Need help! Loose Primer Pockets...

[jockperkins]

Ok, I need some help here. I am shooting a 280AI which was cut with a new SAAMI spec reamer (not the old). The chamber is property headspaced with a go -- no go guage and I am shooting 160 accubonds with Nosler brass, CCI 250 primers and 60 grains of RL 22 (below the listed max per Nosler Reloading manual). The load shoots less that 0.25 at 100 yds which is great; however, after one firing the primer pockets are so loose that if I beat the brass on a hard surface, holding the base at a 45 degree angle to the surface, the primers come out. I see no signs of pressure here either. No flattening of the primers, no cratering, no bolt stick etc etc...

Here is the kicker: if I reduce the loads, hence losing accuracy which I don't like, it is not quite as bad but still loosens the pocket considerably. More than I like. I am hearing from some that the Nosler brass is awfully soft and is prone to such things. I don't want to fireform Remington brass and winchester brass, which I do like in other calibers, only produces nickel plated brass for the 280 Remington. I don't see many options here that I like much.

Does anyone have suggestions on this? I really like the Nosler brass for accuracy and ease of use -- until after you pull the trigger for the first time. I pray to God that Lapua steps in and begins making brass for this caliber or the parent cartridge 280 at some point. I could really use some help here. Perhaps Nosler will hear me and look at their supplier. The brass flass holes, length and weight are sorted for consistency which I love, but it seems way too soft for my liking here...

 

[JD338]

jockperkins

Welcome to the forum and the 280 AI!
I shoot the same load in my custom M700 with R-P brass and have no issues. Case life is excellent but you will have to fire form your cases from 280 Rem brass.

JD338

 

[onesonek]

Blown pockets are a sign of over pressure, it's that simple, period. Now sammi spec'd or not, I have seen reamers/chambers vary. You may have a very tight chamber compared to the manuals test chamber. Reloading manuals are a guide only!
I don't have the manual you are refering to listing R-22. Is it also listing the mag primer?
But regardless, if lowering the charge to reduce pressure, is causing you accuracy problems,,,, then it seems to me a change in powder choice is warrented. I like R-22 in that round myself with previous guns I had chambered in it. But that don't mean it will work in all. Sometimes you just have to play around. I would look at H1000, Retumbo, R-25, VV-N165/N170 or other alternative powders in that range. Sometimes it just don't take much. Going slower might cost you a tad bit velocity, but will keep your load density up and should lower your pressure.
Accuracy is key, a few FPS, isn't going to make any difference at normal hunting ranges.

 

[Guest]

You're well over pressure with this, and that's why you're loosening primer pockets. I looked at my Nosler #5 (don't have #6) and found your load to be well above the max charge for a 160gr bullet. Unless they increased the max load for the 160 in the 280AI by more than 2-3gr (as the max charge in #5 is 58.5gr of RL22) you're over max. And, I'll remind you that max charges are not safe in all rifles. So, you're sitting about 5.5gr above the start charge of 54.5gr of RL22 for a 160gr Nosler bullet (as per Nosler #5), which is the only charge guaranteed safe in all rifles. I'm betting you're reading the 150gr page (max of RL22 is 61.5gr for a 150gr bullet in Nosler #5), but I have no way to be sure. What I am sure of is you need to step back and rethink how you're loading this round.

Maybe I'm wrong, and maybe the max charge of RL22 is well over the 58.5gr listed in #5, but I'm sticking to my statements about you being overpressure in this rifle. The start load is the only safe load, until you work up, looking for pressure signs. And blowing out primer pockets is a definite pressure sign.

Despite what people want to believe, the 280AI is not a 7mmRemMag with less powder. The laws of physics don't allow a smaller vessel to produce the same pressure and velocity on less powder. You'll either run out of "gas" and come up short on velocity (which is what should happen) or you'll push past the pressure threshold and equal the velocity at higher pressures. In your case, you didn't indicate velocity, either. If you're not chronographing these loads, you should be.

 

[jockperkins]

Again, I am showing no pressure signs. If there was excess pressure, I would see it in the primer flattening or cratering. I have run hot loads in this gun and I know what it looks like when I do it. This is not a hot load. Reducing the load to minimum chamber pressures does little to correct the problem. I am not a velocity addict. I look for loads that are accurate and mild ( as mild as they need by for case life etc.). I agree that a few fps changes point of impact so little that it does not make sense when considering the effects of increased chamber pressures etc.

I am not the only one who has had this problem with Nosler brass. The internet is replete with such examples. Yes, some are using the old P.O Ackley chamber which contributes, but others like me are using new SAAMI spec chambers and still experiencing the same.

It also is not the magnum primer. I also have the same with the Winchester Large Rifle Primers. The chamber is not that tight. The neck expands ten thousands when fired and the body does as well. I have head space guages, I have miced the body -- literally looked at everything. If I compare the virgin brass -- it is much smaller than my chamber -- so much so that it can be viewed with the naked eye when compared with a fireformed case.

I am thinking that I might have to go with a Swage Tool and reform the primer pockets -- or fireform from another brand of brass which I hate to do. I have a lot of money tied up in 400 pieces of brass. You would think that Nosler would do something about this -- particularly when you see so many problems listed on the internet. I guess I will have to go the fireforming route with Remington brass (which I loathe) until someone does something about this... Any other suggestions are welcomed.

 

[JD338]

dubyam

Nosler RG #6 lost the 280 AI with the 160 gr AB/PT and RL 22 as a MAX of 60.5 grs.

The Nosler brass has less case capacity than R-P brass so you may have to reduce the MAX by 1-2 grs.
The 160 gr AB 60.0 gr load in R-P brass has given me very good case life, on the order of 12 loadings with 2 case trimmings.

JD338

 

[JD338]

jockperkins,

That load shoots great for me too. This group went .092" c/c.

JD338

 

[Guest]

Thanks for the update, JD. I'm surprised the charge weight changed that much. Upon further inspection, it appears the charges for some of the other powders changed a good bit, too - comparing to the current Nosler.com data.

I still believe this is a pressure issue, as the max charge is not safe in all rifles, by definition.

I'd also argue that .5gr (roughly 1% of the charge) is not "well below max) in any case, either. But that's another story entirely.

Oh, and just for reference, I've seen a tremendous variability in lots of RL22 (and 19, but not so much with 15?) so it could easily be a burn rate issue causing the overpressure situation. My advice is still to throttle back to the start charge, and work up carefully, dropping back a half grain or a grain when you see pressure signs. Accuracy is a different issue entirely, but even if groups are stellar at 60gr, it's not safe and will eventually cause a problem.

 

[jockperkins]

JD 338. Yeah, interesting thing is; I have reduced the load by 2-3 grains and still experience the same. Perplexing...

Any suggestions on fireforming Remington brass without mess and loss of barrel life?

 

[elkeater2]

Quote:
"The neck expands ten thousands when fired and the body does as well. I have head space guages, I have miced the body -- literally looked at everything. If I compare the virgin brass -- it is much smaller than my chamber -- so much so that it can be viewed with the naked eye when compared with a fireformed case."

Is it expanding .010" the entire length then? The go/no-go doesn't tell you chamber diameter and that's what I'm curious about, especially from the "pressure ring" right down to the web and rim.
A chamber cast would be interesting. Since the pocket is stretching that much, the brass must have some place to go and then shrink back some like it always does. Nothing I shoot expands .010" near the base, so if that's the case (no pun!) I think your chamber could be over-diameter in that area.

Soft brass, chamber diam too large near base, maybe too much pressure - I guess I didn't provide any solutions.

 

[jockperkins]

JD 338. Yes your rifle shoots lights out with this load. Mine does as well. In fact, it was your post that led me to the load in the first place. My rifle also shoots 140 grain VLD's well. At least better than I am able to shoot.

Here is a picture of decent mule deer buck I shot this year. Shot him at over 400 yds in open country. My 5 year old is standing next to him...

I am open to hearing your fireforming suggestions...

 

[onesonek]

Primer appearance isn't always the most reliable method of gauging pressure, as primer cup hardness can vary. But now it almost sounds like too large of a chamber maybe???? Sammi spec'd reamers or not,,,it depends on who is using it. I'm use to chambers that at most have .002" over with most being tighter.
And Jim has a point on case capacity variations. Again I don't have that manual so I don't know what brass was used.
What I would do,,,, Take 3-5 new brass, index the heads and measure with a mic after firing a starting level load. Then measure your max load, if you are over .0005" casehead expansion, you are hot regardless of chamber dimensions. But this is the only reliable way of gauging pressure without expensive equipment we have,,,but it also has to be done correctly.
Now honestly I haven't followed Nosler brass as of yet, if their heads are soft or not I do not know. I would also fireform with a bullet loaded into the lands if you haven't already.

 

[JD338]

Nice buck buddy!

So my load got you in trouble? Its my fault! :mrgreen:
Just kidding ya. :grin:

My fire forming load is virgin R-P 280 Rem brass, 57.0 grs RL 19 and a 140 gr bullet. This is a MAX 280 Rem load and a starting load for the 280 AI.

Also, I use Federal GM215M magnum primers in my 280 AI loads. My gunsmith told me I would get better accuracy and he was right!

JD338

 

[jockperkins]

JD 338. Do you seat the bullet into the lands when fireforming? I will give the Federal Primers a try...

 

[jockperkins]

160 load. Cross wind of 3-5 mph and slight rain. I think it will do better under conditions.

 

[onesonek]

"It also is not the magnum primer. I also have the same with the Winchester Large Rifle Primers. The chamber is not that tight. The neck expands ten thousands when fired and the body does as well. I have head space guages, I have miced the body -- literally looked at everything. If I compare the virgin brass -- it is much smaller than my chamber -- so much so that it can be viewed with the naked eye when compared with a fireformed case."

One other thing I forgot to ask,,,,
Are you full length sizing after fireforming?

 

[Antelope_Sniper]

Jock, I've had similar problems with Federal Brass in the past.
I wonder if this latest batch of Nosler brass was made for them my Federal?

 

[jockperkins]

I am full length resizing each time and bumping the shoulder back 0.001. Neck sizing only works for a short period of time before "springback" lengthens the headspace beyond chamber length making it difficult to close the bolt. I know how this works and I don't do it...

I also just went out and weighed some of my virgin 280 Remington brass (parent case) and it is heavier on average than the Nosler that I have been using -- by 8 grains. I am going to fireform some but still waiting for an answer as to whether I should do this with the bullet seated into the lands?

Not happy with Nosler brass so far -- at least on the 280AI. It is accurate but good for 1-2 loadings. I don't have this problem with other brass.

 

[Antelope_Sniper]

Sounds like a bad box of brass to me.
I'd give the proshop a call.

 

[elkeater2]

jockperkins,
If the smith used the SAAMI reamer, and you have the gauges for that spec and the no-go doesn't allow the bolt to close, you should not have to run the bullet into the lands at all. That procedure is kind of a leftover from the pure wildcatters but not always effective. The idea was to keep everything tight if a way undersize case was being blown out. The problem is that the firing pin will most likely strike the primer with enough force to seat the bullet deeper anyway and an undersized case (in headspace terms) will move forward in the chamber.

A true Ackley AI was already .004" short in the chamber to make sure there wasn't any slop and that factory ammo could be fired safely (that is the standard definition of an Ackley Improved chamber-factory ammo can be fired safely). Then when Remington got involved, someone with too much authority and not enough experience decided to make the chamber a total of .014 short. That's the one that ended up being SAAMI. Not only that but the actual radius at the shoulder junction is larger.
So, you should be able to fireform with regular bullets and new or resized .280 Rem brass. The bolt might even close a little hard at that. Those are a lot of planets to get lined up properly, but you should not need to load with the bullet into the lands for fire-forming.
EE2