DUD Remington 7.5 small rifle bench rest primers

[Nic Swink]

Those primers look fine. The question is how did the others get so deeply seated?
Wet powder, primers etc do not make a primer seat so deep.
If you measure the HEIGHT of a primer and the depth of the primer pocket in the case that's the end in my opinion. It can't sink to the shown depth IMO unless you really had 'squared ' the primer pocket to excess. You said you had not done that. I'm back to primer height and pocket depth.

Ok the depth of the new primer pocket is 0.119 and new primer measurement 0.113

 

[LHSmith]

My experience with primers:
#1/ When you want to make them inert - there is no foolproof method to render them 100% safe from going off
#2/ It does not take much contamination to render a primer inert.

 

[M-61]

So your DUD primers sure appear quite greater than .006 below the case head surface. Correctly seated they will measure either flush or slightly below (measure the ones in your second pic and then in the ones in your first pic) Sure looks like a lot more than .006 to me.

 

[wkdickinson]

View attachment 1227082

Those primers look like the are seated correctly.

 

[wkdickinson]

But still, why do the original primers have such deep firing pin impressions, but they still did not ignite?

 

[LHSmith]

They were wet cleaned but I dryed them out with an air compressor and primed them prob 24 hours later

Same happened to me recently-only I thought letting the sun dry them for 2 days would dry them out. Remember with a .204 you got a tiny hole on both ends of the case-unlike a straight wall pistol case. Hard to get moisture out of there. The primer compound got damp with moisture along with some powder.

 

[skeeljc]

Those primers look fine. The question is how did the others get so deeply seated?
Wet powder, primers etc do not make a primer seat so deep.
If you measure the HEIGHT of a primer and the depth of the primer pocket in the case that's the end in my opinion. It can't sink to the shown depth IMO unless you really had 'squared ' the primer pocket to excess. You said you had not done that. I'm back to primer height and pocket depth.

Pictures can be deceiving. The radius on the primer and the primer pocket along with shadows can fool the eye.

 

[GAnderson]

Have you tried firing one a second time yet like several people have advised? If it goes bang, you have found your problem and don't have to go any farther...I really think it would be in your best interest to try one before you go to the trouble of pulling them all apart. Also, what lube method did you use when you sized the casings? A spray lube or sizing wax?

 

[Nic Swink]

Have you tried firing one a second time yet like several people have advised? If it goes bang, you have found your problem and don't have to go any farther...I really think it would be in your best interest to try one before you go to the trouble of pulling them all apart. Also, what lube method did you use when you sized the casings? A spray lube or sizing wax?

Yes I tried firing them a second time just a few hours ago and still nothing

 

[D-4297]

To answer your original question ....... No ! Emphatically No . I've used the Rem 7 1/2 exclusively for the last two and a half years , and never had a single primer failure in over 7,000 rounds . But after all the discussion , I'd be carefully checking F/P length , along with every thing else suggested . It ain't the primers , Boss .

 

[El_Flaco_Colorado]

Remington does not recommend the use of 6-1/2 primers in the 223. See the following:

Warning:

• Remington does not recommend this primer for use in the 17 Remington, 222 Remington, 223 Remington, 204 Ruger, 17 Remington Fireball. Use the 7-1/2 Small Rifle Bench Rest primer in these cartridges.
• This 6-1/2 Small Rifle primer is primarily designed for use in the 22 Hornet.

I remember reading that! Thanks for the reminder. But What other guns can the Rem 6 1/2 be used for? I got 1k and been looking at the books I do have and They really dont have the brand name for a primer just the size. I was lucky I had a neighbor who I was able to get 2k of small pistol along with 1k of misc primers that I bought . So if anyone can think of books that would help understanding primers, thanks in advance.

 

[El_Flaco_Colorado]

As a re-loader, you will run into issues like these. Best thing is to write a list of all possibilities and begin a process of elimination. Here is what I'm thinking. You did end up with damp powder as evidenced by clumping powder. Lesson learned is to warm your brass in oven at lowest setting or a brass dryer until you are certain all traces of moisture are gone. Still - I don't believe there was enough moisture in them to cause the primer to not pop, given you blew them with compressed air. You didn't deepen the primer pockets - so unless your brass is faulty enough to cause misfires (very unlikely), the brass and primer pocket seating depth are not likely the issue. My $10.00 says you pushed your necks back too far with your die setting. If you have a Hornady headspace measuring tool that you put on your dial caliper (or other brand of tool), measure all of your fired cases and compare to the measurements of a fair number of ready-to-fire ammo you have not yet fired (if you have any). If the fired cases are more than .005" longer from base to shoulder than that of the unfired, it shows you that you bumped the shoulders back too much. It could have been .010" too much. I'd take your absolute longest fired case and use this as a temporary basis for setting your shoulders back on your next batch of ammo. I'd bump them no more than .002" is bolt gun and .004" if in semi-auto. Then, do the same comparison of your fired/unfired cases again. I'm betting your new .002" setback length will be considerably longer than the measurement you used to load your first batch- which indicates they were too far back before. The Remington 7 1/2 primers have a little thicker cups which means they need to make solid contact with a firing pin that won't merely push an "unsupported" case forward. If your case was too short, the firing pin merely pushed the case forward -or it was sitting "loosely" and too far away from the firing pin in the chamber - resulting in sporadic misfire when struck. If it turns out that your fired brass measurements reach a certain point that no individual case exceeds, though several reach the same longer measurement - that is most likely the measurement you want to use in the future to set your shoulders back. After all that - and still having problem with dry cases and powder, fully blown-forward shoulders, primers seem to be sitting just below being flush with the brass, I'd re-examine your bolt assembly to ensure no grit or carbon is preventing full firing pin extension, as well as the condition of the tip of the firing pin. THEN I'd look at the possibility of bad batch of primers. Good luck!

Great reply! You taught me a lot As a retired machinist, I felt right at home reading your post!

 

[spitfire_er]

It’s all brand new brass I cleaned and checked before priming and loading. The primers didn’t even pop

Lots of great info here and no better place to obtain advice. Looks like you got the main issues figured out.

Just curious as to why you cleaned brand new brass?

Also a food dehydrator works good for drying brass.

 

[johnfred1965]

I would say the reason the primers look deep in the dud rounds is that they were forced deeper by the firing pin. since they did not go off they stayed deep. the unfired rounds look fine. just need to disassemble, dry, and start over.

 

[KMart]

Ok the depth of the new primer pocket is 0.119 and new primer measurement 0.113

If your primer measurement is at .113" and the primer pocket is at .119", after properly seating the primer, you should have a primer that is seated .006" below the base of the case.
If it is NOT, then you need to check your priming tool to make sure it has the small seater plug in it. Otherwise, the large seater plug will only seat the primer to flush with the base of the primer.

I've read through all of your posts and it seems that you are not giving feedback to a lot of questions like what is the base to datum measurement on both a new case and a fired case.
A lot of us here have had these same problems and figured them out, but without proper feedback we can't help you. It is quite hard to measure .005" on a picture.

 

[fkimble@charter.net]

If your primer measurement is at .113" and the primer pocket is at .119", after properly seating the primer, you should have a primer that is seated .006" below the base of the case.
If it is NOT, then you need to check your priming tool to make sure it has the small seater plug in it. Otherwise, the large seater plug will only seat the primer to flush with the base of the primer.

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.

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

 

[Turbulent Turtle]

Yes I tried firing them a second time just a few hours ago and still nothing

Did you resize your virgin brass before loading?

 

[GAnderson]

Lots of great info here and no better place to obtain advice. Looks like you got the main issues figured out.

Just curious as to why you cleaned brand new brass?

Also a food dehydrator works good for drying brass.

spitfire_er brings up a good question...why did you have to wet clean new brass? Typically(doesn't have to be) new brass is run thru the sizer die, loaded and shot. You would do the normal chamfering of the case mouth, maybe uniform the primer pockets, maybe deburr the flash hole depending on the level of your OCD. But there should be no reason to "wash" new brass.

 

[searcher]

Yes I tried firing them a second time just a few hours ago and still nothing

That makes absolute sense if your necks were pushed back too far. If the brass was "too loose" in the chamber the first time due to excessive headspace, trying to make it pop a second time does nothing to fix the problem. Try this. Pull the bullet and powder from one of the rounds that did not fire. place 2 small pieces (3/16" square) of double-layered masking tape on opposite sides of the SHOULDER. Chamber this non-charged round and fire. If the "dud's pop when you do this - it is further evidence your shoulders were set back too far. If they don't pop, add more tape until the bolt resists closing. If still no pop, it will point to fouled/defective primers. Because we already know they were dampened, that doesn't rule out that they were defective - but suggests dampness probably caused the problem if these are getting a super-solid and supported-case firing pin strike. Good luck!

 

[Dusty Stevens]

Did you set your die up according to the instructions where it touches the shellholder?