Shades of Gray: .300 Whisper & .300 AAC Blackout (NRA Rifleman)
- Thread starter sillymike
- Start date
UPDATE:
I just loaded up (6) rounds using converted randomly selected IVI brass. Date stamps were: '89,'91,'93,'94, and '96. All loaded with 147gr. Hornady .308 FMJ-BT bullets with a OAL of 2.155". No issues with chambering all (6) rounds in either the Remington 700 or the Weatherby Vanguard.
Not sure what your issues are. Can you describe the process that you use to make your brass? What reloading dies are you using? Any chance that's the culprit? I'm using .300 Blackout Lee & Redding die sets.
- Location
- Calgary Ab
Can you measure the outside diameter of the necks of those six rounds. I'm curios as to what they are.
- Location
- Calgary Ab
That's where I get confused. The way I read the SAAMI spec's ,the chamber should be at .335"
And the cartridge at .334" I try to keep my max at .332" thats for my turned necks ( semi auto ) chambers. Still a little tight, for a dirty chamber,I have to keep it clean
My WCC 00 brass. Measure .328 "and the commercial Winchester measure the same with the Sierra 125 Match loaded.
And the cartridge at .334" I try to keep my max at .332" thats for my turned necks ( semi auto ) chambers. Still a little tight, for a dirty chamber,I have to keep it clean
My WCC 00 brass. Measure .328 "and the commercial Winchester measure the same with the Sierra 125 Match loaded.
The SAAMI spec is based on a minimum chamber specification not a maximum one. There's going to be some natural variance involved here. Here are (2) decent threads from the 300blktalk.com board that are related to the topic at hand.
h ttp://www.300blktalk.com/forum/viewtopic.php?f=141&t=80504&hilit=outside+diameter
h ttp://www.300blktalk.com/forum/viewtopic.php?f=141&t=80803&hilit=outside+diameter
I know the .336" is getting on the tight side but it works. There's just a slight hint of resistance while chambering as compared to similar rounds formed by using commercial Winchester brass, however, there is no problem closing the bolt without having to force anything. Admittedly, I would likely not run these rounds in a semi-auto. However, I'm shooting bolt guns at the moment so it's not an issue for me one way or another. If anything, the tighter neck might actually improve accuracy in my circumstnaces.
YMMV.
h ttp://www.300blktalk.com/forum/viewtopic.php?f=141&t=80504&hilit=outside+diameter
h ttp://www.300blktalk.com/forum/viewtopic.php?f=141&t=80803&hilit=outside+diameter
I know the .336" is getting on the tight side but it works. There's just a slight hint of resistance while chambering as compared to similar rounds formed by using commercial Winchester brass, however, there is no problem closing the bolt without having to force anything. Admittedly, I would likely not run these rounds in a semi-auto. However, I'm shooting bolt guns at the moment so it's not an issue for me one way or another. If anything, the tighter neck might actually improve accuracy in my circumstnaces.
YMMV.
Yep, that's definitely a mismatch with my chamber which is 0.335" at the neck. I never fired the round, but I wouldn't either given the hard extraction of the dummy ones in my AR.
I'm just running the brass through the die, trimming and deburring. Nothing out of the ordinary.
I finally got out to shoot some .300 Blackout on converted IVI brass. I've fired (50) rounds so far in my Weatherby without any issues at all regarding chambering. Cases were formed and trimmed to 1.360" and using Carbine 110gr. RN-FMJ bullets. Lousy bullets for use in the Blackout but they work great for fireforming cases or when shooting 50 yards or less. Measured the fired IVI cases and they measured .337"-.338" in neck diameter. Converted commerical Winchester .223 Rem cases measured .334"-.335".
