I was doing load development with my new 280AI and I pierced a primer. It was with 64grs of RL-22 and 140gr accubonds with my bullets seated .015"off the lands COL was 3.345" and my velocity was for a 10 shot string was between 3197 to 3267 as the high. the primer pierced on the 3rd shot which had a velocity of 3205, the rest of the rounds did not pierce any of the primers but they were a little fletter.I was using brand new Nosler brass and CCI BR 210 primers. In nosler's book the charge is a Max charge and the velocity is the same as I was getting, so I am wondering if it was a faulty primer or am I in DANGEROUS territory? My barrel is a Krieger 1-9.5 twist in Win Featherweight countour.
Thanks
Elmer

You have reached the point where you need to back down on the load.

Measuring CHE "should have" told you that you were going beyond a Safe MAX. The Primer Pockets will tell the story too, but not as quickly as the measuring.

It could be the shape of the Firing Pin Tip, or maybe a one in a million Primer, but I'd guess bfrshooter is correct.

Having the same Velocity as shown in a Manual doesn't mean a thing about Pressure and can mislead people into loading beyond a Safe MAX.

quote:

Originally posted by Hot Core:
Measuring CHE "should have" told you that you were going beyond a Safe MAX. The Primer Pockets will tell the story too, but not as quickly as the measuring.

It could be the shape of the Firing Pin Tip, or maybe a one in a million Primer, but I'd guess bfrshooter is correct.

Having the same Velocity as shown in a Manual doesn't mean a thing about Pressure and can mislead people into loading beyond a Safe MAX.

What is CHE?
Thanks
Elmer

C.H.E. = Case Head Expansion..........

Hey Elmer, Leemar nailed it. You can go to this link and find out all about CHE & PRE. CHE is the "old school" way of determining when a person reaches a Safe MAX Pressure. Readings are taken directly from the weakest link in the Firing Sequence - the Case. CHE has been in use for over 100 years.

PRE is about as old and if you have some Factory Ammo to establish a Benchmark Standard, PRE is an excellent Method to use.

There have been a good number of discussions on this Board about CHE & PRE. You can go up to the top, click on "Find", enter CHE & PRE, and you should locate a good bit of Pros and Cons about the methods.

Of course, the Cons are from people who don't know which end of the barrel the Bullet exits from when fired!

Hotcore how do you deal with a full wildcat with no facotry ammo?

Elmer

I don't know what manual you're looking at but 64 grains of any powder behind any bullet in a 280 Ackley is way over max. I don't come close to that kind of powder weight in my Ackley and I'm on the border.

What surprised me is that you shot more rounds AFTER you had the pierced primer.

JMHO

Ray

quote:

Originally posted by Cheechako:
Elmer

I don't know what manual you're looking at but 64 grains of any powder behind any bullet in a 280 Ackley is way over max. I don't come close to that kind of powder weight in my Ackley and I'm on the border.

What surprised me is that you shot more rounds AFTER you had the pierced primer.

JMHO

Ray

I was using the load Nosler has on its website it starts at 60 grs and maxes out at 64grs and it states it is compressed 106%, and I checked with other sources too, I continued shooting because i was not getting a sticky bolt and my cartridges were new so a little flattening could be due the catrigde expanding to fit the chamber,I have been reading some reloading manuals ans some like speer say it might be a firing pin issue. But yes safety first I will back down and work up slowly just to make sure.
Thank you
Elmer

I could never reach 64 with an AI Sundra called 63 with his 7Jrs which is bigger. I found max to be around 65 in my 280PDK and my capacity gain is over twice what the AI is.

When I was testing AIs I always found the case tended to hide pressure ssings until the next half a grain got you into trouble.

Sounds like you have a FAST barrel. Just something to think about Alliant calls 66 grs max with a velocity of 3074 for a 7mm mag 140. They show 77grs of Rl22 in a STW just reaching your velocity with a 145.

quote:

Sounds like you have a FAST barrel.

+1

My personal opinion is that load is way too hot but it's your rifle and your face.

quote:

Originally posted by ramrod340:
Hotcore how do you deal with a full wildcat with no facotry ammo?

CHE covers that by measuring the Case Head Expansion. A person can also use Groove Expansion like "tnekkcc" does.

And there is the always faithful Snug Primer Pocket. The problem here is you need to shoot 3-5 cases at one load level, reload them with the same load, reshoot, repeat, repeat... This takes a good many Range Trips, for people who can't shoot out their back door, to see if the Primer Pockets remain snug for 7-10(or more) loads.

Or load up a series of varying Powder weights, mark the Cases so you know which weight was in it, shoot them and see where the Primers become loose. This way you may go over Pressure early in the series, in the middle, near the top, or not even reach it. If it is early in the series then the loose Primer Pockets on the remaining cases causes them to be trash. And the ones just before the loose level are only going to take a couple more shots before they are loose.

"Primer Appearance" takes a good bit of shooting-experience to understand the vague differences of when they are beginning to be too flat. By then, the Primer Pockets are generally feeling the pressure(aka loosening), but it is one more way.

"Stiff Bolt Opening" is a method one of my califoney buddies uses. Problem here is you are way beyond a normal MAX Pressure by the time you get to this Pressure Level. Changing rifles also means the "feel" is different due to the variance in the smoothness of the Bolt Lug mating surfaces.

"Velocity" is used(abused) by a lot of people who "think" they know what they are doing. Problem here is it can be very misleading. If a person has access to 2-10 rifles chambered for the same cartridge, load each with a Full Length Resized Case containing a Starting Load, they might see 250fps difference between the slowest rifle and the fastest rifle. Of course most only have the one rifle, so they just keep dumping in Powder until they reach a Velocity shown in a Manual or one they think is OK. They won't normally Ka-Boom the rifle with this approach, but they will either not get the full potential of the rifle, short Case life, or somewhere in between. They still don't know anything about the Pressure (unless they use one of the other Methods), but they "think" they do. That is one reason why a chronograph is a total waste of money for a Beginner - it easily misleads them.

"Haphazard Strain Gauge Systems" are a real joke for the people outside a Lab. The topic has been covered on this Board a couple of times and can be located by using the "Find" feature while searching for, "HSGS= Reloaders Pyrite(aka Fool's Gold".

"Primer Pocket Depth" is another indicator. As the Pressure goes up, the depth of the Primer Pocket lessens. Measuring this is possible, but beyond the range of most Reloaders measuring tools.
-----

There may be more that I just don't remember at the moment. But when you look at the list, only CHE and Groove Expansion tell the user what is happening to the Case as the Pressure is gradually increased, while he is doing the shooting. That allows him to STOP and pull bullets on Loads which are obviously too hot before ever firing them.

So, when I messed with Wildcats in my youth, CHE was what I used. From what I can tell, it still looks like the best way to tell what is happening with a Wildcat.

That said, people should use whatever they want to use. If any compelling logic can be made for another Method, I'd enjoy hearing about it myself.

Thanks, pretty much in line with what I do. I basically meassure each head before and after firing. Recording any expansion, velocity, primer appearance and extraction issues if any. If possible I do the firing at 2-300 yds looking for a sweet spot to come to and check in smaller increments.

They say that deer are a lot harder to kill than they were a few years ago - and I guess that RL 22 must be a lot slower than it was last year. My Nosler manual puts the max load at 60.5 and my Sierra manual puts it at 59.5. The only powder that I can find coming close to your 64 grains is Magpro at 63.9.

Ray

quote:

Originally posted by Cheechako:
They say that deer are a lot harder to kill than they were a few years ago - and I guess that RL 22 must be a lot slower than it was last year. My Nosler manual puts the max load at 60.5 and my Sierra manual puts it at 59.5. The only powder that I can find coming close to your 64 grains is Magpro at 63.9.

Ray

Nosler manual number 5 has RL-22 at 63grs max, and Nosler manual number 6 has RL-22 max at 64grs, so the newer manuals have changed. Thanks
Elmer

quote:

Nosler manual number 5 has RL-22 at 63grs max,

My Manual 4 has it at 60.5. Online is the 64. I'd say they have some huge variations in burn speed.

....or a typo, which is certainly possible.

My manual between my ears says 64 gr RL22 is way too hot in his and most rifles.

I had a primer pierce today also...

it was on a load of SR 4759, with one grain below max, and with a 50 grain bullet..

the primer was a Federal Small rifle...

just poor QC it appears...

Sounds like you're over hot bud. 64 grains of RL 19 (which tends to run hot anyway) seems to be over max. I was running - hot- with 60 gr in my 280 straight. No way should you get 4 more grs in an 280 AI (safely). Got back and check your load data.