Why is factory-loaded so easily improved upon?

OK, I get it, it's to do with the initial conditions of a system involving a projectile accelerating through a tunnel subject to damped oscillations. Once it leaves the barrel, it's pretty much in freefall. You want it to leave said tunnel at the point where the oscillation is at the neutral point.
 
OAL = Over all length. If measured to the tip of the bullet also called COAL (cartridge over all length).

ISTR = I seem to remember

HTH

TTFN

:lol:

Thanks Sharpie. I don't think I need anymore daft acronyms in my life, certainly not in my spare time, given how many of the damned things I deal with at work.
 
OK, I get it, it's to do with the initial conditions of a system involving a projectile accelerating through a tunnel subject to damped oscillations. Once it leaves the barrel, it's pretty much in freefall. You want it to leave said tunnel at the point where the oscillation is at the neutral point.

Yes.

I hasten to add that: tinkering with the powder quantity is your first step to accuracy, once you've defined a sensible cartridge overall length, as Sharpie has indicated.

For your homework tonight, read up on the principle of the "load ladder" ie, incremental load variation and testing to find a load that seems more accurate than it's near neighbour sized loads... it's an empirical process and quite simple, to get you somewhere into the ball park. I know it all sounds a huge pain and you could use up quite a bit of ammo on it... but you do quite quickly get homed-in and onto a good load... usually... :D
 
OK, I get it, it's to do with the initial conditions of a system involving a projectile accelerating through a tunnel subject to damped oscillations. Once it leaves the barrel, it's pretty much in freefall. You want it to leave said tunnel at the point where the oscillation is at the neutral point.

One important reason barrels vibrate is because they are never entirely straight. The bore will always wander slightly, sometimes grossly. Shooting a bullet through at around three times the speed of sound is guaranteed to set off vibration, as it tries to straighten out the bore as it goes.

Varmint Al has some impressive finite element simulations of various barrel vibration situations. Varmint Al's Shooting Page
 
In this brave new world of all things reloading now is probably the moment to lob one more variable into the équation in the search for consistency, albeit I quite understand its an unpalatable one.

We cannot ruleout the unhelpful influences that may lurk in the marriage of walnut and steel in this fully stocked rifle and that will first need to be understood prior to containment in part or whole if you wish to be competitive on BSRC match days where 10 rounds are also unhelpfully fired in a few minutes rather than hours.

The good news is there are people on this site who may be trusted to help you identify any such evils and, more importantly, undertake the remedial work required to address the malady. You just need to choose wisely.

K
 
K, I know what you mean, and I'm taking measures to remedy the forend ferrule situation (easy enough), but the fact is that it's not a target rifle, and accuracy starts to wane after something like the fourth or fifth shot. But that's OK, it's a stalking rifle. As much fun as they are, BSRC matches are just practice as far as I'm concerned. Obviously I want to do better, but I don't expect to win anything anytime soon. The first shots will always be the best ones.
 
K, I know what you mean, and I'm taking measures to remedy the forend ferrule situation (easy enough), but the fact is that it's not a target rifle, and accuracy starts to wane after something like the fourth or fifth shot. But that's OK, it's a stalking rifle. As much fun as they are, BSRC matches are just practice as far as I'm concerned. Obviously I want to do better, but I don't expect to win anything anytime soon. The first shots will always be the best ones.

Well, in that case you're gonna have to shoot from a monkey cradle!!

K
 
When I first started reloading I had a similar sort of problem with my Blaser and reloads. In the end I copied the dimensions from a federal 95grn round that shot tight groups and used that as a starting point. If you have some factory ammo that shoots well this can get you into the right ballpark.
atb Tim

That's what I did in the end, but I did it the cheap way, go to shop, ask to see all his .243 ammo and measure them to get an idea of the loaded length and work from there.
From memory I think all the factory ammo was about .060" shorter than the books suggest.

Neil. :)
 
This is an interesting thread, but I am left thinking "What kind of accuracy are you guys looking for at what distances?"

regards


Ian
 
Yep - I suppose I was a bit vague. In my case, I get a ragged hole at 200 yards with my .223 (Norma 40gr through a varmint rifle) and about a 3/4 inch group with 6.5x55 (Federal 140gr in a lighter, stalking rifle) at 200 yards. I realise that to really test the ammunition, I would need to shoot at larger distances. However, for my purposes I am totally happy with this level of performance.

I expect a 6mm benchrest shooter would be after much more, but when I see 'hunting' calibres mentioned, I wonder what kind of accuracy people are striving for. I know that when I am out shooting, my performance on the day, state of mind, range estimation and caffeine intake adversely affect my shooting a lot more than a few fractions of an inch that a reloaded round might improve it.

Anyway, I keep telling myself that because I daren't get into reloading - it would be another hobby that would sap my time. :scared:

regards

Ian
 
As OAL's have come up - and when do they not when wise heads confer on the dark art of reloading? - I'm of the no-doubt-heretical view that while the right seating depth can matter a lot, and usually does, it is by no means most often found on the lands or even within the first handful of "thou" from them.

This seems to be particularly true with long, slim high-BC bullets. In such cases I find that ensuring concentricity makes a greater contribution to accuracy.

I will stop short at this point of advising our friend PM to acquire a concentricity tool as (1) it will prompt howls of protest from those who hate such things, and (2) we have otherwise arrived at the comfortable hiatus that comes with reaching the inevitable -and eminently sensible- "how much accuracy do you need?" stage of any discussion of reloading for hunting purposes. Though I hear dear (mad) old Lear protest as I mention the N-word:

O reason not the need! Our basest beggars are in the poorest thing superfluous.
Allow not nature more than nature needs, Man's life is as cheap as beast's.
 
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I'm confused. What is a monkey cradle?

Ignore. Just a K stab at humour.

You’ll be just fine once you get some decent handloads and shoot a few unhurried 5-shot groups from a decent bench setup with that all-important rear bag.

K

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I cannot remember which member posted about his findings when analysing the charge weight and seating depth of some factory ammo but I did a similar exercise with some Sako .243 ammo which used to perform great but had a batch that been poor performers. There was an alarming spread in charge weight and seating depth.

I am convinced that the attention to detail and precise measurements possible when hand loading do make a real difference when tuning up a load for your rifle.

This is why it is potentially very dangerous to start playing about with swapping bullets or seating depths on factory made ammunition. I would not do it.
Factory ammunition is made to produce consistent case pressures, regardless of what primer, powder, or indeed, mix of powder, they are using in any given production run. If you change the bullet, seat it differently, or effect the neck tension of a cartridge, then you are entering a whole new world of very unpredictable outcomes, some of them possibly very negative.
To give my little bit of advice to the original poster, I would have to say that the reason why hand loaded ammunition is far better than factory ammunition, in my opinion, is that once you have developed an accurate cartridge you can constantly reproduce it. Factory ammunition can vary greatly in performance and is not as reliable as a bespoke cartridge where you know what has gone into making it. This is because factory made cartridges have to be made to very general standards. Also, aside from being able to choose the best made bullet for your hunting requirements, you can also choose which velocity to fire it at, and thus get more predictable terminal performance from it.
I would not feel very confident shooting anything using factory ammunition as, never mind its accuracy, its terminal performance cannot be relied upon to the same degree as with hand loaded ammunition.


Kind regards, Olaf
 
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That's a bit of a generalisation. Surely it depends on the factory you trust to produce your ammunition? :)
 
like airline seats
made to fit all manner of fat, skinny, bony, leggy, lardy, stumpy. undersized and (some) oversized people

some people have no problem, some (most) hate them

some factory ammo will work beyond expectations
some won't shoot for shizzle

by hand loading you are matching ammo to YOUR rifle. that's it
even doing it badly is better than factory and I should know!
 
That's a bit of a generalisation. Surely it depends on the factory you trust to produce your ammunition? :)

No, I don't think it is, that's the thing you see, factory mass produced cartridges are a bit of a generalisation.

Kind regards, Olaf
 
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