Any way the first shot registered 3740 fps out of a 16" NATO chamber 1:9 twist. I told him to stop and lets see whats up.
Thank you for running those number through QL for me.I ran the numbers through QL and this is what it spit out. I got slightly different results than dragon813gt, but in the same ballpark. Take it for what it’s worth.
Cartridge = .223 Rem
COL = 2.250”
Barrel Length = 16.0”
Case = Standard SAAMI .223 Rem
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Bullet = .224, 69, Sierra HPBT MatchK 1380
24.5 gr CFE223
46,411 psi
2590 fps
Seating Depth = 0.407”
Filling/L.R. = 95.3%
Note: The Filling/L.R. number is % of available volume under the bullet that the powder occupies when the bullet is seated to the specified COL.
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Substituting Hornady bullet for the Sierra:
Bullet = .224, 68, Hornady BTHP M 2278
24.5 gr CFE223
48,907 psi
2641 fps
Seating Depth = 0.494”
Filling/L.R. = 98.1%
To get 3740 fps for the Hornady bullet would require:
32.9 gr CFE223
192,086 psi
Filling/L.R. = 131.7 %
In other words, there isn’t enough room under the bullet for that much powder. In fact, there isn’t enough case volume even without the bullet to hold that much powder. A standard SAAMI .223 Rem case will overflow with 30 gr of CFE223.
We have talked and he agrees he should of stopped and let me tear one down to see the actual end results. This has bugged him too, knowing he may have gone over the edge. The bad thing he could not think of any thing he did wrong till we talked. Once I found out he use a Hornady 68gr in place of a Sierra 69gr I showed him the difference. It had not dawn on him that the bullets were that much difference in length. I also found out that he had a few beers during the loading process. This is after a long day working on ranch/farm. This alone can effect your judgement. I try to express the need to have 100% of your concentration during reloading. All it takes is one mistake for some one to get hurt.blue68f100, I want to commend you for noticing the anomalous velocity reading and suggesting that the shooter stop for diagnosis. That was the absolutely right thing to do. And when your guest wouldn't heed your suggestion, backing up was a prudent thing to do.
Personally, I might not invite that guest back until they understood that when I say "stop", everything on that range stops until we can proceed safely.
I also found out that he had a few beers during the loading process.
Every once in a while you'll get a reading from a chrono that simply isn't correct. Sometimes if the sun is down low a chrono will not function properly. Sometimes there isn't any obvious explanation.
If the crazy velocity isn't matched by serious pressure signs on the brass, it isn't right.
I have had times when shooting pistols over a chrono that the numbers have been so bad I just discount them and do it again later. Such as an ES of 450, when you know the load can't that bad.
Obviously that is too hot, but not 3700+ FPS ("serious") hot.The brass did show signs of over pressure, I said this in my original post. Extractor imprinted on the base, brass swipes, primers where flattened to very little rounded edge left.
Blue,What would the data look like with 25.4 gr of CFE-223.
As far as my neighbor, I rather help him out so he does not make the same mistake. He has been reloading as long as I have, 4 decades. But he has had 4 heart attacks which has impacted his memory recall. And he's 5 yrs older than I am. A Vietnam veteran with PTSD too. So he has some health issues he's dealing with too. If I mention something a lot of time it triggers his recall. Other wise he may be lost trying to think of it till he asks a question. Some times I have to explain things several times before it sinks in.
I've been working on his documentation, record keeping. He writes loads on the side of paper ammo boxes, inside on the sleeve but does not date them so you don't know what it is. He does since he know the last entry. I gave him a stack a labels to use, hoping it will clear some of it up.