what are signs of throat /barrel burn out? 280AI

[longbowelk]

I recently bought a used custom 280AI with a Shilen barrel. Has a 1/9 twist. It supposedly only had a couple boxes of rounds fired. I he bolt is a little sticky on the lift. I cleaned it and it had a lot of brown come out which I'm thinking was dirt/dust. I started fire forming some brass using cream of wheat method and wasn't getting a sharp shoulder like I thought so I decided to try reloading 280 rounds to see how they would do. I took and cut small slit on one side of a case and jammed a 162 grain Hornady bullet into the chamber. I tried it several times and got 2.880 to the ogive/ COAL was at 3.46.
This looks to be too long as Sierra manual shows a,160 at 3.325, 175 at 3.41. I realize they are different. Just wondering if anyone can comment if the throat is shot out?

 

[Longrang3r]

Take it to a smith and have them look at it on a borescope.

 

[shortgrass]

The OAL given in reloading manuals is NOT to the lands.

 

[longbowelk]

I had a gunsmith look at the barrel with his borescope. He said it had been throated. The rifling looked to be good. He said I should just shoot it and see if it would group. I can't see a custom barrel intentionally being built this way. Anyone ever heard of this? I have read the barrel can be good and the throat shot out with too hot a load after a couple hundred rounds. Can anyone chime in?

 

[TOM H]

I recently bought a used custom 280AI with a Shilen barrel. Has a 1/9 twist. It supposedly only had a couple boxes of rounds fired. I he bolt is a little sticky on the lift. I cleaned it and it had a lot of brown come out which I'm thinking was dirt/dust. I started fire forming some brass using cream of wheat method and wasn't getting a sharp shoulder like I thought so I decided to try reloading 280 rounds to see how they would do. I took and cut small slit on one side of a case and jammed a 162 grain Hornady bullet into the chamber. I tried it several times and got 2.880 to the ogive/ COAL was at 3.46.
This looks to be too long as Sierra manual shows a,160 at 3.325, 175 at 3.41. I realize they are different. Just wondering if anyone can comment if the throat is shot out?

I have SAAMI spec 280AI and I had it custom throated and I'm over 2.80" to the ogive and my OAL is also over 3.400" with 160gr AB. I don't have them handy to give appr on the Berger 180gr VLD.

The other 280AI is build more to SAMMI spec length and I fireformed brass for that and your not going to get shoulder sharp like you think. Nosler brass I have shoulders are round and after first firing there sharp.

I build mine the way I want and if I did sell it i'd sure explain to future buyer and he get cases and some loaded ammo with data. You didn't get any of that

 

[longbowelk]

Tom H:
Looks like there may be hope on this as my COAL and Ogive is very close. It may be that this was built for 175 and up. I did email the seller to see if he can give me some answers since he put it together of which he must have specified the throat. I have not heard back from the seller as of yet. The smith said it was tapered.
Sounds like it would be ok if the fire formed COW method leaves them a tad rounded that it would be ok to load them up and see what it looks like as far as accuracy.

 

[shortgrass]

Most of the time, when fire forming with a bullet, accuracy is very close to that of ammo loaded in the fire formed cases.

 

[Jokostel]

With my 280 AIs(Nosler/SAMMI Spec) I simply fire whatever remnants of my 280 Rem ammo I have loaded with 140 CTs and RL22... Velocity loss is minimal from the fireforming process... and as others have stated , accuracy isn't compromised.
I even *gasp* fireform nickel 280s..... sadly, some I do cull out, as the shoulders rupture.... but that's to be expected with a harder alloy.