Funny results

[dragman]

I have two 6.5X284's that I just finally finished for this shooting season. While they both shoot AWESOME they are so different in speed it's very strange. I have always been told that berger hybrids are a little faster than the VLD's because of the smaller bearing surface. so I exspected that to hold true and it didn't in this case. here are the details:
6.5X284 custom action, standard neck - 29" Krieger barrel and it's shooting the 140 hybrids @ 2980fps.
6.5X284 Savage action, .290 neck - 29" Hart barrel and it's shooting the 140 Hunting VLD's @ 3085fps.

Same powder and primers, but the custom action is shooting .4 grains more than the savage. I just find it amazing that they can be so different.

 

[BrentM]

What do you suppose the bore difference is in those? I assume same amount of grooves, but one is just faster than the other. ?

 

[dragman]

both the same amount of grooves. The bench gun does have a little more freebore and the bullets are set out a little further than the savage but I didn't think that would make 100 feet difference since it has .4 grains more. I am happy with both just find the difference in speeds odd.

 

[BrentM]

Meh, it's just the savage makes it all better. LOL

Thanks for sharing though. Interesting results.

 

[Lefty7mmstw]

Shoot 'em both a few hundred rounds; I suspect it'll even out as the throats wear a bit. I had a 7rum that was a bit slow to start with. Within a couple hundred rounds it was right where it should have been.

 

[dragman]

I have 150 rounds on the Custom action gun
I have 98 rounds on the Savage

I know they might speed up a little and thats fine I am very happy with the speed of both just don't know why the savage is so much faster. not a bad problem to have since they are both shooting bug hole size groups. gun)

 

[aramarine6]

Any abnormal signs in the brass fired from either gun? Pressure signs from one but not in the other?

 

[dragman]

They are very simlar the savage shows a LITTLE pressure sign but nothing bad. I with the sewting depth difference i can get about 1 full grain more in the custom gun than the savage before im at the top.

 

[Lefty7mmstw]

If the savage is showing any pressure signs you've answered your question as to velocity. It's producing more pressure (you are working the savage harder) with the load than your other rifle. Strain guages would be interesting here.

 

[dragman]

I though of the pressure thing but when I pushed them both up to the same pressure signs there was still a huge gap. I am not really worried about it but it is just crazy I have had 6.5X284's that wouldn't barely get over 2900 until pressure was to great. I think it's a great example of every gun is different!

 

[BrentM]

Curious, what powder are you currently using?

 

[dragman]

Rl17