What would you do?

[codym]

From past experience with a 30-06 AI, it sounds to me like the guy who spoke of a headspace issue from using SAAMI-spec dies and/or factory brass in a longer wildcat chamber has the answer. The guy who suggested expanding the necks to .30 caliber, and then necking back down ( leaving a headspacing shoulder at the base of the neck ) has a fix that will work. I did that with an 8mm expander button to accomplish this with my 30-06 AI years ago, and it did the trick nicely. Since .30 cal. is the next step up from 7mm, that is the correct expander to use in this case. Hopefully the 40 degree shoulders on factory 280 AI brass won't buckle under the expander button. If they do, you may have to use regular 280 Rem. brass and fire-form, since the gradual shoulder on that brass probably won't buckle under the .30 caliber expander button. You could just use 30-06 brass, but the necks will be a bit short.

If you want to permanently fix the problem, have a gunsmith set the barrel back a turn ( to get the extractor cut oriented properly ) and re-cut the chamber with a SAAMI-spec reamer. Otherwise, you're going to have to do the necking-up/necking-down drill every time you load a new batch of brass.

When I had this issue with the 30-06 AI, factory brass only fired about half the time, and the 'smith told me I was sizing them incorrectly. Well, since I was using factory loads for fire-forming, that was incorrect. He wasn't interested in dealing with the problem, so I found a new gunsmith. The second guy new right away what the problem was, and promptly fixed it for me. He told me that his happens all the time with the Ackley Improved cartridges.

The gun works fine now, and factory ammo goes in with a "crush fit" when the shoulder of the cartridge contacts the shoulder of the chamber. Closing the bolt requires some hand pressure, and I can feel the resistance. When you can't feel resistance, the gun will likely not fire that cartridge. When reloading, I am very careful not to bump the shoulder back too far, and the sizing die is not screwed all the way down to contact the shell holder. If I do that, I will be starting over with what has proven to be a very tedious process.

This is what is so confusing to me. Shouldn't every ackley chamber fire the parent cartridge at SAAMI OAL? This is my first foray into AI cartridges and more than likely my last, but I hear many of the guys post that their AI's don't always fire factory parent cartridge rounds and the need for them to be jammed. I understand jamming when you are trying to fireform but the big selling point for an AI cartridge was the ability to shoot the parent cartridge with good accuracy.

On a side note I ordered the shell holder from Redding that you are recommended to use with their 280 AI dies for a wildcat chamber and my head space gauges with be here Friday so I can get some measurements.

 

[25WSM]

On an ackley improved you are supposed to make the chamber .003 thou shorter than the parent case. This will jam the parent case snug enough to fire and not stretch the case. If you are having a factory barrel turned into an ai most gunsmith will leave the factory chamber alone and ream to the ai. They do this so they don't have to set the barrel back. This is lazy gunsmithing. You should always set the barrel back and make the ackley chamber .003 short. You use the go guage as the no go guage and your good. I have fixed many done the lazy way. If you are only going to reload for the rifle and will not fire factory ammo it is ok to do the lazy way. But you will need to create a false shoulder and jam bullets to get perfect brass. Then you just set them back 1 to 2 thou when you size the brass for the reloads. That is the ins and outs of the ackley. If you have an 06 based ackley that is not a 280 you can use 280 brass and size them to your chamber because they are already long and will give you a solid shoulder. I've been building them for over 30 yrs and have had zero issues with ai chambers. By the way the nosler is a true 280 ackley. It's a regular 280 pushed back .003 and they work in any true 280 ackley. I use them in my 280ai 1k rifle. The numbers on the print look confusing til you realize they measure them from a different spot on the print. The nosler 280ai is the PO ackley. I can fire a factory round in my 280ai and measure it to a nosler brass and they are the same. So is the hornady 280ai brass. Shep

 

[nicholasjohn]

This is what is so confusing to me. Shouldn't every ackley chamber fire the parent cartridge at SAAMI OAL? This is my first foray into AI cartridges and more than likely my last, but I hear many of the guys post that their AI's don't always fire factory parent cartridge rounds and the need for them to be jammed. I understand jamming when you are trying to fireform but the big selling point for an AI cartridge was the ability to shoot the parent cartridge with good accuracy.

On a side note I ordered the shell holder from Redding that you are recommended to use with their 280 AI dies for a wildcat chamber and my head space gauges with be here Friday so I can get some measurements.

Yes, Sir - having the capability to use factory ammo in the standard cartridge is one of the big selling points of the Ackley Improved design. That was attractive to me, as well. Using factory 30-06 cartridges in an AI chamber gives you a slight reduction in velocity, but your rifle is still usable even if you don't have your own handloads with you. ( I typically got .308 Winchester velocities with factory 30-06 cartridges, and that was just fine. As is so often said, the deer didn't know the difference.)

I did not have the capability to use factory ammo until I had the second gunsmith did the job correctly. Once these cases were fire-formed & re-loaded, I got full 30-06 AI velocities - which were somewhere around 100 to 150 fps faster than the standard 30-06 ( depending on bullet weight.)

There are about as many different ideas floating around out there on how to execute a chambering job on the Ackley Improved cartridges as there are gunsmiths doing it. They can have their reamers cut any way they want to, but if you want to maintain the capability to safely shoot factory loads, the AI chamber must be cut a little bit shorter than SAAMI specs for the standard cartridge at the neck/shoulder juncture. Otherwise, you will have problems.

 

[nicholasjohn]

On an ackley improved you are supposed to make the chamber .003 thou shorter than the parent case. This will jam the parent case snug enough to fire and not stretch the case. If you are having a factory barrel turned into an ai most gunsmith will leave the factory chamber alone and ream to the ai. They do this so they don't have to set the barrel back. This is lazy gunsmithing. You should always set the barrel back and make the ackley chamber .003 short. You use the go guage as the no go guage and your good. I have fixed many done the lazy way. If you are only going to reload for the rifle and will not fire factory ammo it is ok to do the lazy way. But you will need to create a false shoulder and jam bullets to get perfect brass. Then you just set them back 1 to 2 thou when you size the brass for the reloads. That is the ins and outs of the ackley. If you have an 06 based ackley that is not a 280 you can use 280 brass and size them to your chamber because they are already long and will give you a solid shoulder. I've been building them for over 30 yrs and have had zero issues with ai chambers. By the way the nosler is a true 280 ackley. It's a regular 280 pushed back .003 and they work in any true 280 ackley. I use them in my 280ai 1k rifle. The numbers on the print look confusing til you realize they measure them from a different spot on the print. The nosler 280ai is the PO ackley. I can fire a factory round in my 280ai and measure it to a nosler brass and they are the same. So is the hornady 280ai brass. Shep

Shep,

This is EXACTLY the story I got from the guy who fixed my 30-06 AI for me. You added some detail with the numbers involved in doing it right. Thank you for that, Sir. He didn't refer to it as "the lazy way" to do it, just that it was not done correctly. Being a proper gentleman, he didn't want to bad-mouth the other guy. ( I had probably done enough of that already.)

I can only think of one down-side to setting the barrel back a turn and doing it the right way - that is, the barrel channel in the stock will then be too large for the barrel and it will look funny. Well, that pales in comparison to having a rifle with a headspace problem ( and is potentially unsafe ) and one could either get himself some bedding compound from Brownell's and fix it, or spring for a new barrel and find someone who will do it correctly.

The whole project, which was a long series of frustrations, was also the single most valuable learning experience I've had to date. This rifle, and everybody who helped me with its issues, taught me a ton of lessons. I also learned what questions to ask gunsmiths, which has helped me avoid a lot of troubles with other gun projects. I could go on endlessly about the multitude of reloading tricks I learned while working with this cartridge, most of which apply equally to loading standard cartridges as well. All in all, it wasn't such a bad deal. I'm still glad that it's over, though.


Nick

 

[25WSM]

The proper way is to do it the way po ackley stated. Any other way is just an improved. You can do it with only half a turn of the barrel and it will put your old chamber designation under the wood and you restamp the barrel with the proper cartridge. This moves the barrel back so little you won't even notice the stock fit. Besides it makes for less work when you free float your barrel. Glad you got it figured out. Good luck with it. Don't give up on it just might be a keeper in there still. Shep

 

[25WSM]

By the way the PO ackley books are a great read. If you think you have a new cartridge design think again. It has probaly been done long ago. Those guys took brass and changed them everyway imaginable. Up down bigger smaller skinny fat you name it. Shep

 

[nicholasjohn]

By the way the PO ackley books are a great read. If you think you have a new cartridge design think again. It has probaly been done long ago. Those guys took brass and changed them everyway imaginable. Up down bigger smaller skinny fat you name it. Shep

I have read a couple of Ackley's books. There is a two-volume set that covers a lot of ground. I think that since he has written a procedure for setting up the headspace for his improved cartridges, that doing it the way Ackley did it would be the smartest way to go. These guys who want to re-invent the wheel are causing a lot of problems for people like myself and CODYM. Although I'm glad that I worked out the issues with my 30-06 AI, ( it has been a great performer for a couple of decades now ) I wish that I had gone with the 280 AI like CODYM did. I hope he follows through and sorts out the issues he's having with it, because he'll be glad he did.

Another avenue for dealing with the shoulder location of your reloads, CODYM, is backing off the depth to which the case goes into the die by putting a shim between the die and the press. Somebody out there makes very thin washers to shim the die out of the press in very fine increments, which is the simple way to do it. This may be less expensive than buying different shell holders.

There's also a gadget that I've seen advertised in Rifle and/or Handloader magazine in the past. When turned, the die goes into or out of the press a click at a time. I'm guessing that each click is probably a thousandth of an inch, but I don't really know. Somebody out there probably knows about the nifty device I'm talking about. ( I just went through the most recent issue of Handloader, and couldn't find the advertisement.) A call to Wolfe Publishing would probably turn up the name of the company that makes it. Fixing the rifle though, is still the better idea, in my opinion. Best of luck to CODYM.

 

[codym]

Quick update. Nothing came in this weekend, no gauges or shell holder.
I went ahead and backed the neck sizing die of the shell holder approximately.014 and tried a different primer and brass.
I tested a couple loads with 162 eldms, fireformed nosler 280 ai brass, 210 gmm primers and 4831 sc. no misfires or hang fires. I then tried some 280 rem fire formed brass, neck sized with 4831 sc, 210 gmm, 168 vlds. Again everything fired as supposed to. I then shot 23 Barnes 280 rem factory loads and everything fired. I'm not sure if backing the die off made a difference or if it was the primers. I still think it was a head space problem, but until I have gauges I can't get an accurate measurement. One thing I did find interesting is my Hornady loads have all been with the nosler 280 ai brass and I keep getting spikes in velocity. I will have a few rounds that will be single digit SD and single digit ES then I will get one that's 30-50 FPS one direction or the other. The FF280 rem brass with the VLD load had very consistent numbers with no big spike. In 4 sets of loads 4 rounds a piece, I only had one load with an es of double digits and it was 12. Same powder and primers different brass and different bullets. Kind of thinking of chucking the Nosler Brass and just using FF 280 rem brass. Just some thoughts.

 

[Alibiiv]

Quick update. Nothing came in this weekend, no gauges or shell holder.
I went ahead and backed the neck sizing die of the shell holder approximately.014 and tried a different primer and brass.
I tested a couple loads with 162 eldms, fireformed nosler 280 ai brass, 210 gmm primers and 4831 sc. no misfires or hang fires. I then tried some 280 rem fire formed brass, neck sized with 4831 sc, 210 gmm, 168 vlds. Again everything fired as supposed to. I then shot 23 Barnes 280 rem factory loads and everything fired. I'm not sure if backing the die off made a difference or if it was the primers. I still think it was a head space problem, but until I have gauges I can't get an accurate measurement. One thing I did find interesting is my Hornady loads have all been with the nosler 280 ai brass and I keep getting spikes in velocity. I will have a few rounds that will be single digit SD and single digit ES then I will get one that's 30-50 FPS one direction or the other. The FF280 rem brass with the VLD load had very consistent numbers with no big spike. In 4 sets of loads 4 rounds a piece, I only had one load with an es of double digits and it was 12. Same powder and primers different brass and different bullets. Kind of thinking of chucking the Nosler Brass and just using FF 280 rem brass. Just some thoughts.

This all sounds positive by all means. I'm thinking that you are going in the right direction by backing the neck sizing die off. You might have to buy a new set of reloading dies (.280AI, Wildcat), however I am certain that you will sell your present set in the classifieds here if you want to. I'd "really" like to thank you for the update, it means a lot. Oftentimes you will give a poster a recommendation and you never hear from them again. It's always good to hear that what you recommended worked or helped in some way; or, if it didn't and you came to a different resolve. Thanks!!

 

[codym]

No problem, I appreciate the suggestions. I think the dies will be ok once I account for the .014 difference in depth with the Redding shell holder. I still have load development to do and I will continue to report my findings.

 

[codym]

I wanted to end this thread with my findings and some observations. After lots of measurements, there was some variation in the head space between the nosler 280 AI brass and my fire-formed 280 rem brass. It was further exacerbated by the use of the wrong shell holder for sammi 280 AI dies/brass and the wildcat 280 ackley chambered rifle. Since switching to the .014 corrected shell holder from Redding I have not had any issues with miss fires with GMM 210, GMM 215 or BR2 primers.



A couple interesting things I observed while doing load work up was the very consistent decrease in velocity the further I backed the bullet away from the lands. Obviously I knew this would happen but it was a perfect 10 FPS loss every 10 thou I moved the bullet away from the lands, all the load work up I have done before was never that consistent. I settled on 57.7 gn's h4831SC with 210 GMM primers and a 168 vld, half moa load at 2910 fps about 20 thou off the lands ( 2.745 cbto). It gave me a solid SD of 6 over 30 rounds and an ES of 18. I tried the BR 2's and got similar #'s. I pushed the VLD's up to 3k plus with ejector swipe but no heavy bolt lift, but the accuracy wasn't there. Today I decided to try out some GMM 215's with the same load listed above. I was getting an average of 2930 fps with an ES of 9 and SD of 30 for 15 rounds. I was really surprised to see the primer give me a 20 FPS velocity jump. All rounds measured with a labrador. Anyway I'm happy with where I ended up with this rifle and I appreciate all those that offered suggestions.

 

[Alibiiv]

On an ackley improved you are supposed to make the chamber .003 thou shorter than the parent case. This will jam the parent case snug enough to fire and not stretch the case. If you are having a factory barrel turned into an ai most gunsmith will leave the factory chamber alone and ream to the ai. They do this so they don't have to set the barrel back. This is lazy gunsmithing. You should always set the barrel back and make the ackley chamber .003 short. You use the go guage as the no go guage and your good. I have fixed many done the lazy way. If you are only going to reload for the rifle and will not fire factory ammo it is ok to do the lazy way. But you will need to create a false shoulder and jam bullets to get perfect brass. Then you just set them back 1 to 2 thou when you size the brass for the reloads. That is the ins and outs of the ackley. If you have an 06 based ackley that is not a 280 you can use 280 brass and size them to your chamber because they are already long and will give you a solid shoulder. I've been building them for over 30 yrs and have had zero issues with ai chambers. By the way the nosler is a true 280 ackley. It's a regular 280 pushed back .003 and they work in any true 280 ackley. I use them in my 280ai 1k rifle. The numbers on the print look confusing til you realize they measure them from a different spot on the print. The nosler 280ai is the PO ackley. I can fire a factory round in my 280ai and measure it to a nosler brass and they are the same. So is the hornady 280ai brass. Shep

I'm sorry, but I am going to disagree with you on this, "By the way the nosler is a true 280 ackley." The .280AI (SAAMI) is not the original .280 Ackley Improved Wildcat. For whatever reason and no one seems to know why, Nosler chose to make their case .014 thousandths shorter than the parent case, there is a difference between the Nosler SAAMI and the Original Wildcat .280AI.. Because Nosler chose to do this there is a lot of confusion between the two cartridges. If you disagree find blueprints for the .280 Ackley Improved SAAMI (Nosler) and the .280 Ackley Improved Original Wildcat and compare the dimensions. I think that if you go back a few pages on this thread I did put a link on one of my responses showing discussions in a thread, from another web site, that does a comparison between the two cartridges and the discrepancies that are causing the confusion.