HOME AMMO /GUN TEST

AR/M4 AR General Discussion
1

I have read on this several times on this forum that for duty and home defence that once you chamber a rd you should leave it in the chamber because of the free float firing pin/causing indents. on primer.

I decided to test this myself.

Lk city green tips, Hornady tap 556 62 gr barrier/pmc bronze, remington 55 gr psp.

I chamberd each rd 20 times , I could see a little indentation on each one .

On the 21st try each one fired perfectly.

So what I would really like to know is has everyone that says after 4or 5 times it wont fire , have you really tried this your self or are you just passing on what you have heard?

2

I don’t need to perform this test for myself, as I will continue to rely, and use DocGKR’s sage advice/information regarding ammo/terminal performance…

Here is a quote from DocGKR’s 5.56 Duty Loads thread…

"A large SWAT team in this area had a failure to fire from an M4 with Hornady TAP ammo during an entry–fortunately no officers were hurt and the suspect immediately threw down his weapon when the carbine went click instead of bang. After the incident was concluded, the team went to the range and expended the rest of their carbine ammo and had one additional failure to fire. This same team had 3 Hornady TAP rounds fail to fire in training a couple of years ago. When Pat Rogers was teaching a class at a nearby agency, there were 5 failures to fire using Hornady TAP ammo. In all 10 cases, there appeared to be good primer strikes, but no rounds fired. On analysis, the ammunition had powder and checked out otherwise.

However, despite what appeared to be good primer strikes, two problems were discovered. First, when accurately measured, some of the primer strikes had insufficient firing pin indentations. The failed round from the potential OIS incident had a primer strike of only .013"—the minimum firing pin indent for ignition is .017". In addition, the primers on the other rounds were discovered to have been damaged from repeated chambering. When the same cartridge is repeatedly chambered in the AR15, the floating firing pin lightly taps the primer; with repeated taps, the primer compound gets crushed, resulting in inadequate ignition characteristics–despite what appears to be a normal firing pin impression. Once a round has been chambered, DO NOT RE-CHAMBER IT for duty use. Do NOT re-chamber it again, except for training. This is CRITICAL!!!"

[b]5.56 Duty Loads[/b]

3

The main point: Why risk it? That first shot may save mine or others lives.

4

Sums it up well. I know guys that who after they chamber a round once if they clear the gun that round does not go back in until range time and it is used for practice. Personally I won’t because of issues I have seen with pistol rounds becoming impacted and accuracy and performance falling off because of it. I would believe that it could happen with a rifle just as well. Ammo is cheap my ass is not.

5

Doc’s info is spot on, same thing goes for handgun ammo. Constantly rechambering a round is just a good way for you or an officer to get hurt or killed when you really need that round to function.

To be honest once I chamber a round on any duty weapon it stays chambered, except for the ar platform it then gets rotated into training surplus or placed at the bottom of the mag.

6

I never had a problem, but why risk it when it is so easy to totally avoid. Keep in mind this is a group that is OCD about our gear, equipment and performance.

7

This is the first time I’ve ever heard of this being an issue. The report suggests that the primers were either set in too far or that the firing pin may not be long enough, or do deep enough to provide positive ignition. If the .017 depth is needed and the weapon could only acheive .013…something else sounds off. As far as the other rounds checked that were damaged…did they still fire?

8

The problem with previously chambered rounds, which is what the OP was testing, was with the primer compound being crushed. This caused it to not ignite properly, even with a proper primer strike.

9

It’s interesting that all the ammo failures were Hornady TAP. A coincidence?

I’d guess that Hornady is using improper primers, or is seating them improperly.

10

This may sound off track , but all the reasons given above are also reasons to use mil spec primers if you reload for any simi auto with a floating firing pin. IE: ar 15, m1, m14. absolutly do not use a match primer in them.

I had a unlocked slam fire in a M1 with a match primer. I preach this but alot of people use match primers in gas guns, I used to.

he went into younder village and never returned

11

My guess is that it’s simply a matter of everybody was using the same department-issued TAP ammo…

12

I am in the “it isn’t worth a chance” camp.

I have seen pistol ammo that has been chambered a bunch have serious bullet set back issues. I assume there could be problems as well with rifle ammo.

I personally have had every multiple chambered round fire, but they are all in the training (or bottom of 7th mag) status.

My piece of mind is well worth the $1 round.

13

bullet setback, primer compound crushing, normal wear and tear from the action on the casing and bullet. its our teams policy to mark the bullet tip with a sharpy upon chambering, if at any time you see a round with sharpy mark on it that round gos into your range ammo. its made to shoot plain and simple.

14

Sounds to me like Hornady TAP was the only common denominator.

15

in this instance yes it was hornaday tap but im not going to stake mine or anybody elses life on it. we know this team had a problem with rechambering the tap round before dropping the hammer. how many people dont know their brand does the same ? to each his own and if dedicating a box of duty ammo a year to “loaded chamber rounds” is to much $$$$$ then. . . . . well i have nothing more to say.

16

Hornady has a reputation for primer problems.
I’m not advocating anything other than Dr.Roberts advises, but I am also going to further hypothesize that this specific issue was a Hornady problem.

17

i will totally agree on the hornaday primers and it is documented elsewhere. im simply saying there are to many variables between primers; floating firing pin force and moon phase to totally rule out there being other ammo/weapon combinations that will do the same. i ride on the side of caution and its just my 2 cents worth.

18

I’ll err on the side of caution, as well, but for me, that means using something other than Hornady AND not re-chambering ammo.

19

This is the first I’ve heard this.Excuse me I’ve gotta go remove the first round in my mag.Not gonna chance it.My AR has gone bang every time I’ve pulled the trigger.I wanta keep it that way.

20

[QUOTE=jose45;1231360]This is the first I’ve heard this.Excuse me I’ve gotta go remove the first round in my mag.Not gonna chance it.My AR has gone bang every time I’ve pulled the trigger.I wanta keep it that way.[/QUOTE

were discussing having a round chambered for an amount of time and taking it out when you go to the range to practice then rechamber that same round of duty ammunition again (repeating over and over again). rechamber the same round lets say 25 times and do a thorough visual inspection between it and a new round.