I have been shooting and reloading for a long time and think that I have a pretty good handle on the basics. There is however a recurring phenomenon that keeps me scratching my head. I am talking about loads in the 44 magnum, shot in a handgun and a rifle. Everyone knows that the key to accurate handloads is consistancy. We are also aware that Winchester 296 is at it's best with full power loads, or is at least supposed to be more consistant at that level. It has been found in my testing that often the opposite is true.

Example,
Load #1 fired from a 6 inch 629 consists of new Winchester brass, Winchester primer, 22 gr. Win 296 and a 250 gr. SWC. Measured velocity ranged from 1205-1328. 25 yard accuracy was 6 shots in 1.05", average of two full cylinders.

Load #2, identical except for the powder charge, 24 grains of 296 this time. Velocity was much more consistant, 1338-1366, but accuracy had diminished to 1.98".

Have had the same thing happen with 310 gr. cast bullets fired from a 1894 Marlin.
20 gr. of 296 shot into .920" at 50 yards with an extreme spread of over 100 fps. 22 grains had spread of only 28 fps but grouped 1.96".

This is not always the case, but has happened often enough to me that I don't consider it a fluke. I know there are a lot of things that don't make sense in reloading and shooting, like why one rifle likes a certain load but an identical rifle won't, but these apparently "incosistant" loads greatly outshooting "consistant" loads makes wonder......

By the way, the loads that I shot in Ranch Dog's match were only 20 grains of 296 with that 250 bullet, way below full power but wonderfully accurate for some reason.

Yes, it does seem odd that less consistent velocity loads would have better grouping than those having less velocity variance.

In centerfire rifle reloading, I've also noticed the better grouping with loads that can vary 30 - 60 fps than some loads with 10 - 20 fps. And, as you discerned, this usually happens when comparing lower velocitites to higher ones.

Only thing I can attribute it to is some bullets just don't like to be pushed downbore under or over a certain velocity. Rate of twist, amount of bullet bearing surface, hardness of bullet, etc., etc.

That's why I always establish the best accuracy level and don't worry overly about velocity - usually the sweet spot happens just below published maximums, anyway.

Maybe your plain base bullet doesn't like to be pushed at that speed?

Maybe your plain base bullet doesn't like to be pushed at that speed?
Both the 250 and 310 are gas checked.

TedH,

I know what you mean. I go to the trouble of setting up my crony and adjusting. Write down my data with average of 3 shots or whatever then push the button a few times to get to the extreme spread and write that down (My Pact has AD SD or something but I stick to the extreme) but the #'s don't tell how accurate each was. When I get home and transfer my #'s to my reloading log, I see some real good #'s that were not that accurate on the range. One of these days I'm going to get smart and forget the crony and just go by accuracy at different distances and then maybe see how fast it's going.

Bill

Now you're getting into my routine, Bill!

The chronograph only gets used when working up loads to help find the maximum loadings, then I start working in half and quarter grains up and down to establish the accuracy zone. Once the most accurate load is found, the chronograph is used to verify velocities. After that, who gives a hang? :D

I wouldn't worry about extreme spreads because many times these are nothing but errors for numerous reasons encompassing everything from gas following the bullet to allignment of the moon in orbit? I really think one should simply ignor spreads and just use the average and call it "base-line".

Have seen this many times in many calibers. Load for accuracy and don't dwell on the assumed specifics. If you're plugging one hole groups, who really cares what the chrony says anyway? :)

My first question would be bullet hardness of your cast 250 and 310's? Actually the performance you report resembles the classic symptoms of exceeding the pressure/velocity threshold that the bullet can withstand. Don't know of course, but couple this with bullet sizing, and you have a big slice of the puzzle figured out in most cases such as yours.

What diameter were you sizing your bullets? Typically those S"&W 629's have nice tight chamber throats, and a .430" diameter bullet will shoot nicely in them, however the Marlin 1894 is a totally different animal, and the huge throats and generous barrel proportions in these guns mandates a minimum of .432" bullets for best accuracy potiential using cast bullets.

Just a couple of random observations to consider!

Marshall, That's possible but does not explain why I've had the same things happen with jacketed bullets too, both rifle and handgun loadings.

Marshall,
I was not really concerned about the hotter loads not being as accurate, as I have foud that to be pretty common. I was just stumped as to why a load that had 125-150 fps extreme spread was so accurate. But since you asked, the 250 grain bullets in the Smith are sized to .429, the same as the throats. The 310's in the Marlin are sized to .432". Alloy is wheel weights with a bit of tin added and dropped from the mold into a bucket of water.

I think I'd move the chronograph as far from the bench as I could, and see if that helps.

You will hear many possible reasons for this phenomenon, but none will be definitive. Fact is, if you picked up another revolver and fired these same loads you'd very likely get exactly opposite results. "Rules" of accuracy in loading are, in large part, really just "rules of thumb" -- they may be the Bible in most circumstances, with most guns, or they may be totally worthless with a particular gun.

And actually, who really cares? If a certain load gives horrid consistency shot-to-shot but excellent accuracy from a particular gun, then that's a good load for that gun.

It is a puzzlement and I have been loading ammo for 50 years.

Since I started chronographing (about 20 years ago) I have noticed this time and time again.

I am not as perplexed by a rifle doing this as a handgun, because often 100 fps will not make any difference in the point of impact in a rifle, but in a handgun, especially one shooting heavy bullets, 100 fps can, and usually does make a discernable difference in POI at 25 or 50 yds, yet, as you say, these loads are often the most accurate.

I cannot explain it.

It is one of the first questions I am going to ask St. Peter if and/or when he opens the pearley gates for me..... :confused:

Well put redhawk44. Something else I've wondered about is when using different powders in handgun or rifle, when you reach close to max pressure (not fps) with one powder, the shots will hit a little higher on target. Might be like my 30/30, when too much pressure for load and bullet the shot will hit right or left of others.

Bill

Doing a little range work the past couple of weeks, have noticed another variance.

Shooting the 6.5mm Swede's, I've settled on a pet load for all using the exact same powder and charge, same primer and brass. One load uses the Hornady 129 gr FBSP and the other the Hornady 129 gr SST, which is a boattail polymer tipped bullet.

At 100yds, the flat based soft point hits 3" high and 1" left. The SST's, with same sight setting hit centered and 1" right. Both give MOA accuracy.

Evidently, the flat based bullets give a better gas seal and have a bit more velocity. Haven't run them across the chronograph yet, but will do so eventually.