Nosler .308 110 Varmageddon bullet exploding in flight?

[dellet]

Had an issue with these coming apart last weekend and wondering if anyone else has had problems and under what conditions. I think I know the answer, but wondering if it was more of a perfect storm or if there is an established spin rate, or speed others have had problems. Nosler was no real help, basically saying they don't have an rpm limit because too many other things factor in, but felt that I was pushing the limits.

There are a few things I think contributed to the bullet failure, including operator error, but I am hoping to be able to eliminate or condemn the bullet if I was just pushing it too hard.

The spin I had was 300,000+ rpm. Anyone else spin one apart around that speed?

 

[dellet]

I had the Nolser coming apart in a low velocity/fast twist barrel. A slow rate of fire showed no problems in hundreds of rounds. I think a faster firing rate and a hot barrel was a big factor. Just wondering if others had any failures with the bullet.

 

[rebel]

I had the Nolser coming apart in a low velocity/fast twist barrel. A slow rate of fire showed no problems in hundreds of rounds. I think a faster firing rate and a hot barrel was a big factor. Just wondering if others had any failures with the bullet.

I think you mentioned some slight damage from your seater? Could that have contributed as well? Pure hindsight and just wondering.

 

[dellet]

That’s part of the question, there was a visible ring from the seating stem that could not be felt. So that could be part.

In load work up and testing the bullet I got up to over 340,000 with no problems. That was a slow to medium rate of fire in twist of 1/5, 1/6, 1/7. The 1/7 was only about 285,000.

I down loaded a full grain of powder or about 200 fps/25,000rpm and shot a rapid fire course. bullets started coming apart after about 25-30 rounds.

So the variables were,
A different seating die marking the bullet. There seemed to be a bit more pressure needed to seat the bullet. Possibly due to squeaky clean necks. It was hard to tell because I had switched from a single stage to a progressive for bulk loading.

There was a significant difference in barrel temp.

Both these come under the heading of possible operator error. I may just need to try a repeat and see what variables I can eliminate.