I try to get to the range at least once a month, more often if I have time. When I go I normally take my two carry guns at least and spend some time shooting both guns as if I am qualifying for my CCW. To warm up I toss between 50 and 100 rounds between my 380 and my 9mm.
What I have noticed is that for the first three or four magazines in each gun the 380 seems easier to keep in black on a Silhouette at both 7 and three yards. By the time I have gone through 6 magazines the 9mm is a bit easier to hit where I point. at 10 yards the 9mm is always the tighter group.
I was thinking it was less recoil at first but I am beginning to wonder if the sight plain being about 1/2 inch longer on the 9mm is enough to give it the advantage at 10 yards? Could I be on the right track? I can still qualify with both guns but maybe the 9mm has a more consistent trigger break? Just musing here.
A quick search turned up this… 2/100 of an inch deflection on a 16" rifle barrel iron sight results in a 2" deflection at 25 yards. Sight Radius Calculator, Effect on Accuracy Explained & How Range Time Improves Shooting Skills - FAAC
The formula is
Tan(Barrel Angle) x Distance to Target = Bullet Deflection
(Thank you PewPewTactical for not making me go back to high school math to figure that out) Basically, a shorter sight radius (distance from front to rear sight) makes it harder to see the error in your barrel angle. The longer the barrel, the easier it is to see the error.
Your sight radius will affect your accuracy, but I don’t know if it is causing the shift in accuracy you’re seeing.
I absolutely think the 1/2" sight radious can make a difference. I know that effective pistol shooting is a VERY perishable skill. Something I have demonstrated to myself on many occasions after long breaks from the range.
Here’s a diagram we use in the USCCA Concealed Carry Classes that really illustrates the variation over a distance:
The longer barrel length can change your accuracy a smidge - and over a distance that smidge will definitely increase.
@Dawn I was hoping you’d post that
E Learning: Concealed Carry and Home Defense Fundamentals
"(5) times reviewed *(1) Passed *(3) times studies complete (BOOK)
I really enjoyed that book very much too. The information is a true
fact. Thank You
P.S. Everybody needs this training, even if it is refreshment only.
It is good to know there is some science behind some of my observations. Thanks for the responses.