6.5x47 Lapua Hang fires

[Scott Harris]

I just went back downstairs to shoot some primers on empty cases to see if there was an audible/ visual flash difference between the Wolf, CCI #41 and the CCI BR-4 primers. I loaded 3 of each on empty cases and shot them through my rifle. I believe I have found my problem and it may not be the primers. When I first put this rifle together I had an HS precision stock off of a Rem 700 LTR (miss that stock). Now it has one of the new Magpul Hunter 700 stocks and DBM setups. Several times during the primer test, I would pull the trigger, feel it move, but the firing pin would not release. I could then squeeze the trigger harder to get the firing pin to release. Upon further inspection, I found that the trigger shoe would just barely contact the back of the trigger guard towards the end of the trigger travel. I quick few strokes with a file to clearance the trigger guard and now, no contact, and no hung up firing pin. I still plan on testing primers next week, but I would just about bet that the cocking piece was dragging on the sear because the sear couldn't drop out of the way completely due to the trigger/ guard interference.
As to the audible/ Visual primer tests. Wolf are much weaker than either CCI #41s or CCI BR-4s. The wolf gave a low pop, and barely a puff of smoke out of the 22" barrel. The #41s shot a large column of sparks out the barrel, and the BR-4s shot a slightly smaller spark out the barrel. I video'd the test and I will try to post it later.

and there you go, another rifle ignition problem identified courtesy of Wolf SRM primers.

Ignition problems can be subtle and difficult to detect and these primers might actually be doing you a favor. Switching to another primer might seem to solve the problem, but your should check your SDs. Ignition problems can show up in the form of high SDs....the gun goes bang, but the SD stinks. You can address the issue by using softer/thinner primers, but that's not really fixing the problem. IMHO, the gold standard for ignition is:
24lbs + spring
.250" firing pin fall
standard weight steel pin
small firing pin tip (.062")
NO rubbing of any moving parts

Plenty of rifles out there do not meet these requirements in one way or another, including virtually all the customs.

 

[BoydAllen]

Fellows,
You are looking at your answer. I have seen this before when case capacity and powders' ignition requirements combine and exceed the capability of a given heat of primer to reliably ignite them. The key was the account of there being no issue with the same primers in smaller cases. A friend ran into the same problem with a .22 Cheetah, which is a large capacity case with that was made from what were essentially .308 shaped cases with small primer pockets. A friend had a load that had done well in warm weather that featured moderately slow ball powder, in cooler weather (for California) it would hang fire, click boom. This was before the Russian primers came on the market. He was probably using federal primers. A switch to CCI small rifle magnum primers solved the problem. The cooler primers had not been a problem in smaller cases with easier to ignite powders. This is kind of like BAT actions dancing on the edge of having enough striker energy. The light bolt lift and minimal vibration have their advantages, but if the application requires more than is delivered, or a particular action falls too low, remedial work is required for match winning performance. Cool primers have their advantages, but their energy level can fall below the line for certain applications. This is not say that I would not love to have a BAT action, just that if I were getting erratic performance from known quality barrels and components, I might try a heavier striker spring or add weight to the pin (and some other tricks that are known to have an effect). At the top (far from where I ever was) of short range BR the little things add up quickly.

 

[DHD]

How do you clean your cases? Wet with soap? Yellow powder is not scorched powder, it's been destroyed by citric acid left over from traces of soap in the case. The primer is an explosive....either it fires or it doesn't fire. Your problem is contaminated powder. Almost all soap has citric acid. Do an experiment, pour a tiny bit of soapy water in your primed case and then put powder and a bullet on it. Uncork it after a day and then check out how congealed and yellow your powder has become...you'll need to chip it out. Also, notice the yellow is at the bottom of the case. It's because that's where the soap residue settles. That's also where the primer flame is unsuccessfully trying to ignite the dead powder. The yellow stuff forms a nice inert firewall. . Sometimes, the cartridge will go off, but it will be delayed ignition. That can be from powder that is contaminated but not bad enough to completely prevent ignition. Note that Lemishine is highly concentrated citric acid...far worse than soap. It only takes tiny traces of citric acid to cause problems in my experience.

I fought this stuff for years and progressively used less and less soap and completely eliminated lemishine. The 100% solution required doing a short cycle with baking soda to neutralize the acid. In the end, I was able to eliminate these problems, but the amount of effort forced me to rethink the cleaning regimine. I reflected on how much time was being wasted with wet tumbling and decided to switch over to dry tumbling with plain corn cob media. Soooo much easier and no more problems.

Good information Scott. In my case I don't remember ultrasonic cleaning those cases. I typically clean cases used in my AR's ultrasonicaly (they're so dirty) and I don't have any issues with the Wolf SRM primers with those.

In the end, I solved any problems I had with the Wolf SRM. I don't use them in any case larger than a 6.5 Grendel.

As I stated in my first reply, I will use a Wolf (or PMC) large rifle primers over any other. I have just had too many issues with the Wolf SRM primers to even look for other possible reasons why it happens. CCI 450 primers work fantastic in my larger SR primed cases and life is good.