230 gr Berger OTM Transonic

[Yrcan]

I am shooting the 230 grs Hybrid Target in my 300 win mag.
I have a Tikka T3 Super Varmint, with a Lothar Walter barrel. Twist is 1:8 and length is 26".
I use 71 grs of Viht N570 and this gives me 2747 fps. It is not a hot load, but it gives me the best groups at 100 meters.
I have found that the advertised BC is a bit low. I have tested it out 3 times now, in different conditions, and when I put every data into Applied Ballistics on my smart phone, I allways hit high. It can not be my velocity, becuse I need to dial in 3084 fps to get it right, and there is no way I have that speed.
So I have adjusted the BC up from .743 to .770. This brings me dead senter out to 1200 meters.
Is there anyone else who has come up with a different bc, than the advertised one?

Happy new year to all of you

 

[BGE541]

The biggest thing I notice in using "Reverse DOPE" to get speed of a projectile is that (some) shooters dont accurately measure the scope to bore height which will throw off all of your shooting calc's numbers. IE when I run "Shooter" on my GAP 300 win w/230 OTMs @ 2720 fps with the "default" input of 1.8" for scope to bore lets say at 400 meters in up 7.7 moa. Well If I correct that to what the guns scope to bore is (2.2 in) @ 400 meters it drops to 7.4 moa (what it really is.)

So... Garbage in, Garbage out. Like I think Broz was saying you cant beat hard DOPE. Once you get the settings right on "Shooter" or the like it will truely show you what speed you are throwing them at. For the Bergers I have seen theyre BC's (G7) are very reasonable so from then on out its MV, Air Den or actual Dist to Target that are your variables.

Using H1000 and the OTMs I get about 2720 fps with no pressure.

Enjoy,

BGE

 

[blackdog]

shooters dont accurately measure the scope to bore height which will throw off all of your shooting calc's numbers

Just so that I make sure I'm on the right page here, the measurement is center of bore to center of scope, correct?

 

[BGE541]

Yes Sir, centerline of scope to center line of bore. I was surprised at the actual height of my scope over bore and the impact on data it had. Maybe play around with some numbers on a ballistics calculator and see what it does.

Hope it helps.

 

[joe0121]

Man Berger is really on their stuff. I might have to bite the bullet and stop going cheap with my 208GR Amax. H1000 really likes the big heavy pills. What are you loads if you don't mind divulging.

 

[John-Pure Precision]

Man Berger is really on their stuff. I might have to bite the bullet and stop going cheap with my 208GR Amax. H1000 really likes the big heavy pills. What are you loads if you don't mind divulging.

If you look at the beginning of the thread I have my load data. I jumped in on the thread

 

[backyardsniper]

Hey guys,
I would like to bring this thread back if I could pick yalls brain for a minute. I have 200 of the hornady 225 hpbts and about 100 of the 230 otm's. After reading here I think I will sell the 225s to someone needing something to shoot through a suppressor, and buy more otm's. OK, Here is where it gets weird. I have a 300 win in a mcree chassis with a 20" rock creek barrel. I bought this as kind of an experiment. Folding chassis+ 20" barrel= long range backpack gun. I have 200 rounds of A191 that I got with the gun. I'm getting about 2825 out of the 190gr matchkings in that load. If I'm not mistaken those are loaded with 72.3 gr of reloader 22. Anyway, I have h4831sc on hand and us869. I think the 4831sc might work in the short barrel. Can someone tell me if it would be possible to reach 2700fps with the OTM'S in a 20" barrel. I'm gona shoot this barrel for a while but I believe I will go to a 24"or 26" when I rebarrel unless this 20" really impresses me.

Thanks

 

[Broz]

Can someone tell me if it would be possible to reach 2700fps with the OTM'S in a 20" barrel. I'm gona shoot this barrel for a while but I believe I will go to a 24"or 26" when I rebarrel unless this 20" really impresses me.

Thanks

You might get close to 2700, but I have my doubts. Most of the 300 wins I have loaded the 230's in will show pressure above 2775 from a 28" tube. That is at 4100 feet asl. I feel 2650 would be a more reasonable goal. But I have not tried them in a tube shorter than 26", so I am going of instinct here.

Jeff

 

[Eaglet]

I'm also guessing, my guess is he would not be able to go very much passed 2500 ft-sec. Now, this bullet at 2500 ft-sec does much better than most would think!

 

[BGE541]

Im guessing that with a 20 inch barrel your goal is realistically unobtainable. I have a 26" barrel on my 300 WM and with a stout load that pressure safe at all temps im getting 2720fps. Your quite abit shorter then that and with the heavier weight you need all that barrel or atleast 23 or 24" . I wouldn't waste any large amounts of reloading supplies on this endeavor, quick load agrees with me but I have been wrong... let us know. Not to mention the muzzle blast with a 20 inch barrel on a 300 WM would be alot I guess.

 

[BCMAG2]

I'm currently having a 300 RUM built with a 28" barrel, and intend to shoot the 230 grain Bergers.
Anyone else with that set up care to share their muzzle velocity and loading data?

 

[specialist]

Great thread, I'm running 3250 with r-25 in 30" douglas barrels 210 berger. 4" to 7" at a 1000. Time for 230's