280 ai case bulge

[Black Bart]

Hello all, I have a 280ai with the nosler sammi spec chamber, and when fireforming I get a bulge on one side of the case .200 just above the case head. Started out with rem 280 brass which measured .463 in that area. After fireforming was .470-.471. Called ptg and their reamer is .471 and the redding body die will size brass back down to .4695 for .0015 clearance. I bought some norma 280 brass and found it was .466. better but still exhibited same bulge. What I think is happening is the thin side of brass is bulging in that area because of excess space. I called laupu and their 30-06 brass measures .466 also. I've just found some nosler 280 ai brass at midway but would like to know the size at this area before buying. If anyone has any unfired brass and could measure this area it would be greatly appreciated. I called nosler and they said they would call me back but never did. Hard to imagine engineering .005 clearance in that area. By the way, after sizing brass looks perfect and have a great shooting load 58.5 h4831sc 168 berger fed 215gmm at 2870. 5 firings on the norma brass

 

[expiper]

your chamber is toooo big at the .200 line,,,any of the 06' family of wildcats and stds should be just what this drawing shows,,,,you never have case failures or loose primer pockets,,,,you can get a reamer specd any way you want ,,,,yours is toooo big,,,,there is no cure for your ailment,,,there is no brass big enuff to fill the void without the case head swelling....you can get away with it with mild loads...but if you "push" em you need the .200 line no more than .002-.003 bigger than new brass,,,,,imho...Roger

This drawing is my version of a .280 AI that uses 30-06 brass...so it is short in the neck area and over all...the body dims are same as .280 AI,,,yours should be around this from the shoulder to the case head,,,the front end is different,,,,Dave Kiff helped me with all my design issues,,,he know what works with various brands/types of brass and resize dies,,,,if you want things to work and shoot rite,call Kiff.....

 

[Black Bart]

Thanks ex piper, gunsmiths reamer was used, this was my 1st custom and I see the error of my ways. Still hold out hope that nosler 280 ai brass is closer to reamer spec. Only other option may be to re-chamber to 284 win with that fat body. Thanks Bart

 

[CatShooter]

Thanks ex piper, gunsmiths reamer was used, this was my 1st custom and I see the error of my ways. Still hold out hope that nosler 280 ai brass is closer to reamer spec. Only other option may be to re-chamber to 284 win with that fat body. Thanks Bart

If you are going to build a good rifle, then buy your own reamer (and keep it). Ask the reamer maker to give you minimum body dimensions, and a no turn (0.003" to 0.004" clearance) neck... and you will get no bulge in the body.

 

[bheadboy]

i have had 2 280ai both done with reamer from same co that provides Redding their reamers. never had a problem,

you have a bad chamber from a bad reamer.

Bob

 

[Black Bart]

cat shooter, I will surely go that route in the future! nosler called back and their brass is .466 also and said sammi max is .470 so I have a chunky chamber!

 

[Larryh128]

It probably can be set back a thread & cleaned up. You don't want to continue to shoot /resize that brass or you will get a head separation. Not something that anyone would want. Sounds like the reamer "crankshafted" on him or something came loose.

 

[Black Bart]

I think your right larry, that's what i'll do. Thanks Bart

 

[jonbearman]

I would talk to the smith and see if he would redo it with expiper's reamer so you can use lapua brass. Expiper is the .280AI man,he doesnt bs anyone and I call him best friend.Go his route and you dont have to use lesser quality brass and in a pinch you could use std nosler in an emergency.Roger you are the best.

 

[pburr]

There are essentially 2 different 280AI standards you should research. Nosler submitted the 280AI to SAAMI for standardization so if your chamber is cut with a SAAMI reamer, you should try Nosler brass first. PTG also cuts the reamers used by Redding for their sizing dies in this caliber as well. The SAAMI measurement at the .200 data line of the chamber is .4710.

 

[TonyR]

If anyone has any unfired brass and could measure this area it would be greatly appreciated. I called nosler and they said they would call me back but never did.

I measured one Nosler 280AI case at .4663 inches.

 

[CatShooter]

It probably can be set back a thread & cleaned up. You don't want to continue to shoot /resize that brass or you will get a head separation. Not something that anyone would want. Sounds like the reamer "crankshafted" on him or something came loose.

Because of the straight body taper, your chamber has about 0.015" of taper from head to shoulder - to remove most of that (to get 0.468"), you would have to set the barrel back 1.5 to 2 inches to clean up the old chamber - that's a lot of barrel to remove, for something that is basically cosmetic... and a very badd move.

Black Bart. Even though it is unattractive (you are the only one that sees it , you CAN shoot this chamber and there will be no, none, nada, nunja problems with it.

To get it down to a 0.468" will be more problems than it's worth.

 

[pburr]

Actually, TonyR is pretty spot on. I measured my Nosler cases and they are also in the .466 range. Would be a good .004" under a SAAMI cut chamber. Too loose for my taste. Better to have a chamber cut around .468-ish. Apparently Nosler is turning out their brass well under what they themselves submitted to SAAMI. So now if someone has a true SAAMI cut chamber, the cases are going to get a good bulge like the OP is experiencing. This sucks because I sat on the phone with PTG and explained what I was wanting, sent them a dummy case and still got a reamer back that is .470 at the .200 datum line. If I use it (which I havent yet) I might run into the same issue with brass that wont last for Jack!

Guess its a lot better to be out of a reamer than a brand new Bartlein after waiting months to get.

 

[Black Bart]

Yeah, my chamber is nosler sammi spec at .471. The largest brass in that area is norma and nosler, both at .466. That's .005 gap, ok for ak-47s I guess. On a side note, what kind of velocity could I get with .284 win throated long for 168 berger in a 23in tube?

 

[pburr]

expiper, I have studied your print and was wondering what make of brass is your drawing based on and what is it's overall length? I see on your print that the chamber length is 2.520. That is vastly different than mine is at 2.560 and the Nosler brass I have is only 2.521 in length. The reamer I have is quiet longer than the cases. I guess a better question to anyone would be; what is the optimal chamber length to the length of the brass intended to be used? My brass is to be trimmed to 2.519-2.520 So what would be the best length of the camber neck before the throat starts?

 

[expiper]

Hi pbur,,what's your MOS ?

 

[pburr]

Military Occupation Specialty.....? I retired out of the Navy.

 

[expiper]

g-mornin pbur,,,,just noticed your locationa as Bagram, Afghanistan,,,thought U mite still be over there,,,my reamer works with all 30-06 brass (which is aprox .040" shorter than .280 Rem)...the body dims are correct for .280 AI so it gives same case cap. but not excessive chamber length,,,most 06 brass is ~2.484" outa the bag,,when squeezed down to 7mm they are ~2.494" ,,,,when FFmd (using shotgun powder and t/p --no bullet) they blow to 2.474" ,,,,,,,you can use 280 or 280 AI brass in my chamber if you shorten it the appropriate ammount,,,,Roger

 

[pburr]

Oh ok........actually, I am still in Afghanistan, just as a civilian contractor now. I am changing some numbers on my print to resubmit. The reamer I have from PTG is a waste of time and money for what I am looking for. I'll probably try and sell it since it's unused. It would be perfect for a hunting rig.

 

[TonyR]

Oh ok........actually, I am still in Afghanistan, just as a civilian contractor now. I am changing some numbers on my print to resubmit. The reamer I have from PTG is a waste of time and money for what I am looking for. I'll probably try and sell it since it's unused. It would be perfect for a hunting rig.

Since it is larger than what you want, it might save some $$ if PT&G reground it instead of starting from scratch.