7-6.5 PRC WITH 190gr BERGER HYBRIDS

[SST2500]

Guys, I recently had a 7-6.5 PRC built by a good friend for F-Class. It appears from what I’ve been reading that everyone seems to be shooting the 180 and 184 Berger Hybrids at around the velocity attainable with the .284 (2850 FPS). I really don’t see much of an advantage in that train of thought so I’m currently trying the 190 gr. Berger Hybrid. I started with a mild load at 56 gr. of H4831 SC and have worked up to a load of 58.6 gr. with the 190 Hybrid at 2915 fps. I’m currently getting ready to run a seating depth test to try and get the round to shoot. Thus far, I haven’t really hit any pressure signs at all. If you’re gonna shoot a magnum round, shoot it at a velocity and with a bullet that’s gonna gain an advantage over the 180, just my thoughts. Anyone had luck shooting the190’s in the 7-6.5 and if so where are your nodes showing up at?

 

[tthomp302]

The 180s just plain shoot. That’s why people go with them over the 190s.

 

[EdHarley]

What length barrel do you have? I have a rifle being finished in the same caliber and have not had any luck finding data on the 190s either. Perhaps no one likes them in that caliber.

 

[Yote Hunter]

What twist barrel? Myself and 2 other buddies are building the same caliber except Ackley version. Myself and one other went with a 8 twist to try the 190 gr bullet in. Haven’t completed our rifles yet

 

[EdHarley]

Mine is 1:8 as well.

 

[SST2500]

Barrel is a 1-8.7 twist Bartlein 32” in length. Went out today and tried a seating depth test. 4831sc powder 58.6gr. At 2900 FPS with ES of 4.4. Ran seating depth test from 0.010 off to 0.058 off. 0.028 to 0.040 shot 3 shots into one hole an one .5” flyer at each 0.006 increment. Don’t know what’s causing the flyers. Good friend said this is why no one is shooting the 190 Berger. He may be right. I don’t see much advantage in shooting the 190 much slower as I can get 180 Bergers to 2980 fps with no problem and good groups. May have to put the 190’s on hold and get the rifle running with a consistent load with the 180’s for Nationals. I have two 8 twist Bartlein barrels that are being chambered right now. Mabee the faster twist will help.

 

[Orr89rocz]

Try some powder charge variation in those seating ranges?

 

[Ryan M.]

Most guys are not running 2850 with 180s.
I’m running 2945, you will find the 180s & 184s will shoot quite a bit better than the 190s.

 

[JB10]

A friend on mine that shoots long range used to shoot the 190 but changed to the 180. What he found was the 190 shot great to about 600 yards. Passed that bad groups. Swapped to 180 and shoots way better out to 1,000+ yards for him. Different cartridge than you but same caliber.

 

[SST2500]

I'm running 2825 fps with the 180 Berger in my .284. The 7-6.5 has them running at 2980. With the exact same charge weight, the 180 Lapua Scenars are running 3000 fps in the 7-6.5

 

[RickyK]

I'm running 2825 fps with the 180 Berger in my .284. The 7-6.5 has them running at 2980. With the exact same charge weight, the 180 Lapua Scenars are running 3000 fps in the 7-6.5

How are you getting 155 fps faster with the same charge weight ? Or are you talking about different powders ?

 

[SST2500]

Not same charge weight. I’m running. 52.8 gr. In the .284. In the 7-6.5, I’m running 56.0gr. With the Berger and the Scenar.

 

[Alex Wheeler]

The 7-6.5 is not supposed to be a "magnum" Its just meant to shoot smaller than the 284 and not loose primer pockets. The fact that you can run mid to low 2900s is just a bonus. This case hides pressure signs, it will let you run over 3k. But your expanding the case head and will have trouble.

 

[JLT]

The 7-6.5 is not supposed to be a "magnum" Its just meant to shoot smaller than the 284 and not loose primer pockets. The fact that you can run mid to low 2900s is just a bonus. This case hides pressure signs, it will let you run over 3k. But your expanding the case head and will have trouble.

Absolutely. The same sorts of things happen when one tries to run a Dasher like a .243. Never works out very well.

"Ain't no replacement for displacement." - Caroll Shelby

 

[LVLAaron]

I say this as a bystander and interested party... if people were winning with the Berger LRHT bullets... we'd know.


7mm 190g
.223 85.5g
.308 208g

These bullets on paper seem like barn burners... but there are more threads and discussion on "load data" for these than Berger would care to admit. Compare that to the known rockstar bullets (185 juggs, 180 hybrids) you'll find threads full of people excited to share their match winning loads... and you'll see the same data repeated over and over.

 

[Orr89rocz]

I say this as a bystander and interested party... if people were winning with the Berger LRHT bullets... we'd know.


7mm 190g
.223 85.5g
.308 208g

These bullets on paper seem like barn burners... but there are more threads and discussion on "load data" for these than Berger would care to admit. Compare that to the known rockstar bullets (185 juggs, 180 hybrids) you'll find threads full of people excited to share their match winning loads... and you'll see the same data repeated over and over.

And the .30 220 gr. But that one has the 1000 yard BR heavy gun record in group and score

 

[LVLAaron]

I'm only familiar with the 3 I listed because I live in F-Class world. Those 3 bullets, if they were any good, they would be dominating.

 

[Ned Ludd]

I'm only familiar with the 3 I listed because I live in F-Class world. Those 3 bullets, if they were any good, they would be dominating.

F-TR division at this year's Sierra Cup regional match was won by a shooter using a .223 Rem with the 85.5s, in the face of stiff competition from other shooters using 185 Juggernauts and 200.20Xs. The South Africans dominated F-TR at Worlds this year using the 208s. There are other examples.

A bullet doesn't have to "dominate" to be good. Even a slight advantage can be of benefit over time. These bullets have only been available for 2-3 years, and it takes time for anything new to catch on. Nonetheless, people are winning with them. Are they necessarily any better than previous offerings? I think that remains to be seen. Toppling bullets such as the mighty 90 VLD, the 200.20X, and the 180 Hybrid from their well-earned thrones is not going to happen overnight, because they are proven designs and many are loathe to discard tools that are working well for those that are unproven. However, it will eventually happen.

 

[LVLAaron]

I didn't mean to say they're BAD bullets. I know people can win with them. My point is, they're not easy to tune like the juggs, the 180's, the 200 hybrids...

You give a new shooter a box of 200 hybrids, and a box of 208's - He's going to find a winning load with the 200's ages before he figures out the 208's.

In that same line of thinking, the "old but good" bullets will hold a tune a lot longer through the life of a barrel.

 

[Ned Ludd]

The very top shooters in any discipline will gravitate to the bullet(s) they believe give them an advantage. They are also the ones with the expertise to tune a load using a bullet that may be a bit more finicky and still get the very most out of it. Eventually, the designs that have the best combination of performance and ease of tuning will win out, although ease of tuning alone will not normally trump performance. Once top shooters start winning matches regularly with any new design, others will eventually jump on the bandwagon. This is simply how it happens, but it takes time for all that to happen. As an example of this in F-TR, the 185 Juggernauts used to be the rage until the 200 Hybrids and later the 200.20X bullets came along. How many top F-TR shooters are still using Juggernauts to win national-level matches at 1000 yd right now? My guess would be zero. The 200s simply represent too much of an advantage at 1000 yd. Only time will tell whether any of the LR Hybrids displace the current "go to" bullet choices for top F-Class shooters, but I think the jury is still out.

Per the OP's question, what is the reason that a number of Open shooters have tried the 190 LR Hybrids and gone back to the 180s? As I understand it, performance such as shown by the outliers in post #6 is at least part of the answer. The real question is whether such performance is intrinsic to the bullet design, or whether shooters simply haven't given the 190s what they "want". There have been a few .30 cal bullet designs that have come out in the last decade or so that were tried by numerous top F-TR shooters. However, most, if not all, found them impossible to tune consistently, even with extensive load development. So they are not commonly used today. It is certainly possible that such designs may have flaws. Bullet manufacturers are pushing the envelope in order to increase bullet BC. It is certainly plausible that "too much of a good thing" might lead to going too far with certain aspects of a given design, resulting in inconsistent behavior and/or difficulty of tuning. But the failure to find a solid load with a given bullet does not "prove" it has a design flaw, even if multiple shooters have the same experience. What it does suggest is that some bullet designs at a minimum may be difficult to tune. Once someone testing such a bullet will often go back to the "easy button", i.e. an older proven design, so as not to waste more time and/or barrel life. So the real question is simply how much time and effort someone is willing to devote to a given bullet in order to determine whether they can get it to shoot.