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Posted: 5/30/2008 12:19:39 PM EST
I beleive that the operator has the greatest impact on accuracy, BUT what is the overall thinking on the accuracy at 100 yards between a 5.5" a 7.5" and a 9.25" barrel in 9mm. I tried a search and found nothing.

Experiences?

grouping at 100 yds?

Does adding a 6.5 inch suppressor make a 5 inch barrel any more accurate?

Thanks!
Link Posted: 5/30/2008 5:13:44 PM EST
Bump for a potential builder...anyone..........
Link Posted: 5/30/2008 6:56:23 PM EST
My 5" is cut down from a 16" upper using winchester white box, topped with a trijicon reflex I can put 10 rounds into 3" at 50 yards no problem dropping 6" plates at 100 yards
Link Posted: 5/31/2008 3:49:48 AM EST
[Last Edit: 5/31/2008 3:51:53 AM EST by TacDoc]
10.5" bbl here. Although my 9mm subgun is intended for CQB up to 50-75yds, I can do 3" groups from the bench at 50yds all day long with ANY ammo (AE, WWB, GD, Blazer, etc.)

I think that 100yds with 9mm is a joke, but this is just me
Link Posted: 6/2/2008 4:48:56 PM EST
Thanks! Anyone else?
Link Posted: 6/2/2008 5:15:09 PM EST
I don't want to take a hit from a 9mm at 100 yards I don't think I would be laughing, we have a 2'x2' plate at 100 yards and with a RR full auto with a 100rnd Beta mag dump they all hit it........
Link Posted: 6/2/2008 5:17:09 PM EST
I've never attempted to group, let along shoot at anything at 100. At 50 I can hit 6" plates all day long though. It's a 5" with an EOTech.

I generally shoot at 15 yds and I shoot at a number of different targets. Lately I've been bringing golf balls if I have any available. It's fun with a back stop cause they'll jump and hit the wall and bounce off. I then try to hit the ball on the move. I've gotten pretty good with it.
Link Posted: 6/2/2008 5:30:05 PM EST

Originally Posted By GOLDRUNNER:
I don't want to take a hit from a 9mm at 100 yards I don't think I would be laughing, we have a 2'x2' plate at 100 yards and with a RR full auto with a 100rnd Beta mag dump they all hit it........


Impressive! What barrel length?
Link Posted: 6/3/2008 5:33:20 AM EST
Barrel length affects velocity, not accuracy. However, a longer barrel with greater speed to the bullet means less drop at 100 yds.
Link Posted: 6/3/2008 7:19:38 PM EST
Not be arguementative (because I'm no expert) but I do believe that barrel length affects velocity AND accuracy. With less spin on the bullet from fewer in-barrel rotations, there has got to be an effect on horizontal consistency and accuracy. Does anyone get the same results at 10 yards from a snub nose and a full frame 6" barrel pistol?


Originally Posted By ForestBeast:
Barrel length affects velocity, not accuracy. However, a longer barrel with greater speed to the bullet means less drop at 100 yds.
Link Posted: 6/4/2008 10:04:56 AM EST
If taken to the extreme, my statement won't hold true. A 1/8" long barrel is not going to be accurate. However, I don't think there is a real accuracy (as in precision, group size) difference between a 5 and a 9 inch long 9mm barrel, if all other factors are equal. However, because of the greater velocity, the longer barrel should have less drop and be more practical if you're shooting past 50 yds. I'm no expert either, I just express my opinion sometimes on this website .

One more thng, I think a snub nose revolver not being accurate is more a factor of the sight radius , the recoil, the grip size, etc. If you clamped one in a vise and fired it I bet you'd get some pretty good groups at 25 yds.
Link Posted: 6/4/2008 10:55:01 AM EST
Just a tangential point of fact here, but barrel length shouldn't directly impact rotational velocity -- and by extention should not impact gyroscopic stabilization. A bullet fired in a barrel with, say, a 1:10 rifling twist will make one revolution every ten inches of flight. That's one rotation every ten inches within the barrel, and continues to be one rotation every ten inches outside of the barrel. Eventually forward velocity will be reduced from wind resistance, changing the effective spin rate, but that's fairly immaterial at closer ranges. Yes, a longer barrel that gives higher velocity will spin the bullet at higher RPMs, but that bullet still makes the same number of revolutions per distance forward.

Barrel length effects on accuracy become more pronounced with lesser quality barrels and bullets. If you have a projective bouncing its way down an oversized and irregular bore, the longer barrel gives a greater distance for the bullet to get stabilized and redirected more true to the bore centerline.


Originally Posted By -Sabot42-:
Not be arguementative (because I'm no expert) but I do believe that barrel length affects velocity AND accuracy. With less spin on the bullet from fewer in-barrel rotations, there has got to be an effect on horizontal consistency and accuracy. Does anyone get the same results at 10 yards from a snub nose and a full frame 6" barrel pistol?


Originally Posted By ForestBeast:
Barrel length affects velocity, not accuracy. However, a longer barrel with greater speed to the bullet means less drop at 100 yds.
Link Posted: 6/4/2008 1:51:35 PM EST
[Last Edit: 6/4/2008 1:52:21 PM EST by duncan]
He's right - more velocity with longer barrels.

But as with any other gun, a longer sight radisu should help improve the shooter's accuracy.

As a reloader, I can pick some slower powders like AA#7 or Power Pistol for 9mm and burn up all of hte powder out of a 16" barrel. So you can get near 1400 fps there.

BUT, most 9mm performance bullets are designed for 1300 fps. So I can't tell if the accuracy is improved by higher velocity.

But a heck of a lot less bullet drop.

From 25-50 yards, my Oly 9mm AR is a tackdriver with a 30 round Sten mag.

HK MP5 barrels go to 8.9" using NATO hot 9mm ammo. Pick the 9" barrel.

And the Beretta CX4 Storm and the Ruger PC9 Carbine and the Kel-Tec SUB-2000 and the Sub-9 carbines all have 16" plus barrels.

My Kel Tec shot 9mm quite accurate as well.

Longer definitely.
Link Posted: 6/4/2008 2:35:56 PM EST
Just a range observation, I've picked up many a spent FMJ 9mm and .45 bullet downrange, and they consistently have ONE set of grooves and lands. That means, at least from my observation, that the bullets are spun up immediately upon starting into the rifling, that it they are not grinding forward much if any without grabbing the rifling grooves.

I suspect if you shot lead nose bullets, or very high velocity bullets, there would be some shearing in the grooves, but FMJ seems to bite right in!

I've also seen many rifle bullets in the berm, same scenario, no shearing, just 1 set of lands and grooves in the copper.

Next time to the range, spend some research time looking at the "used" bullets downrange.
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