How do you explain this????

How do you explain this????

I was helping a son do load development, He'd shoot 6 shots, we'd change targets, reload then I'd shoot 6 shots with the same charge so the gun had time to cool a little between shots.
previously my son was doing all the shooting but the shoots were all over the place so this time around We both shot the same charges to get a better picture of group patterns ------ I found it wasn't the loads :(

Springfield XD 3.3 barrel
14 BHN PC'd
Shooting bench with hand and barrel rest
Clear day sun is behind me with no wind
range apr 35 feet
One flier might have been the first shot in this charge but the second was somewhere in the mix
Same brass, primers, boolits and powder charges were weighed
I can see (and have had) an occasional flier but 2 in the same place.
4 shots in a 1 1/4 inch group and 2 touching each other 3 inches away:-?:shock:

The gun is fairly new but still --------.

https://i.imgur.com/iyb1xMA.jpg

Little bumps in the paper are from lead splatter hitting boolit trap

Strong willed female boolits determined to go their own way? :shock:

Honestly, so many possible factors. You seem to have eliminated many of them in advance by weighing everything. Do you know if it was the first two or last two rounds, or somewhere in between? Thinking about barrel fouling or heating. I guess you sights are fixed and couldn't have shifted a bit? Did you change your grip, knowingly or not, during the string? This kind of thing is very hard to determine, but another question would be, did you fire other strings before or after this one, and what were those results?

I am thinking the base was a tad off or the PB had a nick you didn't see.

That is mighty odd for that short of distance. Maybe weigh the brass if you kept it separate, maybe two of them have less or more capacity because of differnt lots and caused a difference in pressure?

I'd guess it would be a change in the gun lockup though. Maybe a little shaved lead or PC at the front of the chamber, or two that had a little longer OAL.

No offense but my first assumption is always the shooter. Slapped the trigger twice?

Sight picture issues would be my first guess.

Quote:

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Originally Posted by T_McD

No offense but my first assumption is always the shooter. Slapped the trigger twice?

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No offense taken, the 2 fliers weren't in a row

Even stranger, then, that the fliers went to the same location. But one could logically assume that whatever the cause was, the cause was the same for both shots. Wild card: Do you wear prescription eyeglasses when shooting? Could the lighting have somehow changed a bit?

IMO, Not enough data with just 12 shots, 6 at a time with two different shooters.

Reshoot/Repeat testing using same parameters, but use more of them ( like 10-15) & see if you have a repeat of the same type of results.

I shoot a minimum of 10 per tenth of a grain & then repeat the best two of the ladder( < that is what "I" call it) or range of loads & then make a determination.

Other than some possible defect with the boolit as was mentioned, that would be where I would start.

That is my suggestion(s).

G'Luck!
:)

Without the gun being locked down in a vice bolted to a concrete table,
I'd lean toward sight picture also.

When you flinch, you flinch consistently in the same manner. That’s my guess.

4 grns = 2 1/4" group
4.1 grns = 7/8" group
4.2 grns = 1 1/4" group + 2 (this target) Will do more testing with 4.1

Just for comparison, in my SR9 using Red Dot( which is kind of close to BE in load data amounts) and both a 124 gr. TC & a 124gr. RN the two best were 3.8gr. & 3.9 gr..

Below & above those 2 amounts the groups opened up.
Like I said, then I retested those 2 amounts with 10 shots each, & confirmed the groups were the most accurate/tightest. 3.9gr. is the one I put an asterisk * next to so in my book it is the best of the two with that lot of Red Dot powder & components used.

You may find that with that firearm, less the two flyers, those 2 loads of 4.1 & 4.2 grains, might be the "node" I think it is called, where the groups are the most accurate/tightest for that particular firearm using those particular components you listed. That is why I suggest a retest with the best 2 of the "ladder"/range of loads. to confirm that one or the other is the best after the testing of all loads is complete.

{ If I find that they do not repeat for some reason, I retest once again the ladder/range once again. Plus I do this with each type & lot of powder, or if any components change for each firearm. I am kind of picky about such things & most don't do what I do, I'd imagine, but I enjoy the doing of it, & that makes it fun for me. YMMV of course. ;) }