.308 185gr Berger Hybrid
- Thread starter MGYSGT
- Start date
Use the BERGER BALLISTIC CALCULATOR here: https://bergerbullets.com/ballistics-calculator/
Be sure to enter the ALTITUDE , TEMPERATURE !
Ned Ludd
Silver $$ Contributor
Barrel length? Freebore length (or COAL)? Will you be loading to mag length?
Having some idea of the setup you're using would allow for better responses. I ran the 185 Hybrids at ~2727-2750 fps over Varget in F-TR for several years. But that was from a bolt rifle with 0.180" freebore and a 30" barrel so that they could be seated long and have optimal case capacity. The 185 Hybrid is a very good bullet design IMO, with an excellent BC for the weight and very good accuracy/precision. I attached the output for the 185 Hybrid at 2500 fps from JBM Ballistics below using generic atmospheric inputs. It may be that 2500 fps is sufficient, but you'd be running pretty close to trans-sonic at 1000 yd. Without more information regarding the rifle setup, it is impossible to say whether you are leaving any velocity on the table at 2500 fps (i.e. how close that load is to MAX pressure).
Having some idea of the setup you're using would allow for better responses. I ran the 185 Hybrids at ~2727-2750 fps over Varget in F-TR for several years. But that was from a bolt rifle with 0.180" freebore and a 30" barrel so that they could be seated long and have optimal case capacity. The 185 Hybrid is a very good bullet design IMO, with an excellent BC for the weight and very good accuracy/precision. I attached the output for the 185 Hybrid at 2500 fps from JBM Ballistics below using generic atmospheric inputs. It may be that 2500 fps is sufficient, but you'd be running pretty close to trans-sonic at 1000 yd. Without more information regarding the rifle setup, it is impossible to say whether you are leaving any velocity on the table at 2500 fps (i.e. how close that load is to MAX pressure).
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284winner
Silver $$ Contributor
I was getting into the 2700 range with my 26" 308 barrel and RL15 using the 185 VLDs. You should easily make 2600 as long as your barrel has some length
MGYSGT
Silver $$ Contributor
Thanks for the info. Barrel is 30", not quite at max load, small mag primer and Peterson brass doesn't show any signs of pressure yet. I can try to get higher, but it is shooting .3 MOA right now and would hate to move out of the node. Guess I won't know if I don't try.
XTR
F-TR obssessed shooting junkie
Be careful with Re15 if you work up in the spring before it’s hot. It is pretty temperature sensitive and I’ve seen it pop primers on large primer brass when it got hot. (Never personally saw it on small primer brass)
if your load is in the mid 2700s now you should be all right (assuming you have the freebore)
if your load is in the mid 2700s now you should be all right (assuming you have the freebore)
dannyjbiggs
Silver $$ Contributor
I won the National F-TR championships in '08 and '09 using that bullet pushed with 48.00 grains of H4350 in Remington .308 BR cases, 30-inch, 1-12 twist barrel, Palma 95 chamber, approaching (but not there) 2,800 fps. (Had to use Varget to get past 2,800 fps.
) Load might not do as well against the competition now?
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MGYSGT
Silver $$ Contributor
48 grains. Wow, I didn't think that would fit. I shall continue to test with powders.I won the National F-TR championships in '08 and '09 using that bullet pushed with 48.00 grains of H4350 in Remington .308 BR cases, 30-inch, 1-12 twist barrel, Palma 95 chamber, approaching (but not there) 2,800 fps. (Had to use Varget to get past 2,800 fps.
At that temperature, you have bigger problems. You’re 50 degrees above the maximum temperature suitable for outdoor leisure activities. Wow.
Won a few matches and National FTR League Championship with the 185g Hybrid great bulletI won the National F-TR championships in '08 and '09 using that bullet pushed with 48.00 grains of H4350 in Remington .308 BR cases, 30-inch, 1-12 twist barrel, Palma 95 chamber, approaching (but not there) 2,800 fps. (Had to use Varget to get past 2,800 fps.
Did you find 5 and 15 thou off lands sweet spots for bullet Seating Dan.
D-4297
Gold $$ Contributor
Never been to Phoenix in the Summer , have you ? That's just a normal summer day temp .
No, sure haven’t. I’d assume it is normal for there. Thanks.
For best results, you're looking to keep the bullet well clear of dropping through the sound barrier and also want to keep it out of the trans-sonic speed zone. The 185 Hybrid at 2,500 fps has no problems with the first condition in any 'normal' ambient condition (air temperature / altitude), but is a bit slow for the second. Google speed of sound and you get a surprising range of values, but ballistician and bullet designer Bryan Litz quotes 1,115 fps, so let's use that. For a decelerating bullet, transonic starts at around 1.2 MACH in standard conditions, ie c.1,340 fps. With standard conditions (29.92 inches mercury pressure / 59-deg F), the Berger calculator says the 185 Hybrid at 2,500 fps MV has 1,232 fps retained velocity at 1,000. But, as @barefooter56 (Phil Hoham of Berger Bullets) says in an earlier post, it's important to input likely air temperature and range altitude. Since you're in a warmish region in summer 
) !!), change the input to say 90-deg and let's assume your shooting location is at sea level or not much above and the bullet is travelling rather faster at long distance, now a calculated 1,279 fps @ 1,000.
So, at 2,500 fps, you're still not in optimal speeds. Bearing in mind too that most loads have MV spreads and the BC of individual bullets vary a little, those calculated end of trip speeds fall within a range and the earlier in its flight / deeper the bullet drops into the transonic range, the more it's affected, so you need a bit of a right-side margin. F/TR competitors shooting at small X / 10-score circles against very serious competition look to ensure they stay well above that 1.2 MACH speed with calculated terminal speeds in the high 1,300s / c. 1,400 fps, usually well above those levels.
Conversely, decades ago the US Army looked at these effects with the old 173gn FMJBT Frankford Arsenal bullet and found that there was a boundary in the transonic zone at around 1,225-1,235 fps. Drop into/below that and group dispersion and wind effects both increased greatly. That might not be a general effect, rather limited to that one bullet. I've no experience with the Berger 185 Hybrid at marginal transonic speeds, so can't comment as to its performance - some designs do better / worse than others in this respect. I do know that one reason its 185gn LRBT 'Juggernaut' stablemate is so loved, especially by those with shorter barrel 308s struggling to get 1,000 yard ballistics is that it is a very tolerant design that copes excellently with such sub-optimal conditions.
As always, go and shoot, and see how you get on! Theory and calculators lay out the basic ground rules, but only take you so far. I agree with those warning about Re15 though. It's the only powder that has caused me temperature related pressure problems in the northern British Isles weather - mid 80s F is a very hot day here, and we're collapsing at a twice a century 90! External ballistics don't matter any more if you start blowing primers and have to retire.
) !!), change the input to say 90-deg and let's assume your shooting location is at sea level or not much above and the bullet is travelling rather faster at long distance, now a calculated 1,279 fps @ 1,000.So, at 2,500 fps, you're still not in optimal speeds. Bearing in mind too that most loads have MV spreads and the BC of individual bullets vary a little, those calculated end of trip speeds fall within a range and the earlier in its flight / deeper the bullet drops into the transonic range, the more it's affected, so you need a bit of a right-side margin. F/TR competitors shooting at small X / 10-score circles against very serious competition look to ensure they stay well above that 1.2 MACH speed with calculated terminal speeds in the high 1,300s / c. 1,400 fps, usually well above those levels.
Conversely, decades ago the US Army looked at these effects with the old 173gn FMJBT Frankford Arsenal bullet and found that there was a boundary in the transonic zone at around 1,225-1,235 fps. Drop into/below that and group dispersion and wind effects both increased greatly. That might not be a general effect, rather limited to that one bullet. I've no experience with the Berger 185 Hybrid at marginal transonic speeds, so can't comment as to its performance - some designs do better / worse than others in this respect. I do know that one reason its 185gn LRBT 'Juggernaut' stablemate is so loved, especially by those with shorter barrel 308s struggling to get 1,000 yard ballistics is that it is a very tolerant design that copes excellently with such sub-optimal conditions.
As always, go and shoot, and see how you get on! Theory and calculators lay out the basic ground rules, but only take you so far. I agree with those warning about Re15 though. It's the only powder that has caused me temperature related pressure problems in the northern British Isles weather - mid 80s F is a very hot day here, and we're collapsing at a twice a century 90! External ballistics don't matter any more if you start blowing primers and have to retire.
LVLAaron
Gold $$ Contributor
That's a pretty typcial FTR load/velocity. I think you'd be wasting time trying to make something else work.
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