230 Berger (.743) past super sonic performance?

[Aimsmall55]

Was just looking at some projected scenarios using the g7 of .380 on the 230 match and was a bit surprised. It seems like after it goes past the super sonic range it lays down. And velocity wise it looses 1 to 2 fps at ever 5 yard interval. Even more interesting the farther out the less the depletion of velocity. I know this is all theoretical so has anybody seen what I'm talking about??

 

[steve123]

Re: 230 Berger (.743) past super sonic performance?

Can you do another graph please, like say with a Hornady 225 for comparison?

The Berger 230 hybrid is definitely a awesome bullet until they go subsonic. Some days I can still hit stuff out to 2400Y and sometimes I feel like I'm wasting time and money shooting that far away and give up. I've come to the conclusion that if I want to shoot past 2200Y I really need a bigger gun.

 

[Aimsmall55]

Re: 230 Berger (.743) past super sonic performance?

Yeah. What's your altitude average weather and specs on rifle. Also how fast are you pushing them

 

[steve123]

Re: 230 Berger (.743) past super sonic performance?

Surgeon XL, Anshutz prone stock, Tubb butt plate system. 30" Krieger 9 twist. The cartridge is 30-375R, 230's at 2960 fps. Usually 7000-10,000 DA.

 

[Aimsmall55]

Re: 230 Berger (.743) past super sonic performance?

Here ya go

 

[Donald]

Re: 230 Berger (.743) past super sonic performance?

Very interesting thanks, has anybody shot the 230s this far?

 

[steve123]

Re: 230 Berger (.743) past super sonic performance?

Thanks!

There's not as much difference as I thought there would be. I'm pretty sure the 225's would handle going subsonic better but then there's the issue of more wind drift with the 225's.

Sorry to bother you again but can you do a typical 338L load of 300gr Berger hybrids at 2800 fps? I like your graphs!

 

[steve123]

Re: 230 Berger (.743) past super sonic performance?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rocky Mountain</div><div class="ubbcode-body">Very interesting thanks, has anybody shot the 230s this far? </div></div>

2356Y is as far as I've tried. Seems like the 230's settle down by then.

 

[shoot4fun]

Re: 230 Berger (.743) past super sonic performance?

Are we talking Hybrid or OTM? I spoke with Bryan Litz about the 230 OTM and his testing showed that this bullet was not as good past transonic as Berger had hoped. The longest distance for me with it has been 1000 yards in a 300WM with a 1 in 10 twist. I am not getting close to the 3000 FPS you are but my barrel is 26". Wish I had a place to stretch it out past where it would hit subsonic velocity.

 

[steve123]

Re: 230 Berger (.743) past super sonic performance?

I'm shooting the hybrid.

In 2012 I got first round hits on steel at 1080Y, 1450Y and 1850Y. The 230HB's made my 30-375R a giant killer.

 

[shoot4fun]

Re: 230 Berger (.743) past super sonic performance?

I notice the Hybrid has a slightly better G7 than the OTM. I feed my Surgeon from AICS mags and the OTM feeds well and shoots great seated to mag length. I just ordered a box of Hybrids and will give them a try. Thanks for the info.

 

[Aimsmall55]

Re: 230 Berger (.743) past super sonic performance?

Well, I shot 900 today with hellacious winds. #'s were spot on but I had about a 16 mph win at my 1oclock. From shooting ftr I knew it was gonna push em low and left. I said what the hell and just squeezed 2 off. The bullets were hitting the plate so hard it knocked it completely over. But this is my dope in elevation with no wind dope. As you can see low left. Hit it with roughly 1960 ft/ lb of knock down power and at 1954 ft per second

 

[Aimsmall55]

Re: 230 Berger (.743) past super sonic performance?

My bad. Had the g7 wrong. This is Litz #'s

 

[steve123]

Re: 230 Berger (.743) past super sonic performance?

Thanks for posting the 338L graph! BC sure makes a big difference doesn't it!

You have a great place to shoot there. Haha, it's fun seeing how much energy the big guns have isn't it! I tore my friends man sized steel off at the weld with a 375CT at 1200Y. We were all watching through our scopes and it gave us a good laugh.

 

[shoot4fun]

Re: 230 Berger (.743) past super sonic performance?

I do find it interesting that your chart for the 230 is set on 3025 FPS and the 225 is 2980 FPS. Is this from actual chrono data the same rifle? If so, do you feel like you may have left some velocity on the table with your 225 load?
Not picking at the data; just wondering. Are these charts being generated from QUick Load?

 

[Aimsmall55]

Re: 230 Berger (.743) past super sonic performance?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: shoot4fun</div><div class="ubbcode-body">I do find it interesting that your chart for the 230 is set on 3025 FPS and the 225 is 2980 FPS. Is this from actual chrono data the same rifle? If so, do you feel like you may have left some velocity on the table with your 225 load?
Not picking at the data; just wondering. Are these charts being generated from QUick Load?</div></div>

My particular rifle shoots the 230's at 3015. A hide member requested that I put up a graph using his rifle specs for the 225. That's the only reason. He just wanted to see the comparison

 

[Aimsmall55]

Re: 230 Berger (.743) past super sonic performance?

My #'s are actual real world data. Shot 3 4 5 and 900 and these#'s put me on target first shot. Looked at quickload but couldn't justify spending the $ when these iPhone deals work so well...

 

[bohem]

Re: 230 Berger (.743) past super sonic performance?

The drop in rate of velocity decay is pretty much guaranteed at subsonic speeds. It's not really at subsonic speeds but at speeds below the critical number.

This is all due to the fact that shock waves in a fluid take a lot of power to keep them and once the velocity drops below where the shockwaves form, the bullet is only experiencing viscous and parasitic drag, which is about 7-12% of the overall drag function at supersonic speeds, especially near the sound barrier where the Cd is very high.

This is easy to see when you look at a Cd vs. Velocity chart, note the shape where from the high speed side the Cd climbs slowly as the velocity approaches ~M1.5 then from 1.5 to 1.0 it climbs much more quickly, then at sonic crossing it drops abruptly to a mere fraction of the value it was at M3+ and especially M1-1.5

 

[shoot4fun]

230 Hybrids arrived. I have not been able to find OTM anywhere but a box of Hybrids came quickly from Midway. A couple of things that I am wondering. Will seating depth be more critical with Hybrid and can I use the same load data I am now. I plan on starting with same seating depth and doing an OCW as soon as work and weather permits.