Are 115 Dtac's a true .585 BC

[6BR4U2]

Just wondering if anyone has tested these to see if they
are indeed a true .585 BC ?

 

[JOHN708]

The short answer, no. Serria makes this bullet for Tubb. Their Infinity 6 ballistic program states the bullet is in the .550 range.

John Skowron

 

[rcw3]

John

Not to bug you for another piece of info, but I am most curious what the Sierra program puts as the b.c. on their 107 gr 6mm bullet,i.e. I want to see what they have as the difference between the DTAC 115 and their 107).

Robert Whitley

 

[JOHN708]

Robert,

They list the 107's at .527 at 2850 fps and above.

John Skowron

 

[DTubb]

The 115 DTAC is now only available with a closed nose configuration,pointed).
Sierra recently retested the BC data for the 115 DTAC at my request. I also have tested them over the Oehler 43 at 1k.

Obviously when using Sierra's data there are multiple BC's based a velocity range.

The 115 DTAC's BC is above .585 for a portion of it's flight when launched at over 2600 FPS.

Sierra will change the 115 data contained in the Infinity program the next time a revision is performed.

DTubb

 

[teele1]

David, is the pointed 115 DTAC a different part number and if so can you let me know what that number is. I just ordered 1000 115 DTACs last month. How long have these pointed DTACs been available.
thank you and shoot strait,
teele1

 

[rcw3]

Robert,

They list the 107's at .527 at 2850 fps and above.

John Skowron

John

I am aware of what they list as the b.c. of the 107 in their published data, I guess I was wondering what the program gave as the number for the 107.

Robert

 

[JOHN708]

Robert,

The Serria Infinity 6 ballistic program lists the 107 at .527 at 2500fps and above.

John

 

[6BR4U2]

Thanks for the info...I would like to say that in my rifle
they shoot really quite good and so far I love um .

So I was just wondering if the BC was really a 585 before I did more testing
My rifle they shoot good jumping them

 

[flatlander]

I've been shooting DTAC 115s for a couple of years out of three 6x47s & a 6XC. I have the DTAC 115 entered in v6 Sierra Infinity as a custom bullet with the BC set at .585. I can plug in the velocities my loads produce, and Infinity gives come-ups from 600 to 800, 900, & 1000 that are within 1/2 MOA or less of what I get on target. At least, that's what I found last June at Raton, using come-ups generated by Infinity during a LR match in the Palma format. IIRC, I used 7500' MSL as the elevation for the George Tubb HP range at Whittington Center.

Bryan Litz or Henry Childs can probably explain why Infinity's results are this close to actual results on target, even though the program uses the G1 model, while the 115's form factor is much better matched using the G7 model. All that really mattered to me was that Infinity's data got me very close on elevation for all three firing lines.

 

[6BR4U2]

Thanks Dennis,

I can't believe that I can jump these this far and still get 1/2moa

were are talking about as much as a 25 thou diff and still shoot exactly the same 1/2moa maybe its the new barrel ... I dont know but they seem to like to be jumped a lot

 

[flatlander]

6BR4U2-
That's one of the things I like so much about the DTACs - they're not at all picky about where they're seated. I've got a good supply of Berger's 115 VLD on hand, and have had best results with them in one of the 6x47s when they're seated to jump at least .010'. That's contrary to what I've generally seen with other VLDs, but whatever works...

 

[Bob3700]

Dennis,

Are you shooting the DTAC's coated? If so, can you see any difference between the Moly and Boron Nitride on target?

I have not shot any 115 DTAC's bare, only coated. Shot both coatings and cannot see one bit if difference on target up to 1K distances.

Bob

 

[JOHN708]

Dennis,

Serria chrono's bullet vel. at various yardage's plus they use Doppler radar. I imagine this will give you way more accurate BC data then a computer model based on bullet diameter, shape and wt.

John

 

[flatlander]

Bob,
I've just gotten started shooting BN coated bullets in 6.5x55 AI & 284 Win., so don't have enough experience with them as yet to have formed much of an opinion. I'm hoping BN's at least as good as moly, which I've been using exclusively for the past 14yrs. It takes a lot of extra time to get a nice smooth finish with the waxing step of the moly process, and to tell the truth, that's one of the biggest reasons I'm trying the BN process.

 

[6BR4U2]

PM inbound to Flatlander
thanks
6br4u2

 

[Dgd6mm]

I called Superior Shooting Systems inc. yesterday and asked them about the pointing and was told that is the only way they come anymore. I'm not concerned about the BC for they shoot and group good for me out to 1100 yards. That's the fartest I've shot them, but my buddy is having verygood results out to 1250 in a .243 AI.