Question on 7mm RM and 180gr. Bergers

[6.5x300 WBY]

Ok mud thx. I am with you. I put it in the calculator and came up with 1.48 sg. That's due to it being in the 80+degree temp for my hunt in SC this AUGUST. WILL BE PRETTY WARM. BUT if I take this ammo out west where it's much colder then I will be down in the 1.25 sg.

So for this I just ordered HSM 168gr hunting VLDs. Should be here next week to give them a try. If they are spot on I will just use them and log that info into my scopes computer. BURRIS ELIMINATOR III.

Thx mud and Cody for assistance

 

[DocDoc]

The other consideration for use on game, is that marginal stability can lead to the bullet point hitting off center and tumbling rather than opening in the animal. That or a closed hp could be why some have had trouble with Bergers on game. For me I want more than 1.5 for hunting.

Ok mud thx. I am with you. I put it in the calculator and came up with 1.48 sg. That's due to it being in the 80+degree temp for my hunt in SC this AUGUST. WILL BE PRETTY WARM. BUT if I take this ammo out west where it's much colder then I will be down in the 1.25 sg.

So for this I just ordered HSM 168gr hunting VLDs. Should be here next week to give them a try. If they are spot on I will just use them and log that info into my scopes computer. BURRIS ELIMINATOR III.

Thx mud and Cody for assistance

 

[codyadams]

The other consideration for use on game, is that marginal stability can lead to the bullet point hitting off center and tumbling rather than opening in the animal. That or a closed hp could be why some have had trouble with Bergers on game. For me I want more than 1.5 for hunting.

This was already hashed out earlier in this thread, but none the less still true!!

 

[barefooter56]

If you input your data into their bullet stability calculator, and you get an SG (unit of measure for gyroscopic stabilization) from 1.0 to 1.49, then your bullet is considered "marginally stable", which means it CAN potentially still be accurate even out to around 600 yards before showing any signs of instability (like key-holing or poor accuracy).

And if you get an SG of 1.5 or higher, your bullet is considered "fully stabilized" even through the transonic (1,340 to 1,126 FPS) and down to subsonic (1,125 and lower) speeds.

So, as long as your input data gives you something above 1.0 to 1.49 SG, you can still be accurate, but it might not be 100% stable. If you get an SG of 1.5 or greater, your bullet will be 100% stable in your rifle in it's current load.

For example, my STW shooting the 180 Hybrids showing a 1.48 SG shows marginally stable, but it's so close to 1.5, I'd consider it to be fully stabilized (personal opinion), but with everything in this sport, it's always best to go shoot them at distance and check your drops and your targets to verify for yourself before shooting at game that far.

Not quite right,
The bullet will be stable and fly point forward all the way to the target. The BC will be affected though. This means that wind will have more affect on the bullet then it would if you were at 1.5 SG. It does not mean the bullet is more likely to be so unstable that it will keyhole or tumble at yardages out past 600 yards. Your maximum range on game should be based on the SAMMI specification for adequate performance on game ( that we use for all of out hunting bullets) of 1800 fps which is still in the supersonic range.

 

[barefooter56]

Mud can you translate this into laymen's terms. I know he explained something but I need an explanation of his explanation. Man I feel like iiam in Astrophysic or something. Good grief. Does he mean I will be good shooting the 180bergers from my Sendero with 9.25 barrel? I am lost. Thx

Please contact us at 660-460-2802 from 8am to 4:30pm EASTERN TIME MON thru FRI and we can run all of your numbers for you in regards to stability factor ETC and explain this all to you for future use. Thanks!

 

[FEENIX]

Please contact us at 660-460-2802 from 8am to 4:30pm EASTERN TIME MON thru FRI and we can run all of your numbers for you in regards to stability factor ETC and explain this all to you for future use. Thanks!

It don't get no better than that ... you guys have always been very helpful.