Failure to fire in 6X47 Lapua

[reverend]

I'm having a problem with failure to fire in 3 rifles I have chambered for 6X47 Lapua. They have different actions, RPA Quadlite, Tubb 2000, and a Stiller Predator. I have previously fired about 3000 rounds through these rifles without a problem.

I have changed a few thing recently. I have started using the RCBS APS hand held priming system, I have a new batch of primers, CCI 450 for APS, and CCI BR-4 for APS. It is colder now, although only about 40 degrees Fahrenheit. It has failed to fire with both primers.

I have had as much as 6 failures to fire in 50 rounds. I have recocked and fired the action as much as 5 times. Sometimes the round goes off, sometimes not. Seems to have a healthy dent where the primer is struck by the firing pin.

I've noticed the primer in the failure to fire rounds seems to be seated deeper than the other rounds. I've pulled the bullets in the failure to fire rounds, in new cases, and there is no evidence of ignition, the primer didn't seem to ignite at all, none of the powder is burned, the case still looks brand new inside without any discoloration.

Am I seating the primer too deep? Any other guesses? Is there a way to adjust the seating depth of the hand held RCBS APS tool?

Thanks for your time.

John

 

[jb1000br]

Headspace?

Try 205m's

JB

 

[Forum Boss]

Did you check the flash-holes in your brass before loading? In some of the brass Jason had there was a small, flattened section of brass extending into the flash hole. It was quite noticeable.

I also use the APS hand primer and have gotten good, consistent results with the CCIs. The CCIs do have the hardest primer cups.

One guy in Florida was having problems with FTF and it was resolved with a different firing pin spring. But here, as I understand it, you've had problem with three rifles.

With no ignition at all, I might suspect bad primers--sometimes it does happen.

First though--check your flash holes for burrs.

 

[BoydAllen]

If the dents in the primers that didn't fire look OK, and the primer pockets are the same depth, with unobstructed flash holes, I would suspect bad primers. Change the primers and try again. I will bet that they fire.

 

[Rustystud]

reverend:

Where all three of these rifles headspaced with the same go and nogo gages?

Apply two thickness of masking tape to the rear of one of your cases. Then attempt to close the bolt. If the bolt closes without any friction you have excessive headspacing. You may be bumping the case shoulder back to much causing the problem.

Have you measured the firing pin protrusion?

Have you tested the same cases with another manufactures primers?

Keep us posted to your findings.
Rustystud

 

[shcal]

One other suggeston,this happened to me), did you uniform the primer pocket? If so you may have gone too far.

 

[AlanPF]

Sounds to me like it must be the primers,or the primer tool). I'd go back to you previous method to confirm that, then look closer at the new method. Maybe its seating them too shallow,with a gap underneath)?

 

[reverend]

OK, so far I,

Checked the flash holes in the failed to fire cases, no brass over these holes. I do not usually check the cases or ream the flash holes or uniform the primer pockets.

Dents in primers look OK.

Rifles were all headspaced with the same go, no go gages. I couldn't close the bolt in any of the rifles with two thickness of masking tape on the rear of the cases.. Might of been able to force them closed but I was unwilling to push that hard.

I rarely full size my cases, these were all just neck sized.

Hard to believe I would suddenly have two different types of primers be bad at the same time.

Rifles have had quite a few rounds through them, I suppose the springs might be getting weak, but probably not all at the same time.

Checked the primer ram, it's the correct one thank goodness.

205m's are hard to come by now. I don't have any remaining supply. I'm not interested in removing these primers from the APS strips, seems like too much effort, but will get into town tomorrow to see what other primers are available.

I think it still may be bad primers, maybe something in how they were stored? Maybe the priming tool? Maybe something about the case and small primer pocket?

I'll use my previous tool and different primers, seems like the most likely scenario.

Thanks for all your input, they were all helpful suggestions.

John

 

[reverend]

In looking at some new unsized brass there are some that have eccentric flash holes, burrs. After neck sizing with the decapping pin in place some cases still appear to have eccentric holes. None of the flash holes appear to be completely occluded.

I will try reaming the flash holes to see if this helps. Thanks for your input.

John

 

[ChrisNam]

John

I recently fitted a 6 Dasher barrel for a switch barrel rifle. I shot 1000's of 284 Win rounds with the action and have never experienced any problems.

I experienced primer cratering with the Dasher right from the start and from approximately the 40th shot started to experience serious misfiring. No such problems with the 284 Win barrel when refitted though.

After the primer cratering I posted the problem on this forum and was told that I would have to polish the firing pin. Quite a job if you are in Namibia.

The misfires started in a club meeting,simultaneously doing fire forming). A friend,small time gun tinkler) disassembled the bolt and, as we found some small brass shivers, cleaned everything. I've since not experienced either primer cratering or misfires.

I'm not very practical and can give no technical analysis. It however seems as if a firing pin which works perfectly with the normal primer may not necessarily do so with the small primer - did you change from a cartridge using a normal primer to the small primer of the 6x47 Lapua? You may have to polish the firing pin.

I know most shooters clean the bolt as a matter of practice, but check if some dirt did not find its way into the bolt

 

[reverend]

OK, I reamed the flash holes of 150 pieces of brass, all previously used, some that had fired, some that had failed to fire. Loaded the cases with the APS system and primers that previously had some failed to fire rounds. Nothing unusual except reaming the flash holes.

Fired 150 rounds at the range, not a single failure to fire. It's hard to believe reaming the flash hole would make that much difference. The flash holes were not completely occluded, some just had a burr in them.

I feel a little silly. I would not have guessed this would be the outcome.

John

 

[Forum Boss]

John,

You shouldn't feel silly. You shouldn't have to ream the flash holes with Lapua brass. I've personally discussed this issue with Lapua regarding the 6.5x47 brass and,to a lesser extent) the latest batch of 6BR brass. Lapua is working on getting back to their previous standards.

It's nice to know there was a simple fix, but as noted, one reason we pay a higher price for Lapua brass is to avoid the need to mess around with flash holes.

 

[tdking]

What was the temperature when you tested the cases with the reamed flash holes? I have seen problems with small rifle primed cases,REM UBR) used for 308 and 708 rifles during cold weather. It doesn't even have to be very cold to make this happen. Forty degrees would be cool enough. It might be a combination of temperature and the flash holes not being reamed that caused the problem. I would try the newly reamed cases on a cold day,30 degrees or so) and see if the problem re-occurs.

Theron