The Original CZ Forum
GENERAL => Ammunition, questions, and handloading techniques => Topic started by: PistolShooter on June 04, 2018, 04:51:17 PM
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I'm loading 180 grain plated bullets with Unique and I want 950-1000 fps but I don't have a chronograph.
Can anyone tell me from experience how much powder to use? This is for my CZ75.
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What bullet shape?
There is data online for a Gold Dot, which is a plated bullet, at 1000 fps, and data for a CPFP in the same speed range.
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I'm using truncated bullets. The data out there varies a lot. I think max charge for the gold dot it 6.7. That seem like a very hot load.
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They also list a 180 gr CPFN over 6.5 (max) gr @ 1059 FPS.
What makes you say the gold Dot load sounds hot?
The data varying is why a chrono helps.
I'd trust the powder manufacturer, the bullet manufacturer, and everyone else...in that order.
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I?ve loaded AP70 (same burn rate as Unique and some say it?s the same stuff) with 180gn coated bullets.
5.0gn made 1000fps. I?d start there with a plated bullet & Unique.
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I can't remember why it seemed hot. It's been a little while since I looked at all my data. I do know that the bullet manufacturers listed max is 6.0 grains but they don't give a velocity. From what I remember, I figured 5 to 6 grains should be enough.
I like to look at multiple sources to gain a better idea of what would give me the desired results but different sources also have different barrel lengths etc.
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What load manual do you own and use ?
???
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I?ve loaded AP70 (same burn rate as Unique and some say it?s the same stuff) with 180gn coated bullets.
5.0gn made 1000fps. I?d start there with a plated bullet & Unique.
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This was out of a CZ TS too
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Thanks Matt101. That's what I was looking for.
I'm using the Lyman #49, Speer #14, a Handloader magazine, and Cam-Pro data.
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http://www.alliantpowder.com/reloaders/RecipePrint.aspx?gtypeid=1&weight=180&shellid=29&bulletid=42&bdid=118
They recommend 6.7 grains of Unique for a velocity of 1000 FPS in a 4" barrel.
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I'm using the Lyman #49...
OK, then you see the data for 175gr lead with Unique on p364 ? That's going to be very similar to your quest. Lead is going to be slightly faster than plated, but close enough for our purposes.
4.7gr = 898fps and 5.8gr = 971fps
If we make a proportion from this data we can see that 5.66gr will result in 950fps. Since we'd need to bump it a tad for plated, then call it 5.7gr. Now, you need to understand that the load is not a straight line. Efficiency of the "burn" grows as the load increases, so our plot is a curved line. But proportions can be used when no direct data presents itself to some reasonable effect. At least it's built on some semblance of published data, and not an outright "guess".
Just so you understand, I used 175gr lead data becasue most plated bullets are closer to lead in behavior. If I knew the plating was extra thick (like a Berry RNHB-TP, or a Speer Gold Dot) then I would have opted for jacketed data.
From studying the data, apparently you'll barely make 950fps and never get to 1000fps with Unique.
;)
Added additional thoughts this AM
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166 PF ^^^^^^^^ with Unique
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Thank you for that info. The campro bullets do have a thicker plating but i'm not sure how they compare to the Berry or Gold Dot bullets .
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From the Campro website:
What?s the CamPro difference?
Thanks to our bullets' thick copper plating, barrel rifling cannot cut or tear the bullets to the lead core, which:
Prevents lead emissions
Prevents small copper particles from shedding off the bullet during its path to the target and reducing the precision of the shot
Protects the barrel from being ridden with lead
Allows the use of the maximum amount of powder recommended for your type of firearm (magnum)
They say their plating is .008" thick
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I found a chat forum where someone said the Gold Dot has .018" thick plating. If that's true that's a very thick layer.
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I got this from another forum:
For example, the regular plated bullets from Xtreme, Berry's, etc have copper plating about .0035" thick, while their heavy plate bullet will be plated to a thickness of .007" to .008". In comparison, traditional drawn jacket bullets vary between about .013" and .026" in the side walls and are usually a bit thicker in the base, due to the jackets being drawn.
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I was able to use someone's chrono at the range today.
Turns out that 6 grains of unique gives me 980-1000 fps.
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I'm looking at the Speer #14 manual.
It says 7.2 - 8.0 grains of unique. 1048 - 1207 fps using 180 grain gold dot and the test barrel is only 4". Has anyone ever tried this much unique? Until now, the highest maximum I've seen is 6.7 grains.
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Oh poop I got that wrong. That was for a 155 grain. Never mind then.
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If you lay 4 reloading manuals on the table you'll see different powder charge levels. You'll also see different primers used, different bullets, different barrel lengths, different brands of pistols, etc., etc., etc.
What is safe/accurate/reliable in one gun may not be in another. One reason for the advice to start lower with the powder charges and work your way upwards verifying what is safe and reliable in your gun as you go.
Sometimes you just can't get where you want to go with some components and some calibers and you have to change something to get where you want to be.
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Yes, the plating on GD is super thick. It's not the same as a regular plated bullet.
BUT Alliant has data for a 180gr plated FN, which is what the OP is shooting. 5.9gr-6.5gr at 1.12 for 1050-ish. Why are are we looking elsewhere for data?
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I like to look at multiple sources to gain a better scope of data. Then i can see to lowest minimum to the highest maximum cause the data always varies and I can't always find data for my exact bullet.
I'm done looking now. Thanks for all the input.
I was using 5.0 grains of unique but my average velocity was 890 fps which was too slow. (I used someone's chrono at the range) I'm now using 5.8 grains which gives me around 950 fps and at 6.0 grains it hover around 1000 fps.
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Originally I asked because I don't have a chrono and I was hoping someone else tried this combo in their cz. Results from cz to another cz should be very similar.