Question on "Fire Formed" Brass

[J-cat]

It's because brass has memory and wants to spring back to it's former dimension.

[JMP]

And, different types of brass will have a different spring back. Even the same type of brass will have different spring back if it is of varying hardness. This is why people use a matching set and count the number of firings on each piece to keep them consistent. Some will anneal the brass to restore some of it's original properties. I do not anneal, rather I keep my brass sets in the same life cycle and that is good enough for me.

[fguffey]

depending on the skill of your machinist.

My machinist? You have a machinist?

If I want a chamber I cut the chamber, I have 64 chamber reamers, I have access to 200+ chamber reamers. Skill of a machinist? If gun smiths were skilled they would measure the length of the chamber from the shoulder to the bolt face and inform the owner the length of the chamber in thousandths. I can measure the length of a chamber three different ways without a head space gage. As we all should know the head space gage is a go, no or beyond gage, the head space gage does not measure the length of the chamber in thousandths.

I think everything is saying the same thing,

Everything? Is saying?

I think everything is saying the same thing, but you are interpreting it differently. The only thing good about getting a near SAAMI spec minimum chamber is that folks will have an easier time getting their dies set up to size for this chamber. Most people shoot for 0.001 clearance for their shoulders, and with big chambers, it is common for novice reloaders to over-size them and end up with 0.005" slop between the shoulder and the chamber. This is all that most folks want to avoid as they want to fit THEIR RIFLE'S chamber.

Who is talking about SAAMI and specifications? My presses and dies have threads, threads make my dies adjustable. My favorite cases are cases that have been shot in trashy old chambers. For the most part cases that are long from the shoulder to the case head will not chamber in one of my rifles. Not a problem, I have presses and dies with threads, all I am required to do is start sizing and 'KNOW WHEN TO QUIT' sizing. Then there are those cases that will not allow the bolt to close and no one knows 'by how much'.

My machinist? A reloader should be able to zero a gage and or micrometer, few can most talk about it. A machinist and or a reloader should be able to measure the length of a case from the shoulder to the case head without a gage, the only skill required is to understand the concept of 'ZERO'.

F. Guffey

[slamfire1]

I have an 1891 Model Argentine Mauser (7.65x53)

Your case gages are calibrated according to SAAMI specs. Your chamber may not meet SAAMI specs for the base to shoulder measurements. If that is the only dimension that is off, you don't have a safety issue. If the amount of case hanging out of the chamber is excessive, you have a safety problem. Case head protrusion is something set at the factory, reloaders and shooters should not bother their heads over it, but it is a safety critical measurement. If your gunsmith does not understand case head protrusion, find another gunsmith. If there is excessive case head protrusion the sidewalls of the case can/will rupture.

You are encountering the same problem you would have if your gunsmith did not use gages when reaming a rifle chamber. A manufacturer or gunsmith that does not follow standards is creating a nonstandard chamber and this will create problems for reloaders. A non standard chamber, such as yours, means you have to use gages to measure your cases, then set your dies according to those gages, and then you have to segregate your brass so that brass is not used in another rifle. Rifle sized for a non standard chamber could be too long, or too short, or another rifle. If your gunsmith is proud not to use gages or cut standard chambers, I would recommend finding another gunsmith.

Is it right to consider that the "fire formed" brass is then about .005"-.007" over max spec?

I have a 30-30 Marlin which the factory cut with a huge, non standard reamer. Fired cases stuck out of the case gage. It was good I had a case gage as that gave me the ability to observe a phenomena and measure a phenomena. To size the case to SAAMI dimensions would have pushed the shoulder back an excessive amount each sizing, and that would have resulted in case head separations in a couple of reloads. To prevent excessive case stretch on the first firing, I lubricated the cases and fired them with lube on the outside. This prevented the case neck from gripping the chamber, slide the case to the bolt face, and this eliminated sidewall stretch.

[ar15barrels]

the head space gage does not measure the length of the chamber in thousandths.

Incremental headspace gauges in 0.001" steps make it easily possible to measure a chamber's shoulder length within 0.001".

[pacrat]

Hinnerk

There are no SAAMI specs for a 7.65x53.
SAAMI...Sporting Arms & Ammunition Manufacturing Institute.
Only does testing and standardization, of American Sporting Arms which are commercially produced here in the USA.

Do you really give a crap what the headspace is to within .001" on a hundred yr old, $200 milsurp? That has already had thousands of rounds of corrosive ammo through it. And has a military cut chamber that was cavernous to begin with a hundred years ago.

Sure you could buy incremental HS gages, and incremental shell holders, you could even buy some Redding Comp Dies with micrometer seating adjustments, and a flex free Co-Ax press to load on. You could easily spend $1,000 on equipment, to make the best possible competition ready ammo available.

And it's still going to be for a 100 yr old, $200 milsurp.

Or you could scroll back to post #6. Take the advice suggested there. And go have some good safe fun with your rifle, knowing your brass will last, and your primers will stay put.


JM2c.....Enjoy

[LynnJr]

Or you can do it like post 13 and instead of doing a sloppy job you can do it correctly at no extra cost which is why you posted in the first place.

[ar15barrels]

Now going very slowly you start turning that die down into the press while putting that piece of brass back into the gun and checking its length.
As you start to move the brass the case will get longer not shorter.
You keep going until you feel you are getting real close then you turn the die down in 1/8 of a turn increments until the bolt just drops without a lot of drag.

With 7/8x14 threaded dies, 1/8 of a turn is a HUGE adjustment.

It is really easy to make a scale on a piece of masking tape to help you determine how far you are screwing the die down.
Simply stick a piece of masking tape on your counter, then lay a metric ruler next to it and make hash marks every 1mm.
You only need about 30-40 marks.
Now peel this back off the counter and wrap it around your die on the 7/8" diameter portion.
Now make a pencil mark on the press.
When you are adjusting your die, each of those 1mm markings that passes the fixed mark on the press will equate to 0.001" of adjustment up or down in the press frame depending on which direction you are turning the die body.

[liber]

With 7/8x14 threaded dies, 1/8 of a turn is a HUGE adjustment.

It is really easy to make a scale on a piece of masking tape to help you determine how far you are screwing the die down.
Simply stick a piece of masking tape on your counter, then lay a metric ruler next to it and make hash marks every 1mm.
You only need about 30-40 marks.
Now peel this back off the counter and wrap it around your die on the 7/8" diameter portion.
Now make a pencil mark on the press.
When you are adjusting your die, each of those 1mm markings that passes the fixed mark on the press will equate to 0.001" of adjustment up or down in the press frame depending on which direction you are turning the die body.

"Youwa a Cweva wabbit!" - Elmer Fudd

[Ferrum]

With 7/8x14 threaded dies, 1/8 of a turn is a HUGE adjustment.

It is really easy to make a scale on a piece of masking tape to help you determine how far you are screwing the die down.
Simply stick a piece of masking tape on your counter, then lay a metric ruler next to it and make hash marks every 1mm.
You only need about 30-40 marks.
Now peel this back off the counter and wrap it around your die on the 7/8" diameter portion.
Now make a pencil mark on the press.
When you are adjusting your die, each of those 1mm markings that passes the fixed mark on the press will equate to 0.001" of adjustment up or down in the press frame depending on which direction you are turning the die body.

I've seen people do this before... One of the better ones I have seen was someone using the pre-printed tape like this for their mm hash marks http://www.ebay.com/itm/Adhesive-Tab...-/111326528590

[fguffey]

Incremental headspace gauges in 0.001" steps make it easily possible to measure a chamber's shoulder length within 0.001".

I am the only one that can make gages in increments of .001", I am also the one that can make gages for short chambers. Then there was Elmer Keith, he used one gage for all chambers. He was one of the few that could move beyond the go, no and beyond gage.

F. Guffey

[JMP]

My machinist? You have a machinist?

If I want a chamber I cut the chamber, I have 64 chamber reamers, I have access to 200+ chamber reamers. Skill of a machinist? If gun smiths were skilled they would measure the length of the chamber from the shoulder to the bolt face and inform the owner the length of the chamber in thousandths. I can measure the length of a chamber three different ways without a head space gage. As we all should know the head space gage is a go, no or beyond gage, the head space gage does not measure the length of the chamber in thousandths.

Guffey, it appears that you are simply more inclined than others. I absolutely need to rely on work done by machinists. I do not cut chambers, I do not make dies, I do not make reamers, etc.

Like you say, the machinist will give you the proper dimensions. You do not rely on work of machinists? So, you have made all your reamers, dies, barrels, etc.? That, my friend, is quite impressive as almost everyone else in the world must rely on some tooling from others. If I tried to make all the tools and built everything from the ground up, I would have terrible accuracy. If you can do so, then good on you.

I'd like to do all that stuff, but I don't have the time to learn. Thus, I am happy to pay a professional to get things done correctly to allow me the accuracy I demand.

If you assume everyone cuts his own chambers, makes his reamers, makes his dies, etc., then you are in the wrong forum. You should be discussing among your fellow professionals.

[bubbala]

http://www.brownells.com/gunsmith-tools-supplies/barrel-tools/barrel-chamfering-accessories/cerrosafe-chamber-casting-alloy-prod384.aspx

why guess?

[slamfire1]

It is really easy to make a scale on a piece of masking tape to help you determine how far you are screwing the die down.
Simply stick a piece of masking tape on your counter, then lay a metric ruler next to it and make hash marks every 1mm.
You only need about 30-40 marks.
Now peel this back off the counter and wrap it around your die on the 7/8" diameter portion.
Now make a pencil mark on the press.
When you are adjusting your die, each of those 1mm markings that passes the fixed mark on the press will equate to 0.001" of adjustment up or down in the press frame depending on which direction you are turning the die body.

Great advice! I am going to try this.

[ar15barrels]

I am the only one that can make gages in increments of .001", I am also the one that can make gages for short chambers.

I am Vinz, Vinz Clortho, Keymaster of Gozer. Volguus Zildrohar, Lord of the Sebouillia. Are you the Gatekeeper?