Berger Integrity

[RH300UM]

Does anybody have info for the maximum velocity that a Berger bullet can be pushed to before coming apart? I know that twist rate has a hand in the outcome also. I am shooting 180 VLD,s at 3334 fps average with a 1 in 9 twist. I am having what appears to be bullet integrity problems at this velocity. I have called and talked to Berger but can not get a definite answer from them. I was just wondering if anyone has had any problems or experinces that they can share.

 

[Broz]

I have had no problems with the 180's at 3200 in a 9 twist and have shot 100's. I think Eddybo had some issues with them somewhere over 3400 in an 8 twist. If he doesn't join in here maybe send him a pm.

Jeff

 

[Mikecr]

You can't ask for a limit 'for Berger bullets' because they are not all the same.
But I had defined(as best I could) the RPM limits of Berger VLDs quite awhile back. Berger didn't like it one bit, but it has always held as useful(still for VLDs).
For your situation:

(720*MV/TW)/1000
(720*3334/9)/1000
KRPMs = 267 [your rate]

(0.308-CAL)*238.095+290
(0.308-.284)*238.095+290
KRPM LIMIT = 296 [The point of expected failures]

For the Eddybo mention:
(720*3400/8)/1000
KRPMs = 306 [This exceeds the 296 limit]

So, it's not RPMs(or the energy to produce them) causing your failures.

 

[RH300UM]

You can't ask for a limit 'for Berger bullets' because they are not all the same.
But I had defined(as best I could) the RPM limits of Berger VLDs quite awhile back. Berger didn't like it one bit, but it has always held as useful(still for VLDs).
For your situation:

(720*MV/TW)/1000
(720*3334/9)/1000
KRPMs = 267 [your rate]

(0.308-CAL)*238.095+290
(0.308-.284)*238.095+290
KRPM LIMIT = 296 [The point of expected failures]

For the Eddybo mention:
(720*3400/8)/1000
KRPMs = 306 [This exceeds the 296 limit]

So, it's not RPMs(or the energy to produce them) causing your failures.

Thanks for the info.
I am thinking that the Berger in 7mm 180gr. is coming apart on me due to the fact that on a few shots taken that the only thing hitting the paper target at 200yds. is shrapnel!!! I have 206 rounds down the barrel now and this has happened 3 times.

 

[Mikecr]

If you don't have a borescope, a local gunsmith probably does. I'd have the bore/crown looked at. It's hard to guess at, so that's just where I'd start.
If there is an issue there, you might salvage the situation with a going of Tubb's FinalFinish.

 

[RH300UM]

If you don't have a borescope, a local gunsmith probably does. I'd have the bore/crown looked at. It's hard to guess at, so that's just where I'd start.
If there is an issue there, you might salvage the situation with a going of Tubb's FinalFinish.

Not sure as to what you are thinking????
This is a new rig with a Brux barrel.
Called 'smith. Was told to try a differnt lot of Bergers.
The ones I was using were in the old yellow box. Thinner jacket?
Might be as simple as this.

 

[Mikecr]

The new 'Match Target' VLDs have thicker jackets than the original VLDs(now called 'hunting' VLDs). This might work around whatever issue there is, at a cost of killing efficiency. But I don't think it's the bullets.

Are you sure it's a 9tw, and not an 8tw?
Have you checked the twist with a cleaning rod?

 

[Ridge Runner]

yep, I've had problems, (3 times out of 3) shooting .264 140's at 3160 fps from an 8 twist, impact ranges were 230, 456, and 493 yards, no bone was encountered and the bullets penetrated maybe 2" total. yet most posts say they are great bullets, I just can't accept that from what I have saw.
RR

 

[RH300UM]

The new 'Match Target' VLDs have thicker jackets than the original VLDs(now called 'hunting' VLDs). This might work around whatever issue there is, at a cost of killing efficiency. But I don't think it's the bullets.

Are you sure it's a 9tw, and not an 8tw?
Have you checked the twist with a cleaning rod?

HOLY S--T !!!!
I have a 1 in 8 twist. Ordered a 1 in 9. I never checked it I just assumed. Now I am the ***. THANKS Mikecr.
Ordered up some 180 SMK's. "smith says these will handle the situation.

 

[eddybo]

yep, I've had problems, (3 times out of 3) shooting .264 140's at 3160 fps from an 8 twist, impact ranges were 230, 456, and 493 yards, no bone was encountered and the bullets penetrated maybe 2" total. yet most posts say they are great bullets, I just can't accept that from what I have saw.
RR

You just scared me. I am running them a little hotter than that in a 6.5WSM and was planning on shooting an antelope with it in a couple weeks, but probably at 700-1K yards, but stuff happens and longrange plans often end with short shot opportunities.