Speer Gold Dot 150 BLK

Discussion about rifles in 300 AAC BLACKOUT (7.62x35mm), hosted by the creator of the cartridge.

Moderators: gds, bakerjw, renegade

User avatar
bangbangping
Silent But Deadly
Posts: 2609
Joined: Sun Sep 15, 2013 6:34 pm
Location: Texas Gulf Coast

Re: Speer Gold Dot 150 BLK

Post by bangbangping » Wed Jan 08, 2020 3:06 pm

dellet wrote:
Tue Jan 07, 2020 11:36 pm
The more people who document and share their actual velocity and drop, the more it will help others.
As mentioned way back, I guesstimated a G1 BC of .360 based on a 100 yard zero and drop at 300. Just ran a few LabRadar results through the JBM online calculator and it's averaging around .351. That's with just a few few bullets, but I still say Speer is FOS with its published .463 BC.

BulletFlight for Android
P1ZombieKiller
Member
Posts: 28
Joined: Mon Mar 19, 2012 10:25 pm

Re: Speer Gold Dot 150 BLK

Post by P1ZombieKiller » Wed Jan 08, 2020 3:12 pm

bangbangping wrote:
Wed Jan 08, 2020 3:06 pm
dellet wrote:
Tue Jan 07, 2020 11:36 pm
The more people who document and share their actual velocity and drop, the more it will help others.
As mentioned way back, I guesstimated a G1 BC of .360 based on a 100 yard zero and drop at 300. Just ran a few LabRadar results through the JBM online calculator and it's averaging around .351. That's with just a few few bullets, but I still say Speer is FOS with its published .463 BC.
I plugged in this bullet and then did my calculations.
I do not know what BC JBM assigned to it, however the calculations were almost perfect for what I experienced. Maybe they did assign it a .360???? I don't know.
Accuracy is not a gift. A gift is something you don't have to earn.
www.P1ZK.com

User avatar
dellet
Silent But Deadly
Posts: 6385
Joined: Fri Nov 30, 2012 1:25 pm

Re: Speer Gold Dot 150 BLK

Post by dellet » Wed Jan 08, 2020 4:21 pm

BC numbers suck :shock:

Flat base bullets and BC numbers suck even more.

For many FB bullets as velocity drops, BC increases. Less speed= less drag= less velocity drop= higher BC. Then nose profile comes into play along with shooting conditions.

Best you can really do is " the BC of that bullet, on that shot was ......

If you use actual drop over distance and correct shooting conditions, Then you can adjust the BC in the calculator until it matches. As long as velocity, sight height, wind, shooting exactly east or west and everything else are exactly correct.

When I plugged both 360 & 460 into the calculator I got a 1/2 MOA difference in drop at 300, or 1.5 inches. If my scope is MOA with 4 clicks per, I need around 1.5 clicks to be dead on at 300. A 20%+ difference in BC only made a 1" error(1/3 MOA) at 300 yards.

So I have 1/2 MOA discrepancy in bullet BC and my scope settings are only accurate to +/- 1/3 MOA, plus all the other factors I can screw up in the calculator. There's a reason I failed tactical sniper school for first round hits on dimes at 300 yards. :mrgreen:

I am not saying correct BC is not important, but the shorter the distance, the more wiggle room you have, and the harder it is to see the value. Basically I know enough about ballistics, to know that I don't know enough, to make precision first round hits at any distance. Busting clays, or hitting steel I have a fighting chance.

Hope that all makes some bit of sense

This is Sierra's BC file for all their bullets. They are very good at listing corrected BC numbers for velocity. if you look close, you find bullets where The BC increase or decrease with velocity drop and a few that lose BC then gain it back as velocity drops.
https://www.sierrabullets.com/wp-conten ... -rifle.pdf
300 Blackout, not just for sub-sonics.

DaedalusX
Silent Operator
Posts: 62
Joined: Thu May 07, 2009 9:54 am

Re: Speer Gold Dot 150 BLK

Post by DaedalusX » Thu Jan 16, 2020 8:29 pm

Has anyone tried loading these long at 2.28+ coal on a R700 or other platform that isn’t limited by usgi ar15 mags coal?

I have a few pounds of 1680 and I’ve been very unimpressed by the accuracy of the Barnes 110/120 TSX loads in the 700 AAC barrel.

User avatar
rebel
Silent But Deadly
Posts: 7241
Joined: Mon Apr 22, 2013 2:01 pm
Location: Moonshine Country

Re: Speer Gold Dot 150 BLK

Post by rebel » Thu Jan 16, 2020 8:54 pm

Yes, I do in my CZ.
You can't beat the mountain, pilgrim. Mountains got its own way.

User avatar
bangbangping
Silent But Deadly
Posts: 2609
Joined: Sun Sep 15, 2013 6:34 pm
Location: Texas Gulf Coast

Re: Speer Gold Dot 150 BLK

Post by bangbangping » Thu Jan 16, 2020 9:16 pm

DaedalusX wrote:
Thu Jan 16, 2020 8:29 pm
Has anyone tried loading these long at 2.28+ coal on a R700 or other platform that isn’t limited by usgi ar15 mags coal?

I have a few pounds of 1680 and I’ve been very unimpressed by the accuracy of the Barnes 110/120 TSX loads in the 700 AAC barrel.
In my Rem M7 the Gold Dot will hit the lands at around 2.288". So I'd say maybe you can, maybe you can't. It will be close.

DaedalusX
Silent Operator
Posts: 62
Joined: Thu May 07, 2009 9:54 am

Re: Speer Gold Dot 150 BLK

Post by DaedalusX » Thu Jan 16, 2020 9:19 pm

Sounds good. I’ll probably start around 2.270 and 22gr 1680 and work my way up. For some reason my R700 is much much more coal sensitive than my Noveske.

User avatar
rebel
Silent But Deadly
Posts: 7241
Joined: Mon Apr 22, 2013 2:01 pm
Location: Moonshine Country

Re: Speer Gold Dot 150 BLK

Post by rebel » Thu Jan 16, 2020 10:31 pm

DaedalusX wrote:
Thu Jan 16, 2020 9:19 pm
Sounds good. I’ll probably start around 2.270 and 22gr 1680 and work my way up. For some reason my R700 is much much more coal sensitive than my Noveske.
Your 700 is not my CZ chamber so I will give no absolutes. I did as you are doing just to see. Even got it to a touch. Backed off and tried again, keeping the bullet base and powder relationship the same. Settled at 2.21 COAL with outstanding accuracy. This bullet "jumps" well due to it's design. Just to save you a bit of components, I'd start there and work up .003 in COAL. Probably add .1 of a grain at a time with that. Shooting 3 shot load development groups, that will be no more than 12 to 15 bullets before your at a touch or a slight jam. ( depending on that 700 chamber ) It would help to get a chamber measurement for your load book.
You can't beat the mountain, pilgrim. Mountains got its own way.

DaedalusX
Silent Operator
Posts: 62
Joined: Thu May 07, 2009 9:54 am

Re: Speer Gold Dot 150 BLK

Post by DaedalusX » Thu Jan 16, 2020 10:59 pm

rebel wrote:
Thu Jan 16, 2020 10:31 pm
DaedalusX wrote:
Thu Jan 16, 2020 9:19 pm
Sounds good. I’ll probably start around 2.270 and 22gr 1680 and work my way up. For some reason my R700 is much much more coal sensitive than my Noveske.
Your 700 is not my CZ chamber so I will give no absolutes. I did as you are doing just to see. Even got it to a touch. Backed off and tried again, keeping the bullet base and powder relationship the same. Settled at 2.21 COAL with outstanding accuracy. This bullet "jumps" well due to it's design. Just to save you a bit of components, I'd start there and work up .003 in COAL. Probably add .1 of a grain at a time with that. Shooting 3 shot load development groups, that will be no more than 12 to 15 bullets before your at a touch or a slight jam. ( depending on that 700 chamber ) It would help to get a chamber measurement for your load book.
Interesting. What are you using for powder ?

User avatar
rebel
Silent But Deadly
Posts: 7241
Joined: Mon Apr 22, 2013 2:01 pm
Location: Moonshine Country

Re: Speer Gold Dot 150 BLK

Post by rebel » Fri Jan 17, 2020 7:31 am

A1680
You can't beat the mountain, pilgrim. Mountains got its own way.

Post Reply