Which is more accurate? 6mmBR or 6mm Dasher

[Steveb]

I am thinking of building either a 6mmBR or Dasher strictly for short range F-Class (600Meters or less). Which is the more accurate cartridge? I want to start using the smaller cartridges for economy and increased wind drift for practice on the shorter courses. I know the Dasher pushes the bullets faster but that may not be an advantage on the shorter ranges unless it puts the bullet velocity into a better more accurate node for an resultant accuracy increase not strictly due to velocity. Would be interested in any info anybody can share. Thanks

 

[johara1]

That is an easy one, My Dashers will shoot in the mid zero's at 100 yds and in 2"'s at 1000 yds. These are 17lb. guns with HV.barrels how many F class guns will do that? I know Rodney just set a 600 yd. record .349. A BR. can't keep up with the conditions as good as the Dasher……. jim

 

[ShootDots]

I have both.. Although I am not VERY experienced with the Dasher>>>BUT I know the 6mmBR very well... If there were mild winds at either 300 or 600 I doubt you would notice any REAL difference in F-Open shooting. Having said that, once the wind starts to huff and puff (say above 10m.p.h. and "switchy") you would notice a definite difference between the BR and the Dasher.. You are talking at least 150f.p.s. additional speed with the same projectiles>>you WILL notice the difference... However, like I said, with relatively calm conditions there would be little or no difference. However, as far as straight up and down pure accuracy, I don't believe there is a penny's worth of difference..

 

[Lapua40X]

... as far as straight up and down pure accuracy, I don't believe there is a penny's worth of difference..

What he said ..............

 

[johara1]

Real world, you don't see the BR. setting the world on fire anymore at 600 and 1000……. jim

 

[MarkS]

Steve,
It boils down to the barrel. If you have a good one. it's not going to matter, if it is a BR, Dasher, BRX or any of the BR IMP. I shoot a 6BRX. What I like about the BR IMP"s, is I can run super hot BR speeds with out the pressure. Aii of my BRX's run best around 2975 f/s. Do both, do a 6br and a Dasher barrel. Flip a coin.

Mark Schronce

 

[Steveb]

Thanks guys for the input. Couple of comments for the replies to give my feed back for the info you kindly took the time and supplied.

First: regarding the drift issue due to the velocity difference. According to my software, the difference is about 1" between the two at 600 meters(700 yards) which is the maximum I intend to shoot this rifle. When you at contending with 33" of drift for a 10 mph wind then 1" more isn't an issue with me. To me then I would find no difference between the two.

Secondly, I do not intend to use this rifle past 600 meters. I use my 300's for the long stuff anyway. Where I live there is a sharp division between ranges of 600 meters and less and those over. If I go to the short range locations there are only the short ranges possible and only need to take the one rifle.

Thirdly, I tend not to run high pressures in my BR anyway since I don't use Varget. Actually I have an accurate load for my existing rifle (which I want to replace with the new one) using 4007 but don't know how fast it is since I have never checked it. It is superbly accurate and since I shoot the close ranges never bothered to check.

However, I do like the idea of a little more flexibility on the pressures and the ability to load a Dasher down to BR velocity if it will preserve the barrel and bullets.

Thanks Guys for all the info.

Steve

 

[johara1]

Steve, i don't know where you got your numbers, but you don't see a BR at 1000 anymore and check the records at 600 and 1000 they are all Dashers i'm sure if they could keep up some one would be using them. I do know at 1000 is 300's 6.5 getting blown off the paper and the Dasher is still on and small. I'm talking from the present not the past…….. jim

 

[dkhunt14]

I agree with jim. Guys have tried the 6BR at Williamsport and they just didn't do as good. John Buhay a couple years ago had a dasher in light gun and won a lot. He told me he didn't want to mess with fireforming and made a 6BR and he didn't hardly win anymore. Over the winter he cut them off and made it a Dasher and went right back to winning again. I think the Dasher has a broader range where you can the bullets to settle down. Some guys don't think that some loads shoot better through the wind, but I believe it does exist. Matt

 

[coford]

My 6BR only gets 2800 FPS before I run into pressure signs. My Dasher easily makes 3000 before pressure shows up. According to my Berger program the difference in a 10 mile per hour wind at 600 yards is 2.54 inches and the difference at 1000 is 8.82 inches (using the 105 Hybrid). In most games 2.54 inches is huge. It could make lots of 9's into 10's. If I could only have one it would be a Dasher.

 

[jlc204]

My 6BR only gets 2800 FPS before I run into pressure signs. My Dasher easily makes 3000 before pressure shows up. According to my Berger program the difference in a 10 mile per hour wind at 600 yards is 2.54 inches and the difference at 1000 is 8.82 inches (using the 105 Hybrid). In most games 2.54 inches is huge. It could make lots of 9's into 10's. If I could only have one it would be a Dasher.

What is your 6br barrel length and what powder are you using? I have a 6br .236 Bartlein 5R 29" and gives me 2920 fps w/ 30.7gr N150 with a 105gr Hybrid. This velocity was determined with a magnetospeed.

 

[johara1]

Maybe i'm missing something but it ain't a race…… I've take the Dasher over 3000 with the pointed DTAC 115's. I found less wind drift if they are tuned better and a little slower with a 103 Spencer. I'm looking for sub 2" groups in the middle at 1000. I'm shooting a shorter barrel and i can get the velocity at 28" and shorter……… jim

 

[brxbrad]

I am thinking of building either a 6mmBR or Dasher strictly for short range F-Class (600Meters or less). Which is the more accurate cartridge?

I believe the question is as broad as it is long. Erik Cortina said it all in his signature section "At some point, the shooter becomes the limiting factor in accuracy!" I've seen BR's out shoot BRX's and BRX's out shoot Dashers and all combinations thereof and if you put the same 3 guys on the same rifles tomorrow, it will all be different. Velocity does not equal accuracy.

 

[Area Man]

Some guys don't think that some loads shoot better through the wind, but I believe it does exist.

Are you saying that identical bullets, leaving identical barrels, at identical velocities and twists, will perform differently depending on the dimensions of the case?

 

[dkhunt14]

Are you saying that identical bullets, leaving identical barrels, at identical velocities and twists, will perform differently depending on the dimensions of the case? quote
I am saying when the bullet is settled down and not pitching and yawing it seems to drift less. With the Dasher you can reach a higher node where this happens over a 6 BR. Maximum speed of bullet isn't where its at. Kinda like what johara1 is saying.

 

[Steveb]

I guess this is what I was asking regarding accuracy between the two.

Does the Dasher velocity move the bullet exit into a node where it is more stable therefore more accurate simply because it is faster? We know that certain bullets "Like" a certain velocity range and that there are multiple ranges (nodes) depending on velocity. However, is the velocity range for accuracy of the BR better, worse or equal to the Dasher given barrels of "equal" worth?

I agree that less drift due to velocity "can", in theory, result in higher points but I haven't seen too much of that in my experience. I have seen a couple of times where it may have resulted in a higher score but can't honestly be sure because I have never tracked it match by match.

Thanks again for the informed comments.

Steve

 

[johara1]

Steveb, It's all about rotation…… I slowed down and it seemed to be moved less by the wind and the accuracy got better. I develop my loads at 100 yds. group shape and size is done there, i want no vertical. I practice at the match.i don't want to wear out a barrel. The 105 Hybrid i could run faster but not as small as the Spencer. I'm sure there may be higher nodes but it will kill the cases,i have fired one set a hundred times and they are still good. I'm shooting a little less than 3000 and my ES is single digits SD is zero most of the time, I,m where i need to be, it shot small with 4 groups in a row and it agged. 2.8"at 1000 yds……………… jim

 

[articmp]

Not to mention, Mr. O'Hara set some new world records this year. And I would almost be willing to bet they won't be beat anytime soon. My money is on Jim to set a new group record in the next 3 years. The man knows what he is doing at 1k! Just hope I can get lucky enough next year to not get slotted with him on the relays, it kills a rookies chances to get points.

 

[BradY]

For F class your shooting for score and not for group. That being said if you can center a small group in the 10 or X ring your going to be successful. I would choose the dasher simply because it will assist you in reducing the lost points. Running in a higher node will help deflect wind more. Will it make a bad shooter a good shooter? No, but you might be lucky enough to lose a 9 instead of an 8, or a 10 instead of a 9. Shooting FO you should take any opportunity to beat the wind possible. Because if you dont, you opposition will.

 

[johara1]

Thanks, articmp. 1983 My score record you may say it was in the middle, 49.5 for 6 matches at Harry Jones and i broke that at Va.49.8333for 6 matches and a group agg. size 3.072". So i had a possible 596 points out of 600 and our ten ring is 7" I wish i had the health to shoot F class but if i laid down in the dirt you would have to call 911…….jim