AR Sponsor
Posted: 12/20/2016 2:12:34 AM EDT
| Looking for a 10.5 barrel for a 223. any suggestions |
|
I purchased an inexpensive PSA 10.5", 1:7 earlier this year and its accuracy at 36 yards is terrible. Replaced with a Green Mountain chrome lined 1:7 on sale for ~ $160 shipped and it shoots as well as my BCM BFH (cold hammer forged) 16", 1:7. Plus the GM service was excellent. GM is now my standard barrel.
Added: Both barrels are rated as 556 but the GM's chamber measures closer to 223. I have found this to be true in all of my sub $200 barrels. |
|
Quoted:
I purchased an inexpensive PSA 10.5", 1:7 earlier this year and its accuracy at 36 yards is terrible. Replaced with a Green Mountain chrome lined 1:7 on sale for ~ $160 shipped and it shoots as well as my BCM BFH (cold hammer forged) 16", 1:7. Plus the GM service was excellent. GM is now my standard barrel. Added: Both barrels are rated as 556 but the GM's chamber measures closer to 223. I have found this to be true in all of my sub $200 barrels. Unless you are using a Michiguns measuring gauge (or one thats similar) it's impossible to determine if you have a chamber that's either 5.56 NATO or .223 Remington because it's the free bore in front of the chamber. Here is an article on the subject... The Chambers The significant difference between the .223 Rem and 5.56 NATO lies in the rifles, rather than the cartridges themselves. Both the .223 and 5.56 rounds will chamber in rifles designed for either cartridge, but the critical component, leade, will be different in each rifle. The leade is the area of the barrel in front of the chamber prior to where the rifling begins. This is where the loaded bullet is located when a cartridge is chambered. The leade is frequently called the “throat.” On a .223 Remington spec rifle, the leade will be 0.085”. This is the standard described by the Sporting Arms and Ammunition Manufacturers’ Institute, Inc. (SAAMI). The leade in a 5.56 NATO spec rifle is 0.162”, or almost double the leade of the .223 rifle. A shorter leade in a SAAMI spec rifle creates a situation where the bullet in a 5.56 NATO round, when chambered, can contact the rifling prior to being fired. By having contact with the rifling prematurely (at the moment of firing), chamber pressure can be dramatically increased, creating the danger of a ruptured case or other cartridge/gun failure. The reverse situation, a .223 Rem round in a 5.56 NATO gun, isn’t dangerous. The leade is longer, so a slight loss in velocity and accuracy may be experienced, but there is not a danger of increased pressures and subsequent catastrophic failure. How serious is the danger of firing 5.56 ammo in .223 guns? Dangerous enough that the SAAMI lists 5.56 military ammo as being not for use in .223 firearms in the technical data sheet titled “Unsafe Firearm-Ammunition Combinations.” From Michiguns web site... .223/5.56? Gage This gage tells you if you have a chamber that is 5.56 NATO (or larger), or something shorter/smaller. The gage looks a lot like a headspace gage but it does not gage headspace. It comes with its own rod which you thread into the tapped hole in the back of the gage. Unload and open your rifle, pull the bolt group, make sure the chamber is clean so there is no false reading, and drop the gage in. If the gage's shoulder "clinks" off on the shoulder of the chamber and the gage drops or pulls free without sticking or resistance, you have a chamber that is 5.56 NATO or larger. If the gage goes in and wants to stick, as in, you let it in and it pulls with a little resistance, or you try and turn it but it does not turn freely, you are short of 5.56 NATO and probably have a .223 chamber. You can color it up with a Sharpie, put it in and spin it (clockwise) to observe where it's contacting the chamber first. Note that the gage will also stick in a .223 Wylde chamber since the Wylde's freebore is smaller in diameter than the 5.56 NATO's. It's my opinion that the Wylde chamber ought to be OK with 5.56 NATO ammo, but I have not delved into this scientifically. I don't own anything with the Wylde chamber, so I have no first-hand experience with it. The smaller freebore, I suppose, would make it more crud-sensitive. |
AR Sponsor