Berger Ogive variance

[Tempest]

Question for F class and Benchrest guys. Think I know answer but want to confirm.

I'm loading now for a 1,000 yard F class match. I had some rounds left over from last match where the rifle shot fantastic and compared to current batch of bullets. Current batch of 200g Berger Hybrids is -.005" shorter ogive than last batch. The barrel is jump sensitive and I know where it likes for best grouping and typically load to to a set COAL (based on ogive).

I don't have any available time to go testing as I would normally do before this match. I can measure the CBTO and figured I would just seat the new bullets to same CBTO as last batch regardless of the COAL. I already measured one and it would not be jammed, just .005" longer on COAL.

Thoughts?

 

[Rich S]

I have had success perfoming seating test and keeping the same distance off/in the lands. It doesnt always match cbto measurenents due to variation between chamber throat and the device used to measure cbto.

 

[Bc'z]

If the die setting remains the same, wouldn't you still have the same jump just .005 less bearing surface in the neck?
Thinking out loud.

 

[powderbrake]

If the die setting remains the same, wouldn't you still have the same jump just .005 less bearing surface in the neck?
Thinking out loud.

No, because the diameter where the seating punch contacts the bullet is not the same as the ogive which is measured with a gage.

I found that different lots of Bergers had different dimensions between the end of the bullet and the ogive, and a different dimension from the base to the ogive.

I also found as Rich S said, that by keeping the same distance into the lands results in the same performance.

 

[Bc'z]

No, because the diameter where the seating punch contacts the bullet is not the same as the ogive which is measured with a gage.

I found that different lots of Bergers had different dimensions between the end of the bullet and the ogive, and a different dimension from the base to the ogive.

I also found as Rich S said, that by keeping the same distance into the lands results in the same performance.

Ok, so back the stem out .005 or until the same cbto is achieved.
Thoughts?
I'm asking because I do like bergers product but also have seen the lot to lot variations.

 

[Jennb]

Ok, so back the stem out .005 or until the same cbto is achieved.
Thoughts?
I'm asking because I do like bergers product but also have seen the lot to lot variations.

Thats all it takes and you are good to go

 

[Tempest]

Great. That's what I plan to do.

Thanks.

 

[Bc'z]

Thats all it takes and you are good to go

Are you kidding me?
I actually came up with a viable solution, and learned something at the same time?

 

[rwj]

Are you kidding me?
I actually came up with a viable solution, and learned something at the same time?

I like eureka moments too... wish I had more!

 

[47WillysGuy]

When shooting Berger hybrids, set and forget’em. When the barrel is done, replace the barrel.

1300+ rounds on 6.5 CM and it shoots great still, just like a laser.

 

[Tempest]

When shooting Berger hybrids, set and forget’em. When the barrel is done, replace the barrel.

1300+ rounds on 6.5 CM and it shoots great still, just like a laser.

This is FTR barrel throated for 200 Hybrids. It likes a specific jump.

 

[PatMiles]

Are you kidding me?
I actually came up with a viable solution, and learned something at the same time?

Hope springs eternal big boy!

 

[Raythemanroe]

Buy bigger lots of bullets and don't wait until before a big match to resupply and tune


Ray

 

[Dusty Stevens]

Buy bigger lots of bullets and don't wait until before a big match to resupply and tune


Ray

No challenges for you? You like the K.I.S.S. method as i do?

 

[Raythemanroe]

No challenges for you? You like the K.I.S.S. method as i do?

Simple is your friend

Ray

 

[Raythemanroe]

When shooting Berger hybrids, set and forget’em. When the barrel is done, replace the barrel.

1300+ rounds on 6.5 CM and it shoots great still, just like a laser.

I love those Creedmoor lasers


Ray

 

[Dusty Stevens]

I love those Creedmoor lasers


Ray

Why do they never bring them to matches?

 

[VaRandy]

Buy bigger batches and risk getting stuck with bullets that will NOT shoot as well as previous lots. Who would have thought major bullet makers would end up with better QC than the Bergers?

 

[Raythemanroe]

Buy bigger batches and risk getting stuck with bullets that will NOT shoot as well as previous lots. Who would have thought major bullet makers would end up with better QC than the Bergers?

Not all barrels are Hummers, but you still got to buy them.. Barrels and bullets, can't play the game skimping with them.

Try to shoot the same lot, powder, bullets and brass. Hard to do buying one small box at a time.. Mass production has it's limitations, many dies are used and replaced more frequently. Buy small production custom bullets or buy big lots and sort them..


Ray

 

[T-shooter]

Manufacturers run the bullet forming dies until they are worn enough to replace. The next new die may not be machined 100% exactly the same so there are bound to be some variance between lots. For instance these are the same part number Hornady bullets in 2 different lots measured with a Hornady comparator on a dial caliper. No matter how you seat these, you won't get the same results. I always seat using the comparator (.010" smaller than the bullet diameter) to get a similar jump. This would still add or reduce the depth if the bullet in the neck/case by .036" slightly changing the case volume. Seating from the tip would effect the jump by .021", bad if you seat them close to the lands.