Quarterbore.Net Forums

cr500 · #1 04-23-2008, 07:45 PM

I am after the quiestest subsonic load in a non suppressed 300 whisper rifle. I read other posts about trail boss but have a few more queries. Will I be able to get 180gn bullets up to 1040 fps with this powder? Will I run out of case volume or will pressure be too high to get up to 1040 fps with 180gn bullets?
Any other recommendations for the fast burning, low density pistol powders, purely for quiet subsonic loads.

pug · #2 04-23-2008, 09:49 PM

I can load some up and let you know if you haven't bought any components yet. Would need to know whether it is bolt action or semi and it won't cycle if it is a semi. I have used N330 with similar weight bullets but not in the 300 whisper.

cr500 · #3 04-23-2008, 09:54 PM

Hello Pug. The rifle is a bolt action, so cycling is not necassary. I have the cases, rifle and bullets (155gn -250gn), but no powder yet. I will need to get the powder soon, just wanted to know which ones to get.

pug · #4 04-23-2008, 10:55 PM

A bolt gun is good to work with and a must if you want the most quiet signature. The sound pressure level generally goes up the larger the bore with everything else equal. It goes down the smaller the charge and also the faster the powder burns. The lighter bullets will be quieter because they take less powder charge to reach the sound barrier. Also flight noise is generally less with a hollow point or at least I think so. The 155 Sierra is a good choice if thats what you have. I have a N330 load which is close that I can use 155s but I will have to work it up before giving any numbers. I think Green Dot can be used in place of N330 (cautiously of course). Trail Boss is very bulky and is used to fill up a high volume case.

pug · #5 04-24-2008, 10:28 PM

Got a moment to load up some subs with the pistol powders on hand. The fastest powder on hand that I felt comfortable loading with a 155gr SMK was N320 which is similar speed to red dot. Hit the upper limit at 5.9gr of N320 with a 155gr SMK set to 2.100" OAL. Pressure looked good for this load.

cr500 · #6 04-24-2008, 11:54 PM

Pug, how was accuracy with this load? Was there much verticle stringing?