Plated bullet question re: velocity

[BJK]

Not cast bullets but purchased Rainier plated bullets. Maybe I'm asking a question I already know the answer to, but here goes. Somewhere I read that Rainier plated bullets shouldn't be driven higher than 1400fps. I have no idea if that's true or not but it stuck in my brain.

I bought 400 Rainier 180 grain .308 bullets for 300BLK. When I found out that Rainier shut it's doors that told me that I had 400 bullets for plinking. Somewhere I plucked a load that I knew would be safe just to put them downrange . No load development was put into it other than to make sure they cycled the AR handgun. They did and accuracy was fine, so I loaded all 400. The next time I shot them I put them past the chrono and got an eye opener... 2900+ fps. Just a hair over the 1400 fps suggested max' velocity. I never expected that velocity. But I can't imagine how it could be a false reading since it's a LabRadar. There's simply nothing that can throw it off, not like with a unit that uses skyscreens.

So here I am. I don't see leading in the bore after firing maybe a dozen rounds. But I have 400 of these and don't want problems. I can disassemble them or I can shoot them and disassemble them that way. Or am I concerned about nothing?

What would you do? ANY input is greatly appreciated. TIA

There are also RPMs to take into account but they don't appear to be flying apart within 50 yards and all holes look to be .30.

[geslayton]

Just to understand this correctly, you’re getting nearly 3000 FPS out of a 300 BLK with 180 grain bullets? I’m thinking you ha e a calibration issue somewhere.


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[shooter bob]

Sounds very hot I don’t see load data for 125 gr bullets at 2900 FPS .What was the load data you used? And did I read correctly it’s at handgun ?

[BJK]

Yes, 10" barrel, yes, over 2900 fps. It sorta floored me too. No pressure signs. But I don't see how a radar unit can return a screwey number. But my shoulder certainly didn't feel like 2900 fps. It made no sense to me either.

I won't have time this weekend, but I'll generate some more data. Maybe I recorded the data incorrectly? That's all that makes sense to me since I didn't save the raw data as I normally do. I just wrote down the resulting average.

This is the load I used: 11.9gr Lil' Gun, 2.190 COAL

Yeah, I know, it makes no sense. I don't get that from .308 Win and much more powder from a longer barrel. I've been thinking about this for 2 months. It's impossible. Operator error is possible. More data will tell me.

edit: The more I think about it I had to have read the data incorrectly. That's all that makes sense to me.

[reddog81]

I’ve had my LabRadar give goofy results before. It’s definitely not unheard of.

What was the load?

[gpidaho]

BJK: Something is very wrong with the load or the LabRadar. I'm using a lot more Lil Gun in my blackout 16" with a way lighter bullet and getting nowhere near those velocities. Gp

[charlie b]

Did you by chance have the Labradar set for pistol? I did that once and it gave screwy readings when the velocity got up past 1700fps.

FWIW, the .308Win load for 155gn jacketed bullets out of full length rifles is 2900fps.

[JimB..]

It’s not likely the bullet. Look at the paper target, if the holes look normal then the bullet is fine. If you have a hole with a spiral shaped tail then the bullet jacket is coming apart.

[BJK]

Yeah, I'm pretty certain I read the data presented to me correctly. It was so off the wall that I made sure what I was seeing was correct (from my perspective). I'll shoot some more and get new data.

[dverna]

What you are reporting is not possible in the .300 BO with any load.

That leaves the Ladradar....

[Smoke4320]

bad chrono reading

[jonp]

That reading sounds a bit high for that 300BO. I'd expect the jacket to separate at that velocity with leading. Berrys recommends 1250 for the plated, at least handgun. Ranier 1400fps. Your over twice that and at something I don't think is reasonable for the BO.

[KenH]

Yes, 10" barrel..... This is the load I used: 11.9gr Lil' Gun, 2.190 COAL .

Seems like QL gives around 1500 fps for 300BO with 10" barrel and 11.9 gr of Lil' Gun. Note, I did say "seems like", but still I'd check the chrono

[BJK]

Thanks gents. Thanks Ken, if it's 1500ish FPS I won't touch a thing. Rainier was probably like all other manufacturers and cautious in their suggested velocity. No wonder I didn't find leading in the barrel or any other problems at the target.

I'd love to know how a radar unit can give such a false reading.

[BJK]

I didn't think I'd have time to generate new data today. I lied.

Much happier with the data this time . It makes sense and is in the ballpark for what I wanted to load. Drumroll please, 1414 av FPS for 10 rounds.

I think I'm going to discuss with the LabRadar people what could have gone wrong the first time with the unit to get such screwy results.

My decision to treat them as plinking bullets was the correct one. The flat meplat and the AR handgun don't get along 100% for feeding.

[jonp]

I didn't think I'd have time to generate new data today. I lied.

Much happier with the data this time . It makes sense and is in the ballpark for what I wanted to load. Drumroll please, 1414 av FPS for 10 rounds.

I think I'm going to discuss with the LabRadar people what could have gone wrong the first time with the unit to get such screwy results.

My decision to treat them as plinking bullets was the correct one. The flat meplat and the AR handgun don't get along 100% for feeding.

Sounds like your right on the money. For plinking since they don't feed well you might as well save yourself some powder and drop the charge weight.

[BJK]

I might do something similar... disassemble them and use them in a Contender .32/20 (uses .308 bullets). No feeding issues in that!

[BJK]

I contacted Labradar.

Here is my inquiry to them:

I have a Labradar and love it for all the reasons you've already heard of from others. I never expected the kind of data I got from it a few weeks ago though. Maybe you can help me understand what happened so that I can prevent it in the future.

The load I was testing used a .30 180 grain bullet out of a 10" barrel using 11.9 grains of Lil' Gun powder (300BLK). I expected somewhere between 1400-1500 fps. I shot a number of rounds and got just shy of 3000 fps as an average. I retested them yesterday and got what I expected, 1414 FPS for an average of 10 rounds.

Again, I'm trying to understand what happened to give the erroneous results so that I don't repeat it.

And the reply:

When you were getting readings in the 3000fps range, were you in the rifle velocity range? Since you are expecting velocities below 1600 fps make sure you have it set to Handgun velocity range, if you are in the incorrect velocity range it will throw your velocities off very very far like what you were seeing.

Me: So it was operator error.

[charlie b]

Yep. It has happened to me. Usually when I go from rifle to pistol I forget to change it. Or, if I am shooting a cast load that goes a bit slower than I expect.

[BJK]