rcmodel
Member in memoriam
CCI #400 is about all I have used in AR'15s and Mini-14's for going on 44 years.(CCI 400) You would be correct. Problem solved.
That ain't the problem, unless you smash them in.
rc
CCI #400 is about all I have used in AR'15s and Mini-14's for going on 44 years.(CCI 400) You would be correct. Problem solved.
My CCI 400 primers (lot No. H05Q) flow in my Savage axis with mid-range loads. Primer sensitivity may change from lot to lot? Rem 7 1/2 show no flow.For posterity, the lot# of these primers is "B11U". and I have 1400 to trade, if you have a bolt-action small-rifle
Very True.It's just the nature of the floating firing pin to ding every primer when the round slams home and the bolt locks and allows the firing pin to bounce off the primer.
Here's the skinny on the Federal GM205MAR primer.
http://68forums.com/forums/showthread.php?32572-Here-s-the-skinny-on-the-Federal-GM205MAR-primer
My friend at RCBS contacted the expert at Federal, and this is what he was told:
Mix is the same as in the standard small rifle primer. The primer cup is thicker, as is the anvil. The thicker cup and anvil “should” desensitize the primer a bit, and “lessen” the chance of a slam-fire. Federal primers are in general, more sensitive than CCI and less tolerant of firing pin blows during loading into the chambers of the M1 Garand, M1-A, and AR platforms.
I hope this helps shed some light.
This is an interesting comment on the best type of primers to use in AR's:
Milspec primers for AR's not necessary?? See what the manufacturers have to say.
http://www.atgreloading.com/t1157-m...essary-see-what-the-manufacturers-have-to-say
by RemMan700 on Tue Aug 30, 2011 9:43 pm
Most people think that the CCI #41 is the only safe primer for fire arms with free floating firing pins such as the AR-15. I contacted several manufacturers to see what they had to say on the subject and if their primers were ok with these types of firearms.
CCI:
Hello,
Could you please tell me what the difference is between the CCI 400 primer and the CCI 41 primer? Does the 41 primer have a thicker/harder cup and less sensitive priming compound then the 400 primer?
Response:
A CCI 400 is our 'standard strength' of small rifle primer.
A CCI #41 primer is a 'magnum' strength of primer, equivalent to our CCI 450 Small Magnum rifle primer, ballistically. The #41 primer also has a feature to help lessen the chance of a slam fire in semi-auto types of firearms. This feature is that there is more distance between the tip of the anvil and the bottom of the cup, creating a slightly less sensitive primer. The #41 primer also has a thicker bottom on the cup than the CCI 400 primer.
Linda Olin
CCI/Speer Technical Services
2299 Snake River Ave.
Lewiston, ID 83501
Then you need to up-grade to a better method of priming.
My RCBS hand priming tool has worked flawlessly for a lot of years.
You just can't beat the 'feel' and control they give you with press priming.
rc
GWStaar, I disable the depth stop and seat by feel on the rcbspro2000. The variances in rim thickness will allow high primers even as the press hits the stop. I use the stop in 40S&W, because it's easy to crush/deform small pistol primers, and for some reason 40's seem to seat deep easily. I think RCmodel is right about making sensitive primers by using too much force, but my force hasn't changed for the last 2000 rounds and I'm seeing slamfires with a new lot of CCI400's. Looking at my loading logs, it would appear I used CCI400 long ago, w/o problems. I'm still thinking I have a bad lot. The only other variable is this FC brass, but I can't make a connection to that at this time.If you are going to prime using any progressive press, you have to make sure you've not only got the crimp out, but that you have a decent presentation to the pocket. That means a rounded or chamfered entry that won't catch an edge.
I accomplish that by either reaming with a reamer that rounds the edge or swaging and then touching the pocket to a reamer for a half second in a Trim Mate (while doing uniforming and flash hole deburring operations)
If you look at commercial brass, you'll notice they all have rounded entry.
Since the O.P. uses a Pro 2000, I'd suggest uniforming pockets so that you can use the depth stop....that's the only way you can be ensured of pockets set the same depth using the press.....makes up for the lack of feel you can only get from a hand primer.
GWStaar, I disable the depth stop and seat by feel on the rcbspro2000. The variances in rim thickness will allow high primers even as the press hits the stop. ............
-edfardos
That statement is completely incorrect. The NATO rated CCI#41 primers are magnum strength primers without a doubt and that is directly from CCI, not a guess. The information is at the bottom of the linked page and other spots on their site too.I think you missing the intended direction of using a harder primer. Using a CCI 450 (or any SR Magnum) primer would be an entirely different load. The CCI 41 should be functionally equivalent to the CCI 400 (same load) but with a harder cup.
The 41's and 34's contain Magnum priming mix and should be treated as such.
That statement is completely incorrect
I wonder if head clearance is a factor when using sensitive primers ?? When comparing head to datum of both lots of ammo, would a difference of .010" have an effect? If the slam fired rounds only had .002" head clearance, would the primer be struck by the inertia firing pin with more force? The rounds with .010" head clearance would have more slop in the chamber. A light tap from the pin may move the round forward in the chamber, not causing a slam fire? But maybe the extractor would keep the round from moving forward? This is with all primers seated correctly, about .004" below the case head. Just thinking out loud.next 100-200 were non-mag primers with PMC brass -- no slam fires
next 201-300 were non-mag primers with FC brass -- slam fires on #225 and #275
This isn't the first mention of a failure of the disconnector to cause a slam fire, but I understood that the AR15 bolt will not allow the hammer to follow the bolt home all the way; instead it is "captured" with the bolt not completely closed. The intent is to prevent simple conversion to full auto (although not select fire) of an AR15. Can someone verify this?I had this happening with my disconnect. If I pulled the trigger and held it bottomed out then the disconnect would work fine. If I pulled the trigger really really slow and careful like I was shooting for accuracy I could hold the trigger half way and the disconnect wouldn't catch. I had it pump 3-4 off at a time while figuring it all out.
rc,The way all AR-15's/M-16's work is, the bolt slides in and out of the bolt carrier.
It is only locked shut at full foreword travel of the bolt carrier.
As the bolt carrier telescopes over the bolt, the cam pin rotates the bolt into full lock-up in the barrel extension.
At all other times?
The firing pin is too short to reach the primer until the bolt carrier has already locked the bolt shut.
Even IF the hammer could hit the firing pin before the bolt is locked?
It is too short to reach the primer until the bolt is rotated into full lock-up by the bolt carrier & cam pin.
In a full-auto M-16, the hammer is tripped (by an unnamed part) of the trigger group AFTER the bolt is fully locked by the carrier.
If the hammer simply followed the bolt carrier down, it would not have enough energy left to fire the primer.
rc