Misfire problems

[BML]

Had an issue yesterday while testing some new loads in my 6.5x284

I FL sized my brass for the first time after having an issue with hard bolt closure. Basically just sized, chambered the round and resized again until the bolt closed with the normal resistance. Loaded like I normally do with Norma brass and Federal 210 primers.

Loaded 9 rounds. First 3 shot fine. All the remaining 6 were mis fires. Firing pin just barely made a mark on the primers. Cycled the them again and was finally able to get 3 of them to fire after a few more misfires.

Any thoughts as to the problem? At first I thought maybe since I FL sized them, but the first three were just fine and all 9 were sized the same.

 

[jdmartin]

BML,
Probably you pushed the shoulder too far and now the case has too much head space.That can cause the firing pin to knock the case forward rather than igniting the primer.Also,if I am correct, it can cause the brass to fail by case head separations after a few firings due to the stretching that occurs as the case re-elongates with firing.
The best way to keep your head space correct is to get head space gauges that fit your calipers or if you do a lot of different calibers, get the Innovative Technologies head space gauge which easily adjusts to every caliber I have except 50BMG.
Innovative Technologies - Reloading Equipment
Head space gauges will allow you to adjust your dies to push the shoulder back just a couple thousandths giving excellent uniformity and better brass life.The technique you used sounds reasonable, but I still would put my money on too much head space.
Darrel

 

[bruce_ventura]

To avoid this type of problem, I check case headspace using a Wilson case gage. I have a case gage for every caliber that I handload (except belted cases, of course). Highly recommended.

 

[BML]

Thanks for the tips. Picking up a head space gauge today.

 

[green 788]

put a couple layers of masking tape, or one layer of duct tape on the case head of one of those rounds that wouldn't fire... see if the bolt will "no go" (failure to close, too tight)...

If the round chambers easily with a layer of duct tape on the case head, then you do have the shoulder bumped back too far.

If the round will not chamber, I wouldn't suspect a shoulder bump excess... could be firing pin issue, or even some bad primers.

Your extractor is going to hold the case pretty close to the bolt face, by the way... so I'm leaning more toward a firing pin issue or some bad primers (at times, primers will have too heavy of a cup, and they're hard to ignite)...

Dan

 

[sp6x6]

Is it a custom?

 

[BML]

Is it a custom?

It's the Savage LRH.

 

[BML]

put a couple layers of masking tape, or one layer of duct tape on the case head of one of those rounds that wouldn't fire... see if the bolt will "no go" (failure to close, too tight)...

If the round chambers easily with a layer of duct tape on the case head, then you do have the shoulder bumped back too far.

If the round will not chamber, I wouldn't suspect a shoulder bump excess... could be firing pin issue, or even some bad primers.

Your extractor is going to hold the case pretty close to the bolt face, by the way... so I'm leaning more toward a firing pin issue or some bad primers (at times, primers will have too heavy of a cup, and they're hard to ignite)...

Dan

I'll try that. Thanks for the tip.

 

[green 788]

what did you find out about your rifle?

 

[BML]

what did you find out about your rifle?

Got about 6-8 inches of snow up here the last couple days. I'm just waiting for it to dry out a little before I try to get those last three rounds to fire. Looked for a headspace gauge in phoenix all last weekend and couldn't find one. Guess I'll have to order one online.

 

[green 788]

I'm not thinking you need a headspace gauge... did you try the tape on the case head trick?

You do still have 3 cartridges that didn't fire, right?

 

[BML]

Just checked it. Put one layer of blue masking tape on the case head and the bolt would not close at all.

The firing pin is just barely leaving a mark on the primers so my guess is it's not a primer issue.

Is it safe to assume then that its a firing pin issue?

 

[MagnumManiac]

Just checked it. Put one layer of blue masking tape on the case head and the bolt would not close at all.

The firing pin is just barely leaving a mark on the primers so my guess is it's not a primer issue.

Is it safe to assume then that its a firing pin issue?

There's only one way to find out, disassemble the bolt and find the problem, it may be a piece of junk in there or too much lube that has accumulated a lot of dust binding things up. I would also be checking that there are no burrs on the cocking piece that could hang up the firing pin assembly.

If you can uncock the bolt, measure how much firing pin protrusion there is, it should be between .050"-.065", anything less than .050" will give you misfires, anything over .065" can cause pierced primers.

gun)

 

[green 788]

Well... you definitely haven't bumped the shoulder back too far... headspace is good...

Does this gun have an Accu-trigger by any chance?

If you don't depress the safety blade enough when pulling the trigger... you get a "click" instead of a bang.

I've seen this happen a lot, to myself and others... if you sort of "side swipe" the trigger when you're pulling it, the sear will drop but the safety blade with keep the gun from firing.