Home Forums Hunting & Shooting Custom Rifles & Wildcats Why is one 6MM more accurate than another

Supposedly the 6MM BR is more accurate than say the 6MM Creedmoor. Why would that be?

Where I decided that it was a good question.

Too many variables go into the equation of accuracy, but one of many is case capacity.

Years ago, in the quest for the ultimate accuracy cartridge for point blank Benchrest shooting, the 6 BR case was determined to have too much capacity, which lead to the 6PPC case, or more correctly the 220 Russian as the platform. The 6 PPC has been top dog for decades.

The 6 Crapmore will never be a contender in any accuracy related category.......

Seems that the 6 Creed is gaining some popularity in long range steel shoots.

Not as much as a 6 Dasher......

There are more 6MM's out there than you can shake a stick at!

What dies are you using for your 6 Dasher?

Whidden sizer and a Forster seater

I've been shooting Dashers since before any manufactures had any dies available.

The smith ran my reamer into a Newlon full length bushing die blank & a Wilson 6 BR inline bullet seater.

Well there seems to be a plethora of dies out for it now, Interesting the Wilson inline seater works for the Dasher. Oddly I see a lot of dies for the Dasher and the BR are out of stock.

The smith ran the Dasher reamer in the 6 BR Wilson die....

What accuracy have you folks had with the Creed?

My experience, many 243s, as many custom BRs, and 2 6mm Rems.

No doubt, the 6BR is THE most accurate round I have used, with the 6.5x47 running pretty close......

Picking which 6, depends on application. I've dusted deer to 400 yds with the BR........but if you want reliable feeding and further distances, you might want a longer cased 6.

Have tried two 6mm Creedmoors, and so far haven't found it shoots as well as the 6.5, and not nearly as well as the 6XC, which has close to the same capacity. It might be a little more accurate than the .243 Winchester (which has just about exactly the same powder capacity), and no doubt offers a little more barrel life, due to the sharper shoulder and longer neck. But so far it hasn't impressed me that much.

The guy behind the scope? Maybe?

Wow. Interesting. Any averages you can report on the 6 CM? Sounds like one might expect the CM to roughly equal the 6 Rem. Not bad. Just not stellar either. I’ve heard good things about the 6x47 Lapua but they might be more fickle I’d guess than a BR. The XC always proved itself over time. I’ve had an interest long ago in the 6x47 Swiss Match but the brass sourcing was always an issue in the USA.

Funny when I was at SHOT the year Lapua was pushing their then new 6.5. It must have been the RUAG booth next to it. Those folks were not happy all the attendees were concentrated at the Lapua booth. Their smug expressions were as if Lapua copied their case, improving it to 6.5?

So to your post JB, could it be Hornady knew in advance of the 6.5 launch, that is outshot the 6? I’d guess perhaps or they simply did it first for Fast market acceptance and overall size.

Thanks for your post.

Not quite. The 6ppc pre-dated the 6BR by three or four years, I believe. The 6 BR was Jim Stekl's attempt to develop an alternative to the ppc. Unfortunately, the lack of availability of formed brass pretty well doomed the BR at that time. The ppc also had no formed brass available but the ppc was easy to form while the BR was an exercise in tedium.
As far as accuracy is concerned, there are numerous 6mm's which seem like they should shoot just as well but they don't. For instance, I have never seen a 6mm Rem or a 243 which would agg any better than about .4 when the chips were down. The smaller 6mm-250 should be better but it isn't. The 6mm International was OK and would probably be close but it never gained any traction. The fact is, the 6ppc and 6BR are just plain better and this probably has more to do with case capacity than anything else. Today, the availability of quality brass really helps these cartridges to shine. When I first started building 6BR's for long range ("F" class) shooting, it almost seemed like cheating. Only the wind kept the other cartridges in the hunt. Today, the use of higher BC bullets to cheat the wind has become SOP (always was, really) so the 6.5's and 7's are ascendant. The 6BR is still capable of better accuracy though and is easy to shoot. A man who can deal with the wind can still win with it. Out of sheer stubborness, I seldom shot the BR but I probably would have done better if I had. GD

I wouldn’t draw any firm conclusions based on a very small sample size. Which is probably why MD keeps saying ‘so far’.

For example, the few 6 Creedmoor barrels I’ve spent time with seemed to shoot as well or better than the 6.5 Creedmoor barrels, and about the same as the 6XC that I’ve worked with. But that’s also a very limited sample size, and the results could be more correlated with individual barrels than any inherent attribute of the cartridges themselves.

The 6PPC came in 1975......


Soon after the introduction of the .308 Winchester-based wildcat .308×1.5" Barnes cartridge, wildcatters and experimenters began developing their own wildcats based on .308 Winchester. By 1963 there were several .22 (5.56 mm) and .24 (6 mm) caliber cartridges based on the Barnes’ cartridge. The new cartridges’ accuracy and efficiency was noticed by the bench rest shooting community. The .24 caliber (6 mm) cartridge version became known as the 6mm Bench Rest or the 6mm BR due to its widespread use in the sport of bench rest shooting.

Because the cartridge was a wildcat and was not standardized until several years later, several variations of the cartridge existed. Cases required fire forming in the chamber as chambers of the rifles varied from one to another.[3] Several 6mm BR variants exist apart from the Remington and Norma versions: the 6mm BRX,[4] 6mm Dasher,[5] 6 mm BRBS[6] 6 mm UBL.[7]
6mm BR Remington

In 1978 Remington started manufacturing their Remington 40-X rifle in the 6mm BR and named their version of the cartridge the 6mm Bench Rest Remington.[8] By 1988 Remington was also manufacturing ammunition.[9] Remington continues to offer the 6mm BR Remington in the 40-X series rifles.[10] The Remington version of this cartridge is now considered to be obsolete.[9]

JS - Are you using Lapua brass? Wonder if it's a bit more consistent? No doubt, barrels matter as other variables.

What accuracy are you seeing in 6 CM ? Thanks.