.223 Lake City Brass To Thick

[Nick Caprinolo]

I was loading some once fired LC .223 brass the other day. I very carefully measured powder charges and noticed that many were filling the case to the top and others were just at the bottom of the neck. After dumping the powder back int the scale pan, the weight was still dead accurate. I then measured the cases and found the neck thickness was the same and the outside of the case measured the same at every point along the case.

I decided to test both cases at the range. Those that appeared to be loaded to the lower level fired perfectly and gave good tight groups. I fired just one of the other rounds and blew the primer, which wrapped itself around the firing pin and was very difficult to remove.

Now I was under the impression that Lake City brass was made to very close tolerances, because it is used by the military. All the brass came from the same batch and markings indicated it was made in 2014.

No more Lake City for me. I can't imagine the increase of over pressure this caused. I have never had a primer do this in the past. The rifle is a home built AR 15, with a fluted heave bull barrel and has always grouped extremely well and has fired several one hole groups. I will split the case today and measure the thickness. I am betting it is way out of spec.

 

[jepp2]

I will split the case today and measure the thickness. I am betting it is way out of spec.

Before you split the case, I would think checking the weight and water capacity differences would be more meaningful.

 

[243winxb]

All the brass came from the same batch

Are the scamp markings the same? If brass has it?



A 223 chamber may produce more pressure then a 5.56 chamber. But the brass has to be the problem.

 

[Nick Caprinolo]

Are the scamp markings the same? If brass has it?

View attachment 1114001

A 223 chamber may produce more pressure then a 5.56 chamber. But the brass has to be the problem.

I used the same load I have been using in the past which is below max. Since all the cases were of the same batch, all markings were the same. The chamber is cut to accept both 5.56 and 223 rounds. Brass was cleaned in an ultra-sonic cleaned and all primer pockets were uniformed after removing the military crimp.

 

[hogpatrol]

The year of manufacture doesn't designate the lot number and they vary lot to lot. Pick another year and you can find the same variances. Bottom line, don't expect cases with the same year to be identical.

 

[Nick Caprinolo]

The year of manufacture doesn't designate the lot number and they vary lot to lot. Pick another year and you can find the same variances. Bottom line, don't expect cases with the same year to be identical.

I would expect that a new box of loaded ammunition is from the same batch.

 

[grovey]

I would of expected them to be closer than that too, but in this case ( no pun intended...) I'd seat some spent primers in them and sort the rest by water capacity before firing.

 

[Nick Caprinolo]

I would of expected them to be closer than that too, but in this case ( no pun intended...) I'd seat some spent primers in them and sort the rest by water capacity before firing.

I would do that if I need the brass, but I have plenty of it. Going to toss the whole lot in the trash. Not worth the trouble of sorting. But for this particular rifle, I have just ordered 100 rounds of Lapua brass.

 

[CharlieNC]

If once fired, I would be more suspicious of the sizing than the original manufacturing based on the huge capacity difference you are noting.

 

[hogpatrol]

LC is ok for magdumping, albeit more expensive than firecrackers.
Aside that, consider LC is actually made for one time use only.

 

[CharlieNC]

Hog I've had great success shooting fclass with LC, as good as Lapua for me. I like the higher capacity too.

 

[hogpatrol]

Hog I've had great success shooting fclass with LC, as good as Lapua for me. I like the higher capacity too.

Are you sorting? Aside that, every LC I pick up at the range goes to the scrap yard. I've never had any luck with it except for making noise or whacking steel. As far as Lapua, I've had just as good performance with IMI and Remington.

 

[Uncle Ed]

Below is from the main page here at Accurate Shooter under the .223

Bottom line, Lake City brass is harder in the base than any brand of .223/5.56 case, has the most case capacity and better than average in weight variation.

I buy bulk once fired Lake City 5.56 and 7.62 brass at a fraction the cost of Lapua brass and don't cry if I loose a few cases.

How Hard is Your Brass? 5.56 and .223 Rem Base Hardness Tests
http://bulletin.accurateshooter.com...r-brass-5-56-and-223-rem-base-hardness-tests/

 

[Bill K]

From all I have read re: the LC brass used by the military, it is and was made heavier to hold the extra pressure that military brass 5.56 is made for.
Just match the cases in weight and reload according to pressure signs in your rifle and it is good brass to use. Just don't mix it with the lighter weight 223 markings.

 

[hogpatrol]

Curious that IMI brass wasn't checked. I prefer it over all other mil brass.

 

[243winxb]

The factory loaded brass/ammo would have had the same amount of powder in each cases. When the factory ammo was fired, it should have produced high pressure in the brass with less internal capacity.

Needs futher nvestigation.

 

[CharlieNC]

Are you sorting? Aside that, every LC I pick up at the range goes to the scrap yard. I've never had any luck with it except for making noise or whacking steel.

I sort by weight because it is quick to do. Earlier this year I purchased the new LC that was on sale, and it was as consistent in all measurements as new Lapua. Like you I would not use range pickup brass with unknown history. A few years ago, when loading components were tight, I purchased prepped once fired brass and it also performed well.

 

[XTR]

Until recently I used nothing but unsorted, 90s vintage LC 223 with mixed headstamps in my F-TR rifle. There is a fair bit of bling brought home with it. Not to discount the experience that the OP relates, but in general I've found it worked pretty well.

 

[Nick Caprinolo]

OK, here are the results of weighting.

Filled both with water.
Blown primer water weight was 29.00 grains
Good primer water weight was 31.4 grains

The blown primer case weight was 102.3 grains
The good primer cased weight was 97.3 grains.

I think this definitively shows that the blown primer case had less capacity, causing extreme pressure.

Those who think there was burned powder residue in the cases, are wrong. Cases were cleaned with an ultrasonic cleaner and primer pockets were clean as a whistle and were then reformed.

 

[CharlieNC]

Same headstamp?