[cubcadet]

I noticed today when i ran a few reloaded rounds through my Colt LE6920 the primers had a lightly indent from loading and ejecting the live rounds.

I did this just to be certain i don't need a small base die. The 6 rounds chambered ok. Didn't have to use the forward exsist.

I looked into this on you tube. Reports i got was not to use cci 400 primers. Thats what I use. They recommend #41 primers. I never heard of this.

Secondly, was its normal cause of the floating firing pin and recommend to load that round in the clip mixed in with others that were not chambered. Has anyone experienced this before?

I know some are gonna ask did i slam the rounds in? I loaded the clip with 30 rounds. I pulled back and let go. The bolt closed all the way. After 6 rounds doing this i inspected the live rounds and noticed the light indent on the primer from the 6 rounds. Yes I did this outdoors where it is safe.

I have been reloading for many years and never seen this on any of my reloaded ammo test running them thru the rifle. They say AR's are different due to a floating firing pin.

I would like any information if anyone used the #41 primers & that solved the issue. I'm not liking keeping the 6 rounds that are indented lightly. I fired those rounds. I wasn't going to put them back in the clip or keep in the house.

I didn't know this so maybe other members read this will know now what the floating firing pin does to 223 ar-15 rounds once its been chambered and not fired. Thank you...

 

[mattg1500]

Yes I have experienced this in 99% of the ammo I have used in my AR, 556 and 223. While on a hunting trip my father in laws Bushmaster 450 actually went off sending a projectile into the ground while he was chambering a round. It is a "slam fire" and usually happens when you hit the bolt release. IMO when I stripped his gun after the incident I felt there was a lack of maintenance causing the pin to be more stiff than mine was on my clean gun, he of course disagreed but my proof was all over my cloth. I went into my box of Hornady 75gr match BTHP and there were at least 10 in there with a slight dimple on the primer from me loading the round then ejecting it without firing. If you look on other forums you will see the impression is normal.

Bushmaster recalled parts on their bcg and sent new ones to owners to try and prevent "slam fires"

I have well over 20000rnds through my DPMS and never had the "slam fire" but have the impression on unfired rounds. I keep them and use them next time with no fear of them going off while in the box or sitting in my mag.

 

[RobOz]

When I started loading for AR type rifles 15 or so years ago I was told to stay away from the Remington 6.5.

With that said, I have loaded thousands of rounds using CCI 41's and CCI 450's. I have always used a magnum primer with my 556/223 AR loads. I also have never had a slam fire.

 

[glock3540]

I've loaded and shot thousands of rounds of 223/556 with standard CCI small rifle primers and have never had an issue

 

[Dogface]

There are a few issues at work here.

You may have a weak firing pin spring. I have never noticed indents on my primers on rounds fed from a magazine.

I always load from a mag. If you put a round into the chamber and let the bolt fly on an AR or M-14 the inertia from the forward movement of the bolt will cause the firing pin to move forward and hit the primer and it could cause a slam fire.

If you load from a mag the bolt will slow as it pushes the round out of the mag and it will not have the momentum needed to cause the firing pin to fly forward contacting the primer.

The CCI 41 and 34 primers are designed for military rounds. They have a harder / thicker cap and will resist a slam fire.

 

[RobOz]

There are a few issues at work here.

You may have a weak firing pin spring. I have never noticed indents on my primers on rounds fed from a magazine.

I always load from a mag. If you put a round into the chamber and let the bolt fly on an AR or M-14 the inertia from the forward movement of the bolt will cause the firing pin to move forward and hit the primer and it could cause a slam fire.

If you load from a mag the bolt will slow as it pushes the round out of the mag and it will not have the momentum needed to cause the firing pin to fly forward contacting the primer.

The CCI 41 and 34 primers are designed for military rounds. They have a harder / thicker cap and will resist a slam fire.

The AR15 does not have a firing pin spring, it has a free floating firing pin.

 

[Steve in PA]

Any rifle with a free floating firing pin will leave a small mark on the primer when you cycle a round through the action.

I've reloaded and shot many, many thousands of rounds through my AR rifle and M1 Garand using regular CCI primers. #400's in the AR, #200's in the M1. As long as you ensure you don't have a high seated primer, there won't be an issue.

 

[cubcadet]

Thank you guys for the response's.

 

[Dogface]

Yes you are right and neither does the M-14. I guess it's an "Old Timers" thing.