6mmBR in a 20" bbl, anyone know how fast w/105s?

[65BR]

8 twist - thanks.

 

[jonbearman]

Consult your manual and see what barrel length they used to publish the data.Then subtract approx 2% per inch till you get to 20" range.This is only approximate.The real way to tell is to shoot through a chronograph. If you dont have access to one then call the bullet manufacturer.They should be able to tell you.

 

[RonAKA]

A formula I have suggests you will lose about 25 fps per inch for a 6BR. Most loading data tables are based on 24", so about 100 fps less.

 

[constructor]

apx 2800-2850 with 30gr Varget

 

[65BR]

Thanks all, had a few guys in handguns - 18" getting 2450 and just over 2600 so looks like a big accelerated loss, getting much under 20, understandably in small bore, small capacity.

I have a Chrono but wanted the info to decide if a 20" 6BR would do what I need, perhaps a 21-22 would be a better compromise. Thanks again.

 

[Fordnutter]

I were struggling to get much more than 2,800fps with 95gr VLD's in a 24" barrel in 6BR guise. I have since rechambered & can get up to 3,000fps. If 21-22" isn't too long for you I think that may be better than 18" - you will really struggle for speed especially with the 105gr. I would think in 18" 2,500fps would be the max you could expect with the 105grainers.

 

[65BR]

Great info all - thanks much, think 21-22 will be the short side of things, likely 22. I'd like 2750-2800 or better if possible, though a 95 BT and even 80-85 Barnes would be solid choices for hunting. My 24" Dakota 10t ran 95s at 2900 or so.

Thanks guys.

 

[LWolken]

I would say 2700fps don't get too optimistic, many loads published on here are over max or near max and your milage might vary from those numbers which are already high with long 28"-30" barrels