Selecting a bullet shape and weight for 100 thru 1000 yards

[Ballistix]

Hi.

I wondered if folks decided on one bullet type to reload with for use at all ranges up to 1000 yards for their rifle. It would make it easier to experiment with loads/ seating depth/ die setup and creating less drop charts.

For example I was thinking of choosing .308 155g sierra mk and maybe one more to compare groups like the Amax 155g for use from 100 and all integers up to 1000 before settling on the one that worked best in my particular set up.

My barrel is 24" with 1:12 twist which I managed to get some 155 smk on the target with at 1100 yards recently.

Thoughts?

sign92

[ovenpaa]

The SMK #2156 and Lapua Scenar would be at the top of my list however availability might be an issue, so whatever you choose make sure you always have around 3 months worth as stock.

There are concerns that the boat tailed bullets have not stabilised fully by the time they get to 100 yards however I have never experienced stability problems with a 1:12 24" barrel and the usual 155 grain bullets available.

[mag41uk]

I shoot the 155gn scenars out of my humble Schmidt Rubin to 900 yards reasonably well.
A few of my buddies use the same in a variety of 308`s and love them.
I buy them in 1000 boxes and share them out!
If you can find some at a good price you wont go far wrong.
If you want some to try I could sort you out with a 100.
I might have some smk`s too.
HTH
Tony

[Ballistix]

Great thanks a lot.

Have just ordered some scenar 155s for my 308.

I presume Lapua Scenar and Sierra MK are the choice for .223 26" barrel 1:9 twist up to 600yards too? I was thinking 69grain.

sign92

[Ballistix]

I shoot the 155gn scenars out of my humble Schmidt Rubin to 900 yards reasonably well.
A few of my buddies use the same in a variety of 308`s and love them.
I buy them in 1000 boxes and share them out!
If you can find some at a good price you wont go far wrong.
If you want some to try I could sort you out with a 100.
I might have some smk`s too.
HTH
Tony

Great thanks for the feedback on the scenars.

And thanks for the offer. I have 100 SMK's in 168g so will look to put them in the swap section I guess.

All the best

[toffe wrapper]

For 308 I use 155 SMK 2156c out of a 26inch barrel
For 223 I use 69 SMK 1380 out of a 20inch 1:9 barrel.

TW

[DaveB]

I have never been a fan of Lapua, but I have used Sierra Matchkings for years. My organisation has precision ammunition specially loaded for it by GD-OTS (General Dynamics - Ordnance and Tactical Systems) in Canada using 175 gr SMKs exclusively.

If you are looking for more exotic alternatives, I can't speak to their availability in the UK, but I have had very good results with Berger and JLK bullets out of the US.

JLK make a .308-155 Palma with a .467 BC (#30155) that has been very successful. Unfortunately most of their .224 bullets are too long for my magazine, but I used to single-load them in my Savage 110 FP. You never mentioned what sort of rifle you have. You might be able to use their 75 gr VLD bullet, but the 80 gr are a bit long for 1-in-9 twist, unless you load them up past normal pressures (using cases with heavy, crimped-in primers intended for machine guns). That's what I used to do.


Berger makes a .224 70 grain VLD bullet with a .371 BC (#22418) that works very well in 1-in-9 twist barrels.

For .308 they have three different choices in 155 grain:
- 155 Gr Match Target BC .439 (#3048)
- 155 gr Match Hybrid Target BC .483 (#3426)
- 155Match Fullbore Target BC .464 (#30416)

[Laurie]

JLKs were briefly available here over the last 18 months or so imported by Brian Fox. Before that, it was some years back in the pre Swampworks ownership era of the JLK facilities by Norman Clark in Rugby long before Norman took Bergers on board.

JLK since the Swampworks takeover only lists VLD form bullets bar one model, the 0.224-inch 77gn CO (conventional ogive) for use in magazine fed AR types for Service Rifle shooters. However, the product range is pretty immaterial right now, and almost certainly into the medium to foreseeable future, for two reaons. One, like other US bullet making companies, Swampworks is overwhelmed by demand and they weren't very good at keeping to delivery schedules before the great US components panic buying spree started; two: Brian says when his present stocks have gone he won't order any more. This is partly down to his health and the amount of hassle and work in exporting ammunition components from the USA, but also and equally pertinent, 'Swampy' insists on payment up front with the order, but won't say when the bullets will be made and delivered. As it was Brian never received the 180gn 7mm VLDs he desperately wanted to meet a large known demand from GB F/O shooters.

So far as the 'ideal' bullet is concerned for 1,000 from a 24-inch barrel 308, it has to be one that has a reputation for stability in transonic flight as you will be running in this zone for the last 150 yards or so with this set-up, irrespective of bullet choice. Preferably it should be one that'll cope with passing through the sound barrier too into subsonic flight, as there's a better than 50/50 chance of that happening with the velocities that a 24-inch barrel will safely deliver with this cartridge.

To list the 'don't use beyond 800 yards' brigade first, that's:

168gn Sierra MK
180gn Sierra MK
All Hornady A-Max bullets except for the 208gn version. (The new HPBT Match models are all OK except for the ancient 168gn model - but they're not available as Hornady Manufacturing has 'temporarily suspended production' thanks to the aforementioned panic buying episode with no date being quoted for their reintroduction.)
168gn Hornady HPBTM
168gn Speer GM
168gn Nosler CC

The problem with all of these designs is a short sharp angle boat-tail section with a double-digit degree angle, The ideal LR bullet design runs in the 7-9-deg range. Go too high and the airflow delaminates around the rear of the bullet causing turbulence, severe drag and a serious risk of the bullet becoming unstable. That's not to say these are poor designs, just poor for long range. The 168gn Sierra MK and its several copies remains one of the best choices for .308 Win for 200-600 yard competition use, although at the high end of that range, their BCs are poor by modern bullet standards so that you may lose out to a higher BC design in a rough day wind-wise.

So for LR shooting with a short-barrel rifle, what do you use? The original 155gn SMK (#2155) is probably still the outstanding design of those that are affordable and available. Its newer sibling which has taken the 'Palma' title over (#2156) is higher BC, and as it's widely used by US Palma and Fullbore sling shooters must be pretty good too at the very least in this respect as many of them are using MVs in the 2,950 fps range which is barely sufficient to ensure remaining supersonic at 1K in all conditions.

The 155.5gn Berger BT Fullbore is an outstanding design, better than the Sierras, but very much more expensive, and only fitfully available. The best choices here are likely to be the 175gn and 185gn Berger LR BT models, high BC and very stable under adverse conditions. Expensive though. The 175 isn't very well known here and so is actually in stock at importers Hannams and (likely) Norman Clark; the 185gn BT 'Juggernaut' is so prized that the occasional shipment that actually turns up goes within days.

Berger Bullets makes an ideal model for people with short-barrel rifles, the 175gn Tactical OTM, which is a bullet designed to be loaded at 2.800-2.850 for magazine operation, is high BC for a design of that type and which, here's the icing on the cake, has been designed to remain 100% stable and behave consistently through subsonic flight / the sound barrier when fired at ~2,600-2,650 fps in a 1-11.25" rifling twist barrel (the recently adopted standard twist rate for all US marksmen and sniper models). Work out what RPM that combination produces and then redo it to get an equivalent MV for 1 in 12-inches. It's around 2,775 fps is I remember aright, which is doable for a 24-inch barrel with some careful powder selection. It though, is even more expensive, than most other Berger thirties and wasn't in stock the last time I asked at either Berger importer.

The 175gn Berger Tactical OTM was designed to outperform the current benchmark in the US sniper military procurement lineup, the 175gn Sierra MK used in the 7.62mm M118LR round, an excellent design, and which remains stable under transonic conditions with a reasonable but not great G7 BC of 0.243. It's available and cheaper than the Bergers though. As with most bullets, it does become a lot flightier under transonic conditions.

Here's a quote from a series of articles in German Salazar's Rifleman's Journal blog on the modern history of US military long-range ammunition, primarily .30-06 and 7.62mm sniper / match rounds:

Although not well understood by many, at around 100 fps above the speed of sound, there is sufficient turbulence that some bullet designs have their subsonic accuracy seriously compromised when they fall to below this speed. Many well designed bullets fired from an appropriate twist barrel will have minimal transonic perturbations, though there is generally some degradation associated with making the transition from the sonic to subsonic region. Through many years of testing, the US Army has decided that the threshold above which this effect can be ignored is 1226 fps in standard atmosphere conditions. Ideally any load will be above this speed at the terminal target distance.

A 24-inch barrel gives the 175gn SMK 2,650-2,750 depending on powder. Using its Litz measured G7 BC of 0.243, 2,750 fps sees te 175gn SMK drop through this velocity at 960 yards in 'standard ballistic conditions' when its MV is at the higher figure. It'll hit the target OK and make round holes, the problem is - and this applies to even the better suited designs at these velocities - is that every wind change moves it a lot more than a suitable LR bullet that's going faster. Group dispersion increases substantially too. Not just theory, been there done that in a season of national league F/TR with a 24-inch 1-12" barrel rifle, and learned what works at 900 yards but not 1,000 the hard way.

Other suggestions? The 190gn Sierra MK with its exceptionally long tail section is noted for its transonic stability - it was a favourite of the 1,200 yard MR competitors until the modern high BC LR designs appeared. And yes, it will work happily in 1-12 inch twist despite what most people believe. Stuff a Lapua case with Viht N550 and get as much velocity as the rifle safely allows - only don't expect a long and happy barrel life!

VLDs which include the 155gn Scenar? Personally, I'd say avoid for 1,000 yards in a short-barrel rifle. All the evidence gained over the years suggests the VLD form offer benefits while the bullet is comfortably supersonic, but they perform less well than a really good 'conventional ogive' design like the 155.5gn Berger BT and 155gn Sierras as you approach the speed of sound.

[ovenpaa]

A superb write up as ever Laurie.

I can confirm the 190 SMK's through a 1:12 24" work incredibly well beyond 1000 with a reasonable load behind them. I watched some cracking shooting from an AI/AE at 1200 yards one summers afternoon using exactly this combination and the shooter kept everything nicely in the middle.

[meles meles]

Mag41UK: How do the 155 gn Scenars compare with standard GP11 rounds at long range in the K31 ?