6dasher ?

[pmarauder]

Donovan, Is your cartridge schematic measurement points accurate in relationship to the end of the case?? Because you are showing a dasher case length of only 1.5". My dasher brass is 1.560. and my neck length is .245. So, I don't think your ,104" freebore diagram is totally accurate. If i am correct, that 105 Hybrid should be moved out another .060" Right?
Jim, I did shoot the 105 Hybrid all season with the .104" freebore. I did quite a bit of testing with it @ 400 yards and had several 5 shot groups well under a half inch CTC. (yes, @ 400) They also shot pretty good at 1000 all season. I dont believe i had any pressure issues or fliers with this freebore. I believe they stayed pretty consistent all season from cold weather to hot weather.
Derek

 

[Blaster-37]

I can attest to that Derek, they worked very well for you. When the dust settled, you were the man. Great shooting.
Greg

 

[johara1]

Free bore is not always what is written on the reamer. You had better have it checked on a optical comparator,i have some marked.136 and are .128.Yes you can get by with it but getting the heel up in the neck would be a lot better. I shot 115 DTAC. in a .128 FB. but .155 it came alive. Pressure dropped and acc. got better. 1.560 brass length? it has to be old lot,new is now 1.555...... jim

 

[johara1]

Derek, I don't test at any mid range,but i do at 1K 2"and 3 " will happen. I did shoot the DTAC. at 500 and .584 happened and 300 .139 happened so i don't get too excited about mid range testing....... jim

 

[pmarauder]

Donovan, I see what you are describing now. I thought you were identifying the 1.5" mark with a red line and the 1.750" mark with the yellow line.
I think we all know that the neck length will not change the relationship between where the bullet's BS / Boat tail junct contacts the case NS junct.
But if the schematic was not accurate, then all measurement relationships would be off.

Jim, The only point I am trying to make is that I shot the 105 Hybrid all season with a .104 FB, and it seemed pretty consistent. Do I think that increasing the FB to .154 will work also?? Yeah. Im having a different reamer built right now.
Derek

 

[johara1]

Derek, What i see is if shoot them jumped you need more free bore but if you use them seated you can get by with less. What i said about the reamer dimensions, it may not be .104.......jim

 

[bricktop]

From what I read here:

http://bulletin.accurateshooter.com/2011/10/new-berger-105gr-6mm-hybrid-bullets-perform-well/

the hybrid has less bearing surface than the 105 VLD, and needs about 0.020" to 0.025" less freebore. The 105VLD sits just at the shoulder junction here with 104 FB:

http://forum.accurateshooter.com/index.php?topic=3794136.msg36110553#msg36110553

But, it seems to be way far in the neck in this drawing (same 104 FB):

http://forum.accurateshooter.com/index.php?topic=3797006.msg36127883#msg36127883

I think your program is pretty cool and I think I might try to make one some day, but maybe the hybrid drawing isn't accurate? Or am I missing something?

Just wondering since I have a fresh dasher barreled action with a 0.112" freebore waiting for all the fixins.

 

[johara1]

What is say is not from reading, I know where the heel of the bullet is with the .155 FB...... jim

 

[johara1]

Donovan, Now the perfect storm, what else can happen........ jim

 

[johara1]

Donovan, It's done.......... jim