ideal bbl length 6 Dasher

[ANDY5]

I am building a new 6 dasher. Planing on shooting 105 Berger Moly's. At what point is the powder completely burnt. My reasoning is I want a 10 1/2# 1000 yd rifle. I am thinking 21 3/4 " with a target crown. 21 3/4 inches ending at the bbl bore dia. with target crown. Number 7 Contour. The load would be appx 33.3 RL15 with burger 105 moly, CCI 450's,that's what shoots in my other dasher). The research for this figure came from Virgils Houston Warehouse. If any one has input on this please respond. The rifle will have West custom rifles bench rest stock from Redwood,carbon fiber and laminated), Pillar & glass bedded, with Kelby type base and single screw rings. Remington 600 blueprinted action, timiney trigger @ 2 oz. sporting a 36x Leupold or weaver t36 with dot.
will appreciate your opinions

 

[ANDY5]

about 26-2700 fps I suspect. the other thing I have eating away at me is that I have been shooting Remington 600's for years and out of the box they could group time after time. Its just eating away at me. What will a dasher do with a short bbl?
Unless someone has already tried this and it was a disaster, I think it is worth trying. These were hunting guns and I shot my deer out to 300 yds. Just the same as the big boys. Is it better to get the bullet out of the bbl sooner or not?
Regards,
Andy5

 

[ANDY5]

You did not misunderstand me. I shoot in my dasher that I have with a 28" bbl the 33.3 varget w/Berger 105M CCI 450 and you are right. It is stout. My shooting partner can't shoot my loads in his rifle. But they don't show presure in mine. I was just trying to come up with a 10 1/2 # class rifle for 1000 yd shooting. I just used my experience with short bbls in the Remington mod 600 for an example of accuracy. I think the 23 1/2" bbl might buck too much for the bench anyway. Just kicking it around and see if there are any positives or negatives out there. Unless someone can give me some positive imput for a short bbl, I will build it with a 28" bbl and turn it down if nessessary to make the weight limit. I have read and read about people shooting one weight rifle so the mussel memory will stay the same and not get lazy with a heavier rifle which lets some relax on the bench and rely on the rifle to do its job.
I value opinions so if you have any more let me know.
Regards,
andy5

 

[techshooter]

I calculate,using QuickLoad) that you would be getting about 2904 FPS from a 33.0 grain load of RL-15 from a 21.75” barrel. However, that is not quite fast enough to hit the OBT accuracy node at 1.013 mS. It would take about 34.7 grains RL-15 to reach that, at 3013 FPS and >71KPSI. Way too hot.

Dropping back to 32.0 grains will hit the next lower node at 2802 FPS, 1.128 mS, and about 56KPSI. I am using an effective barrel length of 22” when calculating the OBT, compensating for the slightly shorter 6BR case from the standard 0.308 case length. All these comparisons are based on actual measured data on my Dasher, and my lot of RL-15. I can say that three lots in a row have been spot on, requiring no load change.

 

[memilanuk]

I want a 10 1/2# 1000 yd rifle.

Andy,

I might be revealing my ignorance of 1k BR rules/classes here... I thought they generally had a 16-1/2-17# and under 'Light Gun' class and a 'Heavy Gun' class. I'm not sure how the heck you would even attempt to make a 10-1/2# gun w/ a 28" barrel, big scope, etc. I guess w/ enough aluminum and carbon fiber anything is possible! :thumb:

Or is it you want a gun that would fit in the 'point blank' 10-1/2# Sporter/Light Varmint class and still be able to shoot competitively in 1k BR? That seems to be asking a lot of one gun