The first round tests of my .223 hunting load resulted in one big issue: the primers were backing out.
foo.c‘s guess is it’s the brass, which was brand new Remington.
So I hit Google to see what I can see.
It seems that Remington brass isn’t regarded as the highest quality brass (not like Norma and Lapua), but it’s generally regarded as good brass. So maybe it’s not the brass?
Some things I’m finding in my reading:
- Too short for the chamber. Could be excessive headspace, could be the cases were sized too short for the chamber.
- Hrm. I’m loading to .223 Rem specs, but the Bushmaster is 5.56 chambered. Could it be things were sized just a wee short for that chamber since a 5.56 chamber (compared to a .223 chamber) has a longer leade and headspace dimensions?
- Too low a pressure.
- This might go along with the above. The chamber was slightly larger, thus when the case expanded it didn’t expand
- Chamber wall cling. That is, there’s enough pressure to expand the case sideways to cling to the chamber walls, but because there’s more free space along the axis running through the bullet from primer to tip, coupled with less pressure, now there’s not enough to fill things backwards including pushing the case back against the bolt face so as a result the primer can back out a bit.
- New brass. It just may be formed to “conservative” tolerances and/or have case uniformity issues. Debur the flash hole, uniform the primer pockets, etc.. to help.
- Full length sized brass, similar issues to the above.
Check out this PDF showing the dimensional differences between .223 and 5.56.
It sounds like the primers backing out may be normal for my situation.
If the loads are very weak, unlikely to see primers backing out as there’s probably just not enough pressure.
If the load is perhaps just under max, that’s enough pressure to cause things to back out.
If the load is max to hot, it’s probably more than enough pressure to cause things to sit tight.
What could cause lower pressure? Well, I’m loading a .223 Remington and shooting from a 5.56x45mm NATO chamber, which is going to be just a hair longer. It could also be due to the shape of the bullet (the ogive on the Barnes TSX). It could also be the length at which I loaded the cartridge really putting the bullet off the lands.
This is all just hypothesizing.
The bummer? After talking with foo.c I had resigned myself to just switching to NATO brass (Lake City, WCC, whatever I happened to have). Thus I took all of the Remington brass from yesterday and threw it with some other dirty .223 brass into the brass tumbler to get cleaned up and put in the bucket for reloading at some future date. Thinking about it now, I should have kept that brass: 1. to measure it and see how the size changed after shooting, 2. to go ahead and reload it and try again. Now that it was fired in that chamber, it may have taken on a different and better shape.
So I’m tempted to keep my NATO brass in reserve and continue with the Remington brass. I will pick up a few more dodads at the store, like something to debur the flash holes and to uniform the primer pockets. No harm in that. Then see how it goes. But this time, I’ll reload that same Remington brass and see how it goes. If I still have primers backing out, then I’ll look at other options.
I might even consider doing a test-run of brass this way. That is, instead of using the Barnes TSX bullets, I’ve got some 55 grain Winchester FMJ. I could work up a quick load with some of those to preserve the Barnes bullets.
Ah, so many things to consider. 🙂
Stuff From Hsoi 
You don’t state your powder or your charge weight. Primers backing out of a fired round are generally a sign of over pressure.
I didn’t restate the load recipe in this posting, but the very first thing in the posting was a link to the page that contained all the details. It was a lot of different powders and weights, thus easier to link than retype it all. 🙂
I don’t think it’s overpressure in this case, or at least it seems unlikely given the charges were no where near max (according to book specs). It could be tho…. there’s no real way of knowing right now, just hypothesizing.
That all said, I’m currently working on making some more loads to chase down this primer issue.
If after reading the spec articles you have any more feedback, I’m all ears. Thank you.
I don’t see anything wrong with any of your data or choices. Personally, I settled on 28 gr. of BLC2 with a 55 grain Winchester HPBT. I consistently print 1″ groups at 100 yds, open sights, in my Colts A2 Sporter NM.
I’ve never heard of any cause of primers backing out of the pocket other than over-pressure.
What about your OAL? If you leave your bullet out to far, allowing it to seat into the rifling. that would raise your pressure. You can check this by seating a bullet long, (in a powderless loading) chambering it and then check for marks on the bullet. Then check your load info for your bullet jump ( the distance the bullet must travel from the point of leaving the case to where it contacts the lands). Maybe this will help. Good luck.
Nice grouping with open sights. You’ve got better vision than I do. 🙂
I hear what you’re saying regarding over-pressure, and that certainly makes sense. When I read about the cartridge being too short as being another possible reason, it does sound strange but I can see that too.
The OAL is 2.250″, which is straight out of the Barnes #4 book. I’m not sure how it compares to the chamber tho. I have an OAL gauge but haven’t used it yet. I probably should do that… maybe today, while the kids are busy playing with their Christmas presents. 🙂 But yes, if the bullet’s seating too far forward that could be raising the pressure. Off the top of my head I’m not convinced it’s this because it’s a .223 load in a 5.56 chamber and the chamber is going to be just a hair longer. But I’m not going on measures here, just on “paper specifications”. There’s no substitute for measuring.
Barnes says that their bullets perform best when seated 0.050″ off the lands, but there’s some variance as I mention here:
https://hsoiblog.wordpress.com/2009/12/14/almost-ready-to-start/
So hrm. You’ve given me a few things to look at before I do my next loads. Going to regroup with a new plan.
Thanx!
I doubt you are getting into the rifling with that OAL. Do the test though.
I’ve shot 300 69 grain Sierra Match Kings over 24.0-24.5 grains of Varget loaded to mag length and not seen any issues with my primers.
I know the TSX is different being all copper, but I’m having a hard time seeing a problem there.
Went back over my data and my loading of 24.2 grains of Varget with the 69 gr SMK makes 2613 fps out of my gun which is pretty comparable to your data with the 62 grain TSX.
I just don’t know much about how new brass behaves as a reloading component, so I’m still suspecting that as everything else looked good to me.
I doubt I’m getting into the rifling too, but I see no reason not to measure and check.
I’ve got some ideas and things I want to look at regarding new brass and the primer situation. Going to experiment some before I go forward with more Barnes bullets (since the’re kinda expensive). 🙂
Pingback: Primer investigation – Part 1 « Stuff From Hsoi
Pingback: Primer Investigation – Part 3, Results « Stuff From Hsoi