Updates regarding the Berger .338 Hybrid

[BryanLitz]

For those interested in this bullet, please visit the Berger Bulletin and read the latest article there.

I'll be happy to discuss the information in that bulletin here.

-Bryan

 

[Broz]

Bryan, Thanks for the link and update. As you may have read I have been struggling with the come ups and velocity in both LB3.0 and Exbal. Here is a link to the thread if interested. http://www.longrangehunting.com/forums/f19/help-needed-lb3-0-338-bergers-57430/

However , I have seen great accuracy with these and have tested them to 1400 yards from my 338 Lapua.

I did on one accation have one of a 5 shot group at 1400 that was not accounted for. The rest of the group (4) were just over 1/2 moa. The target was big enough that I really scratched my head. I wrote it off to pilot error. Maybe it was bullet deformation??

Last question, I have several hundred on hand. Would you feel that the improved design and mods you will make to these will change the tradgectory? If so I would rather wait to further development.

Thanks for your time.

Jeff

 

[BryanLitz]

Jeff,

I think that working with the revised BC's will produce trajectory predictions much closer to what you've seen than the previous BC.

Regarding your one missing shot, I don't think that was caused by the deformation I'm talking about. I say that because even in cases where the bullets are being deformed on every shot, the groups typically only open up to 2 MOA max. If you're shooting great groups and have one shot 'slump', I doubt it would throw it very far out of the group.

With the very good groups you're shooting, I would be inclined to believe that your combination of barrel, powder, load, etc is not producing pressures that are in excess of the bullet's structural limits.

Please continue to report your findings and let me know if the new BC's line up with your observed drop any better.

Take care,
-Bryan

 

[tom m.]

i spose the slump factor does not show up until extended range? i will be testing at 1000 with some this weekend, 338 lap imp, mv 3037. i will plug in the revised b.c., and see how it groups, and report back. thanks for keeping us in the know, most companies would'nt be this honest.
tom

 

[royinidaho]

nothing to say. Just learning. Wanted to subscribe to this thread and don't know of another way. Sorry!

 

[BryanLitz]

Thanks for your support Tom.

If the bullets do 'slump', which there's a good chance they will from a Lapua Improved, you'll see the evidence in group size as close as 100 yards. The BC will drop to about .75, and will apply from the muzzle on out.

If you've been able to shoot small (sub MOA) groups at 100 yards, then you're probably not deforming the bullets, and they'll also group well at all ranges and fly with the known BC of .818.

Take care,
-Bryan

 

[Len Backus]

Roy

Wanted to subscribe to this thread

At the top of the thread see the drop down menu titled THREAD TOOLS, choose SUBSCRIBE.

 

[Broz]

Bryan, This group is hot off the press. This was just shot using the new G7 BC of .419 and LB3.0. These were the first 5 with this BC and I still have not nailed down my Muzzle velocity. But the accuracy of these bullets are telling me to stick with them. 5 3/4" at 1182 yards is not bad from a .338 Lapua hunting rifle with close to 800 down the tube. The Berger Hybrids have CONSISTANTLY shot 1/2 moa to as far as I have shot them and that was 1400 yards. Even in some light wind. Pics were buried in another thread so I wanted to post them here.

ps: yeah it was 5 but one was just off the steel. But hey, 3 out of 4 into 2 1/2"!!

Jeff

 

[ZSteinle]

I dont quite understand why the bullets would slump in a lapua but not so much in the edge. I thought the lapua and edge were very close in case capacity with the slight edge going to the edge. Is it because of the lapua's shorter fatter cause causing the spike in pressure?

 

[jmden]

I dont quite understand why the bullets would slump in a lapua but not so much in the edge. I thought the lapua and edge were very close in case capacity with the slight edge going to the edge. Is it because of the lapua's shorter fatter cause causing the spike in pressure?

Good question...I was wondering the same thing.

 

[Broz]

If I remember correctly, didnt the update state Lapua Improved? I was under the impression it was when loaded to be at 3000 fps or so. I am seeing no problem at 2800 ish.

Quote from Bryans update:
"Cartridges like the .338 Lapua Mag Improved and larger are virtually assured of producing nose slump when loaded to their potential pressures."

 

[ZSteinle]

"The .338 Lapua Mag seems to be a borderline case which may or may not produce nose slump. "

I would assume the Edge and Lupua would be considered borderline. Im guessing under 3000 FPS there should be no problems.

 

[BryanLitz]

Unfortunately the exact thresh-hold between nose slump and no nose slump is not well defined. You might get one .338 LM to shoot fine, but due to differences in barrels and their influence on max pressure, another .338 LM may have problems. Even the same LM could have problems with certain powders (like faster burning ball powders) while other powders might keep pressures below the thresh-hold.

It's not possible to tell if you'll have nose slump based purely on MV either. The slump results from exceeding a certain max acceleration, which is directly proportional to max pressure. The MV is related to max pressure, but it doesn't tell the whole story. For example you could have a 26" barrel produce only 2800 fps but have a higher max pressure than a 30" barrel that produces 2850 fps (for example).

The best way to tell if the bullets will work in your rifle is to test them for precision at 100-300 yards. If you find it difficult to shoot under 1 MOA (in a rifle that's capable of less than 1 MOA) then the bullets are probably slumping. For rifles that do not produce slump, the precision is pretty easy to find. In my Edge, I tried seating depths of 0.015", 0.030", 0.045", and 0.060" off the riflings. All 4 seating depths produced about the same groups. I ended up going with the 0.060" off load because it produced the lowest velocity spread. I'm loading 92 grains of H1000.

-Bryan

-Bryan

 

[tom m.]

well i must be slumping them, heres my data. 338 lap. imp.., 3,037 at 15' so 3,042ish m.v..from my 100 yard zero. target 1001 yards, 57*, 26.65hg, at 80%h, required 19.5 m.o.a. to be dead on. this comes out .790 g1, .391-2g7. they shot rather poor, 11-13 inches, from a gun that is'nt the greatest, but will put smk's in 5-6 inches all day.

i will just wait until the next run, please make sure and keep us posted on what lot number starts what. i have confidence you will get them just right, and shootin lights out. but until then...............
any edge shooters out there wanna buy some bullets? i have lots.
tom