Emphasis on speed

[lwminton]

As I read comments here, I see considerable emphasis on speed and get the sense that faster is better.
I just read this article which concludes to the contrary.

http://www.6mmbr.com/gunweek031.html

Is faster better or is the truth on the paper?

[KentuckyBuddha]

Speed is better in many applications. Within the confines of F-class shooting when you can ONLY choose between .308 and .223 it may very well not be. Why would that seem counter-intuitive?

The truth is always on the paper. Divining the truth to what questions is where you have to be careful.

[JASmith]

The American macho is all about speed!

Having acknowledged that, the referenced article points out a truth -- going with a load your rifle likes is almost always better for hitting the target, tigher groups, and better scores.

The major exception is choice of bullet. One needs to use a bullet that is reasonably able to buck wind and this might take one to the heavier, slower end of options for your cartridge. Going faster with a particular bullet, however, is justified only if one can see a significant improvement in windy condition group sizes.

[KentuckyBuddha]

True.


If you go with the lightest pill you can to go faster is not going to lead to joy in .223 or .308 in that application.


There were lots of great things in that article.

My favorite was the suggestion to take a .22LR and practice wind correction and just shoot a lot more. If that is wrong, I don't want to be right.

[JASmith]

I am pnly just begiinin to relaize the value of the 22 LR for practicing wind correction....

[lamrith]

Not sure you guys caught it, but that is an old article as well (2004?). Not that it is not valid info and good to learn from, but a bit of advancements have happened in the 11yrs since that was written. so just something to keep in mind..

Truth is in the paper.. His liked slower, but your gun built from same Mfg/model might like faster..

[Klem]

I didn't get the impression he was recommending slower loads for everyone, just that his barrel (at the time) preferred a particular load that happened to be slower than the calibre is capable of. The harmonics of his next barrel was no doubt different.

Also bear in mind that F Class shoots at known distances and only needs to punch a hole in paper. His bullets can be travelling slower than a wet week and as long as they are still stable the rainbow trajectory is not going to matter. He dials in the range, points his gun into the sky and gets two unscored sighters before he needs to be on target for the next 10 to score.

With Grendel it is the smallest case of the 6.5 family. Speeds are relatively slower than other 6.5's so unsurprising that guys are concentrated on getting the most out of what the various powders can deliver. This guy is shooting 308 out to 1,000yds in increments of 100 starting from 300yds. He can afford to concentrate on group size at the expense of velocity. If you are shooting a deer with a Grendel or trying to make 1,200yds you don't have that luxury.

Maximising speed allows for longer point-blank-range dangerous space in hunting. It translates into a flatter trajectory which is more forgiving when hunting or in situation where you need to judge distance to target, or do not have the luxury of sighters (e.g. steel targets in Sporting Rifle competition with no sighters, all scored).

Maximising speed, or at least maximising the peak pressure of your loads also maximises the killing potential of the weapon. This goes along with choosing the right bullet for the flesh you want to shred. If using ballistic tips there is a minimum threshold speed at which they are designed to open-up properly. By deliberately slowing your projectile you shorten the maximum effective range of the gun in this scenario. You could go a slightly heavier ballistic tip which is slower but then your point blank range is compromised. The only reason I can think of when hunting flesh that a slower round is of any use is subsonic with a silencer. And if you done any subsonic hunting (e.g. 300Blackout) you quickly realise it is not much more impactful than bow hunting.

Just depends on what you want to do with your gun and this guy has a very specific use for his.

[Allen]

I agree 100% with Klem.

[dmsims21]

I agree 100% with Allen.

[NugginFutz]

Ahem - I agree 100% with dmsims21, et al...

Seriously. I do.

[lamrith]

NugginFutz is dead on the money...

[lwminton]

Thanks for your suggestions, but I was thinking about accuracy in target competition (at 300 yards) not killing game.

[rwh]

I've been shooting the 108 scenar at 300 yards at 2600 fps lately and getting good results, at least by my standards. I ran the berger ballistic calculator with a 10 mph crosswind and the difference on paper between 2600 fps and 2700 fps is about .1 MOA at 300 yards. Having a load you trust that goes where you aim it is more important than velocity at 300 yards. At 600 I give a lot of weight to the ES as well as the velocity when looking for a good load. I need to be confident that the reason my bullets don't all hit where I want them to is because of how I shoot and read the wind, not because of my rifle or ammunition.

[Klem]

Thanks for your suggestions, but I was thinking about accuracy in target competition (at 300 yards) not killing game.

In your very narrow scenario of tightest groups at 300yds then speed is less important than accuracy.

Hunting aside, that still does not mean that less velocity is more accurate. In your case study a guy had a barrel that liked slower velocity loads and he won in competition with them... but then generalising that all barrels like slower speeds because one person's barrel likes slower speeds is a classic research conclusion fallacy. It is called generalization. A sample set of one barrel is about the least generalizable sample of the whole population of barrels as you can get. If you want to generalize that all barrels might do better with slower loads then you need to have a sample size that is representative of the entire population of barrels. The idea that one barrel carries more leverage to the argument because it happens to be a person who wins F Class competitions assumes the rest of the population does not know what they are doing. I think 'first among equals' is more like this guys situation.

In your shoes I would drop the idea of 'slower loads are better' because if that were the case then this would have been common knowledge by the end of the 20th Century. Suggesting slower loads are better on a Grendel forum where every bit of velocity matters is anathema. By contrast the Bench Rest discipline have been honing their loads, calibres and equipment for best accuracy at 300yds for years. No doubt on their forums they would advise you to ditch the light-weight AR15 in favour of heavier bolt action and use a different calibre if you want to be competitive.

If however you are wanting to achieve most accuracy at 300 in an AR15 shooting 6.5Grendel then normal load development up to max peak pressure for your barrel is the go.

[JASmith]

Well said Klem!

The only thing I can add is maximum loads are rarely needed even in the Grendel!

Go for your accuracy node wherever that takes one within the operating pressure limits.