primer problems need wisdom!

[ar15barrels]

i need some veteran wisdom to tell me whats going on! i dont think i flattened them?? idk?














what primers look like before firing

This is caused by excess headspace.
Most likely, the shoulder was pushed back too much.
When you chamber the round, the spring loaded ejector pushes the case all the way forward in the chamber until it stops.
As the case shoulder is short, that leaves a lot of room between the boltface and the case head/primer.
Under pressure, the primers back out until they rest against the bolt.
The pressure is NOT high on these loads.
If the pressure was also high and there was excessive headspace, the corners of the primers would be more square.
Also, the higher pressure would cause the case to stretch rearward and the primers would not be sticking out like that.

STOP sizing brass with your die as it is adjusted now.
Get a more reliable way to measure shoulder length and measure some factory ammo after it is fired in your gun.
Using the length of those cases, adjust your sizing die so it is only pushing the shoulder back about 0.002".
I recommend an RCBS precision mic.
I feel it is the most dependably accurate tool sold for this job.
It is much more accurate than the tools that clamp on to a pair of calipers and use bushings to measure.

[Trainman]

Switch to CCI primers. Winchester SR primers fit a little looser then CCI 400 or 450. I've had them fall out when ejected.

[ejor]

as others have said it.s probable caused by a combo of overly sized cases making to much head space and lower pressure loads. the firing pin pushes the case forward and pressure pushes the primer back in a higher pressure load the case would flow back and push the primer back in.

[GeoffLinder]

well i was struggling to fit 26 grains of varget in those cases before the bullet and your saying you use 27.5... if you use this much powder obviously you wont be crimping these bullets to avoid pressure issues right??

I just reviewed my notes from testing Varget with 55gr loads and realized I stopped at 27gr. Not 28, and decided 26.5 was what would be the right amount to get 3200fps IF you wanted to use Varget for a hot 55gr load. 26.5 didn't show any real pressure sign but was a pain to load and couldn't be done without tamping.

My mistake, Doh, oldzheimers is setting in. BLC2 is the powder that lists max at 27.5gr and can be pushed to 28gr before trouble sets in.

I don't actually use this recipe, I just tested to that point once. Gave me 3230fps range at 27gr and flattened primers to a smear. This is a good bit over what Hodgdon says is max (25.5). Probably about a 55,0000+ psi load. OAL was 2.250" to do so.

You can get that much in (27gr, not 28, Doh again) IF you put it in slowly and tap the case to settle the powder as you do so. Tapping the case gets the grains to align and take up less space. 27gr will fill the case to the brim this way, then when you seat the bullet it compresses the charge a bit. It won't be enough to crush the powder really, but it will be compressed.

This is why I don't like Varget for lighter bullet loads in small cases like .223 PITA to use for it and you never get the full velocity potential. Cheaper ball powders like WW748 and AA2520 or AA2230 work much better here and get you into the 3200fps range easily and safer.

27.5gr WW748 is what I like for 55gr with OAL at 2.245". Any shorter and primers start to flatten. Gives me just about 3200fps out of a 20" bbl AR

[NoNOS67]

well i was struggling to fit 26 grains of varget in those cases before the bullet and your saying you use 27.5... if you use this much powder obviously you wont be crimping these bullets to avoid pressure issues right??

26 under a 55gr pill shouldn't be an issue. If you had the shoulder pushed back too far, that was likely part of your problem.

[tiller]

A compressed load is when the powder charge used takes up more volume in the case than the space left after a bullet is seated.

I usually don't like to use compressed loads and will use a less bulky powder to avoid that. But in some cases it is a necessary evil. It's not really a bad thing if pressure is safe, I just feel better not doing so unless I have to.

Personal issue I guess LOL

well i was struggling to fit 26 grains of varget in those cases before the bullet and your saying you use 27.5... if you use this much powder obviously you wont be crimping these bullets to avoid pressure issues right??

[GeoffLinder]

A compressed load is when the powder charge used takes up more volume in the case than the space left after a bullet is seated.

I usually don't like to use compressed loads and will use a less bulky powder to avoid that. But in some cases it is a necessary evil. It's not really a bad thing if pressure is safe, I just feel better not doing so unless I have to.

Personal issue I guess LOL

[tiller]

25gr Varget is my 69gr SMK load, I use 27.5 if I put Varget under a 55gr, but I consider Varget better for heavy, expensive match bullets. I use WW748 under 55gr, cheaper and doesn't overflow the case like 27.5gr Varget does at that charge level. Need to drop that much Varget slowly and tap the case while filling or it will overflow. Too bulky for light bullets IMHO

ook another good topic...

compressed loads... do you care do explain that??? since youve done a fine job at explaining everything else!!

[tiller]

Someone might have already pointed this out and I missed it reading all posts.

I think I saw a nato stamp on the head of a piece of brass.

So the primer pocket would have to be properly resized prior to reloading them. Maybe someone cut out to much brass or made the pocket to large when they swaged it.

Where did you get the brass and did someone mess with the primer pockets?

I use Dillon swage machine and you do have to be careful.

if you would have read the post you would have know that it was LC09 brass

processed on a 1050

[ronas]

Someone might have already pointed this out and I missed it reading all posts.

I think I saw a nato stamp on the head of a piece of brass.

So the primer pocket would have to be properly resized prior to reloading them. Maybe someone cut out to much brass or made the pocket to large when they swaged it.

Where did you get the brass and did someone mess with the primer pockets?

I use Dillon swage machine and you do have to be careful.

[GeoffLinder]

I never put more than 25 grains of varget behind my 55 gr fmj. Work fine . I am loading 50 grin speer tnt green now with 25.4 and they work flawlessly and destroy ground squirrels.

25gr Varget is my 69gr SMK load, I use 27.5 if I put Varget under a 55gr, but I consider Varget better for heavy, expensive match bullets. I use WW748 under 55gr, cheaper and doesn't overflow the case like 27.5gr Varget does at that charge level. Need to drop that much Varget slowly and tap the case while filling or it will overflow. Too bulky for light bullets IMHO

[edgerly779]

I never put more than 25 grains of varget behind my 55 gr fmj. Work fine . I am loading 50 grin speer tnt green now with 25.4 and they work flawlessly and destroy ground squirrels.

[tiller]

The RCBS trimmer is fine, just make sure to debur the trim cut and bevel the inside of the case mouth to be more gentle on the bullet jacket when seating them.

If you can find a couple hundred fired Lake City cases from same year, they are as good as anything. Just fire them in your chamber once to uniform them, then process them and you will have some very good brass that will last many, many loadings if you only neck size. Lake City is top grade stuff and I prefer it to Lapua myself. It is more uniform in weight from the start compared to the Lapua brass I have worked with, which means it's internal volume is more consistent.

The SB size die will be fine for now as long as you back it out so it does not do much if any shoulder setback.

Sweet your the man!!

[GeoffLinder]

i already have a rcbs trim pro 2... it works decent and i will use it for my bolt loads....

im waiting to try and find new brass hopefully some lapua or i have like 80 rounds of xm193 that i will actually use for my "learning loads" its the only factory amo i have left....

plus i still need a neck sizer die... i was unpreppared to start loading for this gun... as you can tell

also whats neck shaving?? ive looked into flash hole uniforming and flash hole deburring.... also do i need to primer pocket uniform? is that such a thing

The RCBS trimmer is fine, just make sure to debur the trim cut and bevel the inside of the case mouth to be more gentle on the bullet jacket when seating them.

If you can find a couple hundred fired Lake City cases from same year, they are as good as anything. Just fire them in your chamber once to uniform them, then process them and you will have some very good brass that will last many, many loadings if you only neck size. Lake City is top grade stuff and I prefer it to Lapua myself. It is more uniform in weight from the start compared to the Lapua brass I have worked with, which means it's internal volume is more consistent.

The SB size die will be fine for now as long as you back it out so it does not do much if any shoulder setback.

[GeoffLinder]

Probably referring to what most call "neck turning". Used for "shaving" the neck of the case to improve uniformity for more consistent neck tension and also to fit into "tight-necked" custom chambers. If you take a tubing micrometer and measure several spots around the diameter of a case neck, you'll see they vary in thickness from one side to another. Run the case over an expander mandrel first and then "turn" the outside of the neck with a cutter, making it more uniform. Sinclair, K&M, Don Nielsen -aka- Pumpkin and others all make Neck turners.

Primer pocket uniforming...

Do you need to? Not necessarily, but almost everyone interested in accuracy does. You'll also see it referred to as "squaring up" the primer pocket for more consistent primer seating feel and depth.

-Rick

Neck shaving/turning is very important for the final levels of accuracy loading as it makes the entire loaded round concentric with the centerline of the bore/chamber and it uniforms bullet release tension around the bullet so it's doesn't get perturbed as it is popped out of the case mouth and stuffed into the rifling.

Flash hole uniforming or reaming has nothing to do with the primer pocket, this is done inside the case to uniform the hole into the case from the primer pocket. It serves several purposes. 1st, it presents a uniform primer blast to the powder charge by making the opening uniform and it also creates an inside bevel that acts as a guide cone for the primer flash. 2nd, it removes excess metal inside the web of the case around the inside of the flash hole which contributes to internal case volume uniformity which helps reduce SD.