Updates regarding the Berger .338 Hybrid

[Broz]

any edge shooters out there wanna buy some bullets? i have lots.
tom

Hi Tom , I might be interested and I am faily close to you. Shoot me a pm with quantity and prices and lot numbers please.

Thanks!

Jeff

 

[BH Hunter]

I believe that Berger will take your bullets back from you if you don't get rid of them.

 

[ZSteinle]

any one know the Multi BC for the updated .818 G1 standard.

 

[groper]

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

Bryan, you may have answered this in another thread, but as yet i have not found a response from you to kirby allens issues with this pressure theory...

From some of his testing, he stated that he tried some very light loads of H50BMG in the cheytac size cases to the point where he was getting hang fires etc... he estimiated that the pressures would have been 50,000psi or less, but obviously with long barrels and such a large case, velocity was still quite high.... However, he was still getting the accuracy problems and suggested is was more the velocity and specifically the RPM`s rather than pressure deforming the bullets.

Im simply curious, but how are you determining that it is inface 'nose slump' rather than some other form of deformation, and that it is caused from pressure and not excess RPM`s?

 

[Augustus]

Gentlemen, I have been following the various post regarding the 300 Berger. The characteristics of these bullets seem to be similar to the long nose solids I have been playing with for the last year or so. The solids that are over 6 cal. in length are extremely sensitive to twist rates and velocity. Since they are solids, deformation and nose slump are pretty well eliminated as factors yet they demonstrate very predictable issues with accuracy and stability as twist rates decrease and velocity increases. As velocity increases the twist rate must also increase to maintain accuracy and stability. This is bass-ackwards from conventional wisdom.

I believe the projos with very long noses which shifts the CG rearward, very quickly become a different breed of cats and take on characteristics unfamiliar to most. The problem with these bullets can be rectified with tighter twist rates. With the banded solid bullets we have the luxury of being able to twist them as tight as necessary to stabilize them. With the jacketed bullets there is a limit on RPMs and at some point one will begin to see spectacular failure in the structure of the bullet. I would like to see someone fire the Bergers out of an 8 twist, if they can stand up to the forces they will be subjected to I would expect them to fly nicely.

Word to the wise. The banded solids also become more stable and more accurate as velocity decreases when fired from a given twist rate. I am almost certian deformation or structural problems are not a factor because if fired at the same velocity but a tighter twist the accuracy and stability magically reappears.

I think someone with access to two barrels one of which is a 9 twist and the other a 10 twist can determine if this bullet is experencing structural failure or is suffering from the long nose syndrome. Simply start at low velocity, slowly increase the velocity of the loads. If you see loss of accuracy from the 10 twist first you are seeing the long nose syndrome if the 9 twist fails first its probably a structural problem.

You guys would be wise not to sweep this post under the mat. The LONG NOSE SYNDROME is alive and well and will affect any projo regardless of its structure if the ratio of nose to body length crosses an undefined line. I suspect the Berger crossed that line.

 

[Augustus]

I hope I did not confuse everyone with my references to increasing or decreasing twist rates. Simply put, increased twist rate = tighter twist rate.

 

[Varminator 911]

Augustus:

I think you know what you are talking about. Have you tried contacting Berger directly? I think they would consider what you are saying.

 

[tom m.]

augustis' post may indeed make perfect sense.. as in my results posted on page 2, i was only .5moa low at 1k, but horrid accuracy. if the nose were slumping as bryan suggested, would'nt they impact lower yet?
tom

 

[Augustus]

No I have not had any contact with Berger. I have not even fired any of the Hybrids. I have just been watching the reports that have been coming across the wires and it appears they have some of the characteristics of the long nose solids. The problem is they may not can withstand the twist rates required to overcome the LONG NOSE SYNDROME at top velocities. What is the overall length of the 300 Berger Hybrid?

 

[tom m.]

1.820"