68 VS 69gr berger bullets

[ArtinNC]

I have two barrels for my Hall action BR rifle . One is a 1:8 Hart and the other is 1:14 twist LW . I went the the range the other day with the 1:14 twist Hart barrel and shot some very good groups around .200 with the 68 gr bergers at 3100fps, then I tried some 69gr Bergers loaded the same as the 68 gr 3100 fps and in a barn at 100yds shooting at a target 2 ft sq and not one bullet made it on the target. I can't beleave that 3100fps is to fast for a 69 gr Berger when the 68 gr shot so good . The 69gr bullets have a 15 Ogive. I need some comments on this .
Thanks, Art

 

[ArtinNC]

Sorry I forgot to say both barrels are Std 6BR'S

 

[chino1969]

Sorry I forgot to say both barrels are Std 6BR'S

Wow that's some difference!
I would have assumed, as you did, that the 69 grainers would shoot close to the 68's. I have a 1-14" Hart light varmint in 6mm BR that absolutely loves Hornady 65 grn. V-Maxes and Fowler 68 grainers. I've shot 70 grn. Nosler Ballistic Tips pretty well and 68 grn. Starkes and 68 grn. Hammonds pretty well, but hands down performance is the 65 grn. V-Maxes and the 68 grn. Fowler's. I shot a five shot group @200 meters with the 68 grn. Fowlers that measured .276 using VV135 powder. Conditions were perfect with about a gentle 5 mph. crosswind moving right to left. Based on what you said, I'm going to have to determine what the ogive of the bullets are to add some data to my reloading notes for future reference.
Chino69

 

[ArtinNC]

I have also have shot 70gr Nosler, 65gr Vmax, 70gr Sierra, 68gr Watson. And after shooting the 69gr Bergers that never got on target, I shot some more very good groups with the Watson and Sierra and 68gr Bergers. I'm going to load some more 69gr Bergers and try to get to the range again this week and try it again I can't beleave that this happened, this is a new barrel and with only 50 round through the barrel and new Lapua brass. And all round loaded the same. And I have shot the 69gr 15 Ogive Bergers in other guns faster than 3100fps with no problems.
Art

 

[85grBTat3500fps]

hey artinNC,

I looked at the berger web site and if the 69 gr bullet that you are using is the low drag flat base, this is their old descriptionof the bullet)the new verbage is high BC flat base. Then these bullets require a 12 twist as per berger. Hope this helps a bit.

Andrew

 

[ArtinNC]

Andrew,
I was not planning on shoting the 69gr Bergers in this barrel, just fireforming new brass with odd and ends that I wanted to get rid of. But just surprised that the five that I shot, not one got on the 2ft sq target. When the 68gr shot so good.
Thanks, Art

 

[jerrysharrett]

I don't have any 68g and 69g Bergers in house but looking at the Berger web site, the 68g and 69g are made on different jackets and most certainly have different point radii. This means they will need different seating depths and leade engagement to shoot.

First, set a target a 25, and 50 yards to see how the 69g is shooting. You may find that the bullet holes are way out of round on the closer targets. Look at the holes for your 68g at these distances also.