Berger 185 LRBT velocities

[savageshooter86]

According to JBM and everything input it is saying there is only 0.1 MOA difference in wind drift using the 185s at 600 yds and only 0.3 MOA wind drift advantage at 1000 yards. AND it is saying my 168 hybrid actually has 0.7 MOA less drop at 600 and 1 MOA less at 1000 yards***assuming 2800 fps with the 185 LRBT

Just curious what velocities you can safely expect with a 30" barrel and 12 twist? Trying to compare it in JBM to my current load with 168 Hybrids running 2900 fps. This is my FTR rifle for 600/1000 yards

 

[Laurie]

A simple way of comparing different weight bullets once you have a decent G7 BC and ballistics program is to use the ME value of a known bullet's MV and recalculate for the new weight.

ie:

168 @ 2,900 fps = 3138.06 ft/lb ME

3,138.06 ft/lb with a 185gn bullet requires 2,764 fps MV. Bingo!

Actually, I'd say that 2,764 is on the low side for a 30-inch barrel F/TR load with the 185gn Juggernaut, but it does depend on how your barrel is throated. Running an optimal chamber for this bullet, I saw 2,825 fps with small ES values a few seasons back when this bullet was new and still unappreciated by most (and therefore actually available and affordable!). That was in Lapua brass over a stout load of Viht N550 - but we don't have to worry much about ambient temperatures and their effect on pressures in the land of the North Briton!

Anyway, according to Bryan Litz's / Berger's PM Ballistics Solver II program, there's nothing at all between the two at 2,900 fps / 2,764 fps at either 600 or 1,000.

Forget come-up - all that bothers you as a known-distance shooter is drift in a wind change (which I'm glad to say is a LOT less than 10 mph @ 90-deg where I shoot) and retained velocity at the target, ideally 1,400 fps or more.

With the 185 at 2,825 fps MV, you get a marginal wind advantage over the 168 / 2,900 fps load at 1,000 and a worthwhile terminal velocity increase. These bullets seem to really respond at 1,000 to MVs of 2,800 and a bit above, really holding good elevations.

If your 168 Hybrid load performs well at 1,000 though, holding good elevations, don't change to the Juggernaut.

 

[savageshooter86]

worthwhile terminal velocity increase

Do you mean to stay above Mach 1.2?

I ran in JBM with the 185s at 2850 and shows a 0.5 MOA less wind drift at 1000 yards. So that is helping.

Only reason I am asking is I only have 400 168s left and am trying to figure out if I want to stick with these or try the 185s. 185s showed real promise with a quick work up to test the bullets in my 12 twist barrel. And so did the 168s. And as you mention Laurie the 185s were no where to be had when I needed bullets. So made my decision easy at the time

 

[Laurie]

I use 1,400 fps terminal velocity as my target floor - that's officially 1.24 MACH in standard conditions, but I shoot a lot in colder conditions than 59-deg. I have seemed to get better long range elevations if that's what PM Solver 2 says - no proof though.

The half-MOA improvement is at 10 mph. Once you've got the windage 'sorted' in your first shot or two (hopefully!), it's all about changes between shots after that. I've done a lot of backwards calculations taking MOA changes in my corrected wind values off my wind plots, and on the three UK long distance ranges I shoot over, the actual wind changes when translated from MOA values on the target back to wind speeds at 90-deg are surprisingly small, hardly ever above 2 mph. I know people 'over there' who shoot in desert conditions see some frightening shot to shot shifts, but I'm glad to say we rarely get anything really large. Since we shoot 'two to a mound', we plot estimated and actual (corrected) wind values to build a picture / pattern over the match, and it also allows post-match analysis that you can't do with string shooting.

Anyway, a wind shift that equates to say 2 mph at 90-deg (it may be a much larger actual wind speed change, but at a shallow angle onto the bullet's flight) sees the 0.5-MOA difference between the two bullets' performance in the 10 mph crosswind reduce to 0.1-MOA at 1,000 yards or just over an inch. That may or may not produce an extra point or two on the day. However, if it's a 2mph equivalent change, hopefully we see it and reduce any wind-reading error to a maximum of 1 mph and that reduces the difference between the bullets' performance to 0.05 or a twentieth of an MOA, half an inch or so. (The absolute missed wind change effect is still there of course, so the 185gn Juggernaut at 2,825 fps MV moves 0.74-MOA sideways and has to drop a point in this scenario even if elevation is spot-on, and is half-way across the next ring getting perilously close to dropping two points if elevation is a bit out too - frightening isn't it?)

I shoot the 168 Hybrid myself in one of my F/TR rifles at 2,925 fps, and with it being such an efficient bullet it performs very well at long ranges. Everybody thinks I'm nuts using it at 1,000 - but they thought the same when I started using the 185 four or so years back too! The other factor is gun handling. These days, my LR rifle uses a long low-rider type F stock, Dan Pohlabel FLEX-Pod, heavy and very rigid Mini-Gator rear bag and 155.5gn Bergers at 3,054 fps over 8208XBR. It's the least recoiling, easiest to control set-up I've used in F/TR to date and I'll take the 155s extra windage quite happily as a penalty for the other benefits. The 168s don't upset the applecart much more and are therefore an excellent alternative, while the 185 does start to move everything a bit more and noticeably!

 

[savageshooter86]

I had thought about the 155s or the 155.5s but was not sure about the barrel wear and primer pockets pushing them over 3000 fps. Can you help me out with what you have experienced? How many firing on the 168s can your brass go until primers fall out? I am on 5 firing now at the 2900 fps. Using Lapua brass

Also someone had mentioned to me pushing the 155s fast(3000 fps or more) recoils the same or more than the mid weight bullets?

**I got a laugh at my first match I ever shot a couple months ago. Showed up and the vets asked me as the ROOKIE what I was shooting and type of rifle. I told them Berger 168 hybrids over Varget and they all laughed and turned their noses up at me. Told me those would not make it to 1000 and that some ranges won't allow 168s to be shot at 1000 yards. Well I ended up beating the guy(veteran shooter) using my 168s ;D

 

[Trevor60]

A simple way of comparing different weight bullets once you have a decent G7 BC and ballistics program is to use the ME value of a known bullet's MV and recalculate for the new weight.

ie:

168 @ 2,900 fps = 3138.06 ft/lb ME

3,138.06 ft/lb with a 185gn bullet requires 2,764 fps MV. Bingo!

Actually, I'd say that 2,764 is on the low side for a 30-inch barrel F/TR load with the 185gn Juggernaut, but it does depend on how your barrel is throated. Running an optimal chamber for this bullet, I saw 2,825 fps with small ES values a few seasons back when this bullet was new and still unappreciated by most (and therefore actually available and affordable!). That was in Lapua brass over a stout load of Viht N550 - but we don't have to worry much about ambient temperatures and their effect on pressures in the land of the North Briton!

Anyway, according to Bryan Litz's / Berger's PM Ballistics Solver II program, there's nothing at all between the two at 2,900 fps / 2,764 fps at either 600 or 1,000.

could you point me to how I would calculate these numbers.
Thank you
Trevor

 

[Laurie]

The easiest way is to use a simple online MV spreadsheet calculator. I use Airhog's - an airgun site, but no matter ME is ME is ME.


http://www.americanairrifle.com/convert.htm

You get three boxes, one of which must be empty before you click on 'calculate'. So in this case we have the MV (2,900) and bullet weight (168) from savageshooter86 and enter them in their boxes and click 'calculate', the sheet providing the answer in the third (ME) box - 3,138.06 ft/lb

Leave that box as is, clear the MV box and change 168 to 185 in the 'Pellet weight' box - click 'calculate' and it now gives the MV needed by a 185gn projectile to achieve that ME - 2763.5 something fps here.

Voila, sorted! A very useful and quick method for comparing bullet performance. Of course, if and when you range test the 'new' model, you may not achieve that exact MV, or more likely best groups are obtained a bit below or above that velocity. But it tells you what the ballpark figures look like.

It only applies to one rifle / barrel of course and assumes that if needed you change the powder grade to one suited to the 'new' bullet - eg moving from H4895 with 168s / 175s to VarGet or Viht N150 with a 185.

 

[Trevor60]

thank you. I broke my pencil trying to calculate it on paper ;D

 

[DennisH]

thank you. I broke my pencil trying to calculate it on paper ;D

LOL

 

[Laurie]

I had thought about the 155s or the 155.5s but was not sure about the barrel wear and primer pockets pushing them over 3000 fps. Can you help me out with what you have experienced? How many firing on the 168s can your brass go until primers fall out? I am on 5 firing now at the 2900 fps. Using Lapua brass

Also someone had mentioned to me pushing the 155s fast(3000 fps or more) recoils the same or more than the mid weight bullets?

**I got a laugh at my first match I ever shot a couple months ago. Showed up and the vets asked me as the ROOKIE what I was shooting and type of rifle. I told them Berger 168 hybrids over Varget and they all laughed and turned their noses up at me. Told me those would not make it to 1000 and that some ranges won't allow 168s to be shot at 1000 yards. Well I ended up beating the guy(veteran shooter) using my 168s ;D

Go above the 3,000 fps mark with 155s and you will likely see a reduction in case and barrel life. You should get a minimum of six firings out of Lapua standard brass with a load that gives a 155 ~3,050 fps. It's affected by other factors though such as the powder used. At five, six, seven firings when you see the accumulated effects of case-head expansion, it's not necessarily the junk brass box - when you feel primers getting that bit easier to seat, transfer those cases to practice / short-range / load development jobs and you might get another half dozen loadings out of them if you use lower pressures.

This is a personal preference issue - I happily run very tight grouping but lower MV short-distance loads, such as switching to Viht N150 under 155s and dropping from >3,000 fps to the low 2,900s. I've often found that this combination will shoot into quarter-MOA or tighter even with well used cases. Others I know work on the principle of get one load for 1,000 and use it all the time. Different loads and performance are distractions to them. Take your pick!

If you're not annealing, after you've loaded your Lapua cases half a dozen times, they're probably going to produce increased elevations at long ranges due to work hardening of the neck / shoulder area. So, that's an issue irrespective of primer pocket tightness.

This is a particular issue with Lapua 'Palma' brass and its small primer / flash-hole case head. These cases are HARD at the back end and have a lot of metal around the primer. They will take loads that will kill a standard Lapua case in two or three firings and keep going on ... and on ... and on. I know people knocking out scary MVs with 210s, 215s, and 230s with these cases and they seem indestructible. So, annealing becomes a key factor - no good having a sound case with a dozen firings if the front ends are all over the place metallurgically.

I now use Palma brass with my long-range 155gn loads. They work really well with small MV spreads and I expect to get a great life out of them, so my future outlays on cases should drop considerably. (BUT .... I now need an annealing machine - shooting expenditures never finish!)

I shoot the 168gn Hybrids in another rifle and have used 1980s era very light Norma brass of which I acquired many hundreds some years back and am still using. They only weigh 160gn and have very thin necks (0.0120" after a clean-up neck turn for some, 0.0125" for most) so they shouldn't perform as well as thicker neck Lapua in a SAAMI chamber due to extra chamber clearance up front - but they shoot very well indeed despite the 'theory & practice' arguments. At 2,925 fps from a 32-inch barrel over VarGet, they give four firings with full loads and go into the use with N150 and 155s at 2,920 category for another two or three matches afterwards. They aren't as strong as Lapua brass or for that matter modern Norma examples.

I ran my current 155.5gn 3,054 fps load v my 168gn Hybrid 2,925 fps load v my old 185gn Juggernaut 2,825 load through the Sierra Infinity 6 'recoil calculator' a proper little program that includes the essential powder charge weight. For an 18lb rifle, straight recoil energy is calculated as:

155.5 ....... 9.2 ft/lb
168 .......... 9.4 ft/lb
185 .......... 10.0 ft/lb

My subjective experience is that I start to notice adverse gun handling effects when I approach a calculated 10 ft/lb level.

FWIW, I've settled on the 155.5 / 3,050 fps combination from a 32-inch barrel that seems to suit my rifle, my shooting style, wind reading skills such as they are etc and use this as the basis for equivalent performance targets to be obtained from other bullet weights. I really believe the 155.5gn Berger BT Fullbore is one of these once-in-a-generation designs that set standards and perform better than the figures say they should. (The 185gn Juggernaut is another - Thank you for both Mr. Litz !!)

Taking it as a base, equivalent MVs on the muzzle energy scale basis are:

168 ........ 2,934
175 ........ 2,875
185 ........ 2,796
190 ........ 2,759
200 ........ 2,689
208 ........ 2,637
210 ........ 2,624
215 ........ 2,594
230 ........ 2,508

So far as barrel wear is concerned, heavier bullets will reduce barrel life even when all other things are equal (peak pressures, flame temperatures etc). This is because their greater inertia sees them move away from the chamber more slowly and so subject the barrel throat area to heat / pressure stresses for a longer period. If / when the bullet weight reaches the point that a slower burning powder has to be used, this exacerbates the situation as it extends the period of peak pressure and heat over a longer stretch of barrel. Of course, many (most?) super-heavy bullet shooters also use high-energy powders, Re17 and N550 mostly, and this reduces barrel life still further when maximum pressure loads are used with uber-heavies.

On the 168s, I get the same incredulity. It is of course because of the Sierra 168gn MatchKing and its many near copies - superb short to medium range performers but not designed for nor ever intended for 1,000 yard shooting at 308 Win velocities. However, it's a bullet form issue, not weight, and there is no reason why a well designed 168 won't perform as well as equivalent 155 or 175 designs that bracket it weight wise. Just use Berger 168s alone for long ranges, that's the easy to remember and apply rule.

 

[Scott Harris]

Laurie,

I think something is wrong with me....I managed to make it through that entire post! In all seriousness, thanks much for sharing all that good info. Quick question. Do you think the small primer brass is a good choice when shooting in cool to cold weather (< 50 F)? We are shooting a match tomorrow that will likely be in the low 40s and I switched to large primer brass as a precaution.
thanks,
Scott

 

[Laurie]

Do you think the small primer brass is a good choice when shooting in cool to cold weather (< 50 F)? We are shooting a match tomorrow that will likely be in the low 40s and I switched to large primer brass as a precaution.

Good question - the answer appears to be 'Yes', and 'No'! Depends on the powder. When we first saw Palma brass, I ran some side by side tests with standard LRP Lapua in 2-3-deg (low to mid 30s F) temperatures. 155gn Scenar + Viht N140, a near standard 'Target Rifle' combination in the UK, was very disappointing with poor groups and large ES. Same bullet + N150 was fine, just the usual MV drop that SRP brass produces with any powder charge weight. I reran the N140 series later in the year at 12 or 13-deg C and the problems had gone. The 185 Juggernaut and N550 was poor too in cold weather.

On the other hand, the US Palma Teams' tests with the prototype brass included putting 155 Palma SMK + VarGet SRP ammo into a freezer overnight and taking it to the range in an insulated bag the next morning. No problems were encountered.

So, my reactions are a bit like yours - ie play safe unless you know the combination will perform. It might be a good idea to take your LRP ammo for the match, but put a few shots of Palma brass rounds down at the end and see what the elevations look like. If low temperatures do affect their performance, it'll likely show up as reduced velocity initially, so you might see an elevation drop on the target at longer ranges compared to your summer scope settings, even if the elevation consistency remains fine.

I actually reckon you're pretty safe in the low 40s - we shoot a lot in this temperature range in our mild winters and they perform fine in it. Low 30s and below may be a different matter.

I still find these cases a bit of a puzzle. When I did side by side tests, one involved 185 or 190gn bullets with Hodgdon H414 ball powder. I was 100% convinced beforehand that standard brass with F210Ms would vastly outperform Palma + CCI-BR4s given everything said about most ball powders, especially a relatively slow burner such as H414/W760. Yes, MVs were down (as normal), but groups and ES values were WAY smaller with the Palma case loads over five charge weight batches covering a couple of grains for each case type. This was in so-so temperatures, neither cold nor warm.

 

[savageshooter86]

just another thing I have been researching to see if it may help me get to the next level with my loads. Lapua Palma brass. Still seeing what the consensus on primers are? CCI 450 or KVB223M is what I am looking at if I make a switch

 

[BCadvantage]

CCI 450 or KVB556M.

 

[Laurie]

I've used CCI-BR4 throughout. This batch is noticeably 'warmer' than CCI-450 SRM or PMC SRM (Russian primers) and doesn't work nearly as well as this pair in my .223 Rem 90gn loads with 24-25gn powder. But being a bit 'hotter', the BR4 seems well suited to 46-47gn charges in .308 Palma loads.

 

[savageshooter86]

same experience with the 168hybrid? With that load and Varget I am close to 45.9gr load(have gone up higher)

 

[Laurie]

same experience with the 168hybrid? With that load and Varget I am close to 45.9gr load(have gone up higher)

I run this combination 0.5gn higher in Norma LRP brass (very similar capacity to Winchester) with the F210M, so it should happily run as high, more likely higher in Lapua SRP Palma cases - in my moderately long-throat chamber anyway

 

[savageshooter86]

anyone care to share thoughts on if IMR 8208 or CFE223 would be better suited powder for the 185 LRBT?

I don't have Quickload on the new laptop as it does not have a CD drive on it and have not bought an external one yet

 

[broncman]

I use Varget and tula primers for 2800 fps. I do use CFE 223 for another 308 I have for practice and plinking. I have noticed that the powder charge spread is smaller than Varget. Varget gives me a wider charge window so I stick with Varget for my comp rifle. Single digit ES and 2800 fps give me the confidence that if I miss...then I missed. Not the rifle or load.

 

[savageshooter86]

CFE and 8208 are all I have. Bought 8# of each