Berger 208 30 cal?

[Ilya S.]

At .005" off the lands in a chamber with 0.180" fb, the COAL for a 208 Hybrid loaded to .005" off the lands should be very close to 3.016".

Qload says 4400bar for this COAL on 42.5 varget 2619 fps on 32" tube. D-4297's load show 4945 bar

here is mine 208 in qload bullet file

 

[Ned Ludd]

Qload says 4400bar for this COAL on 42.5 varget 2619 fps on 32" tube. D-4297's load show 4945 bar

How are you determining pressure without knowing his case volume, temperature, Lot-specific burn rate (Ba), etc.?

 

[Ilya S.]

My calculation based on 56.4 H2O capcity formed lapua by my chamber and default QL's varget profile at 68F. I dont think he use extra thin norma brass or his varget lot is so soft and he shooting in Alaska. I still thinking 44.0 is too much for 208 with .180 FB.

 

[Ned Ludd]

I see; the pressure value you mentioned was an estimate. Although I generally take such QL estimates that have been made using certain input assumptions with a grain of salt, I agree that 44.1 gr of Varget does seem to be a very stout load for the 208s. Your pressure estimate is not likely to change enough to alter that assessment even if some of the true inputs are slightly different from the ones you actually used. I'm currently running 43.5 gr of Varget underneath the shorter (BTO) 200.20X bullet in Lapua Palma brass, which gives me ~2650 fps from a 30" barrel chambered with 0.180" fb (~3.118" COAL).

 

[Medic505]

What is COAL

I measured a COAL of 3.240 in a chamber that I tried to shoot 215 hybrids from.
***DISCLAIMER*** This chamber was originally cut with a PTG reamer that was supposed to be a .170 freebore, but we all know, what you order and what you eventually get (if you ever get it) from PTG may or may not be what's engraved on the reamer. If my calculations were correct when this chamber was throated for 215's, this should be a .220 freebore. ****READ DISCLAIMER AGAIN**** As best as I can measure, this leaves about .140 of bearing surface in the neck, with the end of the boat tail about even with the neck-shoulder junction. Looks pretty good to me, low mileage barrel so I guess I'll give them a whirl.

 

[D-4297]

I use a Lapua SRP case , cut to 2.110" , as I have neck length clearance to .140" ..... Don't have any idea of velocity on this 208gr load , but it works well with a 200.20x and 200 Hybrid , both set at .005" off . Avg. velocity using Labradar on the 20x & Hybrid , at the Low Node is 2618 fps. And Ben Avery is my home range . Approximately 1720 MSL . Hope that helps with the computations .

 

[XTR]

If you do a kinetic energy calc assuming a velocity of 2650 for the 200.20x you get ~2600 as an estimated velocity for the 208 at a similar pressure. The pressures on the 200s at 2650 are pretty moderate, so even with a longer bearing surface I think this is probably a pretty good place to start thinking you’ve got all of the velocity that you will get. Where it tunes is yet to be seen

 

[Down South]

Shot five of the 208's in a 180 FB chamber , .005 off , at 600 , in a 8 mph steady full value wind . Used my 200.20x load of 44.1 Varget and came up with 3 X's and 2 10's . Even a blind squirrel finds a acorn sometimes ....My tube might like these suckers .

Sounds pretty good so far.......

 

[savageshooter86]

Seems 208 are the business. Assuming they shoot small like the 200.20 should. My observations

 

[HomeSlice]

Seems 208 are the business. Assuming they shoot small like the 200.20 should. My observations

can you decode that for us?

edit: auto spell woes

 

[Ned Ludd]

Seems 208 are the business. Assuming they shoot small like the 200.20 should. My observations

Try comparing the 208 to pointed 200.20Xs and the 220 to pointed 215s. The 200.20X and 215 can be pointed at home for a 4 to 5% increase over the box BC. The 208s and 220s come pointed from the factory, so the BC listed on the box is what you get.

 

[savageshooter86]

can you decode that for us?

edit: auto spell woes

See the attachment I posted above. I ran numbers through JBM ballistics

 

[savageshooter86]

Try comparing the 208 to pointed 200.20Xs and the 220 to pointed 215s. The 200.20X and 215 can be pointed at home for a 4 to 5% increase over the box BC. The 208s and 220s come pointed from the factory, so the BC listed on the box is what you get.

Since this will be new project with a magnum why not buy the 208s to start vs having to but pointing set up and doing all the work

 

[Ned Ludd]

Since this will be new project with a magnum why not buy the 208s to start vs having to but pointing set up and doing all the work

That's a good question. I prefer to point my own bullets because I can do it with much greater consistency than the manufacturer, and it's really not that much work. The point I was trying make is that solely in terms of BC, several of the new offerings from Berger do not represent much (if any) of an advantage over the bullets we've already been using from them for some time. In order to illustrate that fact, you have to be comparing apples to apples (i.e. comparing BCs of bullets pointed by the user to bullets pointed at the factory).

As you noted, for some having bullets pointed by the manufacturer will be a bonus. Nonetheless, I'm hoping there is some additional advantage to some of these new bullets above and beyond that. For example, with its longer bearing surface, does the 208 show better stability than the 200.20X? Or at least, reduced pitch/yaw straight out of the bore? I can imagine there might be better reasons to be shooting these bullets than a perceived increased in BC, which effectively disappears if you're already pointing bullets at home.

 

[D-4297]

I'm not a rocket scientist ; but the guy who designed them is . So maybe , there is something in the design that does make them more stable , less pitch & yaw , or whatever . My initial impression after shooting only five was , "WOW" ! "These things are different" ! Different how ? I don't know the how or why , but different .

 

[Ned Ludd]

I'm not a rocket scientist ; but the guy who designed them is . So maybe , there is something in the design that does make them more stable , less pitch & yaw , or whatever . My initial impression after shooting only five was , "WOW" ! "These things are different" ! Different how ? I don't know the how or why , but different .

That's quite possible. The design is certainly different from the 200.20X. When two bullets have comparable BCs, less tangible differences such as stability, ease of tuning, etc., can make all the difference.

 

[LVLAaron]

I'm not a rocket scientist ; but the guy who designed them is . So maybe , there is something in the design that does make them more stable , less pitch & yaw , or whatever . My initial impression after shooting only five was , "WOW" ! "These things are different" ! Different how ? I don't know the how or why , but different .

I recall seeing somewhere that the weight is balanced more towards the rear of the bullet.

 

[D-4297]

That would make sense . Being propelled ; ( pushed ) with that long thin nose would make it fly more aero-stable for a long distance .
Uh....I think ?

 

[markgrabowski]

I presume that Litz designed this bullet... has he commented anywhere on the pro’s/cons on this bullet or what the intended application it’s been optimized for?

 

[willbas]

I got to shoot the Berger 208's yesterday I was using Varget with a CBTO of 2.350. Center target is Berger 200.20X at 43.4 of Varget same CBTO, the one to the left was me moving windage 1 check left. I now need to check on speed and SD.