Does anybody have the real BC for the Sierra .375, 350 grain Matchking?

I found where somebody said that it was .780 .

And which Drag Function should I use , G1?

27 views and nobody that looked knows the actual BC of this bullet?????

Dennis,

I need to dig through the work Kirby Allen did with this bullet. If memory serves, the bc that Sierra reports was different than what was actually experienced in the field.

Ken

Thanks Ken.
I just got off the phone with Jamison and the gal there said that the BC they use (.780) was given to them by Sierra.
That aint much better than the 338 / 300 gr SMK.

Am dreaming of a heavier hitting rifle than what I have right now (338/300RUM- 300gr SMK @ 2850 MV) and the .375 class of rifle looks like it might have what I am after.
I don't want a 50 because they are just TOO damn brutal to shoot ( on the wallet and the body).

Let me know what you find. I have been digging around but I must not have went deep enough into the archives.

Kirby was testing this bullet out of his 375 Allen Magnum, which has a little more capacity than the 375 Chey Tac. I have a BAT M that I am wavering between the 338 and 375 Allen. The 338 pushes the 338 SMK around 3400fps +/- depending on how long you want your brass to last. The 375 Allen runs around 3250 fps with the 350 SMK, but can be pushed a little harder if you don't care about brass life.

Either caliber will make a Swaro LG give up!

I don't know whether I should go with a Lawton or BAT receiver.
I have a Lawton 7500 on my 338.

I looked at four different programs and could not find this bullet.
Patagonia, Sierra, Loadbase, and ..... let me find it.... Anyways I couldn't otherwise I would have posted and am sure others would have too.

Here is a link to Kirby testing the 375/350. He figures from the drop the BC is around the low 80's, he figured .820.

http://www.longrangehunting.com/forums/f...play-too-27950/

Bro, all I know is what Kirby says as I still don't have my hands on the 375AM. Mine is being built on a Bat. I'll post some pics when it's done. It shouldn't be much longer. I really think you're gonna need one!

.75 will get you much closer to the "real" bc of this bullet. I have discussed this with Mr. Allen before. .8 will get you close with a high MV like what he is running. It does have conditions that will play into effect as well. Best thing to do is shoot the things and make a drop chart up by comparing the results.

You won't find this bullet in the Sierra manual. It was made special per a CheyTac work order. The Sierra quoted BC is a computer estimate because they never shot the bullet. CheyTac did all testing and final approvals.

Actually shooting the bullet and under the enviro conditions converted to sea level and standard day:
The BC average to 3500 yards is .749. The average BC to max supersonic range is .794. This was shot with the "best accuracy load" of 3155 fps.

Dave

I'm already hooked myself Cinch. Problem is I'm getting cold feet on the 375 and thinking about building the 338. Mine will be on the BAT M/ A5 combo. How are you finishing your barrel out- length, contour?

Mine is also a Bat/A5. It will have a 30" Lilja in the "Allen 32" contour. I'll have to look later tonight at what exactly the contour is. I know mine is in the batch he's working on right now, so it shouldn't be too long. I also thought about the 338, but for barrel life I went 375. Maybe if I shoot it out I'll try the 338. Thats the nice thing- barrel is the cheap and easy after you have the rest of it.

Dave,

Thanks for chiming in with the data you guys came up with!

Scott Nye

What are the spec's on that "Allen 32"?

The Allen32 contour is one Kirby had Lilja custom make for his heavy extreme rifles. It is 1.350" for aprox. 6.5" then tapers to .900 at the muzzle at 32". My barrel is only 30" so it will be a little bigger at the muzzle.