302 Whisper

[m21black]

Does anyone have any data on the 302 Whisper?

[Rikky Lee]

I'm currently working with the Lapua 200 grain Subsonic projectile and 110. Results at 50m are one hole but at 100m I'm getting vertical stringing.

Thinking about trying Trail Boss.

[Hoser]

I have been asking that very same question for a while here and elsewhere.

[m21black]

JD Jones emailed me a bunch of data on the 302 Whisper along with the 338 and 375 Whispers last year I just can't find it now... This isn't for me but for another guy, if it was for me I'd call JD up.

[Rikky Lee]

I think we would be all very grateful for any advice on what works. The Laws of Physics are not yet trademarked so there must be a simple answer to this.

The Lapua subsonic projectiles hit hard and kill fast - much better than SMKs but if the 220 SMK is the more efficient long rang (ie 100 on) bullet then I will try it. Seems to me that Trail Boss offers the answer to the space issue but would also be good to hear some real world experiences with it.

I feel the gunshop is going to be hit hard when it opens!!!

[Hoser]

Originally Posted by m21black

This isn't for me but for another guy,

That guy from the Hide?

Originally Posted by m21black

if it was for me I'd call JD up

I did. No info was avail unless I purchased a complete rifle in 302 directly from him.

[m21black]

Originally Posted by Rikky Lee

220 SMK is the more efficient long rang (ie 100 on)

Forget about the 220 grain SMK's you need to understand that in the subsonic world once you hit 1050+/- fps the only way to get more energy is through mass. I shoot the 300 Whisper with nothing but 240grain SMK's they by far have the best ballistic coeffient and are deadly on deer sized game down to squirels. If I could find some 250 grain SMK's I'd have to try them but they are out of production.

[m21black]

how many grains and what kind of velocities?

Originally Posted by Rikky Lee

I'm currently working with the Lapua 200 grain Subsonic projectile and 110. Results at 50m are one hole but at 100m I'm getting vertical stringing.

Thinking about trying Trail Boss.

[Rikky Lee]

With 10.5 grains of powder I get 1000fps ... but ... I need to sit down with a range of loads and chrony and do a proper load table up.

I have some 250 SMKs (precious) so I do not want to waste them. What I want is an accurate 100 plus load with a bolt gun which must be possible. Trail Boss here I come?

Does anyone know what JD's choice of projectile is?

[Rikky Lee]

Here is the results of the velocity testing with the 200 grain Lapua and I think you will see immediately why things have been happening the way they have:

Starting with 11.0 grains of 4198:

a. 847fps
b. 943fps

Av: 895fps but this seems a little on the high side.

11.5 grains:

a. 932fps
b. 1088fps
c. 1161fps
d. 955fps

Av: 940fps (remove b &c due to velocity spike)

12.0 grains:

a. 960fps
b. 981fps
c. 996fps
d. 964fps

Av: 976fps (see that the velocities are stabilizing and there are no spikes)

So what does that tell us? Well it tells me that more powder is needed and a simple straight line graph suggests that 13.75 grains of 4198 should give 1050fps.

Fingers crossed!