By contrast, the PPU 5.56 spent cases look just fine.

quote:

Originally posted by lbj:
By contrast, the PPU 5.56 spent cases look just fine.

Indeed. In fact the primer is less flattened than what I’m accustomed to seeing with most other 223/5.56 loads.

Until I had the Independence 5.56 blow primers, this is the first time I had ever really seen the marks in such details on 5.56 cases.

In the past, ammunition went bang, all was well and to my older eyes, looked fine.
Now there's bolt marks, ejector marks and extractor marks.

I learned some things.

In all fairness the PPU is loaded about 200fps slower on my chrono testing compared to the IMI/Independence. When I do purchase factory ammunition for 5.56 it's almost exclusively PPU. The brass is about 1.5 thousandths thicker than Lake City and I seem to be able to get more reloads out of it.

quote:

Originally posted by lbj:
It's not exactly the good kind of club to belong to.

quote:

Originally posted by NikonUser:
A metric ton of 5.56 ammo? How much is that?

Well, let's see. 55gr for bullet, 80gr for case, 25gr for powder and 10 grain for primer, That's about 170grain per round. (Note to self, next time you charge some cases, weigh a 55gr loaded cartridge, if you have any.)

At 7000 grains per pound, we get about 41 cartridges per pound. A metric ton is 2,200 pounds, so a metric tone of that ammo will be 90,200 cartridges. That represents a sizable investment.

Now that is funny right there.

Well, I am an Ammoholic

The net weight on a 1200 round case of IMI M193 is 14 kg. That works out to a mere 71.42 cases or only 85,704 rounds if that is what I used most of the time. I don't see a problem .

Again, I hope IMI/Federal will make this right for you. I don't have any Independence ammo left and won't be buying anymore.

I will probably donate it to the local PD.
It might make for a good excuse fr the bomb squad guy to blow something up for training purposes.

quote:

Originally posted by swage:
In all fairness the PPU is loaded about 200fps slower on my chrono testing compared to the IMI/Independence. When I do purchase factory ammunition for 5.56 it's almost exclusively PPU. The brass is about 1.5 thousandths thicker than Lake City and I seem to be able to get more reloads out of it.

What are your chrono results for IMI, PPU et al?
What is the barrel length?

quote:

Originally posted by sigfreund:

quote:

Originally posted by rduckwor:
I would be interesting to see a few of them fired from a bolt gun, say a R700 with a free bore that runs into tomorrow, just to see whether the exhibit pressure signs as well.

As discussed in this excellent and comprehensive article, chambers cut to SAAMI specs for the 223 Remington cartridge are usually somewhat smaller in some critical dimensions than those typically found in 5.56mm chambers. That’s the basis for the common belief and claim that it’s unsafe to fire 5.56mm ammunition in 223 Remington chambers. The article points out that the claim is generally untrue, and I regularly fire 5.56mm ammunition in my 223 Remington Tikka T3 myself with no signs that excessive pressures develop as a result.

Despite all that, however, if a cartridge/load shows excessive pressure signs in a 5.56 chamber, I definitely would not then fire it in a rifle marked 223 Remington to see how it did there. I imagine it’s possible that a long freebore might keep pressures down to safe levels, but I wouldn’t bet the rent (or my rifle and eyesight) on the assumption.

Yes, I tend to forget that most bolt guns are chambered for .223. Mine is chambered for 5.56.

RMD

quote:

Originally posted by rduckwor:
Mine is chambered for 5.56.

RMD

Ah. Before I settled on the Tikka, I looked (not too hard, admittedly) for a bolt action chambered for 5.56 without success. What is yours?

quote:

Originally posted by sigfreund:

quote:

Originally posted by rduckwor:
Mine is chambered for 5.56.

RMD

Ah. Before I settled on the Tikka, I looked (not too hard, admittedly) for a bolt action chambered for 5.56 without success. What is yours?

Mossberg MVP. Cheap, rough, but reliable and easy to carry/shoot in the field.

RMD

As I suspected, the local PD was more than happy to take the Independence 5.56 off my hands.

Therefore, it has been disposed of.
I did include a note and a spent case with blown primer.

quote:

Originally posted by rduckwor:
Mossberg MVP. Cheap, rough, but reliable and easy to carry/shoot in the field.

RMD

What kind of accuracy are you getting, and with what ammo? I've got the same rifle and can't seem t I break 2" groups at 100 yards.

quote:

Originally posted by SgtGold:

quote:

Originally posted by rduckwor:
Mossberg MVP. Cheap, rough, but reliable and easy to carry/shoot in the field.

RMD

What kind of accuracy are you getting, and with what ammo? I've got the same rifle and can't seem t I break 2" groups at 100 yards.

I have the 18" Predator model and I can get 0.5 MOA out of it with Nosler 52GR CC match bullets and 26.4 Gr Varget out of a LC case. The 69Gr SMK are 0.7 MOA rounds. Regular milspec M193 is 1-1.5 MOA stuff on a good day.

RMD

quote:

Originally posted by lbj:
I will probably donate it to the local PD.
It might make for a good excuse fr the bomb squad guy to blow something up for training purposes.

quote:

Originally posted by swage:
In all fairness the PPU is loaded about 200fps slower on my chrono testing compared to the IMI/Independence. When I do purchase factory ammunition for 5.56 it's almost exclusively PPU. The brass is about 1.5 thousandths thicker than Lake City and I seem to be able to get more reloads out of it.

What are your chrono results for IMI, PPU et al?
What is the barrel length?

Testing out of my BCM 16":
PPU 55gr averages around 3000-3050fps.
IMI/Independence 55gr hovers around 3200fps.
Freedom Reman 55gr 3100 fps.

quote:

Originally posted by rduckwor:
I have the 18" Predator model and I can get 0.5 MOA out of it with Nosler 52GR CC match bullets and 26.4 Gr Varget out of a LC case. The 69Gr SMK are 0.7 MOA rounds. Regular milspec M193 is 1-1.5 MOA stuff on a good day.

RMD

Thanks.

quote:

Originally posted by rduckwor:
Mossberg MVP. Cheap, rough, but reliable and easy to carry/shoot in the field.

Thanks. I should have thought of it.

I just noticed that the Ruger American Ranch rifle is listed as being chambered for both 223 and 5.56 as well. Several years ago when I was first thinking of a bolt action in the chambering, I checked with Ruger and theirs were 223 only at the time. It’s good to see some other options. I love shooting my Tikka, and especially with cheap bulk FMJ ammunition. I usually shoot Federal AE223, but I believe many shooters would like to not have to worry (even in theory) about using similar 5.56 stuff.

Maybe the rifle manufacturers are beginning to realize that fact.

This thread caused me to take it out and shoot it a bit. I needed to test some rounds for my AR-15 so I took the MVP along. XM193 still 1.5 MOA stuff. Good enough for the purpose intended. I had some hand loads with cheap BulletHead 55 Gr FMJ that I brought for the AR-15. Gawd, it was awful in the MVP maybe two MOA and very inconsistent at that.

At least I found out the Wolf primers are hard enough to avoid slam fires in the AR-15. Not a totally wasted trip.

RMD

I saw a YouTube review where independence ruptured the case and blew out the PMAG mag he was using. Independence seems to be having problems.

quote:

Originally posted by bubbatime:
I saw a YouTube review where independence ruptured the case and blew out the PMAG mag he was using. Independence seems to be having problems.

Did they say it was recent manufacture?

Based on the impressions in the case heads it's rather obvious this lot is well over the maximum pressure. As a reloader my preferred case to load with is the Lake City and in well over 2000 cases I have yet to see one single case that exhibited the pressure signs seen here. I would hope that folks have contacted Independence and at some point we'll see a recall issued for the effected lots.

I also have to wonder if this isn't in part due to what I would describe as a pre-mature bolt release and extraction. Because as I understand it the pressure within the case should be fairly low at the point where the bolt disengages and the case is extracted and by the time the case is ejected the internal pressure should be near nothing. This is not the case here, it appears that not only are hot gases bleeding out the perimeter of the primer there is also enough residual pressure within the case at ejection to drive the primer cup out of the case. This not only has to be beating up the buffer system and receiver but I would think there is also a risk of a burst case which is never ever an enjoyable experience with a high pressure rifle load. I'd also suggest that LBJ post some pics of his bolt face, because I'm wondering if there may be some indication of gas cutting on the bolt face.

quote:

Originally posted by Scooter123:
I'm wondering if there may be some indication of gas cutting on the bolt face.

Yes. Pierced or blown primers are not good for the gun even if the cartridge doesn’t blow up.