Pierced a primer on my 280 AI need info?

[elmerdeer]

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. The loads that I was using came from Noslers 6th edition RL-22 60grs to 64grs max.
Thanks
Elmer

 

[Mikem]

I would say your in 'Dangerous Territory', have you compared that load with any other books, besides Noslers? When your at Max for a load, this sort of thing can happen. And you must have had signs of high pressure.
So in my opinion you should back off on that load, isn't 3200 fps with an 140g bullet fast enough? Its not doing your new rifle, or your brass any good.
Mike.

 

[NorCalMikie]

For starters, the fact that you're using 'new' brass doesn't help. After the brass is fire formed to the chamber, it can't be pushed back into the firing pin.,pierced primer??) Plus the bullets are being jumped to the lands. Nothing to hold the case from moving when it's fired.
Fire formed cases, bullets stuffed into the lands, nothing can move. JMHO.

 

[alf]

Just a couple of comments/questions.....

Loads in manuals are not gospel. Each gun, barrel, chamber, and lot numbers of components are different.

If you pierce a primer, you are OVER SAFE PRESSURES!!!!

Using new brass and piecering primers, you will always be using new brass.

It must be a hunting type gun using Accubonds. Why are you shooting 10 shot groups? In a featherweight, no less.

If you're running 70 fps extreme spreads, I'd do some more load work.,three shot groups)

If you wanted higher velocities, you maybe should have bought a Ultra Mag.

Al

 

[AckleymanII]

Your load sounds hot for fire forming. That velocity is what we hope for in formed brass.

Another thing, did the primer pierce or did the primer pocket open up to let gasses escape out the side.

Primer piercing on max loads is common in rifles that have an oversize firing pin hole in the bolt.

I agree on the comments on the 10 round strings, 3 shot strings is all you need to prove accuracy, 10 shot strings is going to fry your barrel.

 

[flatlander]

Though Elmer didn't specify, since he stated that he's using Nosler brass, I assumed he was talking about the 280 AI cases they sell already formed.

No matter - in my experience with the Reloder series of rifle powders, I've encountered a rather wide range of burning rate variations from lot-to-lot. What this means is that you've got to work up carefully from well below the max listed charge,this is true, no matter what brand of powder you're loading), watching for pressure signs and using your chronograph to help you figure out where you're at.

As an example - I built myself a 250AI and started working with RL15 & JLK 108VLDs,in fully formed cases), using Sierra's data in their #5 manual. I got very obvious pressure signs immediately, even though I started out well below their listed max charge. Another example of lot variation, and perhaps my Krieger has a tighter bore than the barrel on the rifle Sierra used.

 

[elmerdeer]

Your load sounds hot for fire forming. That velocity is what we hope for in formed brass.

Another thing, did the primer pierce or did the primer pocket open up to let gasses escape out the side.

Primer piercing on max loads is common in rifles that have an oversize firing pin hole in the bolt.

I agree on the comments on the 10 round strings, 3 shot strings is all you need to prove accuracy, 10 shot strings is going to fry your barrel.

Guys when I do a 10 shot string I divide it into 2 five shot targets and I shoot very slowly my barrel at the hottest is only warm to the touch and I just chrono the whole 10 shots so I could get a good idea of my velocity and ES and Sd.
And the primer did pierce it did not loose gas on the side.
I also went to the range yesterday and stayed at 63.5grs of RL-22 with a average speed of 3160fps and had no problems whatsoever. And bughole groups at 100yrds with a slight adjusment of seating depth.
Thank you
Elmer

 

[280Ackleyrized]

It has bee my experience that most RL powders are temp sensitive. I tend to shy away from them. If you want a 280AI load, I would strongly reccomend VV N 165 under that 140NAB. Load does 3206fps from a 24 3/4 tube. Pressure signs are nill. Groups run in the .3s for 5 shots. The V V load is the load Jim Borden gives out for 280AI rifles he builds. It was developed by a gentleman in Memphis, TN. Lots of folks on the campfire drive that particular load and most all rifles chambered in 280AI do quite well with it. The majority stop load development after trying it cause it is 'the cat's meow'. PM me if you have any questions.

 

[elmerdeer]

Thank you Gentlemen for all the info, I have learned alot from these forums! As for my exerience with VV n-165 it shoots well at lower velocities but in my barrel with 64 grs i was getting only 3115 average, and the good groups were at 3050FPS with 62.5-63grs, I think my barrel likes RL-22 better speed and accuracy.
Thank you
Elmer

 

[Winchester69]

While pressure exacerbates the condition, pierced primer is usually symptomatic of large firing pin gap. If you're firing a stock action, you may want to investigate. Cratering usually indicates incipient piercing. Bushing the bolt will cure the problem.
.

 

[cliffy]

Pierced primers mean extreme powder overload or WRONG primer application, or wrong burn-speed powder choice. Generally MAGNUM primers leave a lot more pressure latitude than STANDARD primers. If a MAGNUM primer pierces, you're out-of-the-ballpark pressurewise into dangerous no-man-land conditions. Cliffy