I bought a box of this ammo today at the gun show ($14.50/50, not a bad price!) I decided to pull one apart to see the guts of the cartridge. First thing though, I took some measurements:
OAL - 2.245"
Bullet OAL - .985"
Empty case OAL - 1.765"
Loaded cartridge weight - 194.3 grains (avg of 5)
Empty primed case - 96.1 grains
Bullet weight - 75.3 grains
Powder weight - 23.0 grains
It took 6 very solid hits on concrete with my kinetic bullet puller to release the bullet. I can't really tell if the bullet has a cannelure or not, but there is a very definite ring all the way around the bullet where the case mouth was. I don't know if this is the cannelure, or just a ring caused by a very tight crimp on the bullet.
The powder looks to be ball of some sort, definitely not stick. The published velocity of this round is 2750, so I'm not sure which ball powder will generate that velocity with 23.0 grains. It is possible that it isn't even an "off the shelf" powder.
Here is a PMC 55 grain FMJ for comparison: (the PMC had 25.2 grains of ball powder.)
I noted something interesting about the PMC round. The shank of the bullet had some black, sticky stuff on it, and it took a good 15 solid whacks to get the bullet out of the case. It almost seems like it is sealed. It didn't wipe off very easily until I put some degreaser on my rag.
I hope to get to the range soon to do some chrono and accuracy work with my LMT M4 16" upper (1/7.) I should probably run it through my 20" HBAR as well (but it has a lot of rounds down the tube......)
Could be 2520, but size wise from the photo it looks more like 8700 and I am pretty positive it's not that!, but more likely it is not a cannister grade powder.
That doesn't look like a cannelure it looks muchmore like a hard crimp.
Sticky black stuff= sealant.
That's what I figured. The PMC bullet seems like it has cannelure. It has a very distinct, hard edge near the top.
I also thought the sticky black stuff was sealant, but I had never heard that PMC sealed their ammo. That is why I wasn't sure.
I loooove looking at bullets!! Thanks for the pics!!
Can you tell if the primers are sealed also Thanks. -Justin
I don't have any way to decap the primer (I don't reload for .223.) Well, I don't think I can anyway. Maybe I could use my .308 die to punch out the primer..... I'll give that a try and see if I can tell.....
Taper Crimp / 2230 CS
I had a chance to run some rounds over the chronograph this past weekend, and here are the results. I was not able to do any accuracy testing at the same time (unstable wind conditions.)
75 grain BH Blue Box:
Altitude: ~3500 feet
Humidity: Not known exactly, estimated at 30% (Eastern Washington)
Barometric pressue: estimated at 28.3" ( baesd on observed 30.1" on Weather.com from a town close by at 1750 feet elevation.)
Chrono set 10 feet from muzzle (PACT Pc2)
16" LMT 1/7 Chrome lined (approximately 500 rounds down the pipe.)
Extreme spread 66 fps
20" Colt HBAR 1/9 Chrome lined (unsure of rounds, but probably A LOT! friend's rifle.)
Extreme spread 72 fps
I believe the published MV is 2750 from a 20" barrel, so it appears they are a little slower than that. This is likely the result of the conditions under which the measurements were taken. The ES for both rifles was pretty close. I don't however know if those numbers are "good", "average" or "poor." They seem a little high to me for something billed as a "match" load.
I lost an average of 95 fps with the 16" barrel over the 20". I also think that the faster twist on the 16" barrel may have robbed some MV as well. If I had remembered to bring my own 20" HBAR upper (1/7 Colt) I would have a better comparison.
I also wish I had some genuine Hornady TAP to compare as well....
Yes, that does seem to be a lot.
Just for kicks, I ran the ballistics for the two extreme MV's out of the 16" barrel.
I used a BC of 0.395 for a Hornady 75gr BTHP Match bullet.
At 2638 fps, the bullet drop at 300 yards is 26.9"
At 2572 fps, the bullet drop at 300 yards is 28.4"
That's a difference of 1.5" at 300 yards or 0.5" at 100 yards!
This means if you were trying to shoot a group at 100 yards with these, 0.5" of this group would be due to variation in ammo alone!
Does not sound like suitable fodder for those chasing those sub-MOA groups.
Just my $0.02
i load mine with 2520, same bullet, same case
Crap, I just realized I missed a golden opportunity. While we were running the ammo over the chrono, I had another friend out shooting with us with a 14.5" 1/7 barrel. I should have run the ammo through his gun too! RATS RATS RATS.
Maybe I'll try and get him out to a local range soon and see what it does through his. I'd have to run it through mine again to keep it "apples to apples" in terms of atmospheric conditions......
Gaijin - interesting finding there. I'm not really to this ammo for blistering accuracy, but more for personal defense. But, I would like to see the ES come down to 40 or less. That 1.5" at 300 is fine for a man sized target. But if you are running it through an SPR clone looking for superb accuracy, you have one more component to overcome. I wonder if the Red Box stuff is more consistent?
What kind of MV do you get and with what setup? I don't currently reload for 5.56 (surplus is just too cheap) but I think I can do better than $15/50 with reloads for the heavier stuff. But then I have to start collecting my brass after shooting........