280 AI resizing

[Mike Matteson]

I've read all the post , all pretty sound advice , let us know what you figure out , may help one of us in the future . I'm never too old too learnor think I know it all .

I hope you find out what the problem is. That all I can think of except, one other is head spacing maybe need to be check.

 

[TOM H]

First do you have a comparator, and it seem you would have a comparator? You can check a reloading manual length from base to shoulder. I wouldn't know if there a difference between 280AI cases or chambering, it's my understanding there is a different at one time. If you have case that will chamber, that haven't been fired. Use the comparator to see what it is. Check the cases that won't fit with a comparator to see what the difference is. The other is size a case without the expander ball on and see what the case measures compared to a case using the expander ball to the shoulder. The other is just how long is the total case length from base to top of neck. I don't know your reload process is. Annealing I don't see that is a problem. Annealing will extend the life of your brass Annealing relaxes the brass in the neck area, helps stops neck splitting, and help release concentricity. The other is case stretch, if the case have been used several times.

He is shooting pre spec 280AI so no spec on chamber.

 

[Mike Matteson]

Then possible cast the chamber to see what he really has. Brownell has Cerrosafe Chamber Casting Alloy. There is a YouTube videos on how to. Or, take the rifle in and have it rechamber to a known chamber of a 280AI of present design.

 

[rharfo]

It's a Dakota arms rifle pre ruination by Remington. Has 385 rounds fired. Using Rem and Nosler brass. I do have a comparator. In a pinch I can neck size and run it but the issue of full length brass growing needs addressed. Thanks for all the ideas guys. The best forum going…

 

[TOM H]

It's a Dakota arms rifle pre ruination by Remington. Has 385 rounds fired. Using Rem and Nosler brass. I do have a comparator. In a pinch I can neck size and run it but the issue of full length brass growing needs addressed. Thanks for all the ideas guys. The best forum going…

I have pre 280AI. I use Redding body die and neck bushing die, You could fire form new case instead of chamber cast.. You might consider having new die made using bushing without expander. Redding quit making dies for that pre spec.

I have spec 280AI and I use Redding body die and same set up at pre one. I had both rifle builds and outside die difference both pretty nice rifles.

 

[Mike Matteson]

I have pre 280AI. I use Redding body die and neck bushing die, You could fire form new case instead of chamber cast.. You might consider having new die made using bushing without expander. Redding quit making dies for that pre spec.

I have spec 280AI and I use Redding body die and same set up at pre one. I had both rifle builds and outside die difference both pretty nice rifles.

Seeing you have both chambers. Can you send us a picture of both cases fire formed? Or give us or me the difference between the two. I kind gather it's at the shoulder. 1. You can have somebody else built a FL bushing die for that chamber. If the chamber is shorter to the shoulder, and can't get the case to that dimension needed to chamber. 2. You can grind the bottom of the die off some to shorten the dimension to the shoulder to match the other chamber, if that's the problem.. The case base really doesn't really change that much in firing the cases. It's the shoulder and neck that generally grows. By shorting the dimension to the shoulder would help a great deal in case stretch at that base. There has been several post sometime back on setting dimension to the shoulder, and that was one way to create a different dimension to the shoulder. The one thing is causing a tighter dimension at the base of the case. Not really sure on that part. Somebody smarter than me can chime in on this. I can stand to learn a new lesson.

 

[TOM H]

Seeing you have both chambers. Can you send us a picture of both cases fire formed? Or give us or me the difference between the two. I kind gather it's at the shoulder. 1. You can have somebody else built a FL bushing die for that chamber. If the chamber is shorter to the shoulder, and can't get the case to that dimension needed to chamber. 2. You can grind the bottom of the die off some to shorten the dimension to the shoulder to match the other chamber, if that's the problem.. The case base really doesn't really change that much in firing the cases. It's the shoulder and neck that generally grows. By shorting the dimension to the shoulder would help a great deal in case stretch at that base. There has been several post sometime back on setting dimension to the shoulder, and that was one way to create a different dimension to the shoulder. The one thing is causing a tighter dimension at the base of the case. Not really sure on that part. Somebody smarter than me can chime in on this. I can stand to learn a new lesson.

Redding has few articles on different since they made pre spec and spec dies for both 280AI. If you have Nosler manual #6 they have spec on the pre spec 280AI.

This is what Redding body die does https://www.brownells.com/reloading/reloading-dies/rifle-dies/body-dies-prod79088.asp I could size his case in that die I have.

 

[VinceMule]

Been using the socket spinning in a drill motor for years with propane torch, it works without spending a ton of money. Comp shooters have different requirements where they anneal after every firing.

Grind some off the top of the shell holder, and adjust your die to the amount of set back you are wanting to have.

Another issue, All production dies are just that. Often, the web dia is such that you have to bump back the shoulder more than you like in order to size down the web dia. Most advanced reloaders have been down this route....dies do not match the chamber.

Just remember, when you invest in a set of Comp shell holders, anal about bumping back shoulders a certain amount, Then you find out that the Web dia is a shore nuff can of worms to deal with. Manufacturers can not keep up with current demand, so the issue of sizing the shoulder in one step and the web in another step using a ring die is simply over the top. We are stuck with a compromise in the die vs chamber issue.

You can throw money at this project:

Buy your own chamber reamer based on brass dimension you intend to use, then buy a die reamer, find a guy competent in chambering dies AND Heat Treat. Figure $600 for a set of dies and wait time.

Put on your big boy britches and Rock On! Take some off the top of the shell holder, Push the shoulder back till the web dimension fits your chamber, throw brass away as necessary...cost of doing business. I am so anal I have a whole machine shop. Spend your time and effort on issues that really matter, and this issue is on a first grade level and hopefully you will get to the 12th grade.

There is a lot of gadgets you can spend money on wisely, Teslong bore scope, run out gauge, Wind flags. Try not to waste money on issues that give you little if any results.

I use Lapua 30/06 brass in my 280 and 280 AI, PMC brass, and old Win Blue Bag....web issues between these brands of brass are substantial, and more often than not, .0005 is a country mile. I shoot 160-180g Bullets of various types.

 

[VinceMule]

When grinding the top of the shell holder, use a micrometer or caliper, mic from top to bottom. If you take off .003, this usually fixes the issue. Then, size the cases up to, and including "Cam Over", Work the die down slowly, chambering the rounds in the rifle as you go.

If you leave your ammo loaded for 5 or more years, the brass may "spring back" and not chamber. Best to chamber all reloaded rounds if you have a custom or tight chamber prior to going hunting, be sure to have the muzzle pointed in a safe direction.

The bolt face to shoulder issues are usually easily fixed, but often the web is still too large...another can of worms when the chamber dimension does not match the die dimension.

 

[Mike Matteson]

To me it would be a lot easier to rechamber the rifle to present day standards, than going through all the other ways. If I remember correctly, You have both chambers in two different rifles.

 

[VinceMule]

Some gunsmiths will not re-chamber a used barrel due to the fact that carbon can and will chip reamer flutes and the work-hardened metal in the old throat can dull reamers, I have done a bunch myself, not for others.

I have different reamers for different bullets, same caliber, and I mark the barrel accordingly, no big deal. I like to order my reamers with .020-.030 freebore, then use a unitholder to get the seating depth that I like for a particular bullet.