looking to develop a .308 load for 1000 yds. **update and range report**

[snowpro440]

Re: looking to develop a .308 load for 1000 yds.

Yes keep us informed as I am shooting 155 berger vld's now in my .308 and I am thinking of making the switch to something heavier to make the 800 plus yardage with as I'm not getting the velocity that I need.

 

[chkunz]

Re: looking to develop a .308 load for 1000 yds.

One last point on the 168 SMK, they were developed for 300 meter competition and they excelled at that and have been the gold standard for the NMC for many years. It is not fair to knock them for not being applicable for 1000 yards which they are not.

 

[Canadian bushman]

Re: looking to develop a .308 load for 1000 yds.

I am not a pro, but i do have a rifle just like yours. I have shot it in f/tr for about a year. My best 1000yd load to this date is[IMR 4064 44.5grs,win primer,win brass,berger 185bthp, with an oal of 2.525. Can't speak for anyone else, but it shoots great in my rifle. It's my wind reading skills that are in question. Hope this helps.

I also used 185 vld with 43.8 imr 4064 with good accuracy at 1k
This was with a 26" 1:12

 

[Road_Clam]

Re: looking to develop a .308 load for 1000 yds.

One last point on the 168 SMK, they were developed for 300 meter competition and they excelled at that and have been the gold standard for the NMC for many years. It is not fair to knock them for not being applicable for 1000 yards which they are not.

Kind of a bummer about the distance limitations of the 168 smk, my R700 Varmint w/ heavy 26" barrel hands down LOVES that bullet ! I've sucessfully taken the 168's out to 600 yards with excellent consistiancy. I have about 800 of them i've bought here and there cheap on the gun forums But won't try out to 1000 after all the negitive feedback. When I was attempting to decide which bullet and powder combination to attempt my club's 600 yard range qualification I simply went with my most consistiant load (and actually not the best accuracy, but more the best consistiancy). That load was the 168 smk, and 41.7 gr of Win 748. Oddly this combination has some "haters" in the shooting world, many shooters frown on W748 ball powder, but per my data, it's working fantastic for me.

 

[markm87]

Re: looking to develop a .308 load for 1000 yds.

I would not put much worry in staying supersonic. Pick the most accurate bullet you can find and go with it.

There is no real evidence that there is any problems when a bullet goes sub. A lot of people believe it, and I am sure that at least 10 people will say I am wrong - but where are the targets and tests that show it.

I agree with the first part... We shoot 175s out of 20 inch 308s to a thousand all the time. They don't stay super.

But on the second part... When firing 168 Nosler CCs with the different angled boat tail?... I have bullets scatter any and everywhere in a 12 foot circle. They hit transonic and fan out like a mofo.

 

[Road_Clam]

Re: looking to develop a .308 load for 1000 yds.

Just out of curiousity, those of you who have pulled targets at 1000+ ranges what does a bullet sound when it goes subsonic ?

 

[markm87]

Re: looking to develop a .308 load for 1000 yds.

Just out of curiousity, those of you who have pulled targets at 1000+ ranges what does a bullet sound when it goes subsonic ?

That's a good question. I've been wanting to head down range and plop down where the chart shows transonic... and give it a listen.

 

[CatShooter]

Re: looking to develop a .308 load for 1000 yds.

I would not put much worry in staying supersonic. Pick the most accurate bullet you can find and go with it.

There is no real evidence that there is any problems when a bullet goes sub. A lot of people believe it, and I am sure that at least 10 people will say I am wrong - but where are the targets and tests that show it.

I agree with the first part... We shoot 175s out of 20 inch 308s to a thousand all the time. They don't stay super.

But on the second part... When firing 168 Nosler CCs with the different angled boat tail?... I have bullets scatter any and everywhere in a 12 foot circle. They hit transonic and fan out like a mofo.

"Mofo"??? I didn't know that Mofo's scatter on targets

The fact that a Nosler bullet misbehaves, is not proof of anything.

There are people that are shooting at very, very, very, long range - and the bullets are way below the speed of sound when they arrive at the targets - how do they get there (accurately) without going "transonic" (which no one defines).

The transition from above the speed of sound, to below the speed of sound, happens in milliseconds, and tiny fractions of an inch in forward movement... so please explain what is actually happening, instead of speculating...

... cuz the turbulence is ALWAYS behind the bullet, not in front, and it never gets in front.

 

[chkunz]

Re: looking to develop a .308 load for 1000 yds.

When a subsonic bullet goes thru the target in the pits there is almost no aerodynamic sound from the bullet. There is some sound from the bullet penetrating the paper. Sometimes the score is ok from the subsonic bullets but most times they are not flying straight on and things are not well.

 

[chkunz]

Re: looking to develop a .308 load for 1000 yds.

In aeronautics, transonic refers to the condition of flight in which a range of velocities of airflow exist surrounding and flowing past an air vehicle or an aerofoil that are concurrently below, at, and above the speed of sound in the range of Mach 0.8 to 1.0, i.e. 600–768 mph (965–1236 km/h). This condition depends not only on the travel speed of the craft, but also on the temperature of the airflow in the vehicle's local environment. It is formally defined as the range of speeds between the critical Mach number, when some parts of the airflow over an air vehicle or airfoil are supersonic, and a higher speed, typically near Mach 1.2, when the vast majority of the airflow is supersonic. Between these speeds some of the airflow is supersonic, but a significant fraction is not.

Most modern jet powered aircraft are engineered to operate at transonic air speeds. Transonic airspeeds see a rapid increase of drag from about Mach 0.8, and it is the fuel costs of the drag that typically limits the airspeed. Attempts to reduce wave drag can be seen on all high-speed aircraft; most notable is the use of swept wings, but another common form is a wasp-waist fuselage as a side effect of the Whitcomb area rule.

Severe instability can occur at transonic speeds. Shock waves move through the air at the speed of sound. When an object such as an aircraft also moves at the speed of sound, these shock waves build up in front of it to form a single, very large shock wave. During transonic flight, the plane must pass through this large shock wave, as well as contend with the instability caused by air moving faster than sound over parts of the wing and slower in other parts.

Transonic speeds can also occur at the tips of rotor blades of helicopters and aircraft. However, as this puts severe, unequal stresses on the rotor blade, it is avoided and may lead to dangerous accidents if it occurs. It is one of the limiting factors to the size of rotors, and also to the forward speeds of helicopters (as this speed is added to the forward-sweeping (leading) side of the rotor, thus possibly causing localized transonics).

 

[markm87]

Re: looking to develop a .308 load for 1000 yds.

that are shooting at very, very, very, long range - and the bullets are way below the speed of sound when they arrive at the targets - how do they get there (accurately) without going "transonic" (which no one defines).

Could have to do with cross winds...

Here's a snip from an article by Frederick Salberta from this link:

http://riflemansjournal.blogspot.com/2012/02/cartridges-762-nato-long-range-match_04.html

Neither the Army nor the Marine loads were ideal, but in the pre-1995 world that was what was available. In 1995 Sierra developed a new .30 caliber match projectile, the 175 gr. Matchking. This bullet was simply nothing more than an improved version of the old Lake City 174 gr. projectile with a slightly improved ballistic shape resulting in an advertised BC (G1) of .496. One of the features on this bullet was smooth transition from supersonic to subsonic velocity, so that the typical “fan pattern” seen with the 13 degree Sierra 168 gr. boat tails when entering the subsonic realm was largely eliminated if the bullet was fired from a high quality barrel and the side winds were not excessive.

The article is quite lengthy and the issue with the 168's boat tail angle is hit upon several times. It seems to be a widely experienced issue. But no.. I'm not going to be able to scientifically prove this.

 

[js223]

Re: looking to develop a .308 load for 1000 yds.

If you're going to take that class then check your scope elevation adjustments. What I mean is, you will have to start out at just 100yds and they will increase the distance gradually before you get to 1k. Some scopes don't have enough elevation adjustment to cover that much of a change.

 

[barefooter56]

Re: looking to develop a .308 load for 1000 yds.

Road_Clam,
In your class will you be using magazine length rounds or going "single-shot" mode?
Take care,
Phil Hoham
Berger Bullet Tech.

 

[glockaholic]

Re: looking to develop a .308 load for 1000 yds.

I have never heard of an explanation of why the 168 do that. The 155s and 175 don't have that problem. Maybe someone here can educate us?

I don't know Joe but heard Litz say the angle of the boat tail was wrong.

 

[markm87]

Re: looking to develop a .308 load for 1000 yds.

I don't know Joe but heard Litz say the angle of the boat tail was wrong.

Yeah... but what does he know? ;D

 

[rap36case]

Re: looking to develop a .308 load for 1000 yds.

Has anyone else tried the 190 SMK moly for 1000 yards? It seems to shoot more accurately than 175SMK for me.

I have worked up a load for 26" CZ550 308Win with BR2, 4064 42.6gn, WW brass. I use moly coated 190SMK and Smooth Kote. It shoots under 3" at 500yards. I tried it the other day 38F, rainy, 10 to 25mph in my face. The wind did not move it much.

I am eager to try it at a 1000 yards, when they get the berms and tables up in Greenville.

 

[ballison]

Re: looking to develop a .308 load for 1000 yds.

My first consideration is choosing a bullet, then developing a load to stay supersonic to 1000.
Rich K.

I would not put much worry in staying supersonic. Pick the most accurate bullet you can find and go with it.

There is no real evidence that there is any problems when a bullet goes sub. A lot of people believe it, and I am sure that at least 10 people will say I am wrong - but where are the targets and tests that show it.

When a bullet slows to ~1085 fps, and below, nothing happens to it that has any effect on accuracy. All the "Turbulence" is behind the bullet, not in front, so there is nothing to go through.... and there are guys shooting 30 cals at twice+ that distance, with no problems.

Catshooter,

At the risk of sounding smug, I have a degree in Aerospace Engineering, and if you think that all the "turbulence" is behind the bullet, then I recommend taking an aerodynamics course. I think there have been enough people abandoning the 168 SMK's at 1000 yards to eliminate them from consideration. Also, Berger and Brian Litz have spent a lot of time and money developing bullets that handle the transition from supersonic to subsonic (i.e. transonic) that there has to be something to it.

The pic is of a bullet that went subsonic. I was working the pits at this year's regional in Bridgeville, DE, and it was on the target beside me.

 

[RDavies]

Re: looking to develop a .308 load for 1000 yds.

In addition to the solid advice already given above, I will only add that you might take a look at the Berger 168 Hybrid. It's compatible with your 12-twist barrel and can be driven relatively hard due to the short bearing surface. For its weight, it has a very high BC (0.266 G7). I am shooting pointed 168 Hybrids out of a 27" barreled rifle using 43.0 gr H4895 seated at .015" off the lands. This is a fairly mild load, giving 2820 fps and very good accuracy. Using .308 Palma brass, I could easily be pushing these over 2900 fps with H4895.

Your barrel length and twist rate are going to be the limiting factors for you as you start, so bullet/powder selection will be critical at this point to get the most from your setup.

My thoughts exactly. I have used 168 Hybrids in 2 different barrels, one a 12", the other a 13" twist. Currently they are my favourite in my Rem 700, slightly less recoil than with 185s might be the reason this light weight rifle prefers them? These Berger 168 Hybrids are a very very different bullet to the Sierra 168s and do not have the same problems with losing stability in the transonic zone. Not that the transonic zone is a problem with these 168s. They have the same or higher BC than the 175 sierras and can be driven nearly as fast as the 155s. They will also be stable even in cold weather at sea level in a 12" twist.
The 185 Juggernaughts seem to be the most popular bullet out there for 12" twist barrels at 1000yds, but if for some reason they don't work in your barrels, then the 168s are at least worth a try.
As for 308 bullets being shot into the transonic zone, the Match rifle shooters will be the ones to talk to about this, but I have done some shooting out to over 2000yds. My 180gn 7mm hybrids stayed accurate all the way out, as did a friends 308 shooting Berger 210 VLDs.

 

[savageshooter86]

Re: looking to develop a .308 load for 1000 yds.

Yep 168 hybrids will do well at 1000.

Got laughed at my first match when I told them what bullet(168 hybrids) but then they weren't laughing when I beat them. They made it with ease to 1000

 

[barefooter56]

Re: looking to develop a .308 load for 1000 yds.

Guys,
The 168 grain Sierra was initially designed for 300 meter target shooting and is excellent at that range. Even out to 6-800 yards it does a good job. The Berger 168 grain, hybrids and VLD bullets with the proper load will get out to 1000yds with no problem as other shooters in this string have stated. So if you want more BC than a 155 grain bullet but don't like the recoil of a 175, 190, 210,215 grain Berger or Sierra bullet its the right choice. Heavy bullets are great but some shooters find they shoot better with a lot less recoil fatigue and battering because they stay more focused on the target and conditions instead of thinking about getting whopped on the next shot. You may want to test it for yourself to see.
Take care,
Phil Hoham
Berger Bullet Tech