Selecting a bullet shape and weight for 100 thru 1000 yards

[paulbradley]

What an excellent piece Laurie!

[Ballistix]

Goodness me. That is the most comprehensive post on any forum I have ever seen. What an insight.

Thank you very much for sharing the results of what must be tens of thousands of rounds down range over the years!

You asked what rifle mine was and it is a Steyr SSG 04A1 .308. 24" 1:12 twist heavy barrel.

So to conclude if I have understood correctly:

190g = Good as it copes well in transonic flight but will shorten barrel life
180g = steer clear of for 800 to 1000yards
175g Berger Tactical OTM = Very good. Copes well going subsonic but expensive and hard to source
175g Sierra MK = ok but groups affected by wind due to low velocity at target
168g = most bullets steer clear of for 800 to 1000yards
155.5g Berger Boat tail = Very very good, better than Sierra MK but expensive and hard to source
155g Sierra MK #2155 = Very good
155g Sierra Palma #2156 = Very good. Better BC as it is a longer bullet than the old Sierra MK
155g Lapua Scenar = Good but......?


On balance the Sierra Palma 155g #2156 bullet seems probably best for budget, sourcing ability, my barrel life, accuracy from 100 up to 1000yards on my setup with the money I can tolerate spending on heads.

sign92

[Laurie]

If your barrel likes the 'new' Sierra 155 Palma MK (#2156) that'd be an excellent choice. It doesn't seem to suit all barrels though, but it's well worth a try. Whilst the older (2155) model has a lower BC, it's supremely tolerant of barrels and chamber throats so is usually very easy to tune.

It's the 190gn SMK with Viht N550 that burns barrels, the combination of a relatively heavy bullet and the high-energy powder. With a 24-inch barrel, N550 does the business in getting you maximum velocity out of this weight of bullet, but there's always a price to pay in the ballistics game. Viht N150 often gives very respectable velocities and good results with bullets around this weight in .308 and is a lower MV but kinder to your barrel alternative. (I'm a fan of N150 in the cartridge and have used it for years even with 155s for shorter distance loads, but it is a good choice for 175-200gn bullets.)

[User702]

I'd agree that the 2156 is a good starting point and it's what I'm using currently to try and develop a load for 1000 yards, given the trade-off between ballistic performance and cost. I do note though that the lower ballistic performance of the 2156 does mean that it is likely to start going trans/subsonic before 1000 yards, whereas bullets with higher BCs in the 155grn range (Berger 155.5 VLDs, Lapua Scenar, Dyer HBCs) remain supersonic with as low as 2800 fps or so muzzle velocities (according to JBM).

However, I'm still going to try and get a workable 1000 yard round with the 2156c for my Remington before I try something heavier.

[Steve E]

I'd agree that the 2156 is a good starting point and it's what I'm using currently to try and develop a load for 1000 yards, given the trade-off between ballistic performance and cost. I do note though that the lower ballistic performance of the 2156 does mean that it is likely to start going trans/subsonic before 1000 yards, whereas bullets with higher BCs in the 155grn range (Berger 155.5 VLDs, Lapua Scenar, Dyer HBCs) remain supersonic with as low as 2800 fps or so muzzle velocities (according to JBM).

However, I'm still going to try and get a workable 1000 yard round with the 2156c for my Remington before I try something heavier.

What do you mean by try to get a2156 to work at 1000yds, it's the most common bullet used in Palma and Long range TR. It will stay supersonic beyond 1000yds and I use it effectively at 1200. Sierra give them to international Palma Teams.

[User702]

Sorry, it's just that I am using a rifle with a 26" barrel and the data I have from the loads I have developed (and the JBM ballistics calculator) suggest that the bullets will be just below mach 1 at 1000 yards.

I need, therefore, to either push them faster or choose either a heavier bullet or one that has a higher BC.

[Maggot]

Hmmm....

My rifle likes 2156 as well at 1000. I have shot both berger 155.5 and 155 Hybrid and the Hybrid nudged it....right until I found the Dyer HBC.

in "MY" F/TR rifle they seem to shoot admirably with the odd cockup (traceable to the muppet behind the trigger)

Smashing little bullet that is actually available and does not look like its meplat has been formed with an angle grinder!!

Some of the rejects and debris I have found in berger boxews

Dont discount the HBC, unscientific I know but in the right rifle I reckon it's one to watch.