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.308 @ 1k F-TR

I'm sure this has been beat to death, but... 30'' barrel, 1 in 12'' twist. Short throat- 2.770 with 175smk. I've shot 3 palma matches( f-tr) and the rifle shoots very well at the 800 and 900 yd distances, but groups grow considerably at 1000. I tried 190smk, knowing the 1 in 12 was to slow, with speeds of 2650. Sierra balistic chart shows I'm still above speed of sound at 1K, but not by much. Maybe going thru a change period. So I swiched to 175smk, 2775fps, and my groups actually got bigger! confused now. Should I push these bullets any faster? very limited in c.o.a.l. tho. 1 in 12'' twist is more for the 168smk, but I've heard " friends don't let friends shoot 168s at 1000 yards" Maybe I just have a tomatoe stake? Any help is greatly appreciated. :o
 
Try any of the popular 155's, Lapua 155 HPBT, Berger 155.5BT Fullbore, Sierra palma MK. They make the trip to 1000 and beyond very regularly.
 
If you want to stay w/ one bullet all the way out, then Berger 155.5 or lapua 155 Scenar at 3000 ish is the easiest way to fly. If you want to try heavier, the Berger 185 BT works very well at distance, and will shoot just fine out of your 1-12".
 
I just ordered 4 boxes of the new Berger 168g Hybrid bullets. They have a G7 of 0.266 which exceeds the best available 175g bullets! You should be able to get muzzle velocities in the high 2800's with a 30" barrel.

Maybe friends don't let friends shoot 168g bullets becasue they don't want you to find out about the new Berger hybrids!
 
If you have a barrel with a short throat, why not use bullets with a short bearing surface - Berger 155.5BT Fullbore or Sierra 155MK Palma (new 2156 model). Problem solved.
 
memilanuk said:
If you have a barrel with a short throat, why not use bullets with a short bearing surface - Berger 155.5BT Fullbore or Sierra 155MK Palma (new 2156 model). Problem solved.

Monte's suggestion is the right one for the barrel as it is. You could also have the throat moved out some to suit the bullets you want to shoot. I have a 10" twist barrel with a .281" freebore for Berger 210 LR.
 
Thanks guys for the input. Seems 155's may be the way to go, but I was hoping to use something with a higher BC. but obviosly all the Palma shooters are useing the 155.s now and coping with the wind quite well
 
The people who've warned you off 168s really are your friends, at least so far as the Sierra MK model and those that are fairly close copies - the Hornady BTHP Match, Speer Gold Match, and Nosler Custom Competition - are concerned. They are superb short-range performers, but not only have relatively low BCs, are fundamentally unsuited for very long-distance use thanks to an over-steep boattail angle of around 13-degrees. The ideal angle is 7-9 degrees for long range bullets and going into double figures risks the airflow separating from the boat-tail walls and causing turbulence at transonic velocities leading to both a rapid loss of speed and instability. This also applies to the 180gn Sierra MK and to a lesser extent to all .30 cal Hornady A-Max models, the superb 208gn excepted. With .308 Win 168gn / 180gn bullet MVs, instability kicks in around the 900yd mark.

Berger's 168s are a very different matter and are all designed from the off as long-range bullets (unlike the others, the SMK launched 50 years ago as the 168gn International for 300 metre shooting - a role it was and still is superb in).

I agree with the advice given here by others, but you only hint at the shooting you're doing and that affects your choice. If you're sling shooting in a true Palma match run according to international Palma Federation rules, you're limited to .223 Rem / no bullet weight limitation or .308 Win loaded with a bullet of "less than 156gn weight" (hence the apparently strange choice of 155.5gn by Berger looking to squeeze the last ounce of performance out of the envelope). If run under local / US 'any bullet weight rules', you can load what you like and many shooters opt for heavier, higher BC models to reduce the effects of wind changes.

There are two potential downsides to this practice - the heavier the bullet, the heavier the recoil. The 175gn Berger BT Long-Range is a popular 'any bullet weight' choice as it gives substantially reduced wind drift compared to the 155s, but tolerable recoil in a 13lb sling gun. The 185gn Berger BT Long-Range is superb ballistically in .308W, but many shooters find the recoil too heavy with it.

The other argument against the heavies in this context is getting practice in wind reading. If you are going to shoot a lot of 'Palma Rules' matches, you may benefit from using the Palma bullets throughout to gain the experience and wind reading judgment with the 155s and avoid having to mentally switch between coping with two sets of bullet behaviour at long ranges.

If you're going to shoot F/TR, you go for the best ballistic and grouping combination that your rifle and bullet can deliver. Many F/TR competitors stick with the 155s because they do tend to group very consistently, but others have gone for 185s, and the 210gn VLDs. Some use both deciding which ammunition they'll shoot according to the conditions on the day. See the table below of 1,000yd wind drift in a 10mph true crosswind for a range of bullets at equivalent MVs (same muzzle energy).

The point behind all this is that as you've already discovered in your three-distance matches is that .308 Win is a very good 800yd cartridge but a marginal 1,000yd performer unless everything is optimised for this range - a bullet that groups well, has a suitably high BC and is shot at the highest velocity you can squeeze out of your rifle safely and consistent with good accuracy.

Incidentally, you are rather pessimistic in your belief as to what 1-12" twist will stabilise. The 190gn Sierra MK is a short bullet for its weight and this rifling twist works fine in all reasonable temperature and atmospheric conditions. You can also happily stabilise the 185gn Berger BT L-R, but the new 185gn Hybrid is a longer bullet and is marginal for this twist rate, really needing 1-11".

155gn (original Sierra Palma MK #2155) 3,000 fps 106.8" drift
155.5gn Berger 3,000 fps 91.1"
168gn Berger Hybrid 2,886 fps 82.0"
175gn Sierra MK 2,828 fps 97.1"
175gn Berger BT L-R 2,828 fps 85.8"
185gn Berger BT L-R 2,750 fps 81.4"
190gn Sierra MK 2,714 fps 90.0"
200gn Sierra MK 2,645 fps 86.0"
210gn Sierra MK 2,581 fps 77.5"


The other thing you are looking for is a retained velocity at 1,000yd that is not only still supersonic, but is as far above the speed of sound (1,122 fps under standard weather and pressure conditions) as possible to avoid transonic turbulence effects. The best of the 155s at 3,000 fps MV are running around 1,300 fps at this distance, the 185gn Berger at the equivalent 2,750 fps MV has another very useful 50 fps or so velocity. Your 175 and 190gn Sierra combinations are predicted to be travelling at 1,191 and 1,226 fps respectively under standard conditions, the 175gn value getting decidedly 'iffy' as strange things can happen as you approach the speed ofr sound under some conditions.

The worst pickle to be in is some bullets being supersonic and some subsonic as they approach the target and that's possibly what you were getting with your 175gn Sierra MK load. This bullet is VERY susceptible to this issue (been there, got that T shirt!); conversely, the 190gn SMK is famous for its transonic and subsonic stability, why it was long a favourite with British Commonwealth Match Rifle shooters who shoot .308W at 1,000-1.200 yards.

All data in the table is based on G7 BCs from Bryan Litz's book Applied Ballistics for Long Range Shooting 2nd ed and the PC ballistics program supplied with it. Using the G1 BC figures and tables / programs supplied by the bullet companies other than Berger Bullets are OK for shorter distances (up to 600yd), but can be seriously misleading (over-optimistic) for .308W at 1,000yd. Berger Bullets quotes both G1 and G7 BC for its longer range bullets on its website and also has a little free ballistics program that runs G7s for download.

Laurie,
York, England
 
Lynum Up said:
Thanks guys for the input. Seems 155's may be the way to go, but I was hoping to use something with a higher BC. but obviosly all the Palma shooters are useing the 155.s now and coping with the wind quite well

Don't get tied up w/ thinking that heavier bullets have a better BC- some do and some don't. The 175 smk and 155 scenar are about the same, but the scenar can be made to go 250 fps faster. This is only an example, but you get the idea.
 
It is also worth noting for future reference that tighter twists will often shoot lighter bullets very well while offering more flexibility. The conventional wisdom is that twist must be nearly marginal for a given bullet to shoot optimally. I have a 10" twist, .308 tactical rifle that shoots Berger 155.5 FULLBORE so well that I won 1000 yard F/TR matches with it. While I did not like the wind sensitivity compared to the Berger 210 BT-LR, the accuracy and vertical were outstanding.
 
Just a thought, you could try the 155 hybrid bullet from Berger. It has the same BC as the 175SMK (about 4% better than the Laupua Scenar, or 3% better that the 155.5 Fullbore Berger), but you can launch it at 2950-3000 fps easily with a 30" barrel. You'll have downright wonderful ballistics and a one-size-fits-all load that is manageable for 300 and stout enough for 1000 yards.

Please remember that the target gets significantly (effectively) smaller from 800-1000 yards. The 10 ring shrinks from 1.2 MOA to .96 MOA on an F-class target.

In the end, you'll have to find what your rifle likes.

Good luck!
 
Lynum Up said:
I'm sure this has been beat to death, but... 30'' barrel, 1 in 12'' twist. Short throat- 2.770 with 175smk. I've shot 3 palma matches( f-tr) and the rifle shoots very well at the 800 and 900 yd distances, but groups grow considerably at 1000. I tried 190smk, knowing the 1 in 12 was to slow, with speeds of 2650. Sierra balistic chart shows I'm still above speed of sound at 1K, but not by much. Maybe going thru a change period. So I swiched to 175smk, 2775fps, and my groups actually got bigger! confused now. Should I push these bullets any faster? very limited in c.o.a.l. tho. 1 in 12'' twist is more for the 168smk, but I've heard " friends don't let friends shoot 168s at 1000 yards" Maybe I just have a tomatoe stake? Any help is greatly appreciated. :o

Allow me to look at this from another angle. Busdriver already touched on this topic and I want to go into it a little deeper.

What do you mean groups grow considerably at 1,000 yards? In relation to what?

If you are holding 10 ring vertical at 800 and 900, at 1,000 you will suffer! That has nothing to do with the bullet, but in the fact that at 800 yards you are shooting at the same size target that you are at 1,000, but 200 yards closer, big advantage!

For 800 yards all you need is a 1.25 MOA gun, but at 1,000 yards you need a 1 MOA gun, and the bullet has to deal with 200 more yards of conditions.

Another thing with the Palma course is that since we shoot at the same target closer when shooting at 800 and 900 yards, and when you get back to 1,000 it is much harder, or at least it seems that way, and many people struggle with that.

It might just come down to going back and work on your load some more, if that does not work, then change bullets.
 
Erik Cortina said:
Another thing with the Palma course is that since we shoot at the same target closer when shooting at 800 and 900 yards, and when you get back to 1,000 it is much harder, or at least it seems that way, and many people struggle with that.

Erik,

I am not convinced that a shooter who does well at 800 and 900 would not do well at 1000. You make it sound like someone could be shooting national record pace and then completely and embarrassingly blow it at 1000. Do you have an example? :)
 
Yes I do! And when I was in the pits watching your target, it hurt me more than it hurt you probably when I saw your national record slip away from you! All because of the 1,000 yard line!
 
I do some F-T/R shooting and have seen exactly what Erik refers to on many occasions with both F-T/R and Open shooters when people move back to 1000 yards from shorter distances. I also agree with his point about loads and accuracy. I have used a borrowed F-T/R rifle on a number of occasions and it shoots as well as my open guns do except for the wind drift. The owner is an excellent craftsman and is diligent with his preparation and load development; and the results show well compared to most others.
 
Laurie said:
....
155gn (original Sierra Palma MK #2155) 3,000 fps 106.8" drift
155.5gn Berger 3,000 fps 91.1"
168gn Berger Hybrid 2,886 fps 82.0"
175gn Sierra MK 2,828 fps 97.1"
175gn Berger BT L-R 2,828 fps 85.8"
185gn Berger BT L-R 2,750 fps 81.4"
190gn Sierra MK 2,714 fps 90.0"
200gn Sierra MK 2,645 fps 86.0"
210gn Sierra MK 2,581 fps 77.5"
...
Laurie,

Great info.

Have the velocities quoted above been attained in your rifles?

I ask this question because the conventional velocity for the 190 Sierra MK with IMR4064 is less than 2600fps but you are getting over 100fps more. The wind drifts for the heavier bullets are impressive but are those velocities safely attainable?
 
steve_podleski said:
I ask this question because the conventional velocity for the 190 Sierra MK with IMR4064 is less than 2600fps but you are getting over 100fps more. The wind drifts for the heavier bullets are impressive but are those velocities safely attainable?

My 26" Pierce is obtaining 2990 with Berger 155.5 and 8208XBR. My 30" Savage is getting 2620 with Berger 210 BT-LR and RL17. Both are at safe pressures and have been fired at ~100°F.

I will attest to just how good the Berger 210 is at long range. No other bullet I have fired in F-TR competition has performed as well in the wind. On several occasions, I have shot as well or better than the F-Open guys.
 
As to the 800/900 vs 1000 subject... early on one of (then) top prone shooters in the region told me at a match: "8 & 9 are just fore play. 1000 is where you get screwed!" (verbiage changed to protect delicate ears) ::)

Steve (Podleski),

In recent tinkering, I got 2700fps from B185LRBT/RE17 with *zero* pressure signs from a factory 30" barrel (Obermeyer chamber w/ ~1000rd thru it). Actually, I got up over 2800 with minimal pressure signs, but accuracy sucked. The 2700fps load looked good @ 100/300 (1/4 moa vert) but shotgunned (1MOA +) @ 600... so back to the drawing board. It may get another chance, just to make sure the problem wasn't between the Peltors... ???

Other F/TR shooters are getting those velocities using Varget/RE15 as well.

Depending on the range and/or day... even 155(.5)s can give the Open guys a run for their money. Not a bet that I would take, but I've seen it happen. ;)

Monte
 
memilanuk said:
As to the 800/900 vs 1000 subject... early on one of (then) top prone shooters in the region told me at a match: "8 & 9 are just fore play. 1000 is where you get screwed!" (verbiage changed to protect delicate ears) ::)

I heard that one recently as well... funny - because it's true!

Try Varget with your 185's. I can get 2650 comfortably with a 26" barrel. With 30" I think you can make the next node up. Better yet, get a barrel with a little more twist (11) and and a lot more freebore to go to the 208/210 class of bullet.
 

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