The comment often comes up that certain reloading techniques or tolerances are good enough for short range BR but not for long range. The subjects concerned could be powder weighing/throwing, bullet sorting, case preparation, etc. I would like to understand why this is so (if it is). One comment that I can identify with relates to the 'forgiveness' of the 6 PPC caliber used almost exclusively at short range BR. Does this mean that there are no forgiving calibers used for long range shooting? Logically any amount of variation in ammo has the same relative importance at any range. It is obvious that greater distance relates to greater dispersion in absolute terms but how does this make the short range dispersion negligable?
Loading for short range versus long range
- Thread starter Tozguy
- Start date
they both require loads that are as near to uniform as possible.....lots of folks who have never competed in a short range event are critical of their load methods....and lots of folks who have never competed in a long range event are critical of their load methods......short range events usually require more shots per day (usually 10 targets per day) so loading at the range is necessary....while on the other hand long range events consume fewer ctgs per day allowing loading at home or evenings during events......either way is very complex and involves its own set of complexities....Roger
Terry
Gold $$ Contributor
One aspect of long range shooting is the standard deviation in the velocity. A difference in velocity at 600 or 1,000 yards can increase group size by several inches. We measure powder to the kernel, Weigh and measure bullets in several ways, all to get consistency at a very long range. Anything that can change the velocity of each bullet is a factor.
I'm sure you will hear from others. I look forward to learning from them.
I'm sure you will hear from others. I look forward to learning from them.
I do the same thing whether it is short range or long range, consistancy is paramount. Short range for me is 300 yards, long is 1000 yards. Each time I go to a match, I will usually burn about 75-80 rounds a day.
Terry said:
Everything you do is to control verticale dispersion.
There are three big differences between short-range and long-range shooting that affect the choice of calibre and bullets, and loading techniques / precision:
1. Long-range requires more ballistically muscular cartridges. ie heavier and higher BC bullets at high velocities, to reduce wind drift and to remain supersonic, better still with terminal velocities above 1.3 Mach to keep them out of the transsonic turbulence zone.
So, 6PPC at 100/200yd with 66-68gn relatively low BC flat-base bullets at 3,300-3,400 fps using 28.5-30gn powder. 1,000yd BR / F Class etc: 175/180gn 7mm bullets (or equivalent in 6.5mm or .30-cal) at 3,000-3,100 fps from short magnums or .284 Win 50-60+gn powder. BR guns use short but very fat and stiff barrels. Long-range guns (Heavy Gun BR excepted) use long but slimmer barrels to both get the desired MVs and to stay within allowed rifle weights (17lb Light Gun BR; 22lb F Class)
Large cartridges generate greater stresses and more heat on the barrel, stock, action and shooter and make consistency of cartridge behaviour in the chamber / barrel even more important than in short-range shooting as any pressure build-up changes may affect barrel and action vibrations more.
2. A cartridge and load with a fairly large MV spread can still produce tiny groups at up to 200yd. Go beyond 600yd and velocity spreads increasingly translate into vertically strung shots. Have a big enough spread and the shooter won't hold the Bull even if everything else including the shooter's reading of the wind is perfect. Case physical features that affect neck tension etc and charge weights need to be very good indeed, as well as having a load worked up that really suits the rifle and naturally gives small MV ES values.
3. Bullet features, design and quality affect long-range results heavily. (They also affect the short-range BR competitor vitally too, but maybe with the emphasis on different characteristics and attributes, ie high BC is much less important at short ranges.)
None of this is to say that the pinnacle of either type of shooting is easier or more difficult than the other. They both require very good handloading and case preparation practices, skilled load development and so on. many things are constants, but you'll see few (if any) top notch long-range shooters pour powder thrown straight from a measure into the case.
1. Long-range requires more ballistically muscular cartridges. ie heavier and higher BC bullets at high velocities, to reduce wind drift and to remain supersonic, better still with terminal velocities above 1.3 Mach to keep them out of the transsonic turbulence zone.
So, 6PPC at 100/200yd with 66-68gn relatively low BC flat-base bullets at 3,300-3,400 fps using 28.5-30gn powder. 1,000yd BR / F Class etc: 175/180gn 7mm bullets (or equivalent in 6.5mm or .30-cal) at 3,000-3,100 fps from short magnums or .284 Win 50-60+gn powder. BR guns use short but very fat and stiff barrels. Long-range guns (Heavy Gun BR excepted) use long but slimmer barrels to both get the desired MVs and to stay within allowed rifle weights (17lb Light Gun BR; 22lb F Class)
Large cartridges generate greater stresses and more heat on the barrel, stock, action and shooter and make consistency of cartridge behaviour in the chamber / barrel even more important than in short-range shooting as any pressure build-up changes may affect barrel and action vibrations more.
2. A cartridge and load with a fairly large MV spread can still produce tiny groups at up to 200yd. Go beyond 600yd and velocity spreads increasingly translate into vertically strung shots. Have a big enough spread and the shooter won't hold the Bull even if everything else including the shooter's reading of the wind is perfect. Case physical features that affect neck tension etc and charge weights need to be very good indeed, as well as having a load worked up that really suits the rifle and naturally gives small MV ES values.
3. Bullet features, design and quality affect long-range results heavily. (They also affect the short-range BR competitor vitally too, but maybe with the emphasis on different characteristics and attributes, ie high BC is much less important at short ranges.)
None of this is to say that the pinnacle of either type of shooting is easier or more difficult than the other. They both require very good handloading and case preparation practices, skilled load development and so on. many things are constants, but you'll see few (if any) top notch long-range shooters pour powder thrown straight from a measure into the case.
Thank you for the help gents.
Makes sense to me that the usual short range calibers, rifles, and bullets could be more forgiving of variation in MV than the usual long range variety for the reasons mentionned.
If vertical dispersion progresses with distance as you mentionned Laurie, it doesn't sound like it is linear. Should I understand that the rate of velocity loss is exponential? Pardon my ignorance about balistics. Not even sure I can spell it properly.
Laurie, one of your last comments about LR shooters weighing charges versus SR shooters throwing them is another question I would like to ask in a seperate thread.
Makes sense to me that the usual short range calibers, rifles, and bullets could be more forgiving of variation in MV than the usual long range variety for the reasons mentionned.
If vertical dispersion progresses with distance as you mentionned Laurie, it doesn't sound like it is linear. Should I understand that the rate of velocity loss is exponential? Pardon my ignorance about balistics. Not even sure I can spell it properly.
Laurie, one of your last comments about LR shooters weighing charges versus SR shooters throwing them is another question I would like to ask in a seperate thread.
I've seen references to single digit ES several times over the last few months. The question I have is: Are these in 5 shot strings, 10 shot strings, or what? If this is happening in 5 or more shot strings then the next question is HOW Do YOU Do IT?
There is a relationship, but not necessarily linear as 'elevations' on the target are often not as great as is suggested through simply working out the different amounts of drop that differing MVs should produce. It's universally agreed that small MV spreads are a GOOD thing though for long-range shooting (< 20 fps, better still <10 fps if you can achieve that).
Barrel and action harmonics also affect vertical strike through what's called 'compensation' (negative and positive versions apply). Barrels flex vertically in a sine wave type cycle and the muzzle elevation therefore varies according to chamber pressure (affecting amplitude) and bullet 'barrel-time' as that can see the bullet exit at a different point in the 'wave'. The old rear-locking British Enfield actions (actually US citizen James Paris Lee's action if we're being pedantic) had very marked 'positive compensation' in which the muzzle is moving upwards as the bullet exits. If the ammunition had a large MV spread (which military .303 often did), a high velocity example exited the muzzle earlier (and therefore at a marginally reduced elevation) than a lower velocity example at the other end of the pressure / MV range. As the latter had a marginally above average barrel time, it left the muzzle at a slightly later point in the cycler and hence with a higher elevation thereby 'compensating' for what would be a lower strike on the target as dictated by external ballistics factors. It's not just theory - it did work and a lot of Lee action rifles were demon long-range shooters and used well into the 7.62mm single-shot Target / Fullbore Rifle era. Until the three and four-lug actions came onto the scene and 7.62 milspec ammunition standards rose from their dire levels in their early days, many keen British TR shooters had a Mauser system rifle for short (200-600yd) range matches and an Enfield No.4 rifle action based rifle for the long matches.
My first 7.62mm TR rifle was an ex-club No.4 that had been converted from .303 c 1968 or 69 by Fultons of Bisley and had thousands of standard military 7.62 144gn rounds through it. The RSAF Enfield Lock manufactured heavy barrels put onto these rifles and the British Army's first 7.62 sniper jobs had very tight bores indeed and I imagine this encouraged copper fouling. Anyway, when I got this rifle, I couldn't understand why even at 300yd, my first sighting shot from a clean barrel was always an 'outer' at 12 o'clock (nearly 3-MOA high), my second sighter would still be high and my first score shot was in the Bull all being well. Then I read an article on copper fouling and spent a week soaking the barrel with copper solvents and brushing it out and that cured the problem. If I'd had a chronograph I'm sure I would have seen very low MVs for the first shot and then rising with each subsequent shot as the barrel fouled until it plateaued at 2,800 fps or whatever my mild handloads were doing. This is an extreme example but shows the effect that large MV variations can have on some rifle actions.
The last time that an Enfield No.4 action rifle won 'The Imperial' Queen's Prize was sometime around 1980, 12 or so years after Target Rifle replaced Service Rifle. Number 4s continued in use for many years after that though as individual shooters' long-range rifles, and if anything even longer in Canada than in the UK.
Sometime in the early 80s, a combination of the appearance of much stiffer single shot actions, the twin-lug Musgrave but more importantly the four-lug Swing the ancestor of today's RPAs, allied to less variable pressure and velocity 7.62mm service ammunition saw the 2nd generation of front-lockers become superior at all ranges.
There are still a lot of Number 4s around though although they're uncompetitive even in club shoots and many still have their original barrels, mostly totally shot out. With their tight bores and whippy actions, owners have been advised not to shoot the RUAG (RWS) commercial ammunition loaded with the 155gn Sierra MK bullet (the older #2155 model) that the GB NRA now supplies.
Sometime in the early 80s, a combination of the appearance of much stiffer single shot actions, the twin-lug Musgrave but more importantly the four-lug Swing the ancestor of today's RPAs, allied to less variable pressure and velocity 7.62mm service ammunition saw the 2nd generation of front-lockers become superior at all ranges.
There are still a lot of Number 4s around though although they're uncompetitive even in club shoots and many still have their original barrels, mostly totally shot out. With their tight bores and whippy actions, owners have been advised not to shoot the RUAG (RWS) commercial ammunition loaded with the 155gn Sierra MK bullet (the older #2155 model) that the GB NRA now supplies.
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