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reading through this, started me wondering, what is the norm for people when reloading? i have just started reloading for 303, and trying to use a powder thrower or autodiscs, it was annoying me as it was frequently out by around +/-.15gr was i being too pedantic? By Halodins method, not pedantic enough. but how much variance is acceptable for most people? i felt a spread of possibly .3gr accross reloads was a bit much.

I don't know is the short answer, but looking at it another way, can loading one round at X.06 and X.15 produce a different POI even at 100 yards, I'd say yes. Admittedly it isn't a lot, but when the group size is everything, for the sake of taking an extra 10 seconds to drop in an extra kernel or 2, why not? As a minimum I know I can take one thing out of the equation if the results were unexpected.

TattooedGun wrote:I read every 3 outings he anneals. But he could have been talking about his tactical rig as opposed to his long range rig. I read a lot of different posts from him before I went out earlier...

Certainly a stickler for detail, but how much is too much.

The fact his cases have been used 58 times and he has a 1000 yard range IN his back yard certainly suggest he shoots a lot. does that experience translate more to the scores than 0.02 vs 0.1 grain powder difference...

I only dream to shoot half that much but anything better than the 10th grain powder throws I'm using would be wasted time and energy because I can't read wind enough to be accurate enough to be anything like fulfilling to the equipment. That's not to say that those with the experience can't get use out of that much increase in accuracy of powder throws.

Hypothetical question. Do you think misjudging the wind by 0.5mph over that distance would be more than or equal to the amount of difference between 0.1 grain of powder difference in his hypothetical load.

0.5mph at 90degrees would place your shot approximately 2.5" from point of aim.

It's all hypothetical really, because in the UK most of us don't have the luxury of a 1000 yard range in our back garden so the time spent getting the accuracy out of the ammunition is generally the only thing we can do between range visits. But there comes a point where you have to wonder if you're actually gaining anything out of the experience other than a mental advantage of knowing that your ammunition is bowl more accurately filled than over someone filling to 1/10th.

If only for my curiosity I'd be interested to see the difference in fps between ammunition with those kind of powder load variance and see what kind of real world difference one may be able to expect from being that anal about it, verses, for example wind drift miscalculations which only really come with experience.

I don't know if this is mathematically accurate, but there's someone on another forum with a similar line of thought. So according to this, the spread when using a balance beam that's accurate to 1/10th grain, could potentially increase your groups size by about 3mm @ 100 yards. Is anyone able to confirm if this is approximately correct?

I wasn't ever actually trying to measure 1/100ths of a grain, guys. I simply wanted a scale more accurate than +/- 0.1 grain. That equates to a possible range of 0.2 grains. 1/100th was the next logical step in my mind for a scale.

If plus 0.1 grain gives + 7FPS, and under 0.1 grain gives - 7FPS, thats a spread of 14FPS with a standard scale.

OK, now let's apply that to a bullet trajectory.

.277 diameter, 150 grain, 0.5 BC, 2800FPS vs 2814FPS.

At 400 yards, that is a 0.4" trajectory variance.

At 600 yards, that is a 1.0" trajectory variance.

At 1000 yards, that is a 4.1" trajectory variance.

I don't know about others, but throwing 0.4MOA out the window at 1000 yards doesn't sound very good to me.

http://www.thehighroad.org/archive/inde ... 86616.html

Guys, I know you're really enjoying doing this with maths, but might I suggest having a look at what happens in the real world? Loading to 0.02gr is about as accurate as possible given stick powder. It is part of a reloading regime that can deliver a 2-5 inch vertical spread over 20 shots at 1000 yards.

Powder makes no difference beyond that, wind and atmospherics make much more. I know that because I've been out and done it, like Matt and ENS, and the other guys we shoot with.

Mr_Logic wrote:Guys, I know you're really enjoying doing this with maths, but might I suggest having a look at what happens in the real world? Loading to 0.02gr is about as accurate as possible given stick powder. It is part of a reloading regime that can deliver a 2-5 inch vertical spread over 20 shots at 1000 yards.

Powder makes no difference beyond that, wind and atmospherics make much more. I know that because I've been out and done it, like Matt and ENS, and the other guys we shoot with.

Ha, ironically thats the divisions a Gempro 250 works to.

I found all the farting about with calculations a bit pointless as it usually surprises you in the field. I tend to establish zeros (by shooting) and adjust on them.

Personally I would load to 0.02gr, but would not get upset if it was 0.04 or a bit more as I am not worried about long range anymore. That said, it took an adjustment of 0.20 of a grain to account for different brass in getting my M67 to group properly again (from 45.0-45.2N140 lapua to Fed brass).

I shot a 1MOA group with it using an old SLR sling so it works fine.

I still load to this tolerance with my AR and again, using 77gr SMKs it dropped to about 1MOA against factory GGG so it a gain worth having in my opinion.

I shoot that badly with my No4 that I reckon if I used a shottie I would do better, but that is still no reason not to make the reloading effort, its one variable less.

Yes it takes longer, and no I am not sure it gives any advantage over a chargemaster, but currently I am happy KNOWING exactly what I am putting into my brass and have the time.

If I was offered one (with a shooting shed thingy...accept no substitutes) I would have one as I have heard nothing but good (Tom does alright with one), but currently its slings bags and bullets I am afraid. They do cut the time down, but if I was really worried I would go for a Dillon which is a hole new ball game. You have to decide what you want to achieve. Huge output (and in the case of a well setup Dillon still have pretty good consistency but you might get the odd hiccup) or a slower more hands on process or you go to the other end (BR and F) and hand load to the Nth degree.

I think that with reloading, you try what works and do what you think is needed. I started sizing without a ball then running a mandrel through them to expand and found my accuracy improved. I do that for all my 308 now. I think in some cases the gains may not be dramatic, but its one less thing to worry about just as you leap across the ditch on century and fall in the mud.

Naturally you fossil class poofters would not understand that but hey......

(only joking girls, you lot lay in it, we roll and fall in it )

There are no free rides or shortcuts in reloading. You get the odd lucky break, and experience will speed thing sup but you still have to develop the load which to an extent is part of the fun....sometimes.

Thanks, that ties up with my last post. What equipment do you use to hand-load to .02 grains?

Mr_Logic wrote:Guys, I know you're really enjoying doing this with maths, but might I suggest having a look at what happens in the real world? Loading to 0.02gr is about as accurate as possible given stick powder. It is part of a reloading regime that can deliver a 2-5 inch vertical spread over 20 shots at 1000 yards.

Powder makes no difference beyond that, wind and atmospherics make much more. I know that because I've been out and done it, like Matt and ENS, and the other guys we shoot with.

Interesting.

HALODIN wrote:I don't know if this is mathematically accurate, but there's someone on another forum with a similar line of thought. So according to this, the spread when using a balance beam that's accurate to 1/10th grain, could potentially increase your groups size by about 3mm @ 100 yards. Is anyone able to confirm if this is approximately correct?

I wasn't ever actually trying to measure 1/100ths of a grain, guys. I simply wanted a scale more accurate than +/- 0.1 grain. That equates to a possible range of 0.2 grains. 1/100th was the next logical step in my mind for a scale.

If plus 0.1 grain gives + 7FPS, and under 0.1 grain gives - 7FPS, thats a spread of 14FPS with a standard scale.

OK, now let's apply that to a bullet trajectory.

.277 diameter, 150 grain, 0.5 BC, 2800FPS vs 2814FPS.

At 400 yards, that is a 0.4" trajectory variance.

At 600 yards, that is a 1.0" trajectory variance.

At 1000 yards, that is a 4.1" trajectory variance.

I don't know about others, but throwing 0.4MOA out the window at 1000 yards doesn't sound very good to me.

http://www.thehighroad.org/archive/inde ... 86616.html

From the same thread;

I simply wanted a scale more accurate than +/- 0.1 grain. That equates to a possible range of 0.2 grains.

Matt, a scale that measures to the nearest 0.1 grains has an "error" range of 0.099 grains since for example, a weight reported as 30.0 grains could be anywhere between 29.950 and 30.049 grains. I haven't seen your calculations but that error range alone would reduce your estimated 4.1" trajectory variance to 2.05". In addition, we can assume as many hits above the intended POI as below so the error is now +/- 1.025" or +/- 0.1MOA @ 1000 yards. The WORLD RECORD for benchrest at 1000 yards is 1.403" (http://accurateshooter.wordpress.com/20 ... 000-yards/), so for someone going for the benchrest world record using the kind of specialized equipment that is required, a scale capable of measuring to 0.01 grains might be a worthwhile investment. It would be interesting to ask Tom Sarver what kind of scale he uses.

That 1 inch variance @ 1000 yards doesn't agree with Mr_Logic's statement above. Hopefully he can put more skin on the bones.

The thing is, you're missing the other variables at play here. Ammunition doesn't have a constant change in velocity for a given powder weight, not even with the same powder, it changes as the load does. It changes massively between powders. So you can't correlate a +/- FPS depending on charge weight variance, so the effect of a charge weight change is always an unknown, and its severity will change depending on the load.

All you can do is say that you need to minimise it. In the real world, getting on the range and shooting ammo and reading the wind will have a much more profound effect on score than the last Nth of a grain. I can use a 0.02gr scale, which I have, but most of the time I don't bother. It's a PITA and takes ages. My Chargemaster is good enough as a rule - IMR8208 tends to give very low ES even off the Chargemaster, so that'll do.