I've had my Model1Sales.com 300 Fireball upper for a couple of months now and want to share my thoughts on it's performance and quality.
I ordered the 16" CAR upper in A3 flat top configuration @ $365
Added the 4 rail gas block @ $38
Added bolt carrier group and extended charging handle @ $148
For a total of $571 with shipping.
The fit and finish are pretty standard with 300 Fireball stamped on the barrel.
The first thing I did was remove the gas block to drill the gas port to 1/8" (.125). To my surprise the barrel port and gas block were already 1/8". I added an adjustable gas tube and drilled it's port to 1/8". I attached my home-milled .308 suppressor (tax stamp in hand) with all the testing below shot through the suppressor.
I tried a box of Cor-bon ammo with 220gr Sierra MatchKings and SSK stamped brass. This ammo wouldn't cycle or lock the bolt back with an empty magazine even with the adjustable gas tube fully open. The Ammo was also a little too fast and noisy. The rounds I chrono'd were running in the high 1000's and about every 3rd round would go transonic and make a lot of noise. I believe part of the feeding problem might be due to the SSK brass. The sound meter would also show about 3dbi louder with the transonic rounds.
I wanted to lighten the rifle's buffer but couldn't get the buffer tip off so I cut 3 coils off the buffer spring instead.
I hand loaded some ammo using Winchester .223 brass, Remington 7 1/2 primers, 11.2gr of AA1680 and 220gr SMKs with a COL of 2.09 which gave me a speed around 970fps. These rounds cycled and locked the bolt back no problem. I had to close the gas tube a little to keep the ejected brass from denting its mouth when it struck the ejection block.
I also tried Hornady 220 Round Nose Soft Points with 10.3gr of AA1680 with a COL of 2.0 and it's running in the low 900s and cycles very reliably too. I'm going to bump up the powder to get the speed up to 1000fps.
I've only shot the rifle at 50 yards and the accuracy seems fine but can't really say more than that.
Overall I'm very happy with the Model1Sales 300 Fireball CAR upper but if you plan to shoot Cor-bon's factory load you may want to look elsewhere or be prepared to do a little gunsmithing. You might consider waiting to purchase this upper because Model1Sales will probably convert to 300 AAC Blackout sometime in the future.
Linear Mode
