Help reading primers

[jba6511]

Made up my first batch of 9mm following the Hornady handbook of cartridge reloading 9th edition. I would like some assistance to determine if the rounds I made are showing signs of overpressure. Also, the load data called for a C.O.L of 1.15 but I noticed that my rounds would vary anwhere from 1.40 - 1.51 using mixed brass. Is this anything I should worry about? The rounds that gave me the best accuracy were at the vary minimum of 4.0 while I shot 4.1 horribly. Is there any concern here with being at the starting load? The pistol still cycled and feed reliably. Thanks to everyone who has helped me get this far.

1 black strip = 4.0 gr
1 blue strip = 4.1 gr
yellow coloring = 4.2 gr
1 red strip = 4.3 gr
black X = 4.5 gr
blue X = 4.6 gr
non marked are factory rounds from the same gun for comparison.

 

[Clarke123]

Other than a more careful look at your Black & Blue "X's" ....
What powder, primer and projectile are you using?
Knowing these would greatly assist in determining what (if anything to look for)

BTW: I'm not that far from you in Cumming, GA!

 

[jba6511]

Powder is unique, primers are federal spp match, bullets are armscor 124 gr FMJ, brass is mixed Speer and blazer. Thanks for the assistance

 

[Clarke123]

My Lyman 49th Edition shows a loading for a 125 Grain JHP (which is heavier than 124 Grains and therefore considered safe to use for a similar 124 Grain Projectile)
It shows a Minimum loading of 4.5 GR and Maximum of 5.0 GR of Unique with a OAL of 1.075" ... Making all of your loads very much on the "safe" side.
I personally use the Armscore OR Berry Plated 124's over 4.3 GR of Universal at a OAL of 1.142" and a very, very light crimp @ .378" (I actually use a Lyman Headspace gauge to check them!) ... and all of my 9'mm pistols LOVE them. Universal and Unique are almost interchangable, and neither like minimum loads (bad to smoke and blow residue).

So, I would say that given what I see in your pictures, AND what is published: Your only decision is which one gives you the best performance and easiest to reload!

BTW: OAL IS an important factor in loading (Too little can cause an undesirable spike in pressure!). Further, the "crimp" on straight walled auto-pistol cartridges is
always tappered and always, always very slight as the cartridges "headspace" on the case mouth: too much taper results in no headspace, which is NOT GOOD!
Revolver loadings require a different crimp strategy for the particular caliber being loaded.

 

[jba6511]

Thanks for the info. Now I need to come up with a good technique for judging accuracy.

 

[Clarke123]

Well, I can certainly understand that ... I'm not a great shot and that is a disadvantage to
determining "most accurate" loads! When testing loads, I normally use one of the rifle lanes that has a bench and seat
where I can do a better job of "firing from a braced position" using some sort of support on the bench.

My "off hand" goal is a "pie plate" grouping at 25 yards.
Yes, there are pistols that are capable of 2" groups at 25 yards ... just not in my hands!

 

[Boregauge]

To me it looks like you are not having any overpressure problems,I myself use the same load for target shooting as I carry why train with one spec. and carrry with another. if that much in powder difference saves you that much money and is worth it when it comes down to hitting your target in a bad situation than do so. It looks like to me that you are shooting a fairly new glock that is giving you the heavy firing pin strikes.Make up a load that you are comfortable shooting and by the book and stick with it,your shooting will improve if you stay constant with your loads and I suspect the primer strikes will change with wear. if you see any outward bulging of the primer that would indicate overpressure.as far as overall length get it as close as you can,bullet length & weight will vary some but shouldnt vary much if they do buy a better brand bullet and check them. just my .02 cents

 

[jba6511]

Thanks, these were indeed shot of out a new gen 4 glock 19. I will try shooting from a rest to help with the accuracy. Does 10-15 rounds at each weight starting at 4.0 and increasing by .2 sound like enough to get a good sample for accuracy?

 

[Clarke123]

In developing a load there are several factors at work here ... you, your weapon, and your load.
If you are "new" to shooting a GLOCK there is some getting used to the trigger (READ the GLOCK web page on how they recommend using their trigger ... this will help LOTS).

For me, It should take no more than 5 rounds per loading to give a good idea of how well a load shoots ... but that's me, and not you.

Keep in mind: Light loads might look really good on a 5 yard target, but shoot too low or erratic on a 25 yard target ,,, the idea is to "shoot what you would carry" and saving a few grains of powder isn't worth it ... After all, a pound of powder has 7000 Grains in it!

Then there's the "fudge factor" as in how accurately your powder measure throws. I always err on the side of it occasionally throwing a little heavy (and load so that it will NEVER EXCEED MAXIMUM). If you determine that you want all loads "at MAX" then plan on trickle charging every one of them.

BTW: The (published) starting load of 4.5 Grains of Unique is where I would start, but (again) that's me (and not you)

 

[Clarke123]

GLOCK Trigger Pull

To quote GLOCK:
A special feature of the "SAFE ACTION"® System allows the trigger to "reset" with only limited forward movement of the trigger. It is not necessary for the user to completely release the trigger in order to fire a second controlled shot or when there is a need to fire several rounds quickly. After a round is fired, it is only necessary to release the trigger until it "resets", which can be heard and felt. This "reset" feature of the "SAFE ACTION"® System enables subsequent shots to be fired quickly and accurately. All three pistol safeties automatically re-engage when the user releases the trigger to its forward position.

Use the above ONLY WHEN THE PISTOL IS POINTED AT YOUR TARGET!

And Others:
http://m14forum.com/handguns/108002-gen-4-glock-trigger-pull.html
http://thefiringline.com/forums/showthread.php?t=375320
http://pistol-forum.com/showthread.php?4942-Glock-shooting-rolling-the-trigger/page2