Failure to fire

[Vandelayindustries]

Rifle-
Brand new.
6mm Creedmoor. Defiance anti-x with PVA carbon prefit, trigger tech rough diamond.

Conditions:
10*F ammo left out (under cover) for an hour before firing.

What I’ve checked:
1.Recheck headspace with go/ no go gauge. All good.
2.same lot of primers in a different rifle fired all 10 rounds no issue.

Factory ammo:
Ran all 12 rounds that I fired through it flawlessly (sig elite series -100 gr).

Hand load:
7 out of 16 rounds did not fire.
Using CCI200, virgin Peterson brass (did not run through a sizer), H4350 (1.0gr under book max) ,95 tmk. COAL 2.770.

Question:
I’m assuming it’s something with the hand load. I’d normally suspect the primer but no issues in another rifle. Next thought was the firing pin/spring but it ran all the factory ammo just fine. Not sure what’s going on?

Picture:
Top of the pic- factory sig.
Next rows are all my hand loads. The ones that stick up higher are the FTF rounds.

Ideas?

Edit to add info after a page of discussion:
1. Yes there is powder in all the cases
2. Datum to case head is the same on both fired vs no fired
3. The rounds that did fire had the primers seated flush.
4. Primers set from .0045-.014 below flush all FTF. I believe Sammi spec is up to .008 below flush.
5. One of the primes set to .0045 below flush did not fire but was pushed further down to .0095 below flush

 

[madmixerman]

If it were me, I would check the base to datum on the FTF brass vs. the ones that fired.

 

[shoot4fun]

You should pull a bullet in one or two or those that didn't go bang just to be sure they have powder.
Yes, I know, you did everything perfect but stuff happens.

 

[DShortt]

I suspect that either the firing pin spring is weak, or something is dragging in the bolt assembly and slowing the speed of the firing pin drop.
I'd disassemble the bolt, look for any signs of interference/rubbing, give it all a good, thorough cleaning and try again.

Edit to add, that's assuming the base to datum line measurement is correct and there was a powder charge as mentioned above.

 

[64Rambler]

Maybe it's the camera angle, but the 2nd row of FTF look to have deep seated primers, and a few with light strikes. If you have any unfired rounds, check how deep from flush your primers are sitting and compare with the FTF rounds. All fired rounds should be more or less flush with the base.

 

[Doug Casner]

I had that in a .308 TC one time . I pushed the shoulders back too much but you didnt push them back at all. Doug

 

[Vandelayindustries]

If it were me, I would check the base to datum on the FTF brass vs. the ones that fired.

1.5525 in the virgin brass (ftf). The ones that went bang are 1.5535

 

[Vandelayindustries]

You should pull a bullet in one or two or those that didn't go bang just to be sure they have powder.
Yes, I know, you did everything perfect but stuff happens.

I can hear it when I shake them. And missing 7 rounds would be a little crazy but yeah all good on the powder in the case part

 

[Vandelayindustries]

Maybe it's the camera angle, but the 2nd row of FTF look to have deep seated primers, and a few with light strikes. If you have any unfired rounds, check how deep from flush your primers are sitting and compare with the FTF rounds. All fired rounds should be more or less flush with the base.

That might be the winning answer. Just going off of feel, the unfired definitely feel and look deeper. Below flush for sure.
Maybe I should pull one apart that was ftf then reseat that same primer flush and see if it goes bang? I don’t see any safety issues with that as a check?

EDIT: The depth below flush measure .013-.014 on average

 

[ShtrRdy]

Does the Petersen brass use a small flash hole?

 

[Vandelayindustries]

Does the Petersen brass use a small flash hole?

I don’t know. The primer pocket measures .208 on new and .2085 on 1x fired brass using calipers. I don’t have a pin gauge but here’s a pic if it helps

 

[Hemipowrd]

Had this happen with CCI 200s on my 300 PRC when I was developing loads. Had some failures to fire when primers were seated .004" below flush and also when seated .010" below flush. In my application it liked .007" below flush. The ones seated .004" that failed to fire would fire on the second try. The ones seated .010" below flush that failed to fire would not fire on multiple subsequent attempts (probably too much crush).

 

[ShtrRdy]

I don’t know. The primer pocket measures .208 on new and .2085 on 1x fired brass using calipers. I don’t have a pin gauge but here’s a pic if it helps

if you have a resizing die for something larger like 300 Win Mag, would you please see of the decapping pin will fit in the Peterson 6mm CM brass flash hole?

 

[shoot4fun]

I can hear it when I shake them. And missing 7 rounds would be a little crazy but yeah all good on the powder in the case part

I know BUT I saw a guy show up for a match with no powder in FIFTY.
The way I knew was the primer, though it never made a noise, moved the bullet forward just enough to know something happened. He confirmed to me when he pulled bullets at home later.
@DShortt could be on the right track but why did that happen on only seven rounds and all of them your reload?

 

[ShtrRdy]

Had this happen with CCI 200s on my 300 PRC when I was developing loads. Had some failures to fire when primers were seated .004" below flush and also when seated .010" below flush. In my application it liked .007" below flush. The ones seated .004" that failed to fire would fire on the second try. The ones seated .010" below flush that failed to fire would not fire on multiple subsequent attempts (probably too much crush).

That's interesting. I usually use CCI Large Rifle primers for my rifle cartridge needs and have never had a problem over 1000's of rounds. There may be a manufactured lot that has these problems.

Did you check firing pin protrusion on that bolt?

 

[coldboreshot]

If it were me, I would check the base to datum on the FTF brass vs. the ones that fired.

This^^^^^^^^^^^
Verify the length. Possibly the virgin brass headspace on those 7 were shallower and brass moved forward upon firing and firing pin did not have enough resistance for a stable strike on the primer. Most virgin brass in my experience needs no sizing on first firing to where it will begin expansion in the chamber.

 

[coldboreshot]

This^^^^^^^^^^^
Verify the length. Possibly the virgin brass headspace on those 7 were shallower and brass moved forward upon firing and firing pin did not have enough resistance for a stable strike on the primer. Most virgin brass in my experience needs no sizing on first firing to where it will begin expansion in the chamber.

Additionally, check the rims at the based of the brass and verify those 7 had good capture by the extractor when they were chambered.

 

[DShortt]

I know BUT I saw a guy show up for a match with no powder in FIFTY.
The way I knew was the primer, though it never made a noise, moved the bullet forward just enough to know something happened. He confirmed to me when he pulled bullets at home later.
@DShortt could be on the right track but why did that happen on only seven rounds and all of them your reload?

I have had that happen twice on 2 different rifles. Random FTF. First time, it drove me nuts until I finally figured it out.
Second go around, I arrived at that conclusion much faster.

Going to edit the post to include checking the firing pin protrusion as well.

I've had a lot of weird things happen over the years. Just 'lucky' that way.

Edit - post #15 already mentioned pin protrusion.

 

[shoot4fun]

I have had that happen twice on 2 different rifles. Random FTF. First time, it drove me nuts until I finally figured it out.
Second go around, I arrived at that conclusion much faster.

Going to edit the post to include checking the firing pin protrusion as well.

I've had a lot of weird things happen over the years. Just 'lucky' that way.

Edit - post #15 already mentioned pin protrusion.

Yes, if it can (or can't ) it will at some point.
My guess is the primers not properly seated in virgin brass.

 

[Vandelayindustries]

if you have a resizing die for something larger like 300 Win Mag, would you please see of the decapping pin will fit in the Peterson 6mm CM brass flash hole?

300wm recap pin does indeed fit