Diagnose my ammo problem...

[Fentonite]

I took the 260 out today to try a few different loads from Southwest Ammunition (I still don't reload, yet). Two of the loads did fine. When I was trying out their 136 grain Scenar-L, I ran into a problem closing my bolt after a few rounds. I finally found that a primer had come out of the case, and was blocking the bolt lugs from rotating into position. When I inspected the brass, I found that 4 of the 10 rounds I had fired of that load had either bulging or missing primers. The brass from the other two loads (139 Scenar in Lapua brass, and 142 SMK) were just fine. I shot the 142 after this load, and there were no problems. Seems like this ammo is loaded too hot? I've had good luck with this company in the past, but am reluctant to shoot more of that ammo. Of course, I have over 200 rounds of it...

Here's a pic of what I was seeing. Recommendations?

http://i841.photobucket.com/albums/zz339/fentonite/A4BD6C4B-6D73-47F2-A610-BD25AA3FB250-17567-0000038A97E00350_zpsdbb08c38.jpg

[JM Ver. 2.0]

My buddy had some 308 that the primers fell out of. They weren't loaded too hot. The primer pockets were just too loose.

Check that before you assume they're loaded hot.

Sent from my teepee using smoke signals.

[Delfuego]

Hey Fentonite, I haven't had any issue with the SW 260 in my rifle. I have shot their 139 scenar and 142 smk in both Lapua and RP brass. I have yet to use their SWA (Silver State Armory) Brass yet. I would call them to see if they have had similar issues, they are pretty nice folks.
Or you could give them to me and let me see how they work in my rifle.... [pick-me] I still have some 142's on hand if you want to test them.
In all honesty, let me know how it turns out.

[Fentonite]

My buddy had some 308 that the primers fell out of. They weren't loaded too hot. The primer pockets were just too loose.

Check that before you assume they're loaded hot.

Sent from my teepee using smoke signals.

Will do, thanks. Good advice.


Hey Fentonite, I haven't had any issue with the SW 260 in my rifle. I have shot their 139 scenar and 142 smk in both Lapua and RP brass. I have yet to use their SWA (Silver State Armory) Brass yet. I would call them to see if they have had similar issues, they are pretty nice folks.
Or you could give them to me and let me see how they work in my rifle.... [pick-me] I still have some 142's on hand if you want to test them.
In all honesty, let me know how it turns out.

I sent them an email, but I know they're really busy, and might take a bit to get back to me. I agree that they are good folks, and run a class act. I liked their 139 Scenar, but since they stopped selling it and started selling the 136 Scenar-L instead, I figured I'd transition over. I'll let you know what I hear. Thanks.

[spqrzilla]

I have actually seen that behavior when loaded too light believe it or not. I'd check velocity on that batch myself.

[Fentonite]

I have actually seen that behavior when loaded too light believe it or not. I'd check velocity on that batch myself.

Looks like it's time to get a chrono...

[XC700116]

Looks like loose pockets to me as the primers aren't flatened, and there's no evidence of ejector markss on the case heads.

[JM Ver. 2.0]

Looks like loose pockets to me as the primers aren't flatened, and there's no evidence of ejector markss on the case heads.

That's what I thought too. The primers look perfect.

Sent from my teepee using smoke signals.

[Zombie Steve]

If there are no signs of overpressure like extractor marks, I'd bet you're too light.. not enough juice to reseat the primer on the bolt face.

[MarkCO]

Loose primer pockets or bad batch of primers would be my starting theory. Light loads should not even do that unless they are cheating the system and using a smaller charge of a faster powder and getting a spike, but not enough to cause flow issues.

Measure the ID of the primer pockets and compare with spec.

[spleify]

Im guessing loose primer pockets also.

[Hoser]

I have only seen that once before. A new reloader pushed the shoulders back too far essentially creating excessive headspace. That combined with too light of a load it looked just like that.

But... Southwest Ammo is a solid company that knows what they are doing. I would call them and ask.

[Hoser]

If the primers can be pushed back in with your finger or are simply falling out, the ammo was too spicey and the primer pockets are shot.

Measure an unfired case at the web and then measure a fired case.

[spqrzilla]

Hoser's advice - candy ass that it is - is dead on.

Its fascinating how very different conditions can create what are superficially similar symptoms.

[Zombie Steve]

I'll agree there has to be a lot of room for the primer to come out like that... headspace is probably part of the problem.

I had this same problem with .308 when I started reloading. Pushed the shoulder too much, and the primers would back out (well, they all back out, but when the powder goes off it gets re-seated by the bolt face as the brass expands). This only happened on my start and low end charges. As I worked up, the issue went away.

Now that I'm seeing your pic on my computer and not on my phone, I don't see any issue with smearing / swiping or extractor marks on the brass. I'm still guessing too low of pressure.

Do you have a micrometer? Mic the case web before and after. More than .0005" growth in the case web on new brass is a pretty good indicator of high pressure.

If the issue was loose primer pockets, they'd be flattened.

[Fentonite]

Ok, so here is how ignorant I am... I don't know where the "web" is on a case. Call me what you will. But what the hell, I decided to measure some rounds. I measured the OD of the groove that the extractor goes in...

On an unfired round, the measurement was consistenly 0.398-0.400:
http://i841.photobucket.com/albums/zz339/fentonite/cca7655d5e2b25f8e853bcd7c2d7767c.jpg

On fired brass that didn't have the problem, the measurement remained 0.398-0.400:
http://i841.photobucket.com/albums/zz339/fentonite/03D60673-D819-4344-93AE-0A1EB6FFBD36-18375-000003A45E671BAB_zpsdf315fa8.jpg

On the four rounds that had primer problems, the measurements were 0.405, 0.408, 0.410 and 0.411:
http://i841.photobucket.com/albums/zz339/fentonite/4C56F277-3A87-49B3-A624-BEC01DFF97D3-18375-000003A46E95A5FC_zps33bb8651.jpg

Seems like this would mean something, to someone smarter than me...

[JM Ver. 2.0]

Look up case specs for the primer pocket. Measure that. But I'd agree the fired cases with primer issues are out of spec.

Sent from my teepee using smoke signals.

[Zombie Steve]

Web measurement would be the base of the case just north of the extractor groove.

[spqrzilla]

Its hard to measure accurately in the extractor groove with calipers but if you have got good measurements, then a batch of excessively soft brass is a possibility.

[Fentonite]

Seems odd - there's no significant difference among web measurements between unfired, fired, and the problematic 4 fired rounds. Just the difference within the extractor groove. Thanks for everybody's input. I'll post whatever response Southwest Ammunition gives me.

[Zombie Steve]

Seems odd - there's no significant difference among web measurements between unfired, fired, and the problematic 4 fired rounds. Just the difference within the extractor groove. Thanks for everybody's input. I'll post whatever response Southwest Ammunition gives me.

Which supports my / others' idea that the round is underpressure, not over. A chrono really would help. You can use mine if you're in the neighborhood.

[Fentonite]

Thanks for the offer, Steve. I think it's just time for me to buy one!

[R&S]

you might check this out

http://www.google.com/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=YnIHegMeMA9XGM&tbnid=HVET0qwe2qB5PM:&ved=0CAUQjRw&url=http%3A%2F%2Fwww.surplusrifleforum.com%2Fviewt opic.php%3Fp%3D196497&ei=GPEzUr7qFpPkqQHhwYH4Dw&bvm=bv.52164340,d.aWM&psig=AFQjCNHJIKrC-7r7T_CmUK59IUQLHXcIhA&ust=1379222160751886

[Fentonite]

I spoke with the guys at Southwest. They told me that they've heard from quite a few folks that their new load was showing pressure signs, and they are re-figuring the load. Sent me a shipping label to send back my ammo, and they will make it right. Thanks for all the advice.