the BC is slightly comprised being under 1.5 SG.

 

[AZShooter]

Great minds think alike. I guess I am a bit late on the 215 usage as you guys have been doing it for a while. I have heard of some 308s really smoking with RL-17. I got to 47 gr and saw some pressure signs so I stopped.

As for the 7 mag his loads are above book for what Hodgdon says they should get with H4831.

I crunched a higher velocity loading for the 7 mag with that 160 accubond. The 308 still pulled ahead with the projected load with the accubond and retumbo @ 3050 fps. It was further wasy before the 308/ 215 gr bullet began to pull away from the 160 accubond.

 

[bigngreen]

I finally loaded my 308 to top pressure with a 215 and am running 2684 fps, using Lapua palma brass and 3.205 coal to do it but the thing hums, the 215 is just one of those bullets that just really deliver in what ever you put them in. I'm pumped about the 200.20X though, tried to get my hands on some to hunt with but failed.

 

[MudRunner2005]

Great minds think alike. I guess I am a bit late on the 215 usage as you guys have been doing it for a while. I have heard of some 308s really smoking with RL-17. I got to 47 gr and saw some pressure signs so I stopped.

As for the 7 mag his loads are above book for what Hodgdon says they should get with H4831.

I crunched a higher velocity loading for the 7 mag with that 160 accubond. The 308 still pulled ahead with the projected load with the accubond and retumbo @ 3050 fps. It was further wasy before the 308/ 215 gr bullet began to pull away from the 160 accubond.

Here's some fun comparisons of my rifles and loads...

Of course drop is going to be significantly different for the .308, but Drift is impressive despite velocity differentials.

Using values of 100 yard zero, 1000 yard target, with a 5 MPH full-value 90º wind...

.308 Win pushing 168 VLD @ 2775 - Drop: 343.9 / Drift: 44.9

.308 Win pushing a 210 VLD @ 2,500 - Drop: 374.2 / Drift: 37.2

.25-06 AI pushing 115 VLD @ 3,400 - Drop: 216.5 / Drift: 33.3

7mmRM pushing a 168 VLD @ 3,115 fps MV - Drop: 227.6 / Drift: 26.4

7mm STW pushing a 195 EOL Hybrid @ 3,000 - Drop: 226.9 / Drift: 21.6

.300 Ackley using a 210 VLD @ 3,000 - Drop: 241.6 / Drift: 27.6

 

[MudRunner2005]

I finally loaded my 308 to top pressure with a 215 and am running 2684 fps, using Lapua palma brass and 3.205 coal to do it but the thing hums, the 215 is just one of those bullets that just really deliver in what ever you put them in. I'm pumped about the 200.20X though, tried to get my hands on some to hunt with but failed.

I'm interested to hear your results when you do get them tested.

 

[roninflag]

great numbers for a .308. for coues using a 7nmm I would shoot 140 berger at 3200 or a 168 berger at 2950. very little wind drift, drop. high enough energy for a coues deer.

 

[AZShooter]

Thanks for mentioning the OAL Bigngreen. Now I know why my load topped out at a much lower velocity. The 30 BR reamer I used to make the 308 has a shorter throat. When I ordered the reamer I asked for a longer throat than the original Robinett throat as I wanted to shoot 168s in the 30 BR.

My OAL is exactly 3" with the bullet engaging the lands with .010."



Ron,

I too would shoot the 168 Berger from a 7 rem mag. BUT my friend wanted the accubonds. My 284 win shoots the 168 VLDs at 2835 fps and was used for last year's coues at 450 yds.

With all the other rifles I can't imagine using my 308 for my rare big game tags, but it could be a good junior hunter rifle with its low recoil.

This year I am going back to my 257 weatherby shooting 115 VLDs at 3650 fps. IMO it may be the best blend of flat shooting, wind drift and moderate recoil of the magnums.

 

[gohring3006]

I ran the 215 for a while in 30-06 at 2650 fps. I was impressed with the ballistics.
I since switched to the 208 ELD, and I'm equally impressed. A little less BC but quite a bit cheaper. When loading for 10 different rifles I try to save where I can..
These new bullets and powders have made these old cartridges shoot with the best of them...
My 30-06 shooting the 208 ELD takes 9 mils to 1000 yards @2650 fps and my 6.5 with 140 ELD @2700 fps is 9.1 mils... Who would ever thought the ole 30-06 would keep up
with the latest and greatest target round...

 

[Bravo 4]

I run 230otm in my .308 for long range, they are best for wind even at slow speeds. 215s were about equal but not 100% stabilized(10 twist) and not mag length loadable.

Just asking for clarification: are you saying the longer 230 grain Bergers will stabilize in your 10" twist rifle and fit in the mag, but the shorter 215 grain Berger won't stabilize or fit the mag?
Maybe I'm wrong here but that sounds backwards.

 

[MudRunner2005]

Just asking for clarification: are you saying the longer 230 grain Bergers will stabilize in your 10" twist rifle and fit in the mag, but the shorter 215 grain Berger won't stabilize or fit the mag?
Maybe I'm wrong here but that sounds backwards.

I saw that and thought the same thing...