Newby here..... Just a few ????'s.

[A.Williams]

Newby here..... Just a few ????\'s.

First off I love this site. I've been here lurking for awhile but this is my first post. My first question is, are the manufacturers B.C.'s close to correct or not. For instance, Midway lists the .284 150gr Scirocco's B.C. at .515. Is this correct? If so that is alot of B.C. for a 150gr bullet. Sierra lists their 168gr Matchking at only .488. Seems like Swift might be pushing the pencil a little on the Scirocco's #'s.

How about the 162gr. Hornady A-Max? Hornady claims .625 for it. So, has anyone actually confirmed these B.C.'s with drop charts? If so, I'd be interested in knowing the results as I'll be working up loads shortly for a 7mm WSM. Also will a 1-9.5" twist barrel be enough to stabilize the A-MAX?

A. Williams

 

[Brent]

Re: Newby here..... Just a few ????\'s.

A.Williams, welcome aboard.

I've done some testing of bc's with the 30 cal Sciroccos and they are spot on and even registered a bit higher on the Oehler 43 when shot through the acoustic target. I shot the 180 at 1000 yds a couple days ago and velocity was 3190 on average and it took 26.25 moa to zero, first hit dead on. I had the bc set to .507, I think, the program on the palm pilot was set for the 180 Ballistic Silvertip and both hit dead on with the same load of 92.5gr RL25 in the 300 Ultra. It was only 20 degrees out too.

Several guys here shoot the 7mms so they'd be able to tell you more about that specific caliber. I would guess they're not far off though.

Hope that helps some...

 

[Guest]

Re: Newby here..... Just a few ????\'s.

A.Williams--
I have shot a few of the 162 gr. Amax's thru my .280AI and the .625 seems to be pretty close. The Barnes' BC's seem to be the only ones that are a little liberal on the numbers. Good Luck on your new rifle... CJ

 

[Tim Behle]

Re: Newby here..... Just a few ????\'s.

I don't test my own BC's. I just can't bring myself to put the Crony that far away from the muzzle.

The BC I've been using for the AMax's is .534, and it seems to be working great for the Point Blank Ballistics program I use.

The Berger 180's have a BC of .698, and it works well with the program too.

I'm working now with some Nosler 175 partitions, showing a BC of .519, and so far it has been on out to 500 yards.

I'm shooting these in a 7 mm Remington Magnum, with a 9.5 twist.

 

[Brent]

Re: Newby here..... Just a few ????\'s.

Tim,

I don't set cronograph way out there either, I just measure the drop with the velocity taken at the muzzle. The BC is just the only other thing left to modify then.

The acoustic target is way out there but that's a big triangle with 42" sides and not a big deal.

 

[A.Williams]

Re: Newby here..... Just a few ????\'s.

Sorry guys. Been out of town all week. Thanks for all the help, my questions seem to have been answered. I have a few more I hope you guys can help me with.

It seems the Sciroccos numbers are close but how does it expand at low impact velocities. I ran some numbers and the 7mm WSM w/150gr Scirocco will still be going about 1780 fps @ 800 yards. Eight hundred yards being the furthest that this bullet will retain 1000 ft/lbs, (what many consider minimum ft/lbs for deer). I'm not sure I buy into the ft/lbs of energy thing but that's ok because 800 yds is about my shooting limit right now anyway.

Anyhow, I would be interested in hearing from those who have used this bullet. Will it reliably expand at 1600fps and above as the Nosler Btip does? If not what kind of velocity is needed for reliable expansion? I believe it was Dave King that experimented with this bullet alot. I would like to hear from you as well Dave. Thanks in advance!!! Back out of town on Monday

A. Williams

 

[Brent]

Re: Newby here..... Just a few ????\'s.

My brother killed two animals so far with factory loaded 180 SCI in his 300 Ultra, one was a caribou at about 80 yards and it stopped under the hide on a broadside shot in the lungs. The other was a moose at about 250 yards, it passed all the way through on a quartering to him shot with twice the penitration.

I would guess they don't open up near as quickly as the BT's do at LR. At that distance, he said the exit wasn't as devasting as the ballistic tips are on game. The exit was two to three times as small easy, but did the job perfectly.

100-300 yards I'd pick the SCI and after that I think the BT is in fine shape without causing too much excess damage.

 

[4mesh063]

Re: Newby here..... Just a few ????\'s.

A Williams,

For what it's worth, I usually worry more about selecting a bullet that arrives on target than one that expands well. Most all your target bullets are hollow points anyhow and they will expand somewhat. The lead is generally harder than a hunting bullet so they hold up under more speed and rotation and the fact is, most hunting bullets are intended to hold together anyhow. The Ballistic tip mentioned above does wreck the hell out of an animal, even at longer range, but that doesn't mean they go right down either. For shorter range, say 600 and under, I'd choose a "Good" hunting bullet such as a partition style. After that, I'd say I want a boat tail Match bullet. Cut some bullets apart on your table saw using a jig and a carbide blade and you'll see a lot of voids in typical off the shelf hunting bullets. That's why guys don't use them in matches.

Last but not least, (I allways get a kick out of this) if you're worried about wounding a deer, don't shoot at em! I basically feel, "It's deer season, that makes it a real bad time to be a deer!"

 

[Guest]

Re: Newby here..... Just a few ????\'s.

I have seen the 162 A-Max terminal effects on 3 whitetail doe this year. I think it is the best long range hunting bullet I have ever seen in the 7mm caliber, BAR NONE!

 

[Mysticplayer]

Re: Newby here..... Just a few ????\'s.

If you are expecting impact vels 2500fps and lower, forget about a "tough" bullet. The Nosler BT, Hornady SST and Amax are much better choices.

I presently use the 165gr SST in my 30 cal rifles and love it both for performance in flight and on game. Should hold together even for 3000fps impacts.

As to 1000ft/lbs, I too am not a big believer. If the bullet gets to the boiler room and busts some vital organs, the animal will go down. Going down fast or slow is a matter of the state of the animal.

Been there where tiny cartridges and/or small bullets have flattened big game and seen small big game take big energy and wander off "dead" and not know it.

Got to hit them in the right place first...

Jerry

 

[5R LR SHTR]

i have been doing some research on BCs as well and i would totally agree that deriving the numbers is subject. i have an article that a guy did thatis ten pages long and he tested the the 155 grn laupua scenar, 155.5 Berger FBBT, and the scierra 155 match king. supriseingly the numbers weren't that far off but out to 1k yds there were significant differences. just depends on what yu want to shoot and the application of what you are doing i.e. trgt hunting etc. i can not remember the website i found the article but it was well worth the read of ten pages. i am trying out some hornady amax 140s in my new 260 simply bc they have a huge BC and some guys have had some awesome results but i shoot mostly 175 SMK out of my 308 just because they shoot so well.