6BR vs 22 BR same weight bullet (moved to reloading forum)

[JeffG]

I just dove into the 22 BR (9twist) world. I have had great success with the 6BR (8twist and 14twist). These are/I am never gonna be dedicated bench rest shooters..I just like tiny groups!

Just for my own curiosity; since the fast twist 22 should like 62-70g, and the slow twist 6mm likes the same range of bullet weights..who's gonna win the velocity race with equal weight bullets?...22 slug will have a higher BC, 6mm will have more surface for the powder charge to push against (= higher case pressure?)

Am I just creating another gun to do the same thing as one of my sixes?

 

[Immike]

We are shooting (my son) a 22br with a 1-7 twist and push a 90 gr berger. Loaded - 32.5 gr of H4350. It will shoot brother.

 

[Tommie]

The 6mm will be faster. That's assuming all other variables are equal.

 

[Immike]

I think that the BC's of the 22 will make up for it and more.

 

[Ackman]

Most accurate 55/58gr loads in my 6BR are about the same velocity as the most accurate 50gr loads through the 22BR. Barrels are 14" twist. The 22BR is great but I think the 6BR is better.

 

[22BRGUY]

Im with Immike

 

[stacy]

I'M WITH IMMIKE

 

[Immike]

I think they are both amazing cartridges hands down. A guy can't go wrong with either one of them. If they ever make a heavy hybrid for the 22 then look out for the 22br!!!!!

 

[LCazador]

The 6mm or bigger bore will always be faster if the same bullet weight is used . I have experienced the same with the 7mmBR and 6.5BR . The same 120gr bullet goes faster in the 7BR . And the same goes for 223 with 55gr. bullet and 6X45 , 223 necked up to 6mm . It has to do with the expansion ratio of the bore diameter vs. bullet weight and powder charge vs case volume . The bigger bore will always be faster and in most cases be more accurate !!

 

[22BRGUY]

Seems like a decision between higher BC (22BR) and higher velocity (6BR). Just me but I favor higher BC. Best wishes to all for good thread.

 

[Tommie]

Again, to answer your original question as to which is "faster"...the 6mm will be faster with equal weight bullets.

 

[Immike]

Tommy is there a point where the 2 cross paths on speed such as at 600yrds or so? I am not able to run any programs in my present location (man cave )

 

[Coleridge]

Why not compare apples to apples....

A 6BR shooting a 105 is all over the same speed as a 22BR shooting 90's & both have pretty much the SAME BC (.224" 90VLD=.551, .243" 105Hybrid=.547). The 6BR will be easier on barrels & will likely shoot better because less twist is needed (not as much centripetal force exaggerating any imperfections in bullet weight distribution).

In the exact same bullet weight the 6BR will be easily faster mainly because it builds pressure slower (more room for expansion & more surface area to push against) which means you could add more powder in the 6 v/s the 22BR to get same pressures; more powder in the same case with same weight projectile = "more faster" bullet. It's not a guess it's fact. A larger bore in same weight is faster.