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Posted: 1/12/2007 4:14:05 AM EDT
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Here's the deal. I've got a "pre ban" Eagle Arms 20" HBAR sitting in the safe. Chamber is in .223, so she doesn't get shot much.....I'd venture a guess of less than 500rnds total thru her. (I'm the original owner....bought it brand new in '91 or '92). Here's my question. An HBAR config. is pretty much nothing but needless weight for my use. And the .223 chamber prevents me from using surplus ammo. I've been toying with the idea of having the chamber reamed to 5.56mm specs, and have the barrel fluted under the handguards. Problem is....she's a damn tackdriver when I do my part with quality .223 fodder. Reaming the chamber to 5.56 will surely effect this to some extent. Now, this isn't my only AR, so I'm not "desperate" to build somthing that'll shoot cheap surplus. Do I just leave "well enough" alone? I could just build another upper, but at that point, I'm only $150 away from another complete rifle! Perhapse just the fluting job and leave the chamber alone? Problem is, I don't do much "precision" shooting with it, so don't tend to keep more expensive .223 around. Let's hear some oppinions. What would y'all do? |
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This one has been beat to death before but the slightly tighter neck and shorter throat of the SAAMI spec .223 chamber is not going to have any significant adverse effect when firing 5.56mm NATO ammuntiion in a well maintained AR-15. When the US Military introduced the M-16 they had problems developing a suitable ball propellant for the M-16 that would produce the required velocity at less than or equal to 52,000 psi average peak pressure. Since the velocity could not be reduced without compromising the penetration standard of the time, they waived the pressure requirements as it was not felt that an additional one or two thousand psi was going to damage the rifles or significantly increase wear. The waiver was in effect for several years until a suitable propellant was developed and previously made ammunition worked its way through the supply chain. And the waiver was granted during that period of time with the understanding the weapons would be used in environmentally challenging conditions with frequent full auto fire (ie: in Vietnam). Furthermore the 52,000 psi specification was an average pressure - individual pressures as high as 60,000 psi were approved under the M193 ball ammunition specification even without the waiver. So in effect even if you pick up an additional one or two thousand psi in pressure when firing 5.56mm NATO ammunition in a .223 chamber (and it's an IF, not a for sure that you will even get that much extra pressure) it won't hurt the rifle unless perhaps you plan on putting several thousand rounds through it on full auto with a very dirty chamber. I'd leave the gun alone, particularly if it is already a tack driver and just shoot quality surplus ball ammunition in it. (I would not shoot low quality 5.56mm or .223 ammunition in anything I own.) If you feel you just have to have it reamed to a larger chamber dimension, go with a Wylde chamber which is a good compromise between the .223 and 5.56mm chambers |
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Think I have the same upper... 1/8 20" Golden Eagle upper from Eagle Arms, bought mine in 90-91 for NRA high power matches. tack driver, but extremely heavy, close to 13 pounds. Thought about having mine turned down by Randal, and flat topped for a scope. ended up just building a complete ft rifle last spring, and my Eagle just sits in the safe. Don't know about yours, but mine has a larger than standard diameter heavy bolt carrier. |
No...mine's not one of the "Golden Eagles". Standard a2, just with a heavy barrel. A barrel that in my humble oppinion, is too damn heavy for it's own good. That's why I've toyed with the idea of fluting it. (it'd be a waste to turn it down to Gov. profile...but would be a great candidate for fluting) I know there's been alot of debate on the ".223 chamber" subject, but for the record, this upper simply ain't happy shooting 5.56mm! After a short time, it'll stard failing to extract (I've swapped out extractors....still "no joy"). I'm convinced that the issue is with the chamber. So......I can either ream the chamber, leave the upper and build a replacement gov. profile upper (though I'd probably just end up building another complete rifle), which leads to option 3....throw it back in the safe for another 10 years!  |
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