DUD Remington 7.5 small rifle bench rest primers

[Nic Swink]

Did you resize your virgin brass before loading?

Yes

 

[Turbulent Turtle]

Yes

That's your problem right there. Don't do that unless you know exactly the dimensions of your chamber and you have the sizing die set perfectly. You need a comparator and fired brass from your rifle to set your sizing die properly. My experience has been that it takes virgin brass two firings to get to final dimension.

 

[gunsandgunsmithing]

This is actually pretty good!

Ammo Primer Misfires - Why They Happen - Guns and Ammo

If you experience an ammo misfire, you thoroughly investigate to determine the cause - firearm firing pin, bad primer, old ammo - so you can address and fix the problem.

www.gunsandammo.com

 

[LCazador]

When measuring the primer height of a new, never seated primer, You want to measure the height of the cup, not including the anvil which will be protruding a couple thousandths. The anvil will be pushed into the compound when the primer is seated. If done incorrectly, your measurement will be off making the numbers look better than it really is.

My gut feeling from 55 years of reloading, is that a slightly overly deep primer combined with a new undersized(new brass is typically a few .001's short at the shoulder so it will fit in most any chamber). These clearances add up to produce a too soft primer hit. Often times you will need to seat a bullet to jamb in the lands to hold the case head back against back against the bolt face to insure proper ignition.

I read thru the whole post. You mention cleaning new brass. Most likely reason to do so would be if you lubed the cases to size. As I mentioned new brass is already a little to short. Did You size the new brass?

Ref what to do with the 6 1/2 Rem primers: I would just consider them as small pistol primers. Will work fine in that role. Definitely would not use them in a 223 or other modern caliber unless for reduced lead bullet loads.

Frank

I think Frank nails it right here. Excessive head space because the brass is new. Then what if it was full length sized with even more headspace introduced? Primers probably not seated deep enough due to dished primer pocket. And then on top of that moisture in the cases. For proper fireform on new brass I use a moderate load with a bullet seated out to contact the lands to keep the brass head against the bolt face.

 

[G Liles]

This happened to me once, had me scratching my head, then I pulled the bullets guess what, no powder!!! Even though I was by myself I still had to see if any body saw what I had done!! You know like what you do after you fall !!

 

[LHSmith]

I’m really not sure how to check head space I’m gonna have to read into it

I thought this was brought up before in this post but a quick check without tools is to apply thin adhesive tape (scotch or masking) to the case head (without a primer or bullet) and trim it even with the case head OD. Chamber the round and try to gently close the bolt. If it closes without any resistance -apply another layer of tape, etc. until you feel resistance. Typical scotch tape measures ~ 0.003". Let us know the results and what model rifle is it and is it strictly factory - no aftermarket barrel?
My vote still goes to water in the case from cleaning and nothing else.
Also my prep for new brass (after visual inspection for defects) is to run it through the die part way (to the point I feel the expander entering the neck and as the expander clears the neck, I lower the ram- the shell holder should still be some distance away from contacting the die. This is done to simply iron out dents and make the neck round. I like dry lube in the necks to avoid cleaning lube from the case.

 

[GAnderson]

This happened to me once, had me scratching my head, then I pulled the bullets guess what, no powder!!! Even though I was by myself I still had to see if any body saw what I had done!! You know like what you do after you fall !!

Surely your primers went off...the primer would have still detonated whether you had powder in the casing or not and generally a primer has enough power to lodge the bullet in the barrel, so I would think after the first one you tried, it would become obvious what had happened. I am not making lite of what you posted, just trying to figure out how your primer did not go off even without powder...

 

[SSL]

A friend of mine had a .35 Remington T/C barrel that did something similar. It would put a healthy dent in the primers of about every third cartridge, even factory rounds, but not fire the primers. I tried seating bullets jammed as far into the lands as the action design would allow to keep the cartridge bases firmly against the receiver face, had the chamber gauged, switched primers, tried new brass, saved cases that did fire and tried them with only minimal neck sizing...all to no avail. The receiver performed flawlessly with barrels chambered for .44 Magnum, .45/70, .223, .30 Herret and .357 Herret. Just not that darned .35 Remington. It gave me quite a few sleepless nights and we never did find a solution. He finally pitched it. Problems like this can be frustrating, to say the least.

 

[Tokay444]

I thinks it’s clear by this point what the issue was for OP.

 

[TAJ45]

Just another swing at this:

Re brass having shlder pushed back too far when sized - put two or 3 pcs of scotch tape on base w none over the sides, see if the dud will chamber.
Maybe 3 pcs on one. 2 pcs on second, one on the last round. Just a crude way to chevk for excessive head space. Hth. Tom

 

[FNSafari]

Just another swing at this:

Re brass having shlder pushed back too far when sized - put two or 3 pcs of scotch tape on base w none over the sides, see if the dud will chamber.
Maybe 3 pcs on one. 2 pcs on second, one on the last round. Just a crude way to chevk for excessive head space. Hth. Tom

Try you rem 7.5s in another rifle and see if you get the same dud ratio. If not, clean your offending rifles bolt scrupulously, replace the firing pin spring and check the firing pin for any damage near the tip. I had some issue with them many years ago but it was because I left a couple of sleeves in my barn and moisture got to them.

 

[Turbulent Turtle]

Yes

I wanted to add a few thoughts,
I believe your issue is that you resized the virgin brass and by doing so, you pushed back the shoulders far enough down that you created a headspace situation. When the firing pin hits the primer, the shock is softened by the fact the case can move forward and thus absorb some of the energy of the firing pin. The brisance of the primer is affected by this and sometimes it fires, sometimes it doesn't. In my experience, primers that have been hit and did not fire, will not fire on subsequent firing pin strikes; the cup has been deformed and it can't transmit the energy to the compound on the anvil probably because there is not room left between the cup and the anvil.

BEWARE: when you deprime, the primer is likely, but not guaranteed, to fire. I would just a universal decaping die and fire them. Eye and ear protection are de rigueur (a must.)

I do not believe the small amount of moisture affected the powder or the primer.

Never, ever, EVER resize virgin brass unless you know exactly what you are doing and you can ignore my post.

 

[skeeljc]

I thinks it’s clear by this point what the issue was for OP.

Moisture.

 

[G Liles]

Surely your primers went off..

I never said the primers didn’t go off!!

 

[Tokay444]

Moisture.

A myriad of operator error related issues, including, but not limited to, moisture.

 

[EOD Rob]

I agree with all above. Seems like you ended up with some bad brass my friend.
However, did you only attempt to fire them the one time? If not, Id give them another swing, like AjC said. At least then you will know for sure!!!

Rob

 

[jonbearman]

I have fired 100's of them and not one fail to fire so you should take them down and inspect the primers and pockets to make sure the flash holes are drilled.

 

[skeeljc]

A myriad of operator error related issues, including, but not limited to, moisture.

I think moisture was the only thing preventing his reloads from going bang. Only some of the batch of reloads failed to go off. What does that tell you? It is very unlikely to be a mechanical issue. Water was a part of the reloading process.

 

[Tokay444]

I agree with all above. Seems like you ended up with some bad brass my friend.
However, did you only attempt to fire them the one time? If not, Id give them another swing, like AjC said. At least then you will know for sure!!!

Rob

Pretty sure the brass is fine.

 

[Tokay444]

I think moisture was the only thing preventing his reloads from going bang. Only some of the batch of reloads failed to go off. What does that tell you? It is very unlikely to be a mechanical issue. Water was a part of the reloading process.

The excessive head space created by bumping shoulders on virgin brass didn’t help. As stated, the primers haven’t gone off. As also stated, you could soak primers in water and they would still go off.