Very accurate load but too slow...

First topic message reminder :

Hi,

My goal was finding loads that were very accurate with mild recoil.  They were beautiful on the bench.  But I found them too slow offhand.  It seems that my flyers are magnified with poor follow through compared to the faster loads.

Here's an example of a slow but accurate load.
Precision Delta 148 HBWC, 2.9 HP38, S&W model 14-5    Avg vel. 677fps

When I bump the speed up my off hand accuracy is much more consistent.
Precision Delta 148 HBWC, 3.0 Bullseye, S&W S&W model 14-5, 6"   Avg vel 807fps

It seems like a faster bullet will mask some errors in concentration.  Do any of you have a certain velocity range that you look for?

Thanks,
Dave

bdas,

While you do not see "appreciable movement" in the videos prior to the exit of the bullet, it is there. Movement is both a change in barrel placement as well as the angle relative to the target, with the greater influence being the the angle relative to the target. A 6" displacement at a 50 yard target is around 12 minutes of angle.  If one were to use the breach of a 6" barrel as a pivot point, then the physical movement of the barrel is only a mere .020." This is not a lot of rotational/angular movement, but it shows up on the target. 

This is also a sound mathematical explanation of why sight alignment is so important compared to our physical movement during aiming and shooting.

-Ron

When shooting a 6" longslide, it will let you know very quickly if you are not being consistent with trigger squeeze or grip pressure. The pistol whips more than a 5" and you can really feel the difference/error. That minute amount of time that the bullet is in the barrel longer (1") really makes a huge difference.
Jon

Very interesting.  And, beautiful model 14.

the amount of movement of the pistol due to wobble/flinch while the bullet is in the barrel would still be negligible. 

So, what I'm understanding regarding fliers is my error in alignment occurs before I pull the trigger.  But, why would follow through matter if the bullet leaves the barrel so fast?  

Thanks,
Dave

Follow through to me is about concentration.  If I'm focused on the front sight before the shot and intend to do so during and after (follow through) then I am more likely to continue the pre-shot focus long enough to get the bullet out of the gun.  Without follow through, the mind may abort the focus just a pinch too soon without even knowing it.  My kids all have a habit to go bang then shift eyes to the target to look for hits on the paper.  They see em too.  They're in the white not black.  Once I explained follow through, they improved dramatically.

BDAS wrote
    "Out of curiosity, how much difference is there in the point-of-impact?  A few inches?"

I would say it is closer to 6-8". If it was only a couple of inches I may never have noticed it.

Len

r_zerr wrote:bdas,

While you do not see "appreciable movement" in the videos prior to the exit of the bullet, it is there. Movement is both a change in barrel placement as well as the angle relative to the target, with the greater influence being the the angle relative to the target. A 6" displacement at a 50 yard target is around 12 minutes of angle.  If one were to use the breach of a 6" barrel as a pivot point, then the physical movement of the barrel is only a mere .020." This is not a lot of rotational/angular movement, but it shows up on the target. 

This is also a sound mathematical explanation of why sight alignment is so important compared to our physical movement during aiming and shooting.

-Ron

Ron, 0.02" is about 10 pixels high in that video.  Vertical muzzle movement of that magnitude over the course of 5 frames would be very obvious in that video.  Also keep in mind that in those 5 frames of video we're looking at the whole process from the frame before ignition until the bullet is well clear of the barrel, and the muzzle does not appear to move vertically at all during that time span (due to shooter movement or Newton's 3rd law).  In this discussion, we're talking about the difference between the time in barrel of one load, versus the time in barrel of a different load, (or between a 5" vs 6" barrel) which is going to be a fraction of the total time in barrel (which is already tiny).  These small variations in the time in barrel are simply not long enough for the shooter's wobble/flinch to result in 6" changes in the POI at 50 yards.  It's just not possible.

Barrel deflections that are moving at recoil speed (10's or 100's of feet per second), as Len described, are a different matter.  It's entirely possible that that could cause 0.02" of muzzle deflection in these time spans.

bdas,

my first reaction was to say, "no," but then your last line added significantly and I have to say "yes." I can see where the recoil speed and angular velocity of the muzzle seriously play into it. I think it is safe to say that there is a lot going on, and they all add up, but that added to what I had stuck in my head.

-Ron