Reloading Problem/anomaly

[gb32]

Ok, just got back started into reloading specifically for IDPA/USPSA. I've ran into a problem that I have never heard of. Maybe someone can shed some light on this. I'm loading 9mm minor w/ Berry's 147gr. 3.0-3.1 TG, OAL 1.15, crimp is .378. What is happening is when I run some over the chrono I have one reading way out of line with the others and it's always the first shot. For example:

783

872

904

914

903

895

908

886

898

901

What could be causing this? I recheck all my setting when I load and spot check every time a refill the primers. Machine is a SDB btw.

On another front I'm running a ISMI 13 lb spring and had some failures to feed today. Slide not coming back far enough to strip another round. I'm not trying to load the lightest possible load for recoil. I just want to get something that will work in the gun reliably and I can shoot more loading my own versus buying factory ammo. If anyone can shed some light on either of these issues I would be very thankful, GB.

[TimWarner]

I don't have my references handy right now, but 3.0 to 3.1gr under a 147gr seems on the light side. If I remember correctly 3.5 is a more common load.

When I get home from work I'll poke around and see what I can find. Or do a search here for titegroup and 147gr, should turn up quite a few nice minor loads.

[L9X25]

Could it just be a combination of the light load and a tight cold barrel? The barrel warms up and expands over the first 2 shots and then the velocity becomes consistent?

Also, how are you cycling the first round?

Try locking the slide back and allowing the slide to close full force to see if the gun is locking up differently.

[Guy Neill]

It's not uncommon for the first shot from a semi-auto to be different. I don't know that anyone fully understands why, but most credit to the difference in chambering from manually by hand to automatically by the gun.

The cold barrel is likely a further influence.

Also, the benchrest people will fire a couple of fouling shots before firing for record, so bore condition could also factor in.

If you can fathom why the difference, we would all like to know.

Guy

[Patrick Sweeney]

My BHP makes Minor with a 147 lead bullet and 2.7 of Titegroup. So a 3.0-3.1 load might do it. What I found was that I shot a whole lot better with a 138PF load than I did with a 128PF load. The lighter load was just too slow.

As for the first slow being slower, perhaps clenaing the bore? Lube or bore solvent left in the bore might decrease friction, decreasing burn of a light load, and bringing lower velocity?

You could test the theories several ways:

Chill barrel after shooting and see if the velocity drops. (Freon, its replacement, in a can.)

Lube the bore after shooting and see if the velocity drops.

Report back.

[n2ipsc]

It's not uncommon for the first shot from a semi-auto to be different. I don't know that anyone fully understands why, but most credit to the difference in chambering from manually by hand to automatically by the gun.

The cold barrel is likely a further influence.

+1 to both. If the shot string he cites is representative, tossing the first two velocities out, the remainder are reasonably consistent.

When I chrono for handloading records, I'll rip off five quick shots, THEN shoot the record string.

Another consideration we once stumbled on quite by accident, and only because a fellow shooter wanted to test his new chronograph at the same time a couple of us were playing around with recoil springs and sight movement/tracking... is the recoil spring. What we found with both .40's and .45's was that, below some spring weight, velocities started becoming erratic. "Heavying up" the recoil spring reduced sdev - step-change - at some point in every gun we tested. Don't know if anyone else has encountered the same, but if you're experiencing cycling/feeding problems anyway, may be worth a try...intuitively, it's not hard to imagine inconsistent lockup playing a part...? YMMV...

[ima45dv8]

My BHP makes Minor with a 147 lead bullet and 2.7 of Titegroup. So a 3.0-3.1 load might do it. What I found was that I shot a whole lot better with a 138PF load than I did with a 128PF load. The lighter load was just too slow.

As for the first slow being slower, perhaps clenaing the bore? Lube or bore solvent left in the bore might decrease friction, decreasing burn of a light load, and bringing lower velocity?

You could test the theories several ways:

Chill barrel after shooting and see if the velocity drops. (Freon, its replacement, in a can.)

Lube the bore after shooting and see if the velocity drops.

Report back.

Good suggestion. A cheap alternative to canned Freon is canned air, of the type for blowing crud out of keyboards, etc. Turn the can upside down, and voila, instant Freeze-Mist!

[RePete]

(Freon, its replacement, in a can.)

Lube the bore after shooting and see if the velocity drops.

Good suggestion. A cheap alternative to canned Freon is canned air, of the type for blowing crud out of keyboards, etc. Turn the can upside down, and voila, instant Freeze-Mist!

Not a good idea, Freon is ozone really not friendly, plus it's illegal to release into the atmosphere.

It's also a very stupid idea, one mishap and you could very easily lose an eye or freeze a body part.

RePete.

[Patrick Sweeney]

By "freon, its replacement in a can" I meant the new non-freon. Unless you know where to buy it you can't even buy the old stuff anymore.

And yes, you can freeze a finger. You can also shoot yourself with a firearm if you aren't careful. Me, I assumed that since this is a grown-up crowd we'd all know better than to point the business end of a compressed substance at ourselves and press the trigger.

Rule #1 applies to more than just firearms.

[darwin-t]

Ok, just got back started into reloading specifically for IDPA/USPSA. I've ran into a problem that I have never heard of. Maybe someone can shed some light on this. I'm loading 9mm minor w/ Berry's 147gr. 3.0-3.1 TG, OAL 1.15, crimp is .378.

I don't have an answer for the first shots being slower.

What I've been loading with titegroup

Charge 3.3 3.6 3.8

Average Velocity 835 880 919

Power Factor 123 129 135

from a 3" barrel. 1.140 OAL. I've been happy with all three, especially the first two. Low recoil and pretty accurate.

I don't see slower speeds for first shots, but the first ones recorded might not be the first ones I shoot.I usually shoot or two one before I start recording.

If you throw out the first two, the extreme spread is only 27 - lower than mine are - although I shoot 30 shot strings.

[Patrick Sweeney]

Unfortunately, chronoman will not let you shoot a couple of "warmup" shots before he starts recording velocities. So the problem has a real downside, unless you can figure the origin.

Again, keep us posted of any testing you do and results you do or don't get.

[Harmon]

3.3 was silly soft in my glock 34 and i didnt have any of the problems you say your having...cmon, whats 2 tenths of a grain?

sounds like its a cold bore thing causing the low vel

[gb32]

Something I was thinking about was this. I go to work for UPS at 0315 and go to the range afterward. The gun has been sitting into a car in 30 degree temps all morning. Maybe have something to do with it. For now, I'm going to bump it to 3.3 to hopefully eliminate the functioning issues and go from there. I appreciate all the input BTW. Thanks, Gary B.

[LPatterson]

Something I was thinking about was this. I go to work for UPS at 0315 and go to the range afterward. The gun has been sitting into a car in 30 degree temps all morning. Maybe have something to do with it. For now, I'm going to bump it to 3.3 to hopefully eliminate the functioning issues and go from there. I appreciate all the input BTW. Thanks, Gary B.

Aren't you violating UPS Next Day Air policy for UPS workers handling firearms?

[ipscbob]

Another consideration we once stumbled on quite by accident, and only because a fellow shooter wanted to test his new chronograph at the same time a couple of us were playing around with recoil springs and sight movement/tracking... is the recoil spring. What we found with both .40's and .45's was that, below some spring weight, velocities started becoming erratic. "Heavying up" the recoil spring reduced sdev - step-change - at some point in every gun we tested. Don't know if anyone else has encountered the same, but if you're experiencing cycling/feeding problems anyway, may be worth a try...intuitively, it's not hard to imagine inconsistent lockup playing a part...? YMMV...

I have experienced this myself and have attributed the variability to the light spring allowing the barrel to unlock a bit earlier.

This also might be due to differences in powder position in the case affecting ignition. Try tilting muzzle down to the ground, slowly rasing it up and chronoing the shot and see if there is a difference. This is very common with light loads that only fill a small portion of the case.