What do you think of these flattened primers?

[Norrick]

327 Fed. Mag from a Ruger SP101 4.2 inch

Image of load data (sorry, I tried formatting it as a table in the text editor with no luck).


Here is the primers for said load data:



So obviously I've got some flattened primers (look at A1 and F7!!), but to me, they all look somewhat flattened, even the lower power loads.

Other than the very first round, nothing was difficult to extract, other than a couple occasions where I had some unburned powder from the prior round stuck between the casing and cylinder wall. Nothing unusual looking about the extracted cases.

Do you guys think this is too hot for a small pistol primer? I'm using CCI 500's because I can't find small magnum pistol anywhere.

There are no typos in the load data. Something I'm realizing is this round is a bit finicky with regards to consistency. I think its because the small case volume is more easily affected by any variation.

Lastly, this thing shoots low. Like way low. I am aiming for the top 2 targets in this picture. Those are 5.5 inch circles at approx 15 yards. Rear sights are as high as they will go and I'm feeling like the screw is about to fall out.

 

[Hooda Thunkit]

7F is flat. 1A is close, hard to see.

The rest - I can see the edges of the primers, and still see curved corners.

Could just be variations in the powder drop.

I see nothing I would worry about.

The shooting low is another matter. Either get a lower front sight, or file the one you have.

 

[Havok7416]

Perhaps I am thinking about this wrong but in my mind adjusting the rear sight up would cause you to aim lower (rear sight higher than the front causing a downward inclination to the barrel).

 

[Hooda Thunkit]

Perhaps I am thinking about this wrong but in my mind adjusting the rear sight up would cause you to aim lower (rear sight higher than the front causing a downward inclination to the barrel).

One moves the rear sight in the direction one wants the bullet to go.

The front sight is moved opposite the direction one wants the bullet to go.

 

[daverich4]

Perhaps I am thinking about this wrong but in my mind adjusting the rear sight up would cause you to aim lower (rear sight higher than the front causing a downward inclination to the barrel).

That’s backwards. If you raise the rear sight, you have to tip the barrel up a little to get the front sight to align in the same spot with the rear sight.

 

[243winxb]

A1 and F7

Primers didnt fall out after firing, a good thing. When you seat new primer, take note if these 2 require the same seating force as the rest.

Shooting that low needs looked at. How was the revolver held, off hand, from a rest, 2 hands? I would shoot again @ 25 yards & have another person shoot it also.

No 2 people see iron sights exactly the same.

A lower front sight may be needed. Or a trip back to Ruger.

 

[Blue68f100]

Mag primers will show less primer flattening than the std ones. Federals or Winchester may blow out on some of those. Also the H110 is one powder that needs a Mag primer to get a complete burn.

Primer are a poor source for reading pressures, but it's about all we have. As long as you have a rounded edge you still have a little margin. I see around 5 that appear to be over pressure. Plotting out your velocities it will help you detect pressure indicators, too.

 

[Norrick]

Primers didnt fall out after firing, a good thing. When you seat new primer, take note if these 2 require the same seating force as the rest.

Shooting that low needs looked at. How was the revolver held, off hand, from a rest, 2 hands? I would shoot again @ 25 yards & have another person shoot it also.

No 2 people see iron sights exactly the same.

A lower front sight may be needed. Or a trip back to Ruger.

Sitting in a chair, two hands (supporting hand below butt of grip), supporting forearm/elbow resting on table, single action.

 

[EricBu]

Sheeeeit, flat primers. You're barely walking the edge. When you have to bang the brass out of the cylinders.....THAT's when it's time to back it down.

I keed, I keed....

You're probably right there on the edge with a couple of those, if you aren't experiencing exceptional accuracy with some of those hotter loads.....back 'em down. FYI, I always seem to find the sweet spot for my magnums with H110 on the high side of the middle range, and H110 is kind of senstitive to brass prep more so than other powders. Clean that pocket out really well, and debur/clean up the flash hole. The more consistent there and with the primer seating......the better your SD will get.

Edit: I don't see why people are telling you to adjust your sites. Just hang the target lower...and maybe a tad to the right. You'll be dead on. Sheesh, newbies.

 

[Frulk]

I’ve shot American Eagle 100 grain factory loads that look like A1.

You seem to be very detail oriented and looking at your data I see nothing that raises any concern for me.

You need to get above that 115grain threshold in the .327FM. I’ve been working up loads with 120gr PCHC. Heaps of fun! Be safe!

 

[mdi]

Primers are a poor method for high pressure signs. Revolvers normally will show "flat" primers with upper, but not excessive loads. A flat primer from pressure is really flat; flattened to completely flow into the pocket leaving no radius just a line and a smaller firing pin dent.










s You've got a chrony so use that to check your loads.

 

[Jonesy814]

Perhaps I am thinking about this wrong but in my mind adjusting the rear sight up would cause you to aim lower (rear sight higher than the front causing a downward inclination to the barrel).

No because you bring the front sight up to line it up with the rear by tipping the barrel up a bit. If you dont you will not have the top of the front sight even with the top of the rear sight

 

[denton]

Years ago, I started to research an article on reading primers. I loaded cartridges from mild to max, fired them, carefully marked the primers and popped them out.

Under a microscope, I arranged the primers from least to most flattened.

There was no discernable correlation between primer flatness and powder charge over the range of normal pressures.

I conclude that trying to estimate pressure from primer flatness is an exercise in futility.

 

[denton]

[Oops]

 

[lordpaxman]

Do you guys think this is too hot for a small pistol primer? I'm using CCI 500's because I can't find small magnum pistol anywhere.

My CCI 500’s are a steel color, your primers don’t look like CCI 500s, they are more “brass” looking. They look more like Federals. Can you confirm the primer manufacturer? And, that’s just an observation on my screen. Federals are softer primers but I agree with the others that the flattened primer in this case looks normal on a high pressure round.
I don’t load 327 mag, but did the velocities correlate with the published data? I’d only get worried with hard extraction or velocities above published numbers.
I did seen an anomaly in your data, load 2 had a smaller Vavg than load 1, but was more powder. The SDs on those first two were quite high, I’d wonder a bit about either the process or if AA7 is a good choice depending on what V you want. Of course powder forward-powder back plays a role too.
Oh, and, load 2 should have gone in C1-C5 slot, you’re playing with us OCD types .
Check and see what factory loads for your gun print at. Lighter bullets tend to print lower, heavier bullets higher. But if this is what you want to shoot, check with Dawson Precision, they have a calculator that can get you an appropriate front sight for correcting this. And yes it will be lower than the one you have, assuming you can change yours out.
For those that are confused on which way sights move the POI, the front and rear are exact opposites. Move the rear sight the direction you want the POI to go. Good luck.

 

[EMC45]

I was given factory once fired .327 brass and nearly every one of them had flattened primers.

 

[FROGO207]

Yep bullet weight and dwell time in the barrel will determine POI/POA differences. Before adjusting as mentioned get someone else to try it. Also lighter loads where you can will move POI a bit upward. Pistol was probably regulated for heavier bullets. Also the stiff extraction was a bit heavy and might have been a larger charge. As long as my brass ejects easily and the velocity is in range I'll choot'em.

 

[Soonerpesek]

Edit: I don't see why people are telling you to adjust your sites. Just hang the target lower...and maybe a tad to the right. You'll be dead on. Sheesh, newbies.

This can't be LIKED enough...!!!

 

[merlynski]

One of the things it took 'newbie me' a long time ago to understand is that I am not adjusting the point of impact, the bullet goes where the bullet goes. What I am doing is adjusting the sights so that looking through the sights has them lined up with the point of impact. Once I figured that out adjusting a scope or open sights became easy. You can adjust point of impact by changing the bullet and/or the velocity.

 

[SASS#23149]

the primers look fine to me, as to shooting low..
shot it benched or supported somehow, AND have another shooter shoot it.and try loading all cylinder fulls one round short, and don't look when closing the cylinder. Let that spot be a surprise, see if u are pulling down. I suspect you are

 

[GooseGestapo]

Are you using small RIFLE primers in the .327?

I do! I use almost exactly the same loads in my Single-7.
Instead of the 115 you’re using, I use the Lee .311” 113gr FNGC

If I use a pistol primer I get cratering.
The .327 runs this hot. SAAMI pressure is several thousand psi above a .357mag.
Not for the timid, for sure!
As such, my favorite load is the above 113gr FNGC over 10.0gr of #2400. It’s accurate and tolerates small pistol primers. Velocity is only down about 50-100fps.

Shooting low means you need to shorten the front sight.
Novak makes replacement front sights for the SP101. Seems an employee gave you a .357mag front sight... Ruger possibly can send you another, or better yet put another in for you.

Exactly the reason I haven’t gotten a SP101...
Check out the Ruger forums.

 

[jmorris]

Lastly, this thing shoots low. Like way low.

All of those loads shot low like that?

 

[AK Hunter]

There is nothing wrong with having flat primers, it's when it starts pushing the firing pin back or forming a flow of metal around the firing pin that you need to be concerned. Also check the case for bulging, cracking or splitting. If it's a bolt action you can feel for how hard the bolt is to open after firing, on a semi auto check for extractor or ejector pin marks. There are a lot of ways to check for over pressure.

 

[Average Joe]

I have seen some flattened primers like yours on factory loads. Nothing to worry about.

 

[Jonesy814]

The primers in the OP’s first post are not CCI 500’s either. I have used CCI primers exclusively for 7 years and they are all nickel plated.