Shot my first reloads - primer questions

[Fumbler]

I shot some 357mag reloads today while out hunting.
Cases were Federal, bullets were Win 158gf JHP, primers were Win small pistol magnum, powder was Alliant Blue Dot.
I loaded 9.5, 9.7, 9.9, 10.1, 10.3, 10.5, and 10.7gr.
Bullets were seated to the cannelure.

I fired two rounds of each load through my GP-100 6" (thats all I had time for).
There is a tiny bit (barely noticeable) of primer flow in the 9.7, 10.1, and 10.5gr casings, but not in the others.
The primers were flatest on the 9.9gr loads and almost as flat on the 10.7gr loads. The 9.9gr loads are about as flat as the primers on some 180gr Winchester Supreme partitions that I fired.

Are Winchester primers soft?
Am I getting too much pressure?
None of the rounds recoiled unusually high, the heaviest recoil was with the 10.7gr loads, they felt like the Win Partitions in recoil.

 

[jdkelly]

Just some thoughts

Fumbler,

I'm no expert but here are some thoughts:

Winchester primers are not soft, I use Federals when Winchester won't function with "soft" hitting firing pin/hammers.

This is assuming that you got your reloading data from published manuals (and crossed checked it with a second source-both powder and bullet).

If I'm just telling things you already know, I'm sorry to waste your time.

1) Primers are not a great indicator of pressure, other then as an indicator of over pressure. Use a chronograph to measure velocity and cross to data books.

2) If you had high pressure signs at 9.7gr then going to 10.3 and 10.7 was not a good idea. You can get high pressure if the "wrong" bullet is used or if it is seated to far into the case.

3) If you have pressure signs when you wouldn't expect it, stop and figure out why. Set the problem loads down and shoot some thing else if you need to. Check all your components, powder, maybe pull a couple bullets (with the correct equipment) and measure the bullet for weight and dia.. Check your powder also.

4) Don't work up loads in .4 grain steps at the "high" end of the load data. In some cases a .2 grain change can have a very large effect.

5) You need to know what OAL to seat your bullets, using the cannelure as a reference is not a great way to do it.


Respectfully,

jdkelly

 

[larryw]

Shot your first reloads and can still count to ten using your fingers? Congratulations!

Mr Kelly is right, primers aren't a good way to judge pressure. Especially since you got mild flow in the mid of the range. WSP are on the harder side. One reason for the flattened primers could be seating variations (primer not seated fully and getting hammered home when you fire). a .2gr jump from load to load is just fine.

Seating to the crimp groove is fine as long as your revo can still revolve with all chambers filled, and you're still within published loading parameters. You are seating to a measured COL, right?

Now the thing to do is hit the range when you have more time and see what load shoots best in your gun. Take your time and shoot some (rested) groups at 25 or 50 yards. Balance the best groups against what you want to accomplish with the gun; tightest group may not be the "best" load for you.

 

[Fumbler]

Thanks for the info.
the data came from a friend's reloading manual (forgot which one) and Alliant's website.

I went in .2gr increments.
I fired one round of each, then went back and fired another round of each.
Only one of the 9.9 and 10.5gr casings had noticeable primer flow, both were fired in the second go around.

I guess I've just gotta spend more time with it.
I've gotta get a chrono, multiple manuals, calipers, bullet puller so I can recheck powder...

Does anyone have a good pic of primer flow?
I don't even know if what I'm looking at is primer flow.
I tried to take a pic of the heads but I can't get my camera to focus on them

Edited to add:
Forgot to mention, overall length is 1.58"

 

[only1asterisk]

No expert here either,

Without a chronograph I wouldn't load anything over about 10 grains of Blue Dot under a 158 grain JHP without specific data for that bullet.

Short of strain gauges, velocity is the best indicator of pressure there is. Without a chronograph you don't even have that. Reading primers is voodoo, esp. in revolvers. Even then, 2 rounds isn't a big enough sample.

I wouldn't worry much. I don't think you could hurt your revolver with the loads you listed. But, to be as safe as possible, you may want to consider sticking to midrange loads until you have some experience and a chronograph.
If I were to guess I'd bet some of your chambers are oily from the last cleaning and the primers are getting smashed.


David

 

[Fumbler]

You know what? they were in fact oily.
Last time I shot the gun was a while ago and I always wipe down everything with a lightly oiled patch, including the chambers.

I still havent found a pic of primer flow.
The primers that I think show some flow have a very slight ridge around the firing pin dent. This ridge is about .002-.003" wide at the widest parts and is raised above the primer just enough to see it in good light, about .001 at the most.

 

[only1asterisk]

I don't know of any online pictures showing "pressure signs" in primers. I'm sure some members could come up with some pictures, but I don't have any. Speer #13 load manual has pictures of pierced and cratered primers. But not the opposite page were it shows a 44 Magnum casehead after being loaded to 48000psi that looks identical to one loaded to 32000psi. If you have a problem with a primer, it is more likely be a problem with something OTHER THAN pressure. I have seen people ruin rifle actions with loads that showed no problems until excess headspace developed.
Make sure you remove the oil from your chambers prior to firing. This is causing undue wear and tear itself.

Good luck,

David

 

[Fumbler]

"cratered" primers and "primer flow" are the same things right?

Again, thanks for the info.

 

[larryw]

Yes.

Cratering/flow is a raised portion of metal surrounding the firing pin punch. Not necessarily a sign of high pressure; but then again, maybe...

I have a couple guns that crater primers with mild loads due to an oversized firing pin hole in the bolt/slide. Berettas are also notorious for this as they punch the firing pin hole from the breech face instead of drill.

How's your breech face look?

 

[Smythe77]

Agree to stick with mid-loads on your 357 or even 38Spl loads.

Above all do not let any oil or even oily fingers touch primers. Now if you are shooting in SA then the hammer drop of your Ruger should ignite any make of primer. I do a lot of DA shooting since I did a lot of PPC shooting in the past & ONLY use Federal primers as they are the "thin skin" ones & with 5.5 pound trigger pull in DA the hammer drop will only ignite Federal & not CCI, Winchester, of Remington primers.

 

[stans]

I see cratered primers with factory magnum ammo in all of my revolvers. Reading primers and case head expansion is one thing in bolt action and single shot rifles and handguns, but it is almost useless in revolvers and semi-autos. I follow the data in reloading manuals and use a Shooting Chrony (cheap and works fine for me) to work up handgun loads. Now that doesn't mean that I don't look at primers and case heads in handguns, I do and I compare them to fired factory rounds. I also monitor fired case extraction pressure. If it takes more force to extract fired reloads than factory loads, then pressure is way too high.

 

[dmftoy1]

Probably a stupid question.

How do you determine excessive pressure with a Chronograph? I'm assuming that it's just when you see velocity that's way in excess of what the load data is telling you??

Is it possible to have excessive pressure with a lower velocity?

Just curious. I haven't purchased a chrono (yet) and was wondering what I could see with one other than whether I was getting the velocity I was expecting.

Regards,
Dave

 

[dfaugh]

Just a thought

and I don't know if this applies.

My buddy and I were experimenting with some cast bullet loads in 8x57 Mauser. He had made up some rounds in .5 grn increments, based on cast bullet load data from a manual. On the initial batch, accuracy was dismal, to say the least. He did not crimp the cases on this initial batch. So, the next batch he crimped them, and long before we reached max loads, we were seeing primer cratering and some primers backing out slightly. (of course we stopped shooting them, didn't progress to "hotter loads".) Our conclusion was that we had excess pressure caused by too much crimp. Something else to consider.

 

[Mal H]

dmftoy1 - "Is it possible to have excessive pressure with a lower velocity?"

Yes, it is. It's possible to have a lower than expected velocity with excessive pressure. It all depends on the powder/bullet/bore length combination. For that reason, I don't think the "get a chrono" advice is all that useful for detecting extreme pressures and it's especially not useful to gauge it.

Let's take it to the extreme and see what the muzzle velocity is when the load is really excessive. The receiver and barrel are cracked, the bullet is still lodged in the barrel about 1 foot forward and you are on the way to the hospital for some stitches in your hand from the exploding trigger assb and stock. Lessee, what did the old chronograph read? Nothing? Can't be, the pressure was so high!

The best detector of high pressure is the casing and case extraction (stans has already covered that). The diameter of the web area should remain practically constant. If you measure an increase as small as .0005" at the web, you should look at your load data and decrease it. A larger increase in web diameter means you're overloading - stop! Check all aspects of the loading process. (This is all assuming you are using a good quality brand of brass.)

 

[jdkelly]

... "why is that" saftey indicator...

How do you determine excessive pressure with a Chronograph?---dmftoy1

You can't, but higher then normal velocity can be a danger indicator and can be an early sign of over pressure at lower then Max loads.

If you're getting a much higher then expected velocity at a 20% below max load, then you might want to figure out why before you try a max load.

It's just one of those "why is that" saftey indicators.

Respectfully,

jdkelly

 

[dmftoy1]

Yup, I can see that it might indicate something if you're seeing higher than expected velocities. The problem I'm running into right now is that all the load data I can find for my Model 500 is showing velocity in a 8 3/8 or longer barrel and I'm shooting in a 4-inch. I know my 4-inch will be less than the 8 3/8 but how much? Seems like somewhat of a guessing game. I could be running excessive pressures and still have less velocity than what the load data indicates.

Have a good one,
Dave

 

[jdkelly]

I'd have to plead total ignorance...

dmftoy1,

I'd have to plead total ignorance about the S&W 500. But I would suggest that you find someone knowledgeable before you step into the unknown.


Respectfully,

jdkelly

 

[dmftoy1]

Yup, I've just been loading very light loads for myself. Makes it much more pleasant and I don't have a nasty flinch after 5-10 rounds.

Have a good one,
Dave

 

[Fumbler]

My breechface looks normal, you could see the imprints of the caseheads, but that was there before shooting the reloads.
It is perfectly flat.
Thanks for the info.

One more question. Where do you measure the webbing?
Directly in front of the groove that's in front of the rim?

 

[Mal H]

"Directly in front of the groove that's in front of the rim?"

That's correct. Measure just above the rim for rimmed cases, above the extraction groove for rimless or rebated and above the belt for belted cases.

Of course measuring after a case has been fired is useless for determining high pressure, so you should record some measurements of your unfired cases or keep some unfired cases in reserve.

I don't want you to think that you need to measure every case every time. I only measure them when a high pressure load is suspected or some other sign shows up such as hard extraction, cratered or severely flattened primers.

 

[Fumbler]

Thanks for the help

 

[redneck2]

Fwiw...

this has been covered a lot in "Handloader" magazine. The idea of measuring webbing and case head expansion was either developed by or at least made popular by Ken Waters in his "Pet Loads" book (which I have). This was made popular in the 60's-70's when chronographs were extremely expensive and rare

John Barsness did at least two different articles on typical pressure signs. This was under VERY controlled conditions in high tech laboratories with a number of different firearms

Conclusions....typical pressure signs are almost totally unreliable, especially in handguns. Flattened primers typically don't occur until the 60,000# plus range, which is WAY above most handgun levels. As noted above, the clearance around the firing pin had way more effect on primer flow than pressure

Chamber clearance and brand of brass had more to do with case expansion than pressure

The conclusion was to use bullet/powder combos from load manuals and verify with a chronograph. Too much speed = too much pressure, and this method is FAR more accurate than primers or measuring cases

Edit to add....from time to time, someone will question why the old load manuals had higher loads than the newer ones (sometimes significantly higher). Some of the factories used the primer and case head method of load development. With the advent of affordable pressure test equipment and chronographs, their reaction was...

 

[taliv]

i recently tested a bunch of loads in 45 acp where i used the same case, bullet and powder (loaded in dillon 1050) and changed only the primers. one brand of primers (clearly softer) showed much more "flattening" than the other even though they averaged only 2 fps more. both were well under max loads.

specifically i chrono'd about 50 shots from a 16" barrel carbine, and 5.5g VV N320 and a Hornady 230g RN. they averaged 985.03 fps with Win Large/Magnum Primers and 986.78 fps with Federal 155 large magnum primers. (std dev of 8.06 and 9.08 fps respectively)

the point is that flattening is relative to the brand of primer.