Pointed dtacs

[jsthntn247]

I've been noticing some vertical at longer ranges when using the pointed dtacs so I figures I would sort some out to see if I could notice any variance. My es is very low with this load so I figured it was something with the bullets. I sorted 100 bullets base to ogive and only found 1 bullet with more than .001 variance and it was out by .007, so definitely something wrong with it. 99 out of 100 being within .001 was actually better than the Bergers. So I figured I would now sort the same bullets base to tip (overall length). They measured .025 difference with the same 100 bullets. After measuring each bullet I sorted them in .005 increments. The shorter bullets had a large meplat and the longer ones were needle pointed. Also if I measured one and it was long but the meplat was wide like a shorter bullet that bullets base to ogive measurement would differ from the others every time. I will have to shoot these at distance to see if this is where the vertical is coming from but the difference is easy to see. These two bullets have identical BTO measurements but vary in length by .020.

 

[Dgd6mm]

I knew they varied, but that's bad. Tubb's needs to have Sierra do something about it, if possible. I know that some shooters take even a more consistent made bullet and still re-point them. When they came unpointed I seen as much as .015 difference in oal, but that was it. I do not point, but would if I thought needed. I also have wanted for a long time to transition to the Berger 105 Hybrid, but the DTAC's shoot good for me out of my 6mm Competition Match barrels. But with your findings I may have to give it a second thought.

 

[jsthntn247]

I finished sorting the rest of the box. The BTO is overall more consistent than some Bergers I have. The overall length of bullets varied .025 and a box of Bergers .017, so there again, not horrible. The problem comes in when they don't length sort the bullets first before pointing. The longer bullets get jammed further into the pointing die and the meplat gets closed further. I noticed this when pointing 90 vlds also and had to length sort before pointing. This has to effect the bc of the bullets. For now I will just keep them sorted and shoot them that way. Probably get them un pointed next time and do it myself.

 

[jbpmidas]

I don't think you can get the 115 Sierra in an unpointed form, can you?

 

[Dgd6mm]

I believe they all come pointed these days.

 

[jsthntn247]

I'll test them and see if they impact different. If so I'll have to put 2 different bc calculations and shoot them in different batches.....or get some Bergers.

 

[jbpmidas]

Careful Brad, you're going to take all of the fun out of shooting!