Nosler .280AI....Bolt won't close...

[JRH]

Hey Guys,

Due to an unexpected confluence of events, I recently had the fortune to purchase a Mauser 98 produced by a respected custom gunmaker a few decades ago. The barrel is marked .280 Improved, and the seller identified the gun as a .280 Ackley improved. (The seller has been involved with the owners of this gun for over 20years.)

In any case, I purchased a box of Nosler .280 AI brass only to find that the shells won't completely chamber. (The Bolt stops just before camming completely shut).

Unfortunately, since I just received the gun this week I do not have any standard Remmington .280 brass, dies etc to compare.

So, my question is...any thoughts on why the Nosler Brass will not chamber, and what else to consider in the meantime?

JRH

 

[LoneStar]

Because the AI cartridges are wildcats, there are no SAAMI specifications for the chambers or for the cases. This means that differences of several thousanths of an inch can and do occur. My guess is that the chamber was cut to minimum dimensions, while the brass is on the long side in the head-to-shoulder dimension. Remember that Ackley designed the series so that the AI chambers were cut on the short side so that factory ammo would chamber with a slight crush fit. I'm sure that you can push the shoulder back a bit on those AI cases and they'll work fine.

.

 

[GRT338]

Lets start by saying "IMHO" thats in my humble opinion, you could have a very "tight" chamber, or the 280 Improved could possibly be the RCBS version, with just a little different shoulder angle..hopefully, you have the 280Ackley version which is a fantastic cartridge/cal. I would suggest you take the rifle to a gunsmith and have him do a "chamber cast" and find out just "What cal. your rifle is chambered for". If you dont have a qualified smith close to you...then try finding someone with a Full Length resizing die for the 280AI and try sizing the cases one at a time to see if you can get them to chamber. Thats where I would start. I fell sure you will have another "opinion" or two shortly. Whatever you decide to do, go slow and be careful.

GRT338

 

[JRH]

Lets start by saying "IMHO" thats in my humble opinion, you could have a very "tight" chamber, or the 280 Improved could possibly be the RCBS version, with just a little different shoulder angle..hopefully, you have the 280Ackley version which is a fantastic cartridge/cal.

GRT338

Thx Guys,

As I mentioned I have no reason to suspect that this rifle is not an Ackeley other than the fact that the Nosler .280 AI brass did not fully chamber. (I confirmed with the owner, and have in writing, that the gun is chambered in .280 AI.)

I suspected that a tight chamber was likely the cause, however I always like to get others peoples opinions (which I greatly appreciate). Sounds like I need to get some FL resizing dies...

Once again, thanks for the info...any additional thoughts would be appreciated...

JRH

Thanks Guys,

 

[rick smith]

I would pull bullets from a couple of the Nosler ammo. Try that brass in the rifle. Could just be bullet contact but you now have some cases you can work with without the chance of firing one. Also buy or load some 280 ammo to form in your rifle. Cases fireformed to your chamber will give you some dimentions to start with. I wouldn't just start FL sizing the Nosler brass without any idea where you are headed. The Stoney Point Head Space gauges would be very handy. I load for two different 280AIs and both are a little different, have to keep ammo for each seperate if I happen to have both here at the same time. You will enjoy yours, just remember it is not a 7Mag so don't try to make your loads too hot.Rick.

 

[JRH]

I would pull bullets from a couple of the Nosler ammo. Try that brass in the rifle.

Rick,

Just to clarify. I have unprimed Nosler .280 AI Brass that I was checking the chambering with.

JRH

 

[Rob1SG]

The shoulder angle maybe different of your rifle. 40 VS 23 degrees since it is a wildcat who knows have a gunsmith plug the chamber to see exactly what the chamber is. 280 Rem brass could be used to fireform also.

 

[JD338]

JRH,

Since the 280AI is not a S.A.A.M.I. standard, there are wide variances in case / chamber specs. The 280 AI has a 40* shoulder and the 280 RCBS has a 30* shoulder.

I would suggest you fire a 280 Rem factory load to fire form the case and determin what your chamber specs actually are.

If you have a 280AI, I would try bumping back the shoulder of the Nosler brass.

You are going to really like the 280 Improved. I have a 280 AI and the performance is great.

JD338

 

[JRH]

I finally got a chance to shoot the rifle last weekend while on a Pheasant hunting trip in Western Ohio.

I fired the standard .280 Remington brass which chambered with a nice slight "crush".

After comparing the fireformed brass to the Nosler .280 AI brass it appears that what I have is a .280 RCBS improved....

JC

......................... .280 REM.....................Fireformed Brass.................. .280 AI Nosler brass.....................