Need some advice

[Ackley Man]

The minimum SAMI spec for which ever caliber you are talking about will work for a field gun. I have two and and have never had a problem. It is importantant, however, that you must keep the chamber clean by using a chamber brush. .003 would not be enough clearance because that would only be .0015 per side. With a minimum SAMI spec you won't have to turn neck to get them to chamber but it will offer the minimum clearance. If you do get a barrel chambered for the minimum make sure that the gunsmith tells you the measurement that he reamed to so you can check your loaded rounds as a precaution. I did see one instance when one particular brand and lot number of cases with thick necks ended up being tight in a minimum SAMI neck but that was a very rare exception and I believe that the brass manurfacturer let them slip by final inspection. I have used four different manufacturers for mine and have never encountered the problem. The only monetary issue that you may run into is that since gunsmiths traditionally don't stock and use minimum SAMI spec reamers you may get hit for the price of the reamer. You may luck out and find a gunsmith who used one for someone else and does have the reamer. Your best bet would be to talk with some smiths who do bench rest work.

 

[Ackley Man]

Gee wiz I just read the below article from Fred Sinclair and it seems to mirror what I have been saying throughout this thread - mabe I just have difficulty in getting my points across and need to take a refresher course in creative writting. By the way, I believe Fred was an inductee in the Bench Rest Hall of Fame. He not only has been a competitive shooter and hunter for 40 years but founded Sinclair International in Fort Wayne Indiana many years ago and has remained on staff as an adviser subsequent to his sale of the company to Brownells a couple of years ago. I am quite sure that he qualifies as an expert in shooting community.

Since everyone always gets worked up about neck turning for the factory necks, here is the opinion/methods of some pretty competent reloaders! But they also want to sell neck turners so...

Outside Case Neck Turning for Factory Rifles | The Reloading Press

The first couple of paragraphs will help YOU decide whether or not to neck turn for those factory necks.

Should just about end the debate IMO

 

[Ackley Man]

The minimum SAMI spec for which ever caliber you are talking about will work for a field gun. I have two and and have never had a problem. It is importantant, however, that you must keep the chamber clean by using a chamber brush. .003 would not be enough clearance because that would only be .0015 per side. With a minimum SAMI spec you won't have to turn neck to get them to chamber but it will offer the minimum clearance. If you do get a barrel chambered for the minimum make sure that the gunsmith tells you the measurement that he reamed to so you can check your loaded rounds as a precaution. I did see one instance when one particular brand and lot number of cases with thick necks ended up being tight in a minimum SAMI neck but that was a very rare exception and I believe that the brass manurfacturer let them slip by final inspection. I have used four different manufacturers for mine and have never encountered the problem. The only monetary issue that you may run into is that since gunsmiths traditionally don't stock and use minimum SAMI spec reamers you may get hit for the price of the reamer. You may luck out and find a gunsmith who used one for someone else and does have the reamer. Your best bet would be to talk with some smiths who do bench rest work.

Based on what I have read on this thread has brought up a question. What would be the minimum clearance on a tight neck chamber to allow it to be used in the field as a hunting rifle ? I know some previous posts have stated not to use a tight neck chamber for a hunting rifle, but would like some opinions on where to draw the line between the benefit of a tighter chamber for accuracy, versus to tight a chamber to where it would cause trouble in the field. Would .003 clearance on the brass to neck chamber be enough ? To rephrase the question, is there a happy medium between tight neck chamber for better accuracy and SAAMI spec dimensions ?

 

[nheninge]

I think Ackley maybe you have confused some of my cartridge neck and chamber necks d/t some poor writing on my part. Communication is a bitch when you can't read body language etc. I try to be clear, but sometimes it just doesn't come through! Somehow we all seem to be on the same page, with minor differences. If we both agree on the article, then we are on common ground.

I rely TOTALLY on my smith to determine sufficient neck clearance. The three basic categories are tight, no-turn, and factory. 0.003 is likely not enough. Maybe a no-turn neck is your happy median trueblue.

By finicky I mean exactly what you state. Improper turning (even by a thou) can cause accuracy problems in a tight neck along with dirt etc. Same train of thought.

What I mean by turning a neck to 0.012 increases the movement of the brass each time the case is fired in a factory neck. To quote Fred (clearly a better author) ...The downside to removing too much brass during the neck turning operation is to avoid excessive expansion of the case neck when it expands to seal the chamber. This can result in excessive work hardening of the brass, as it has to expand further than it normally would.

Work hardening results in splits, but can be remedied with annealing
Redding recommends no more than 0.007 thou to minimize this work hardening when resizing cartridge necks.

 

[TOM H]

Fred Sincalir when he owned that company he had a different version that he use to write in his calalog about factory chamber and when to turn necks. He use to say if variation was more than .003" it may result in loss of accuracy and not to turn necks if vairation is .001" or less. In the 99 catalog he talked about case wall /neck thickness and how sizing in a standard die may result an uneven collapse in that the thicker wall will react differently than the thinner side. His columes changed over the years to include cleaning up the necks 70%/80%.


This new deal from Brownells company called Sinclair on how to turn necks isn't what Fred use to write about. For many years the colume in Sinclair catalog on when and how to turn necks for a factory rifle was the standard to go by.