AR-15 and case life

[Chappy]

I have been reloading 223 Rem for my Ruger M77 for many years.  I am careful and inspect my brass and usually toss it after 12 firings.  So far, I have had no case related problems - "knock on wood."  Last week, I purchased a new Bushmaster Predator AR-15 type rifle.  On their website is the usual "do not use reloads as this voids your warranty."  That did not surprise/bother me.  But then they went on to say that "if you use reloads and/or surplus ammo long enough, sooner or later you will experience a case head separation that will probably destroy the upper part of the aluminum AR and possibly the bottom unit as well."

My question to all of you, and especially those who reload for your AR is: Do you know of anyone who had a case head separation in these rifles, and if so, what damage did it cause?  Also, how many times to do you guys reload a case- on average?  Also, what brands work best for you? I have had good luck with R-P and Winchester in my M-77.

Thanks for letting me pick your brains!

[John Traveler]

I've fired many tens of thousands of reloaded .223 in my AR-15 type rifles and seen or observed the firing of many tens of thousands more by friends at the ranges.

I've yet to see the results of a "blown up" receiver from case head separation.  You can normally get upwards of a dozen reloads from the same case before it becomes unserviceable from neck splits or enlarged primer pocket.  GI brass is what I mostly use, but commercial WW, RP, FED is good too.  The worse was korean made PMC brand brass with poor quality control and heat treatment.

The AR multilug lockup is normally quite safe in the event of a case head separation.  A premature ignition from firing pin slam-fire however is very hazardous, and hard primers are used in military production and reloading to minimize this risk.  Premature firing of a cartridge before full lockup IS likely to wreck the upper/lower receiver and magazine.

Incidentally, some lots of 5.56x45 NATO ammunition were recalled early in the Afghanistan war because of reported case head splits.  No weapons or soldiers were injured, just the ammo failure.

[Old Syko]

A supposed Mil-spec rifle that can't handle Mil-spec ammo?  What's the point?  I've gotten as many as 20 loadings on Lake City brass with light to moderate loads.  Heavy loads on the other hand result in brass going into the recycle bucket after as few as 6 loadings.  Most commercial brass is not heat treated and will fail long before mil brass.  Any commercial federal brass i come by goes straight to the recycle bucket.  Just not worth the effort.  Pick up some LC from Jeff Bartlett or one of the other Mil-surp suppliers and give that Bushy it's due.

[John Traveler]

All commercial bottle-necked brass is heat treated before loading.  It is an essential step of ammo manufacture and helps assure proper bullet pull and absence of neck cracking during storage. The biggest difference is that on commercial brass, the rainbow heat treating colors are polished off in a subsequent operation, while the MIL-SPEC requires that the heat treating colors remain as proof of the heat treating step.

Lake City and other arsenals certainly makes good military brass, and is probably the most commonly found.  However, ALL of the commercial manufacturers at one time or another have produced MIL-SPEC 5.56x45 NATO for Government use, and they are all required to meet the military specifications.  For that matter, almost all foreign military production of 5.56x45 NATO caliber was originally produced on US supplied equipment and made to US MIL-SPEC, including that produced in korea, taiwan, singapore, the philipines, etc.  Quality control has fluctuated at times, but all of these producers were brought under the umbrella of US military-industrial technical assistance.

[Chappy]

Thanks for your replies.  I suspected that Bushmaster was being a bit extreme - probably to cover themselves in case someone does wreck a gun using reloads.
I have another question for you:  Do you crimp your AR ammo?  The hunting bullets I plan to use in this rifle are not made to be crimped.  Yesterday, I shot 40 of my uncrimped reloads (R-P brass, WSR primers, Benchmark powder, and Speer 50 gr. TNT bullets) and did not notice any bullet set back or pull out.  Using an awkward rest, I shot a nickle sized 3 shot group at 100 yards.  That made my day!  Speaking of rests: my current rests that work well for bolt guns do not accomadate the AR's magazine and pistol grip very well.  I am considering mounting a Harris 9-13 inch bipod that swivels and has the notched/spring loaded legs.  Have any of you used one of these?  How did you like it?  Thanks again for sharing your knowledge and experience!

[John Traveler]

Bullet crimping is not needed if you have a tight bullet/neck fit.  That tight fit is obtained by using a proper sized (0.222-0.223" diameter) expander plug.  MIL-SPEC ammo requires crimping and neck sealant for reliability in full-auto weapons and rough handling.  Likewise the crimped in primers.  You can duplicate this neck sealant by applying solvent-thinned asphaltum varnish to the inside of the case mouth.

What is needed on each reload is careful case length inspection, trimming, and deburring.  This caliber tends to stretch cases on every firing.  As a young shooter and new reloader, I experienced a few instances where the fired case mouth developed shreds of extruded brass. Too long a case will prevent chambering of course.  But if only a bit overlength, will result in the extruded case mouth and overpressures.   Not good.

This caliber and AR platform is noted for it's excellent accuracy.  If you add a bipod, make sure that it doesn't clamp onto the barrel front sight mounting band like the military-issued bipod.  That device is infamous for lousing up accuracy when used in the prone position.

[Old Syko]

Like John has already said no crimp is necessary.  If neck tension becomes too light dump the brass.  Unless you intend to submerge your ammo for long periods of time or abuse it in some other manner befitting military use no sealant is necessary either.  A more important factor to list when loading for an AR is coal.  I use 2.250" as a standard as I use about 8 different brands of magazines and this length allows all to function without fail.

[Chappy]

Glad to hear that crimping is not required.  My needs will not require any special sealants either.  Good point about when bullets get loose in the case, it's time to toss the case.  I keep my brass trimmed.  I full-length resize the cases, but use a RCBS precision mic and just push back the shoulder enough to chamber easily.  Bushmaster says that the Predator barrels have a SAAMI spec chamber.  Fired R-P brass measured 1.4636, SAAMI minimum for this caliber.  I had to reseat my reloads a little deeper to get them into the AR magazine.  2.250 seems to be a good COL.  As I noted above, Speer 50 gr. TNTs shot well.  I need to reseat some of my reloads that have Nosler 50gr BT bullets and see how they shoot.  I have also ordered some 55 gr. Nosler BTs as the Predator's 1in8 rifling is supposed to be good for heavier bullets.
I had not heard about the military's bipod problems, but it should not affect me as the Predator's barrel is free floated and the bipod would attach to the handguard tube.