I am getting loose primer pockets in my brass for my .257AI. Brass is Remington and the loads have been 53 grains of R22 under a 120 grain bullet. Primers are CCI large rifle. Brass has only been reloaded a few times.

And the Nosler book shows 47.5gr of RL22 as Max. Reliant lists 52 as max for the 25-06 which has 8% greater case capacity. The simple answer is you are running too high a pressure and expanding the case head.

Yup!! You are WAY TOO HOT on those loads!! If you want a 257 Wby, buy one.

This is funny.....are you using some of P O Ackley's data?????....

The two previous posts are dead nuts accurate....

Many folks think the "AI" symbol in the cartridge designation means "Ackley Improved".....well it don't...it actually is Latin for: Atikuprid Idemgulate and translated to English means "bad decision"

It's not a .257 weatherby and never will be! Back up about five grains.

Goes to show even data found here and not challenged is not always good. I had asked some time ago for loads and also read other threads. I found many people used 53 grains or R22 for 100 grain bullets and one guy said he was using 53 grains for 117's. I started much lower and worked up to the 53 grains. No outward signs of over pressure. I did have problems of IMR 4350 even below max according to my Sierra software. Real sticky bolt with those loads and I never got to the max load. These pieces of brass with the loose pockets might actually be from those but I still plan to back down to the max Roberts load and work from there.

As for bad decision I am about to agree. If I had it to do again I would have built a 6.5x55.
I have just always liked the .257 Roberts and have known several guys with the Improved version that shot very well.

Jacobite

You need access to and use of a chronograph.
Signs of pressure include speed, not just the oldtimer indicators of bolt lift, etc.

BNagel

I think you would like your rifle much more if you used a tough 100 grain bullet. It will make much higher velocities without expanding the case heads. It is not an elk rifle anyway and the 100 grain bullet will work well on deer plus it will shoot very flat to 400 yards.

quote:

Originally posted by Jacobite:
...I did have problems of IMR 4350 even below max according to my Sierra software. Real sticky bolt with those loads and I never got to the max load. These pieces of brass with the loose pockets might actually be from those but I still plan to back down to the max Roberts load and work from there.

Hey Don, Since you seem not to know what those Cases were subjected to, you might be absolutely correct, or perhaps that Load is simply too HOT for your rifle.

While I'm at this point, I'll take the opportunity to totally disagree with BNagel's wording concerning the use of a chronograph. (No offense intended BNagel, just disagree because you are wrong. ) There is no possible way to determine what Pressure happens to be by looking at Velocity - too many variables.

I know many regulars would be disappointed if I did not include the previous paragraph concerning the nearly worthless chronographs.
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As for detecting when too much Pressure is in your AI, the only good way possible is with either good old, time-proven, never-fail CHE or Groove Expansion measurements with a 0.0001" capable Blade Micrometer.

Watching Primer Pockets get too loose is another way, but you don't know what is happening while you are shooting, thus you can end up ruining a lot of Cases that don't need to be ruined.

quote:

As for bad decision I am about to agree. If I had it to do again I would have built a 6.5x55. I have just always liked the .257 Roberts and have known several guys with the Improved version that shot very well.

I'd encourage you not to be too quick to put a Black Cloud over the 257RobAI. You have it and I feel sure it will be a fine Cartridge for you.

I had a run with Wildcats in my youth and just got tired of the minor extra things I had to do to get them preforming better than Standard Cartridges. Doesn't mean "you" should toss the AI on the scrap heap (along with all the chronographs ).

If you want it to perform at the SAFE MAX AI level for your specific firearm with your specific components, it is easy enough to do, but you need a 0.0001" capable Blade Micrometer.

Best of luck to you and the 257RobAI.

I have tried bullets from 75 grains thru 120 grain bullets. My gun actually liked 115 grain Combined technologies Silvertips best. However I am out of those and had lots of the 120's so I plan to use them this year for deer. Just can't get 100 grainers to shoot yet. I do have a Chrony but I don't worry about speed until I get a load that shoots good. Then I use the chrony so I can find out my drop. Believe it or not I am not that worried about speed. I just wanted the AI to give me a bit more for heavier bullets. I am so used to larger bores it is hard for me to shoot something as small as a 100 grain bullet for deer.

quote:

Originally posted by Jacobite:
I have tried bullets from 75 grains thru 120 grain bullets. My gun actually liked 115 grain Combined technologies Silvertips best. However I am out of those and had lots of the 120's so I plan to use them this year for deer. Just can't get 100 grainers to shoot yet. I do have a Chrony but I don't worry about speed until I get a load that shoots good. Then I use the chrony so I can find out my drop. Believe it or not I am not that worried about speed. I just wanted the AI to give me a bit more for heavier bullets. I am so used to larger bores it is hard for me to shoot something as small as a 100 grain bullet for deer.

I have killed a lot of white tails with the 100 grn Sierra out of a 25/06. Only one bullet was not a through and through - it was head on. Deer are not very hard to kill and a 120 is not all that heavy either. I never got very good accuracy with 120 grain bullets in my rifle but the 100 grain Sierra's shot tiny groups.

You can have a load that doesn't show over pressure signs, sticky bolt, flattened primers, but when you get loose primer pockets, you are definetly over pressure. I shoot a 260ai & my loads are only 1-2" higher than a std. 260. My brass lasts 10 firings easy.

You may have a slightly over size chamber and the overpressure is showing itself by ballooning the arse end of your cases.

the 257 doesn't need to perform like a weatherby magnum to perform effectively on whitetails. You just need to know the rifle (and your) limitations.

I have a 257RAI VZ24 that has given me some loose primer pockets.
At 3900 fps 75 gr, the pockets get loose on the first firing.

It really pisses me off, as by the time I get brass formed, I have some effort into it.


The solutions are obvious:
1) Back off on the powder charge
2) Jamming the bullet into the lands makes the threshold of loose primer pockets a couple grains lower. Either don't jam or back off.

you know 20 plus years ago there was a fellow who made a tool that would fix loose pockets, no joke , i cant remember who but he is probably dead and gone anyway. i like ackley cartridges.

quote:

Originally posted by Jacobite:
...I don't worry about speed until I get a load that shoots good. Then I use the chrony so I can find out my drop.

Hey Don, That is the best way to use one - after Load Development.

quote:

I just wanted the AI to give me a bit more for heavier bullets.

Sounds reasonable.

quote:

I am so used to larger bores it is hard for me to shoot something as small as a 100 grain bullet for deer.

Same reason I have a problem with the 243Win and the lack of Blood Trails.

On the other hand, one of my buddies has a Short Action M700 in 257Rob that he uses 100gr BarnesX Bullets in...., and it Kills everything he shoots at.

He Killed a Cow Elk with it last year, his Guide had some kind of rifle problem so he used it to Kill another Cow for himself.

Heard from him two days ago and he rolled some Deer with it a couple of weeks ago.

But, I agree, when you look at those Weenie Bullets, they sure do look small.

Hang in there, you will eventually find the Load you want.

Thanks Hot Core things will work out. I am building a .308 on a K98 action now. Looks like I will have two rifles to work loads up for this spring.

here we go again.
why does everyone go AI and think they suddenly have a magnum. they aren't about improving velocity as much as about cases lasting longer. the 5% more powder and the 50 or 60 fps. you gain from an ackley improvement isn't going to mean a pinch of ant crap in the feild. that isn't to say they aren't worth doing, it's a great classic way to start into "wildcatting", and they do have thier benifits. people just seem to look in the wrong places with the wrong frame of mind. ackely's listed loads are hot because he actually sort of BS'd us all( i'll admit) in his books. if he didn't no-one would have any intrest in them during the Golden age of wildcatting with all the really hot cartridges that were being done at the time. he even states in his writings that the real reason for the improvement is for case longevity, and the few fps gain is more or les a by-product of being able to extend the life of the cases. shoot them with just standard loads.....stepped up of course, over what is in the manuals(we all know what that's about) i have 7x57improved cases that are around 20 loads old and still perfectly good, that's what it's about.
jackobite,one thing to look at is how the standard cases fit in the chamber. do they stay good and tight against the boltface on first firing, that is very important to primer pocket condition. if the firing pin is pushing them away from the boltface, they will slam back against the bolt and spread the case head enough to open the pockets right off the get-go. the ackley shoulder is moved back about .003" so the std. case is a crush fit in the chamber to keep the case head against the boltface. it is done this way to prevent what i just described from happening. i've seen allot of ackley jobs chambered with the shoulder in the same place as the std. chamber and they have pocket problems all the time. the correct way for a smith to do it is to take a thread off the barrel and then ream it for the ackely, so that the ackley shoulder cleans cleans up in the std. chamber .003 back. allot of guys just shove the ackley reamer in a standard chamber thinking the just made an ackley the easy way, but it actually makes a monster.

This barrel was never a standard Roberts barrel. it was built as an AI from scratch. I just screwed up. I took info from this site that was not challenged by anyone and trusted it. Big mistake.
Fortunately all I did was screw up about 50 pieces of brass. I bought new brass and will start working up again on my own without asking for advise from others who shoot the round.

I do wish everyone would quit assuming all I wanted was to make a standard cartridge into a magnum! Was I looking for a little gain? Yes, I was, but I did not intentionally hot rod this thing to make it something it was not. As for brass lasting long I have brass from other guns including my .300 Win Mag that has more loadings than I can count. Easily into the 15-20 times bracket. This is the first time I have ever had case issues even when I loaded for my 7TCU with compressed loads.

quote:

Originally posted by merlinron:
...50 or 60 fps. you gain from an ackley improvement isn't going to mean a pinch of ant crap

Never measured that, but it sure sounds like a small amount.

quote:

... ackely's listed loads are hot because he actually sort of BS'd us all

I have Mr. Ackley's Books and having lived through those times, I'd suggest the real reason the Velocities appeared to be a bit higher than we typically see today, were due to changes in the actual Components, Bullet Diameters and Barrel Lengths. It is very important to remember just how long ago his Reloading Books were written. And that a lot of the data was never actually shot by Mr. Ackley, a good bit of it was submitted by the Wildcatters and simply included.

Mr. Ackley was a true guru, experimenter and Wildcatter who has not been equaled by many. We all benefit from his efforts today in the various Modern Cartridges we use.

quote:

he even states in his writings that the real reason for the improvement is for case longevity, and the few fps gain is more or les a by-product of being able to extend the life of the cases.

I can see how a person would get that impression from his writings. Back then there were about 5 "common"(easy to purchase within a few hours drive) Rifle Powders - all IMR 4895, 4064, 4320, 4350, 4831. Of course there a few Alcan and Herter's, but they were not all over the place. I really don't know how many exist today with nearly every slight Burning Rate gap covered. It appears to me that the Powder Companies are now focused on providing Equivalent Burn Rates that are less Temperature Sensitive. The more the better "if" the market will support all of them.

quote:

jackobite,one thing to look at is how the standard cases fit in the chamber. do they stay good and tight against the boltface on first firing,

Excellent point. Fire Forming on the initial shot is always an excellent idea, even in Standard Chambers.

quote:

Originally posted by Don:
I do wish everyone would quit assuming all I wanted was to make a standard cartridge into a magnum!

HEY! Not me!!!

But, we have plenty of folks that do think they can do that simply because "they" are the ones doing the Reloading.
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If you Reload a long time and only "screw-up" 50-cases(occasionally), you will be doing better than most.

Along the Magnumizing line:

"More Power to you!" - Briscoe Darling

quote:

Originally posted by harry carey:
you know 20 plus years ago there was a fellow who made a tool that would fix loose pockets, no joke , i cant remember who but he is probably dead and gone anyway. i like ackley cartridges.

If you haven't yet thrown away those 50 cases with expanded primer pockets...there is a fix. It's called the Case Saver,
made by RW Hart & Sons. $31 each, either large or small pocket size. CASE SAVER

HotCore...I had a sense you'd show up condemning chronographs again. If nothing else sir, you are predictable.

quote:

...50 or 60 fps. you gain from an ackley improvement isn't going to mean a pinch of ant crap

I can relate to that. How fast would a .311 180gr RN bullet be moving at 160m when starting out a 2350fps? Well, the damage it did and the total penetration was pretty impressive! A far cry from just 'bouncing off'. I once thought a 150gr .311 bullet was too fast at 2600fps because it did too much damage!

quote:

Originally posted by onefunzr2:
...HotCore...I had a sense you'd show up condemning chronographs again. If nothing else sir, you are predictable.

Which means I really should enter a correction to:

quote:

But, we have plenty of folks that do think they can do that simply because "they" are the ones doing the Reloading.

It should read, "But, we have plenty of folks that do think they can do that simply because "they" are the ones doing the Reloading and mistakenly believe they can determine they are still at a SAFE Pressure by looking at a Velocity."

Well you know, I have a situation in which I have no idea what is going on and a chronograph would probably help me gain a better idea. It is the 22 hornet that with a certain load, produces rapid barrel heating. A slightly hotter load which involves a greater degree of powder compaction, leaves the barrel nice and cool. Terminal effects do appear different and accuracy is better. I do not have to know but I am burning with curiosity! But not enough to go and buy one! The problem with a chrony as I see it is our human nature. We could easily start to ‘worship’ the damn thing! In reality, all that counts is knowing the trajectory and range and bullet performance at those ranges. Same goes for pressure traces. Not really needed but hell it would be fun!