Does BC=Accuracy?

[Ggmac]

148 gr dewc most accurate 38 spec load .

 

[rbduffer]

BC variation within a lot can give dispersion. When a bullet gets long to gain BC, they can get finicky. Matt

dk nailed it. BC reduces the effects of wind and gravity. But a short fat bullet is physically more stable than a long skinny one. Much easier for high BC bullet to get "finicky".

 

[Toby Bradshaw]

I just prefer higher BC bullets for any rifle I use to shoot long range because they use up less scope elevation adjustment and get to the target quicker which makes them less affected by wind.

Wind deflection isn't a function of time of flight, but of lag time.

My 22BR (40gr NBT) is going 500fps faster at 100 yards than my 6BR (105gr Berger VLD) is at the muzzle. Even with a shorter time of flight for the 22BR the wind deflection is 50% greater than for the 6BR at 100 yards.

 

[Alex Wheeler]

If B.C. alone was the be all end all to long range precision. None of us in our right mind would be shooting 6mm in 1000 yard benchrest.

Here's an interesting result to a test I did at 1000 with 3 different "modifications" to the same bullet.


View attachment 1017408

Now, a guy would think that maybe the highest impacts, hence highest bc, would have less vertical dispersion when shot at 1000. And, knowing I'm splitting hairs, so I loaded 2 IDENTICAL tests, just to see if the results would repeat. In other words, see if my testing method is producing reliable data.

View attachment 1017409

There you have It!

Now switch bullets(even lot numbers), and all bets are off, the results may reverse....or not.

Tom

Giving away more secrets! LOL

I thought you had to point your bullets to shoot well at 1k???

Pointing, trimming, annealing, NOT always a good thing. Often they can be though. You have to test. The targets above show why Tom shoots so damn small. He tests things most do not even think to test. I used to think pointing was something that way always a good thing because with the bullets I shot it was. Toms testing has shown not all bullets respond the same.

 

[dkhunt14]

I have seen pointing give less wind drift and score higher but it also opened up groups. It induced more vertical dispersion. Matt

 

[Fast14riot]

Better BC can improve precision, but has no bearing on accuracy.

 

[Richard Coody]

Better BC can improve precision, but has no bearing on accuracy.

A lot of.100 yard benchrest shooters still shoot flat based bullets. No doubt those PPC's shoot some mighty small groups

BC has become important as the distances shooter are competing at continues to increase. i wonder if the shooters influenced the bullet makers or these awesome new high BC bullets brought the shooters into the sport. my experience is those high BC bullets like the VLD are harder to tune. Berger changed that with the hybrid. bullets are just getting better and better.

 

[savagedasher]

A lot of.100 yard benchrest shooters still shoot flat based bullets. No doubt those PPC's shoot some mighty small groups

BC has become important as the distances shooter are competing at continues to increase. i wonder if the shooters influenced the bullet makers or these awesome new high BC bullets brought the shooters into the sport. my experience is those high BC bullets like the VLD are harder to tune. Berger changed that with the hybrid. bullets are just getting better and better.

Bart should know he makes both. Larry

 

[Ledd Slinger]

Wind deflection isn't a function of time of flight, but of lag time.

My 22BR (40gr NBT) is going 500fps faster at 100 yards than my 6BR (105gr Berger VLD) is at the muzzle. Even with a shorter time of flight for the 22BR the wind deflection is 50% greater than for the 6BR at 100 yards.

We could compare apples to oranges and argue details of ballistics all day, but id prefer not to.

I was implying all else being equal with same caliber, bullet weight and bullet speed. A higher BC bullet will reach the target faster due to less loss of speed which results in less wind drift due to less time in flight.

 

[Northridge]

We could compare apples to oranges and argue details of ballistics all day, but id prefer not to.

I was implying all else being equal with same caliber, bullet weight and bullet speed. A higher BC bullet will reach the target faster due to less loss of speed which results in less wind drift due to less time in flight.

Ledd Slinger, very often my loads that have more "hang time" in flight and shorter prepped bullets OAL destroy my faster load longer bullet data by a large margin. I 'm a bit of a "freak" like Tom Mousel & test every change, be it small or big and am never supersized with the findings. Often the data that helps me compete or shoot the smallest contradicts SCIENCE & Main stream thinking. I try to take nothing at face value and test, test , test for my own verification and not what a book or the latest product or manufacturer is promoting.

Shawn Williams

 

[Pigdog]

interesting discussion, so in a 6.5mm as an example would you be better off going with a 136 scenar-L with a relatively poor BC but very good consistency and easy to load for or a new 140RDF with an extremely high BC but POSSIBLY not as good quality control and accuracy or ease of getting good accuracy???

 

[Ringostar]

interesting discussion, so in a 6.5mm as an example would you be better off going with a 136 scenar-L with a relatively poor BC but very good consistency and easy to load for or a new 140RDF with an extremely high BC but POSSIBLY not as good quality control and accuracy or ease of getting good accuracy???

I haven't tried the RDF, buy tried the Custom Comps many years ago. I still have an unopened box of 250. I don't know that I'll ever use them up. I use the 136 Scenar L in my 47L. I recently got 500 more. While measuring them base to ogive, I had .002 variation through the entire batch. That is great for a factory bullet. I will take consistent over a little higher bc.

 

[JaoeyP]

Thanks for the thoughts guys! Very interesting taking in everyone's responses. This came up because I'm tinkering with loads for a 243 Howa and have found myself wanting to be able to shoot some of the higher BC, sexier, 95gr bullets. But, if they won't stabilize in this rifle I'll be looking at the 75-87gr options. I got to thinking that while there are advantages to shooting a higher BC bullet would it really be more accurate. Thanks again.

 

[Ledd Slinger]

Thanks for the thoughts guys! Very interesting taking in everyone's responses. This came up because I'm tinkering with loads for a 243 Howa and have found myself wanting to be able to shoot some of the higher BC, sexier, 95gr bullets. But, if they won't stabilize in this rifle I'll be looking at the 75-87gr options. I got to thinking that while there are advantages to shooting a higher BC bullet would it really be more accurate. Thanks again.

Just gotta test em to see. Your barrel twist rate should let you know if it will stabilize the heavier bullets properly before you spend the money and time on testing them.

 

[JaoeyP]

Just gotta test em to see. Your barrel twist rate should let you know if it will stabilize the heavier bullets properly before you spend the money and time on testing them.

I did a lot of research before hand and some had luck stabilizing the 95gr high BC bullets, some didn't. I thought it a fun project to try.

 

[Hydenseek]

 

[Mr Underbridge]

I can tell you with 100% certainty that in a vacuum the BC does not affect accuracy

 

[Berger.Fan222]

I've shot the triple deuce (222 Rem) in a few F-Class matches. Scores at 300 yards are much higher than at 600 yards, because the low BC (0.250 or so) bullets between 50 and 55 grains get pushed all around in the wind at 600 yards.

It sure shoots little tiny groups at 100 yards though and is ok at 300 on calm days.

I don't chase BC as the be all end all of shooting though. The Triple Deuce and a .223 with an 80 SMK (BC 0.45ish) has won more matches for our family than all the other rifles combined.

 

[CharlieNC]

So for LR 7mm beating 6.5mm beating 6mm beating 308 beating 223. What is it?

 

[Richard Coody]

So for LR 7mm beating 6.5mm beating 6mm beating 308 beating 223. What is it?

and you can keep going up 408 Cheytec BC 949

but there is a tradeoff between what is practical and not. Recoil fatigue is why many have gone to the dasher. Do you shoot better with a lower recoiling rifle. i think most have found that to be true.