6 Dasher Twist Rate

[Mags]

Apologies if this is beating a dead horse, but have a question about optimal twist rates.

I've settled on the Dasher for my new PRS rifle and am trying to decide on a barrel. Everything I've read has been 8" or 7.5" but my smith is saying that I should go straight to 1:7.

I will be shooting nothing but 105gr hybrids, 107 SMKs, or even 108 BTs depending on what it seems to like best - nothing lighter. I've done the twist calculator and everything up to an 8" twist seems to stabilize up to 108s... just wondering if the 7T is going to be too fast for the 105s.

Barrel will be a Hawk Hill M24 finished at 26", no neck turn and .135 free bore. Any insight is greatly appreciated.

Thanks!

 

[swd]

For PRS shooting you'll never know the the difference. Given the choice I'd go 7.5". It's enough for 110SMK's which is a bullet you should look also. .620ish BC out of a Dasher at 2950-3000 is big medicine.

 

[ncboiler]

I've got a 7.5 twist Hawk Hill barrel that I am going to use. I figured it won't hurt to have a little faster twist with the 105's and it won't limit me on the 110's if I wanted to try those.

 

[Mags]

That's what my thinking was. 7.5 seems to be the sweet spot for those of us wanting to run heavies. I have a feeling the 105 hybrids are going to be tough to beat, but if I could get the 110s to go mid 29s I may be persuaded to switch.

 

[Pakratt99]

I'm running a 24" Brux in 7.5t with the 110smk in a Dasher @2825 for PRS styled matches, grouping is phenomenal. From all the math I've done the 7t recommendation on the 110-115 class bullets is probably to provide a bit of fudge factor if someone gets a barrel a little on the slow side, with a cut barrel that shouldn't be a problem. I can get more velocity but H4895 worked a little better than RL16 for me and the node with the Hodgdon was a little lower velocity wise but with the velocity I'm seeing it should still be above trans sonic to 1325yd which is more than enough for me.

 

[Mags]

^That would be more than enough for most PRS style matches. Low 28s seems silly to run the heavies though when the 105s will go 3k or close to it with a long enough throat. Come ups and wind drift will be pretty much the same, if not a little better with the hybrids.

RL-16 was the ticket in my 6 creedmoor but it sounds like Varget is pretty tough to beat in the Dasher. Time will tell, have plenty of both powders and projectiles to test.

Thanks for the insight guys, 7.5t it is.

 

[swd]

^That would be more than enough for most PRS style matches. Low 28s seems silly to run the heavies though when the 105s will go 3k or close to it with a long enough throat. Come ups and wind drift will be pretty much the same, if not a little better with the hybrids.

RL-16 was the ticket in my 6 creedmoor but it sounds like Varget is pretty tough to beat in the Dasher. Time will tell, have plenty of both powders and projectiles to test.

Thanks for the insight guys, 7.5t it is.

A Dasher will push 110's to 3000 fps give or take depending on your barrel. Varget, 4895, RL15 and RL16 are all THE Dasher powders. None are necessarily better than the other except the one that shoots the best in your rifle.

 

[Sheldon N]

I'm running 105's in an 8 twist Dasher, that's what the vast majority of guys in PRS run. Go 7.5 if you want to try the Sierra 110's. Couple shooters I know have tried them in their Dashers and the safe load level was in the lower 2900's with a 26" barrel. My buddy last match was 2920 fps. My node for the 105's is 2965 fps. I've had it over 3000 but backed off to where it shot best.

My two Dasher barrlels are 8 twist, but if I had a choice I'd lean towards 7.5.

 

[KenOath]

I run an 8tw with 107 sierras from Dasher and straight BR with good results, if you plan on running the 105 hybrid or 110 sierra then a 7 or 7.5TW would be a better option.

Cheers Rushty

 

[Mags]

A Dasher will push 110's to 3000 fps give or take depending on your barrel. Varget, 4895, RL15 and RL16 are all THE Dasher powders. None are necessarily better than the other except the one that shoots the best in your rifle.

You might get them there depending on barrel but of all the load data I've seen it looks like low 29s is about the ceiling as far as accuracy and pressure goes. Not that 110s at those velocities are bad by any means, I just think you hit diminishing returns going with heavier bullets compared to the hybrids.

Thanks for the replies. I went with a 7.5 twist just so I had the option of going heavier if I wanted to. Going to start with 105s because I have a feeling that's where I'll find a happy medium between velocity and accuracy, but I will keep 107s, 108s, and some 110s on deck in case they don't work out.

 

[Dan Hall]

I would go with a 1-7. A little more twist is better than not enough.

 

[Mags]

I would go with a 1-7. A little more twist is better than not enough.

You're probably right. However I haven't found any 6mm pill that would shoot in a 7" twist but not a 7.5"... with 117s MAYBE but I won't be shooting anything that heavy.

The 115s stabilized just fine in an 8 twist barrel I was testing a while back, so I figured might as well split the difference.

 

[shoot4fun]

I would go with no heavier than the 110 SMK and more likely would stick with the 105 Hybrid.
The speed king powder for 6 Dasher is Alliant 2000-MR. I shot it behind 105 Hybrids at the 1,000 yard nationals in GA last fall. My node wasn't even the highest one but I was hitting 3185 FPS with 28" barrel. That was after just one 1K rounds thru the Bartlein 7.5 twist too. Those number can outrun the 6 Creedmoor!

 

[Mulligan]

I would go with no heavier than the 110 SMK and more likely would stick with the 105 Hybrid.
The speed king powder for 6 Dasher is Alliant 2000-MR. I shot it behind 105 Hybrids at the 1,000 yard nationals in GA last fall. My node wasn't even the highest one but I was hitting 3185 FPS with 28" barrel. That was after just one 1K rounds thru the Bartlein 7.5 twist too. Those number can outrun the 6 Creedmoor!

Tag @Thumper

 

[Dan Hall]

Mags...a 1-7.5 will work great. Mostly I'm just seeing that we need to go tighter than 1-8.