Another Trail boss question

[cr500]

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]

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]

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]

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]

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]

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

[pug]

Actually didn't even shoot at a target just checking velocity. With a velocity spread of only 11 fps it should have been accurate but can't tell you for sure. Maybe I will get the rest and chrono all set up on the bench this weekend.

[cr500]

With an extreme spread of only 11fps, I dont think there will be much verticle stringing. I will wait to see if anyone does OK with Trail boss, otherwise, I might go to the N320 powder as well.

[pug]

Which weight do you want a Trail Boss load for?

110,125,150,155 or 180

Because of the bulk of trail boss I would say the lighter you go the more chance of getting all the charge to fit in the case. It takes up almost twice the space of most pistol powders.

Better ask now because when the guys get my garage up I am going to be busy for a while.

[cr500]

I will mainly use it for 155 and 180gn bullets, all subsonic.

[pug]

Unfortunately it is overcast today and the chrony isn't triggering reliablely but I did fire off some 155s. Like I said with Trail Boss being bulky not much goes inside a whisper case and 5gr of it is just about a full load with the 155 set to 2.100" OAL. You could fully seat the 155 and it would be a 100% density load. The chrony gave readings from 950 to 1010 and also some in the 3000 range so not conclusive. They were all subsonic and "sounded" good.

[320pf]

Pug,

Did you have the sky-screens on your chrono?

I have had the same problm with my chron on cloudy days. A friend of mine, however, told me he rarely uses the sky-screens on his chrono. So I tried his advice. I have found that I only need the sky-screens when it is sunny out and the sun is on the sensors. I can usually get the chrono to work on a sunny days without the skyscreens by just tilting it a bit away from the sun so the sun is not directly shining on the sensors.



320pf

[pug]

Just got through trying that. The sun came back out so I tried some more loads out. Got 400-800 spread so pulled the screens off and no difference still erratic changed the battery same thing. Have had to fix the cables several times so it is probably that and makes me think there may be something to having it all in one box.