Anyone loading for Noveske .300 FB barrels?

[Garrett]

Since Noveske has released a bunch of new .300 Fireball barrels, I thought I'd see if anyone had worked up any loads that were subsonic, and still cycled reliably in them yet.

I recently put together an upper using a 16" barrel, and finally got to go shoot it this past weekend. I was using some of my loads that I'd worked up for my 10" Contender. So at the time I developed them, cycling in a semi-auto was not a consideration. These used a charge of AA#9 and a 220 gr. SMK. The gun has a full-length A1 rifle stock / buffer tube, and I am using the Noveske (non-adjustable) gas block that was provided with the barrel.

I did not have my chronograph out but around 1/3 of the shots were supersonic. Also, I was only getting reliable cycling around half of the time. This load is averaging 1052 fps. through my 10" Contender, so it doesn't surprise me that it is going to go supersonic through a longer barrel at least part of the time. However, I was hoping for better cycling reliability.

I have loaded up some ammo using H110 and AA1680 with a few different bullet weights, and I'll hopefully get a chance to chrono them this week.

But to save me any more time, has anyone already worked up a load that runs well in the Noveske 16" barrel and stays subsonic? What type of setup on the rifle?

Thanks. I'll report back my findings as well.

[N310toN170]

I've got my Noveske 16" ordered. I posted a link to this thread on the >300 Whisper Rifles and Pistols section of the forum in which there has been a considerable amount of discussion of these particular barrels.

Hopefully, we'll get additional input from there. Otherwise I'll post or PM you my load development results as well.

[Garrett]

Here is what I have come up with so far:

My preferred Contender load using AA#9 and a 220 gr. SMK runs well. The only cycling issues appeared to have been mag-related (I'll make a separate post on that later). Interestingly enough, I got slightly more velocity from my 10" Contender than the 16" AR15 with this load.

I tried a starting load of 8.5 gr. of H110 with the 220 gr. SMK. This cycled fine, but only gave me velocities in the 800-900 fps. range. Might be something to the comments about H110 being inconsistent in the cold. It was a sunny 32 degrees F. at the range today. I had an extreme spread of 114 fps. from my min to max velocity. I might wait until summer to try this powder again. I got similar inconsistencies shooting this load in the Contender today as well.

With a 180 gr. bullet and H110, I got somewhat more consistent results, but some loads would have a single round drop off by over 100 fps.

I picked up a pound of AA1680 after I had loaded the other ammo, but I only initially loaded it with 150 gr. bullets intended for use in a .30-30. My starting load was all supersonic with one slow exception. Seems like there may be some cold-weather inconsistencies with this powder as well. This same load stayed subsonic in the Contender except for two high-speed fliers. I'm going to have to try some heavy loads with this powder.

These all have me scratching my head a little. In the past, .300 Whisper has been a very consistent performer. My most consistent load used a mild charge of AA#2. Unfortunately, this load is not likely to cycle at all in a semi-auto.

My other comment is that I really need to get a brass catcher. I don't like making brass all that much, and it was never a problem keeping track of it when I was stuffing them in one at a time.

[TerroristHunter]

been shooting 220 SBTHP just under 1100 with 11.7 grains of aa1680 and even got it to lock the bolt open. additionally, you must break in the action by shooting a couple hundered rounds.. Good luck