Does it all Just Come Down to Muzzle Velocity?

Hi All,

A question.  When considering powder type, load, crimp, etc....do all of these variables only influence the velocity of the bullet when it leaves the muzzle?  And is the velocity of the bullet from a given barrel the only thing that matters for accuracy?   This assumes that you remove the gun action and the person pulling the trigger.

Put another way...if a gun shoots well with a tight crip that gives more FPS for a given load, would adding more powder to achieve the same velocity also give the accurate result? Same can be said for powder type.

Best,

Joe

Re: type, load, and crimp—yes and no.  Different powders and seating depths and crimps affect the pressure and manner of combustion.  The goal is reaching an ideal velocity (for that projectile and barrel combination) as consistently as possible.  One output is velocity, but that isn’t the only thing that changes.  There are other concerns as well—some shooters might consider completeness of combustion to the mix. A “faster” burning load (regardless of muzzle velocity) burns more completely, which might mean fewer alibis.  It might recoil differently in hand, for better or for worse.  All these considerations can drive powder choice and load design.  770 foot per second can feel very different with different powders.

Re: velocity—yes and no.  You need a quality machined barrel fitted properly to your pistol.  The bullets need to be concentric and physically as uniform as possible.  The cases should all be uniform, which ensures they pass through loading equipment without variations in fill, seating, or crimp.  If you control for all of those, then the only thing that makes a difference is getting all of the bullets as close to the ideal velocity as possible with an acceptable level of cleanliness and recoil feel.

(With the caveat that precision pistols are not F-class rifles—you don’t need absurd levels of precision to get good results. Accurate “enough” with softer felt recoil works great across 2/3 of the bullseye course… so loading a soft well-known “pet load” and putting the energy and attention into practice pays more dividends.)

Re: does tight crimp equal more powder?  No.  This is not math with transitive variables.  A thou or two more crimp doesn’t necessarily increase velocities.  What it can do is increase the pressure needed to unseat the bullet and drive it into the lands, which—in theory—gives a more consistent and complete powder burn.  It’s not the same thing as dumping in another 0.05 or 0.1 grains of a given powder.

each powder behaves differently, each bullet behaves differently, and each combination will behave differently. 

Its like when i did my "short range" load testing for my wee lil 44 magnum.. red dot powder was providing the same rough velocity range.. but the groups it provided were 

1. exactly at point of aim
2. the group size, on that day, was providing no more then an inch wide and the height was all due to sight alignment.. 

It was shooting at 20 yards double action like my 357 magnum shooting SB factory 148 grain wadcutters at 25 FEET.

Now my mornings shooting with said 357 and various handloads and that sb 148 grain ammo proves another point that most over look. 

   Distance is a big bugger to accuracy.  With my handloads that were providing a crappy 2" circle at 25 FEET,  same handloades were providing an extra 2" of impact circle on target for every 10 yards i stepped back.. 

The SB 148 at 25 FEET were a nice 1/1.5" group, 2 cylinders shot double action, two hands on gun. 

  Doubled the range, and I actually trippled the impact circle on the target.