Whooz yer daddy?? UPDATE!!

[livnlg55345]

The Sinclair web site stated they had them exclusive distribution of the new 338 bullet till the end of the month. So, one suspect that after June 1st the Gunstop should have them.
Sinclair has sme other exclusives, too...like the all SS Wilson Trimmer....Heck money talks.....and Brownells / Sinclair is a larger entitiy so I trust that they have more pull the John at the GS. Well, perhaps Eric Stecker can get out the load manual before the end of the year......as claimed in a You tube video from Shot Show. The 338 bullet was supposed to be out last year....On one of the BR boards.....there are those with their panties in a wad over the change in the Berger 6mm 105gr Match Target VLD.

[justaguy]

http://www.gunbroker.com/Auction/ViewIt ... =169493035

http://www.gunbroker.com/Auction/ViewIt ... =170305995

http://www.gunbroker.com/Auction/ViewIt ... =170022566

http://www.gunbroker.com/Auction/ViewIt ... =169657227

[JoeH]

What kind of barrel life can one expect with this caliber?

[Seismic Sam]

What kind of barrel life can one expect with this caliber?

Considerably longer than the 300 or 7mm Ultramags, which are WAAYY overbore and thus barrel burners. Same for the 30-378 and 338-378 Weatherby. Don't have an exact number of shots, but the Lazzeroni rifles, which are designed to be extreme hunting guns and NOTHING else, are reported to have a barrel life of less than 300 rounds. The other factor is that my barrel was lapped and cryoed, which will also make it last longer.

[RAGGED]

What kind of barrel life can one expect with this caliber?

I know Sako's hammer forged barrel is said to go 3000 rounds with out any hint of accuracy loss, granted that’s with factory ammo and not heavy home loads but having chronoed factory ammo I can tell you the stuff isn't light. 92.2 grns of Retumbo pushes the 300 SMK’s to 2740-2750 FPS out of my TRG

[Seismic Sam]

Actually, 2750 with a 300 grain bullet is about max for both the .338 Lapua and Ultramag. The Remington factory loads are a bit wimped out and probably are 200 FPS under the handloading manual's max'es, but I guess I'm not surprised that Lapua factory ammo might be right up there.

[Seismic Sam]

Well, went out to the range with my 338 RUM loads and the 300 grain Berger hybrid, and got a bit of a surprise. Originally, I had done a series of 1 grain increments with Sierra 300 grain MK's from 90 to 94 grains with Retumbo, and as luck would have it the 94 grain load had the lowest velocity SD and a vaelocity of 2740, which is pretty much max for a 300 grain bullet. So when the Berger bulets showed up, I ran a series of 5 shot strings from 92.5 grains to 94.0 grains in 0.3 grain increments, and with my first load at 92.5 my velocity was 2740. ???? Shot 2 more strings, velocity did NOT increase, but the outlines of an ejector mark began to appear on the case head, indicating increasing pressure.

Called it a day, and have loaded up some Berger 300 hybrid's starting at 89 grains and going up in half grain increments. Now, early on when I got the rifle, I had seen signs of the velocity petering out as you got to max posted velocity, so it appears that the 338 RUM has a glass ceiling for velocity, but not pressure. Another veteran handloader at the range told me that I was using to faast a powder and needed to get a slower burning one, but Retumbo is almost as slow as they get.

As such, it would appear that it takes somewhat LESS powder to drive the Berger bullet than the 300 MK, which is quite an interesting THEORY. When I shoot the new string of reduced loads, I'll let you know how it turns out. To add final insult to injury, my chrono had a very weak battery and lost the data from my shooting session. Luckily, all the shots were pretty much the same velocity, so I didn't lose much.

[RAGGED]

I can't wait till John gets some of these in so I can buy them, should be fun.

[livnlg55345]

At the GS I got some Berger 168's on Sat. Guess was there? The 338 bullets.

[RAGGED]

Picked up 100 of them from John on Sat, only to read this today, somewhat disappointing but I have a good stock of 300 SMK's that I will work with till they get the issues sorted out.


http://02b0516.netsolhost.com/blog1/?p=133

Update Regarding the .338 Hybrids
Filed under: BC, Making it Shoot — mgallagher @ 12:38 pm
As expected, the release of the new 300 grain .338 Hybrid bullets has made quite a splash. The purpose of this bulletin is to share some facts that have been learned about this bullet since its release. There are two major facts that I’ll elaborate on.
1) The BC of the bullet is being revised, and
2) The bullet has limitations regarding its structural integrity.

Revised BC Assessment
For unknown reasons, the original BC test produced results that were not repeatable for this bullet. Upon releasing these bullets to the public, we started to hear that trajectories predicted with the advertised BC’s were not matching the observed drop. We took this feedback seriously, and performed several more careful BC tests. The results of each of these tests have produced a repeatable BC, but it’s lower than the original value by about 7%.

The revised BC’s for the 300 grain .338 Hybrid are:
G7 BC = 0.419
G1 BC = 0.818

The above BC’s have been measured in multiple tests in multiple barrels, and produce calculated trajectories that match the observations of some credible shooters.

We’re grateful for the feedback of the shooters who brought this matter to our attention and allowed us to correct the inaccurate information. Greater care will be taken with future tests in an effort to prevent this from happening again.

Limitations to the Bullet’s Structural Integrity
Another thing that happened when we released these bullets to the public is that they were fired in cartridges that are more energetic than the .338 Edge which I used for the initial evaluations. Upon exposure to the extreme pressures and accelerations produced by some of the larger cartridges, some negative results were observed; poor groups, and lower observed BC (even lower than the revised values above). Our current working theory is that the poor precision and reduced BC are a result of nose slump. Nose slump is when the bullet is accelerated so fast that the base of the nose can’t support its own weight, and bulges out to fill the barrel. This produces a bullet with a longer bearing surface and a shorter nose which explains the compromised BC. Since this deformation doesn’t occur exactly the same every time, poor precision also results.

The exact threshold of pressure/acceleration that will cause nose slump with this bullet is not known. There are a number of small to medium capacity cartridges that shoot these bullets very well, with extremely good precision and a repeatable BC. So far there have been no reported cases of nose slump with cartridges in the following class: .338 Winchester Mag, .338 Norma Mag, .338 RUM, and .338 Edge, etc.

The .338 Lapua Mag seems to be a borderline case which may or may not produce nose slump. Factors that affect pressure/acceleration will affect the likeliness of nose slump occurring. For example, ball powders are typically faster burning than stick powders, so they produce higher peak pressures, and are more likely to produce nose slump. Tighter bores can also cause elevated pressures and tip the scales toward nose slump.

Cartridges like the .338 Lapua Mag Improved and larger are virtually assured of producing nose slump when loaded to their potential pressures.

If you’re working up a load with these bullets and having difficulty finding a precise load, it’s likely that you’re exceeding the pressure threshold where nose slump happens. In small to medium cartridges, the hybrid ogive design makes it quite easy to find an accurate load. The bullet is quite insensitive to seating depth. If you’re working with a large capacity case and having poor results, you should consider reducing the powder charge until good groups are achieved.

When designing a bullet for use in hunting applications, the toughness of the bullet is always a trade-off. Terminally, you want a bullet that is capable of reliable expansion/fragmentation at low impact velocities. However, the bullet can’t be so thin-skinned that it doesn’t survive being launched at very high speeds. This being our first time working with a bullet this large, a construction was selected which we felt would strike the best balance between toughness and terminal performance. Simply put, we erred too much on the side of terminal performance. The result is a bullet that’s perfectly suited for small to medium capacity cases, but simply isn’t tough enough to survive being fired from the more energetic magnums.

The good news is that the situation has been identified and several solutions are already being worked on. We know the design needs to be ‘toughened up’ for successful use in larger cartridges, and we’re considering the best way to do this.

In Summary
The Berger .338 caliber 300 grain Hybrid bullet is still the highest BC bullet in its class. The performance gap just isn’t as big as originally thought.

In its current form, the bullet is perfectly suitable for many popular small to medium capacity cartridges. From my .338 Edge test rifle, I’ve shot multiple 10 shot groups at 1000 yards under 10” and the bullets performed with a very repeatable BC. For the time being, those with larger capacity cartridges will have to wait for the bullet to be toughened up in order to achieve good performance. We don’t have an anticipated timeline for this revision, but it is a top priority.

On a personal note, I want to express my gratitude for the shooters who’ve provided the critical feedback which helped us to understand the situation enough to take action. Having an open dialogue and exchange of information is the best way to ensure we’re doing everything we can to make the best bullets possible.

Take care,
-Bryan

[Seismic Sam]

Well, that would explain the horseshyte 1" groups I wa sgetting. Still not sure about whey these bullets seem to need less powder that the 300 MK's. I'm in Germany for two weeks, so I will check out my reduced loads at the end of June...

[RAGGED]

Well, that would explain the horseshyte 1" groups I wa sgetting. Still not sure about whey these bullets seem to need less powder that the 300 MK's. I'm in Germany for two weeks, so I will check out my reduced loads at the end of June...

I read somewhere that the BT angle will be changing for the 2nd run, they new angle will get back most of the BC that was lost. I hope they can make them a bit tougher so they hold up. I have to say to have a project delayed this much and have it come out flawed looks REALLY bad. This leaves a guy wondering WTF happened and how did this stuff pass any sort of R&D tests, they had to have know the majority of this stuff was going to be used in the big super magnums like the RUM, LM and Edge. I find it odd that they tested this bullet in 338 Edge and saw no issues when most Edge guys are launching the 300 SMK's at 2800-2950 FPS, a fair bit higher then most LM and RUM loads.

[livnlg55345]

The proposed up grade change in the boat tail from 7 to 9 degrees was on the potential upgrades/drawing board before they released the bullet for sale. Long before all these issues have to to light. One has to consider that they are being repsonsive to the matter, not dismissing it. Well, the were supposed to have had this bullet out LAST YEAR in early fall...
So, things take time and a work thru of the problem....then to validate the changes will take time.

[RAGGED]

The proposed up grade change in the boat tail from 7 to 9 degrees was on the potential upgrades/drawing board before they released the bullet for sale. Long before all these issues have to to light. One has to consider that they are being repsonsive to the matter, not dismissing it. Well, the were supposed to have had this bullet out LAST YEAR in early fall...
So, things take time and a work thru of the problem....then to validate the changes will take time.

While I understand it takes time I feel it would have been better to delay the launch even further if they were unsure of their numbers or design, this is about as big of an OOPS as I've seen in a long time. The "nose slump" issue seems to be an even larger issue than the overstated BC's. I just can't wrap my head around how any of this didn't show its face in testing, it's a real black eye on the entire program, and I am a huge fan of Berger. These bullets should have never been released until they were thoroughly tested, playing fast a loose with testing is a no no, at least where I work!

[Seismic Sam]

And thinking about it a bit more along with your comments, maybe my peculiar results with my near max loads giving constant velocity WAS the result of nose slump. If the bullet collapses backwards and creates a longer bearing surface and more friction, there goes your velocity potential.

You're also right on as to how they could just see this problem with the .338 Edge, but not the .338 RUM. That makes no sense at all, despite their claims.