280 Ackley Question

I spoke with the people at Redding, the base of the chamber is over SAAMI spec by .002 (spec max is .473 fired case is .475), dies bring back to .470 so the base brass is being worked .005. Will look into custom dies.
 
I have a 280 Ackley and noticed when FL sizing brass that the bottom of the case took a lot of effort to get through the die. When the gun was chambered I sent FL sized cases and the Redding dies to the gunsmith (SAAMII Dies). I took a fired case marked 4 spots bottom of the case 1/4, 1/2 and just before the shoulder:
Fired case bottom up .475 - .467 - .460 - .455
FL sized case bottom up .470 - .463 - .457 - .452

Is this an issue?? I did the same with my factory 308 and did not see as much of a difference between the cases.
Not sure if this is the problem, but could be the problem is the lathe that was used to do the chamber. Even though barrel may be indicated in to a tenth or two, the tailstock can be way off. I purchased a new high quality lathe and its tailstock center was two and 7 tenth thousands high. This would produce a chamber that was approximately 7 thousands fat, or big at the mouth or back of the chamber, even though the throat indicated in at zero, and reamer held in front by the bushing on the reamer. The tailstock is the enemy in this case. I had my tailstock surface ground but still have concerns. Maybe a floating reamer holder?
 
I'll say it one last time. There is no need to FL size in a bolt gun with a concentric chamber.

Here's the cheap way.

Buy a Lee collet die and a Lee FL die. Cut 1/2" off the FL die and use it to bump shoulders.
 
I spoke with the people at Redding, the base of the chamber is over SAAMI spec by .002 (spec max is .473 fired case is .475), dies bring back to .470 so the base brass is being worked .005. Will look into custom dies.
Other than not liking what your micrometer is saying, are you having any adverse effects? If you are reducing the overall OD .005. That means you're only moving each part of the wall in .0025. I'm not seeing a detrimental issue worth spending time and money on.
 
I kind of look at this as a contract issue between purchaser and the gunsmith. You ordered and paid for a barrel chambered as .280AI in accordance to SAAMI specs and IF the chamber is not within SAAMI specs than the purchasing contract was not fulfilled. Return barrel and get one in accordance to SAAMI specs. I would give the gunsmith a call and discuss next steps on return. If Redding provides their opinion in writing it would go a long way in getting the barrel replaced.
 
Well the gunsmith is no longer in business so it is what it is. If anybody can recommend good custom dies i know Hornady will from fired brass but any suggestions would be great.
 
Well the gunsmith is no longer in business so it is what it is. If anybody can recommend good custom dies i know Hornady will from fired brass but any suggestions would be great.
Saw a video of a gunsmith that chambered a barrel and took a guage pin the exact size of the reamer and the pin was a tight slide fit. He did not use tailstock, he used a holder on carriage or cross slide line that was line bored by the spindle. Brass would last a good while fired in that chamber.
 
Well the gunsmith is no longer in business so it is what it is. If anybody can recommend good custom dies i know Hornady will from fired brass but any suggestions would be great.
you have several options. Here are two below.


or

 
This would be amusing were it not so sad.

OK OP you have a fat chamber.

If you have a fat bank account, let yourself be stampeded into spending $100s for custom dies.

Spending others' money is easy.

Honing out the die (as was suggested) will work just as well.
 
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