Dasher Free bore

[SDDasher]

I have two different Dasher's- One has a free bore of .155 and the other .104. How much difference should this cause in velocity assuming using same case, powder, primer, bullet, etc.? Barrels are the same length; 30", Krieger 1x8 twist in both, one is a Savage Target Action and the other a Panda Action.

 

[Phil]

You`ll have more room in the case with the extra freebore.

I know Jim and Donovan use the longer freebore,i`m sure others do too.

 

[SDDasher]

I should have also said same powder weight. I have about 100 fps more with the .155 freebore and don't understand why.

 

[savagedasher]

If I did my figures right with H4350 the one with 105 fb the fill ratio 107.2 % 59691 PSI
150 fb fill ratio 105.6% 57701 PSI which amounts to approx 2000 PSI Good Shooting Larry

 

[SDDasher]

I am using H4895 with my best node in the Savage (104) free bore the next to max node at 3012fps and the Panda (115) free bore best node near max at 3113fps. My question is there a way to adjust for free bore in QuickLoad?

 

[savagedasher]

Sure you just adjust OAL length it adds or takes away powder capacity taken up by seating depth Good Shooting Larry

 

[SDDasher]

Thanks Larry!