whent shooting with my 30-06 today
firs was a Sierra 180 gr. round nose with 55 gr of Norma MP
second was Swift 180 gr A frame with 55 gr of Norma MP
the swift no sign of pressure primer flat but still round no hard extraction
the Sierra no hard extraction no sign of pressure primer still round but hat on hold the circonference a black smudge
any idea both same load both same weight both no hard extraction both primer still round
only the Sierra load showed a black smudge Hal way around the primer

Sounds more like a primer leak than a pressure problem. Deprime the smudged one and check for a hole or crack in the primer.

will do
and what is funny the Sierra round nose was 200 fps slower Thant the swift at 2600 fps and the Sierra was 2380 fps

Winchester primer ? They had some problems a while back.

I use federal primer
and this load data was taken on the Norma load web site they have date for about 5 180 gr. bullet of diffente configuration and I took the middle one

Maybe make sure you didn't have one piece of brass that was too long and increasing pressure.

all cases where trim and neck turned
primer pocket uniformed

Here are some rules for you:
1. There aren't any rules; too many variables
2. Leaking primers are a pressure result if it happened more than once..
3. Just because a load is in a book does not mean it will work in your combination of equipment. It means it worked in the tester's setup only.
4. Without guessing on each item, here are things it could be:
a. Your bore is tight.
b. Your brass is soft. (most likely cause; I have had soft WW)
c. Your primers are soft. (second most likely cause)
d. You have a hot/non standard lot of powder. (it happens)
Meaning that your book load is too hot for your system and you will have to either reduce it, or find out which of the three possibilities above fit, and change that. Only way is to try another variable; rifle, brass, or primer.
Have fun.

primers are federal and they are OK with same powder charge and swift 180 gr. bullet no pressure sight and 2600fps
with the Sierra 2400 fps same case same powder same primer 180gr RN
and brass is once fire norma brass
so after all you said the mystery still remains
why would same everything and 200 fps slower and soot half way around primer pocket only

Reloading is not mysterious; it is a complex combination of several factors and variables. If you changed one variable and the results change, then that was the cause for the differing outcome.
Case in point, yesterday; guy came in and said that his 270 that I barreled showed high pressure signs with a load that "my friend uses, with the exact same components".
I asked him what was different; he said, just the barrel.
I said there is your answer; act accordingly.

quote:

Originally posted by canuck4570:
and soot half way around primer pocket only

See 4 b. and c. above.

yes only half around the primer
the only thing I can think of is that a day earlier I dismantled the bolt and oiled the firing pin, spring with break free clp and it must of clean the dirt that was inside the bolt and with the recoil (carbon lite from sako ) it kicks like a magnum at 7 pound with scope spit out of the firing pin hole a whent on the prime because the scout was a bit liquid
but why the 200fps slower everything being the same

the bullet itself.
if it's a softer jacket/core combination you'll have a lower engraving pressure and a lower engraving pressure spike.

if you have soot around the primer I'd say you have an over size primer pocket from a previous event.
or junk brass.
or the primers are smaller than the pocket, they do come in different diameters etc.

I'd look at the primers sliding home super easy when you loaded the cases.
the higher pressure [and thus faster] loads had enough pressure to push the primers back and outward to stop the gas from leaking.

no has I said earlier Lapua brass once fired
primer did not slip in the swift loading
they whent in good pressure

Once fired Lapua brass or not, it still could be a bad piece or lot. Shit happens.

it would of done the same thing out of 20 + swift that I shot the same day
it only happen with the Sierra bullet
so not the case bad primer
shot the same thing with 45 gr. of reloader 15 and no problem
only with MRP powder

I give up.

me to
and the second mystery is
why do I get 2400 fps with one (Sierra 180 gr.
and 2600 with the swift A frame 180 gr.
same everything on both

anyway guys. thank for the help

Just my $.02, since this is obviously a low pressure load could the primer be backing out some and leaking before the case pushes back against the bolt face and re-seats it??

I reseize my case only 2 thousand could but doubt it
Has I said earlier I had dissassemble my firing pin before to oil it and I think I put to much oil so when I fired and with the recoil some oil must of spilled out of the firing pin hole
the soot was mostly liquid and blank
what I did I loaded the same load and I will go to the range and try it out this time I wiped the interior of the bolt to take the excess oil out and I will see
will give some new on that

My first reloading manual, printed about 50 years ago, had a drawing of soot around a primer and cited it as a consequence of excess pressure.

I wonder, however, if incompletely cleaned primer pockets could have any part in it. I've always scraped the crap out and washed the cases in Shellite (white gas) but recently wiped them out with a tissue while still wet.

Frankly, I was amazed how much dirt came out on the paper.

The RN bullet probably has a longer bearing surface in the barrel. More barrel time.

My 6.5X55 with 160 gr RN used to give better velocities than that!

the Sierra jacket could be more "Sticky". try comparing the copper fouling of the two bullets after cleaning the bore properly.

Check primer reseating by hand and see how firm it is. It is easy to note if primer pocket has expanded even a little bit.

quote:

Originally posted by canuck4570:
primers are federal and they are OK with same powder charge and swift 180 gr. bullet no pressure sight and 2600fps
with the Sierra 2400 fps same case same powder same primer 180gr RN
and brass is once fire norma brass
so after all you said the mystery still remains
why would same everything and 200 fps slower and soot half way around primer pocket only

quote:

Originally posted by sambarman338:
My first reloading manual, printed about 50 years ago, had a drawing of soot around a primer and cited it as a consequence of excess pressure.

I wonder, however, if incompletely cleaned primer pockets could have any part in it. I've always scraped the crap out and washed the cases in Shellite (white gas) but recently wiped them out with a tissue while still wet.

Frankly, I was amazed how much dirt came out on the paper.

There's a sequel to this story: when seating primers, I like them to be below the level of the case head, all the easier since a friend gave me an in-line primer seater, which usually puts them in perfectly, without straining.

However, yesterday I had one round fail to fire in my Win/Miroku 86 .45-70, seemingly because the primer was too deep, and beyond the proper reach of the firing pin.

So, maybe traces of crap in the bottom of the primer pocket can serve a purpose

quote:

Originally posted by dpcd:
Here are some rules for you:
1. There aren't any rules; too many variables
2. Leaking primers are a pressure result if it happened more than once..
3. Just because a load is in a book does not mean it will work in your combination of equipment. It means it worked in the tester's setup only.
4. Without guessing on each item, here are things it could be:
a. Your bore is tight.
b. Your brass is soft. (most likely cause; I have had soft WW)
c. Your primers are soft. (second most likely cause)
d. You have a hot/non standard lot of powder. (it happens)
Meaning that your book load is too hot for your system and you will have to either reduce it, or find out which of the three possibilities above fit, and change that. Only way is to try another variable; rifle, brass, or primer.
Have fun.

This is the only answer that's needed. Just read it, work through it, and do a proper work up. There are no quick fixes.

quote:

Originally posted by canuck4570:
no has I said earlier Lapua brass once fired
primer did not slip in the swift loading
they whent in good pressure

You said earlier
"and brass is once fire norma brass"

Doesn't really matter what brass it is, how many rounds with the Sierra bullet did you fire, did they all have a black smudge around the primer?

You obviously haven't reloaded a lot or at least chronographed loads much but you will rarely get the same velocity from different bullets even if the same weight, same powder and charge, same case and primer. Different bullets have different jackets, different cores inside the jackets, different bearing surfaces in the barrel and different neck tension in the case, just different, different, different.

This is the very reason you don't start with the same powder charge for different bullets or different cases for that matter

then checking it all tomorrow,,,, aaand it's different again.

Your at a point of too much pressure and its time to cut back a grain...Its easy as that the rest is pure BS...In other words, your probably safe but your sure pushing the sting,so cut back one grain, your loss in velocity won't change a thing at your end or the deer in front.

Basic load work up starts with primer inspection, flat primers are a consideration, black rings are worse, backed out primers worse and sticky bolts are bad..but primers are variable in softness/hardness/size so they are not the ultimate in pressure signs, but never hurts to try different primers and brass, after you cut back that grain and start over your work up..

The next thing to look for as a rule is an extractor mark on the brass head and then probably getting ready for a sticky bolt, back off two grains time, the extraction mark is a warning to pay attention to, as your getting close to real max..

During this exercise its important to use the chronograph as you can be in 65,000 PSI territory for all you know and knowing your velocity is a eye savor..A loud crack as opposed to a normal boom says run for your life.

That gets you by, but we fly by the seat of our pants as reloaders, and the more years of experience the better, you learn hands on and might suggest you learn the hard way..

I work up loads to the guns absolute max and then test them to how many reloads they take, if 10 Im good with the load and I will usually get even more reloads, and have to trim 3 to 4 times, that's the final test..I want to know my guns exact max load, then I cut back a grain or two and call it good..

To the newbie, start loading two grs. below book max for awhile, shoot them up then up the load a grain, shoot them, then another to book max if your comfortable, and remember you can always cut back a grain, if concerned and it probably won't make a bit of difference..and you can play with the accuracy all the time your working up loads, and in many cases that's when to stop and use the chronograph, better and accurate load that's 100 fps slow than a big ole group 200 fps faster..

Most reloading books are actually a couple of grs below max, and some like with the 7x57, 8x57 may be 4 grs. under max and in some cases I,ve seen them 8 grs. below max depending on the gun and because of unreasonable law suits the bean counters played it overly safe. but that's another thread.

If Ive bored you and in your case I would try a different primer, use new brass, trimmed properly if that worked see how many times you can load that load without loose primers.

if I cut down I will be in the 2300 fps
this is not natural in a 30-06
45 grain of R15 is not even a max load on the Sierra book
I should be running in the 2600 at top load with Sierra

quote:

Originally posted by canuck4570:
primers are federal and they are OK with same powder charge and swift 180 gr. bullet no pressure sight and 2600fps
with the Sierra 2400 fps same case same powder same primer 180gr RN
and brass is once fire norma brass
so after all you said the mystery still remains
why would same everything and 200 fps slower and soot half way around primer pocket only

dpcd pretty much covered it all.

Also 2600 is only 8% faster than 2400 f/s. As I am sure you know and will have read many times on the forum a 100 f/s difference and "who cares". A 200 f/s is just more of the same.

Something to also remember with pressure. It is peak pressure that gives uu either high or low pressure signs. However, it is more average pressure that determines velocity. The Sierra bullet could be causing different ignition characteristics which result in a lower average pressure. The reason a 30/378 is much faster than a 308 is because of the higher average pressure afforded by the much greater volume of gas.

Just read what dpcd said and remember you are only looking at small percentage difference with Sierra and also again remember preak pressure which is what "you see" is not the same as average pressure.

It is obvious to me that your rifle just does not like that load and probably that bullet.

My 280AI shoots well with several bullets, powders and loads from 139gr Hornady to 160 gr Accubonds, with a whole lot in between. But it just does not like the 140 gr Accubond except for one load using AR2209. It just does not make sense.

A rifle that will put 5 shots into the bull at 200 meters with 150 gr Corelokt will do 2.5 inch 3 shot groups with 140 gr Accubonds at 100 meters. But that one load of AR2209 gives MOA. Go figure

AT what point did you switch from 55 grs of Norma MP to 45 grs. of RL-15, at 2300 fps..I must have missed something..

Why did you outside or inside neck trim, in most case short of a custom bench rest 0 tolerance chamber I wouldn't recommend that..Its a poor practice in most cases to be used only if needed..

How many cases had the black ring, was the case itself smuged? I just one case the primer was loose. new brass or how many times fired.

2 case where fired and the case was not smudged

Why don't you try some other 180 grainer like a Hornady or whatever and see what velocity it does.

I had a cratering/pierced primer problem with my .204 Savage FCV.

It was apparently due to what I'd call a "tolerance mismatch."

The diameter of the firing pin hole was evidently at maximum allowable diameter (or close to it) and the firing pin was at minimum allowable diameter (or close to it).

I had Greg Tannel bush the bolt and turn the firing pin which resolved my problem.

My informal testing before bushing led me to believe that CCI primers were more likely to crater/pierce than Tula primers. Federal Match were less likely to deform than even the Tulas.

JFWIW.