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Old December 30, 2011, 08:32 PM   #26
dacaur
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And the million dollar question, if you have a load you think is good, and you go out and shoot a ten round group "for score", so you can "score" how big the group is, how do you tell the difference between a bad load and a bad shot?
Thats why you need a good rest, to take your skill (or lack thereof) out the the equation as much as possible. In addition to a good rest, I will throw out the furthest out 2-3 shots when measuing my groups for load development.
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Old December 31, 2011, 06:08 PM   #27
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I reload to enjoy shooting more. Don't have a chrono as most manuals give estimated vel per grain of powder. I'm such a great shot I'd probably shoot the chrono anyway, so I figured I'd just save that money.
Well, this is okay... But, the key you are really missing is 'consistency'... 'consistency'.... 'consistency' . Multiple shots over a chronograph will tell this. The tighter the ES, the potential for tighter groups. Simple as that. I've recently tested some Trail Boss loades with ES over 100fps. Very unexceptable. Will it hit the steel man-sized target at 25 yards? Yep. Every time. Will it give me 2" groups at 25 Yards? Nope. For me this isn't even a 'plinking' load. Won't be using that load any more! On the other hand, today I tested some Titegroup loads for .45 Colt and two of the loads the ES was just over 30, and SD under 10. These are 'good' loads for some serious testing now (for fun of course ) .

Let's use another example. I have always used Unique for my medium loads over the past 30 years. This powder has served me well for .357, .44Special, .44Mag, and .45 Colt. Last year I got a chronograph (bottom is sore from kicking myself from not getting one sooner) and have been 'very' busy using it. With the chronograph, I have found that there are actually 'better' powders out there more consistent in some of the calibers I reload with! Also there are different levels of the same powder that work better than others. 5.5g might suck, but 6.0g just comes together.... Chronographs help you find the 'sweet' point over a range of loads for that powder. No second guessing! I'll still use Unique of course (The Skeeter load is a dandy) ... But I won't be looking at it through Rose Colored Glasses now .

Being consistent usually means you have a better chance of hitting the point of aim. As you should know, the same bullet will impact at different points on the target at different velocities (it isn't a laser after all) . Gravity is a constant on the bullet (basic physics 101) and there are other factors as well. Different loads can move the bullet left or right too..


How do you know it is an accurate load? That is a toughy. Us humans have good days ... and bad days...At least I do! A ransom rest is the 'absolute' way (I don't have one). But from rest usually is good enough. First if you are a 'bad' shot, all bets are off. I am not an expert, but I know I am not truly 'bad' anymore. So it is pretty easy to see how the load is grouping. If I truly suspect I am having a bad day, I'll shoot a 'known' good load. That usually will tell me what is what! .

If I was a newbie, I'd ask for a known good load and use it. For example, I'd say to you "Load up 8.0g of Unique under 250g RNFP in .45 Colt". Shoots decent in all my .45 Colt revolvers. If you have a good shooter in the family, have him/her try it in your gun. That helps too determine if you are the problem. Might not be the load either... could be the gun... So many variables!

Just a couple rambling thoughts!
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Last edited by rclark; December 31, 2011 at 06:25 PM.
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Old December 31, 2011, 08:23 PM   #28
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Developing a .45 ACP Load

First, I decide what I'm trying to accomplish. Let's say I want a bulk, lead-bullet target reload that shoots to the fixed sights of a 1911, which is zeroed at 50 yards with WWUSA 230 JHP.

Before I do anything else, I need to know what the baseline mechanical accuracy is, of the gun and sight combination I'm using. In this case it was an Auto Ordnance WWII Model, using the stock barrel and with only mild accuracy work. King’s ‘High Hardball’ sights had also been added.



Because I'm a stickler about these things, I will have already zeroed those sights. I will also have shot the gun enough, from a rest at 50 yards, to know that it is capable of 3 1/2", five shot groups with jacketed factory ammo it likes.

That done, I decide what I want my bulk .45 ACP reload to accomplish. My bulk load is expected to do everything passably; punch targets, kill varmints and serve as a defense load, if called upon. A 200 grain LSWC of the Hensley & Gibbs #68 pattern does all these chores just fine. Since I've had uniformly good luck with Missouri Bullet Company, I select their Bullseye #1
. A Brinell hardness of 12 is plenty for the 850 fps, +/- 25 fps, I am looking to achieve.

Next I look at powders, beginning with what I have on hand. One of those is Winchester 231 and it's worked great for me in a number of standard velocity pistol loads. So I start hunting a charge weight that will get the velocity I require w/o straining anything. I always go to the manufacturer's data first, and Hodgdon's shows a starting load of 4.4 grains gives 771 fps and 11,000 CUP; and that the max load of 5.6 grains does 914 fps at 16,900 CUP. Given that I'm using range pick-up brass, I want to keep pressures low. Clearly, my go-to pistol powder, W231, will work in this application. I decide I'm going to start at 5.0 grains and see how it works out. My particular 1911 l likes SWC's at 1.250" OAL, so I'm loading these a froghair over Hodgdon's recommended 1.225". Experience and research tell me this is fine and if anything, pressures will be a little lower as a result.

This load will be tested for-

1. Function
2. Accuracy, and
3. Velocity

Ten rounds just ain’t enough to do that, so I load 50-75 rounds at the outset. It takes a few to get the OAL and taper crimp just right, so I set these aside for the function check. When those two things smooth out, I finish the batch. I load three mags with the first 21 rounds produced, step out back and shoot them at random reactive targets--pebbles, dandelions, soda cans, etc.--against the pond dam, at about 20 yards. The gun runs fine, recoil is soft and the load shoots where it looks. Ejection is about six feet, over my right shoulder; examination of fired cases and primers confirm that the load is a pussycat. The last two mags are fired with the gun held loosely, upside down, weak hand etc. and the gun runs 100% with them. At this point I field strip the gun and check the barrel (which was scrubbed clean at the outset) for signs of leading. If it is minimal or non-existent, I proceed to velocity and accuracy testing.

Next, I set up the old Chrony Beta Master and fire ten shots to determine velocity. The average is 826 fps, which is within my acceptable range. Now, right here is where I part company with ‘serious’ reloaders. Unless the standard deviation and extreme spreads are ridiculously high, I totally ignore them. Why? One, I’m using Heinz 57 brass your ES/SD numbers will always be higher than if you’re using brass from one manufacturer, one lot. The second reason is that I’m not trying to win bullseye matches. If these loads will stay on the head of a B27E at 50 yards, I’m happy as a clam.

Now the work starts. Wait for good light. Bust a few off at 25 yards just to see what kind of day I’m having… not shooting too shabby today, thank goodness. So I set up the bench, chair and other trappings at the 50 yard stake. Hang a target & shoot a few rounds of my standard WWUSA 230 JHP, to get the baseline POI I’m trying to match my bulk load to. Damn, I’m shooting a little left today. So I trudge back, plant my butt in the chair, hunker down and blap off five rounds of the LSWC.
Well, son of a gun.


The 5.0 grain grouped right at 4" at 50 yards from a rest, in mixed brass. Five more groups fired from the bench confirm that this load shoots better than I can hold it. Over the past six years, it has supplanted every other .45 ACP load I’ve loaded. It has proven to feed as slick as hardball. I really don’t need anything else from a reload. Only one thing bothered me about it… it was almost too easy to find!
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Old December 31, 2011, 10:11 PM   #29
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I guess I just don't seem to be doing this right after reading all the things folks are doing to determine which load to use.

I just shoot two groups of 5 using a rest or sandbags to try to remove some of the human factor. This is a total of 10 rounds per different load. I start at the lowest published level and work it up 0.1 grain at a time. One thing I have noticed with the powders I have used is most will have the best groups in a small range such as plus or minus 0.1 grains of powder. When the spread is over more then 3 different loads, I still use the closest one in the middle. I settle for the one in the middle. I also watch for signs of over pressure, and if shooting a semi-auto if it will consistently work the action.

I guess most people shooting .45 put a lot more effort into the process and need to get every advantage possible. Being only a fair shot, but I still enjoy it I think doing all the extras would probably be wasted on someone like me.
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Old January 1, 2012, 05:10 PM   #30
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Jammer,

Velocity variation affects a handgun somewhat differently than a rifle. For a handgun you will generally find bullet weight matters more to vertical impact than exact velocity does. At short ranges (say, up to 25 yards at least, but usually more) heavier bullets can normally be counted on to impact higher, and for a fixed sight gun, choosing bullet weight to adjust the vertical impact is an alternative to filing the sights.

The effect of velocity variation on bullet trajectory at typical handgun ranges is not usually much unless you are working with catsneeze loads. At a .45 ACP commercial hardball velocity of about 830 fps, you need 110 fps variation for the trajectory from a fixed barrel to have 2.1" of vertical drop difference at 50 yards. Most of us can load more consistently than that without really trying. Furthermore, you don’t fire from a fixed barrel, like one in a vice. So you also have the fact the gun will recoil upward rapidly enough that a slower bullet, taking longer to get out of the barrel, is launched at a slightly higher muzzle angle, and that will tend to compensate for the speed difference and erase at least part of that drop.

Velocity variation is, however, an indicator of another problem than just its direct effect on trajectory. Assuming your powder charges are pretty even, wide velocity variation tends to indicate inconsistent ignition. When ignition is erratic, the lower velocity rounds often turn out to have actual ignition delays in firing, sometimes tens of milliseconds after the primer is struck. In a handgun, you won't normally be aware of this by feel, but trigger overtravel slap, hand muscle contractions, and any degree of flinch you have will now all have more time to move the muzzle off point of aim (POA) before the bullet clears the muzzle. The result is measurably bigger groups. Thus, the gun could shoot erratic velocity loads well from a Ransom rest, but still be hard for the shooter to score with. You want ignition to be fast and consistent. A low velocity standard deviation (SD)*, which is usually calculated for you by the chronograph, is a good statistical indicator of ignition consistency. I prefer SD to extreme spread (ES) for this because a difference in ES is more likely to be due to an anomaly than a difference in SD, such as the result of a low powder charge combining with an inadequately seated primer.

From the above, you can see how a chronograph can help you pick the best powder and primer and crimping practice and bullet seating depth for your load, all of which affect ignition consistency. Is it really necessary? No. You can also just test loads and components until you identify the ones with the best precision. That is the object of the exercise, after all. The chronograph lets you do that with fewer shots, but you don’t have to have it.

The Ransom Rest is the same way. It’s a nice testing tool, but you don’t have to have it. In my experience, someone who is good off the sandbags can often outperform the Ransom Rest with the 1911 style pistols. This is because a 1911’s sights are on the slide, and if the slide doesn’t return to the exact same position on the frame every time, but the barrel still locks up consistently in the slide, the guy on the bags can correct the sight alignment for the next shot, while the Ransom Rest just keeps the frame fixed in place, allowing the barrel and sights to be slightly off. You have to have a gun with the slide well fit to the frame to get the Ransom Rest’s best results.

Below is a 25 yard group shot of bags from my Goldcup back in 1985 after I’d just finished fitting it up for the second time. The bushing was a solid bushing I’d fit by hand, but all other parts were original, with the barrel modified by weld-ups I’d filed and scraped to fit by hand. Old school. The masking tape is over a .22 or .38 hole, as I used to have the frugal habit of salvaging targets from others that I could still use, and pasting them up.



As to working up a load, I find for jacketed bullets you just work up to best accuracy, as described by others. For lead bullets I work differently. The .45 ACP is supposed to headspace on the case mouth, but a good half or more of the 1911’s I’ve seen are actually headspacing on the extractor hook. This tilts the bullet in the chamber and causes lead bullets to deform enough by the angle at which they enter the throat to unbalance them a little and cause groups to open up. So I seat my lead bullets out to headspace on the bullet. That insures it is properly aligned in the bore at firing, improves start pressure consistency, and results in sometimes significantly better precision and less leading. An illustration of how to tell if you are seating your lead bullets to headspace on the bullet is the third from the left, below. If your bullet shape is wrong for this, your cartridges may get long enough to have magazine fit and feeding problems working this way. I never have, but you'll have to experiment for yourself to be sure.



As to groups, the rule of thumb is the extreme spread (the two furthest holes) of a three shot group tells you 95% of all future 3 shot groups will be no more than 2.5 times bigger. For a 5 shot group, it is 1.5 times bigger. For a 10 shot group it is 1.2 times bigger, IIRC. I'll have to double check, but I think that looks about right. So, larger groups do narrow the probable error substantially. They can also give you a lot of double holes and make it harder to measure where the exact center is. Fortunately, if you overlap two identical targets each containing 5 shots aimed at the same place on the targets, then evaluate the combined group size, and using the average location of their two centers as your estimated average center, then you have the same effect as a 10 shot group with all ten holes located exactly.

As described by others, just keep working loads for each bullet up in small charge increments until you find the range of best charge. Try different primers until you find the one with that gives you the best result with your powder. Try different powders to see if any improve results further. Try small changes in crimp and bullet seating depth. Bear in mind that a gun that has not had accuracy work done will not show as much difference between loads as one that has, but it won’t usually shoot with as much precision, either.


* SD is actually what is called sample standard deviation, which serves as an estimate of population standard deviation, σ (sigma). Sigma is the root mean square of all deviations from average in a normal distribution.
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Old January 1, 2012, 07:53 PM   #31
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Thanks, Unclenick, makes sense to me.

I come from the trades. (I'm a carpenter by trade, a general contractor by profession, although I've thrown up my hands, retired, and sworn never to return to construction.)

The fastest, best, most accurate carpenters I know do what they can to avoid using a tape measure, because usually there is no advantage in knowing the number, and it creates opportunity for error. They have truly ingenious methods for dealing with angles without measuring them. Their precision is something you spend a lifetime to learn.

This whole thread reminds me of that.

I see a trend, (I asked this question on a couple forums, which, I believe, have different pools of folks) and that trend is towards ten well-placed holes being fairly indicative of a load's accuracy.

Perhaps I'm making this too complicated, perhaps ten rounds for function and ten rounds off of sandbags will tell me what I want to know about a load.

I'd be willing to bet that all my 200 SWC loads headspace on the extractor, by the time I get them long enough to match that picture, they're way too long to go into a magazine.

I shot plates for years, (and have the scars to prove it, most people are wrong about splash from metal plates) and I just discovered that my very favorite plate load tumbles!

Apparently I worked it up so it would hit the plate and be light, rather than checking it for accuracy...
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Old January 2, 2012, 03:02 PM   #32
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Interesting about the plate load. I wonder why it's tumbling. A light, short bullet is technically overstabilized by a 1911 barrel.

Try loading a bullet headspaced round just to see what happens. I've had no trouble doing it with the 200 grain H&G 68 design, and its nose isn't especially short. The magazines have a bit of extra room, anyway. With round nose bullets you may find some too long and some not. Some have noses that are eliptical like the military ball, while some have hemispherical noses and are shorter, even at the same weight. The Goldcup that shot the group had a lengthened extension (hood) from weldup and fit, and I'd throated the barrel, so the chamber was long. Despite that length, it still worked with all the cast 185's and 200's I tried in it.
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Old January 2, 2012, 03:25 PM   #33
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Something else that might help you, is shooting your bench rested test groups at a closer distance. I initially test loads and sight my adjustable sighted handguns in at five yards. It sure is a lot easier to get the group centered and get tight groups off of sandbags.

A quick check of a ballistic calculator, shows that with the vast majority handgun loads, if they're sighted in dead on at five yards they are only .1 to .3 inches low at twenty five yards. Thats well with in the margin of error, at least with me doing the shooting.
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Old January 3, 2012, 12:44 PM   #34
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I prefer SD to extreme spread (ES) for this because a difference in ES is more likely to be due to an anomaly
What I do is 'throw out' the 'obvious' bad velocities. For example, if all the shots are between 870 and 900 except one shot is 810, I'll 'ignore' that one shot. To me that makes ES just a bit more meaningful. That's why in a lot of my load data, I'll show 13 shots instead of 15, or 28 instead of 30 to come up with the numbers....

Quote:
I initially test loads and sight my adjustable sighted handguns in at five yards.
I use 15 yards for this. If doesn't group at this distance, it won't at 25. To me 5 yards is to close as they'd all be in one hole and not tell you much (other than your sights are 'close').
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Last edited by rclark; January 3, 2012 at 12:56 PM.
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Old January 3, 2012, 11:11 PM   #35
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Quote:
Originally Posted by rclark
What I do is 'throw out' the 'obvious' bad velocities. For example, if all the shots are between 870 and 900 except one shot is 810, I'll 'ignore' that one shot. To me that makes ES just a bit more meaningful.

The problem with extreme spread is it contains less information and is therefore a poorer measure of consistency than standard deviation. The extreme spread is the difference in the one pair of numbers in the group that have the least probability of being as far apart as they are, but you if you throw out the information in the rest of the datapoints, you don’t know if that one extremely separated pair were comfortably inside the probable range of distribution or were unrepresentatively far apart. You need standard deviation to tell. And if they are exceptionally far apart, then calculating standard deviation dilutes their influence with the numbers from the more closely spaced velocities, so they don’t throw the whole result off as far as they can do by themselves.

In general, if the velocity distribution is normal and the calculated standard deviation is an accurate estimate of population standard deviation, it tells you about 1/3 of future velocities will be further apart than twice the standard deviation's value, and about 2/3 will be closer together. Only 1 in 22 will be further apart than four times the SD value. Only about one in 370 will be further apart than six times its value. Only about one in 1579 will be further apart than eight times its value. So it presents a pretty clear picture of what to expect down the road.
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