Fire Forming

[std7mag]

Ok, in the process of "Improving" my 7mm-08.

I have new Nosler brass, that I"m planning on hand loading for fire forming.
Question....

Should I wait till I have the chamber finish reamed, and set the bullets off of the lands like I would normally do?

Or do I go ahead, and load to "factory" specs for COAL?

Thanks!!!

Std7mag\

PS: If anyone has some load data for the Improved 7mm-08 would love to know about it!!

 

[4runnerman]

Just a FYI- Full Length Sizing and just bumping the shoulder is more accurate then Fire formed brass.

 

[std7mag]

I thought I would have to fire form, due to the shoulder moved forward, and the steeper angle of the shoulder, not to mention less taper on the body...

 

[603Country]

I'd fireform the brass in the improved chamber, then resize with the AI sizing die from then on. And be sure you set the sizing die to just bump the shoulder to the amount desired. No need to cam the press over when sizing the brass. That could, in some rifles, set the shoulder too far back and lead to eventual case head separations. Ask how I know that....

 

[jepp2]

Should I wait till I have the chamber finish reamed, and set the bullets off of the lands like I would normally do?

For my 22-250 AI, I started using the directions in the Nosler manual. I seat the bullets about 0.020" INTO the lands and use a faster burning powder (I use IMR 4895). It works very well for me with no stretching in the web. Just never had enough nerve to try the COW method. Too much can go wrong.

 

[Snyper]

I thought I would have to fire form, due to the shoulder moved forward, and the steeper angle of the shoulder, not to mention less taper on the body...

You DO have to fire-form, but no matter how you seat the bullets, the case will form to fit the chamber

I don't really understand the waiting until the chamber is "finish reamed" since it makes no sense to me why you'd fire it before all the reaming was finished in the first place

 

[Snyper]

No need to cam the press over when sizing the brass. That could, in some rifles, set the shoulder too far back and lead to eventual case head separations

It won't set the shoulders back as long as the die isn't set too deep.

Camming over means they will all be identical instead of just guessing when to stop the stroke

 

[Mike / Tx]

If it is chambered properly you should be able to fire standard cases in it with no issues what so ever, all that is really being adjusted is the angle of the shoulder and the datum line should remain the same.

When I form cases in my .223 AI, 30-30 AI, or 25-06 AI, I simply load up a decent standard weight load and get in some target time. Thing is though, these loads are usually pretty darned accurate themselves and I HAVE hunted with them as well. No sense just wasting components if you have a good purpose to use them on.

I NEVER seat the bullets into the lands on these either. As mentioned if it is chambered properly the shoulder should be against a portion of the chamber and hold it in position. Once I have them formed and have loaded to the higher loads, I usually have to bump them after about the third load. This usually shows as a snug feeling when I close the bolt.

 

[603Country]

Snyper, when using my RCBS Rockchucker press if the die isn't screwed in far enough to meet the case holder, there will be no camover. Point I'm making is that the die needs to be set to bump the shoulder back by whatever amount you want, but not necessarily to the max that the fully screwed in die may or may not allow. For instance, my 220 Swift has a very snug chamber in its Douglas barrel. You can camover the press with the die screwed all the way in and you won't bump the shoulder back too much. In my 223, which has a more generous factory rifle chamber, if you set the die so that the press cams over, you have pushed the shoulder back too far. A couple of reloads like that and you will have case separations. I know this because I did that.

I can't even imagine how I would go about guessing where to stop the stroke.

 

[jason75979]

Snyper, when using my RCBS Rockchucker press if the die isn't screwed in far enough to meet the case holder, there will be no camover. Point I'm making is that the die needs to be set to bump the shoulder back by whatever amount you want, but not necessarily to the max that the fully screwed in die may or may not allow. For instance, my 220 Swift has a very snug chamber in its Douglas barrel. You can camover the press with the die screwed all the way in and you won't bump the shoulder back too much. In my 223, which has a more generous factory rifle chamber, if you set the die so that the press cams over, you have pushed the shoulder back too far. A couple of reloads like that and you will have case separations. I know this because I did that.

I can't even imagine how I would go about guessing where to stop the stroke.

"Cam-over" refers to the linkage of the press working to it's full potential. If the die is set correctly, the press will "cam-over" and resize the case correctly as well as set the shoulder back the intended amount consistently, IF the press reaches the "stops" that were designed to promote more uniform movement and stop points.
The die being set correctly for this action helps jus' a bit too.

 

[243winxb]

Choose the bullet your going to use . Set the OAL you want. Give the dummy round to the gun smith that's going to chamber the barrel.

 

[steve4102]

I fireform all my AI brass in my garage with no bullet.

I use the fast pistol powder, cream of wheat and tissue paper method.

Works great, saves on bullets, saves on gas and smells good too.

 

[HiBC]

603,if I read you correctly,I think there may be a slight semantics error.Its only in the words.
If you are running your press through the full stroke,you are doing that part right.
Where there may be some confusion,if you take the die out of the press,and run the handle through the full stroke on nothing but air,it has still toggled,or "cammed" over.It simply means the toggles went from 11 o'clock to 12 oclock to 1 oclock,peaked over.
I thnk Snyper's interpretation of what you said,and my initial interpretation,was that you were trying to control shoulder setback by "feel" and short stroking the press.That would be ill advised.
He is correctly stating the press should be fully stroked,and setback controlled by die adjustment.
I figured out you consider "cam over"the bump you feel when shell holder tightly contacts die body.Agreed,we do not always do it that way.

If an Ackley Improved chamber is cut properly,the original Ackley intent was firing factory loaded ammo to fireform cases.Ideally,the chamber is cut slightly tight,so the juncture of the neck and shoulder contacts chamber,in a small circle.This is enough to hold the case head against the bolt.

Its also true you can jam a bullet into the rifling to help hold the case head against the bolt if you feel a need.I have done that in my .257 AI but it isn't necessary.It was a good use for 117 gr round nose bullets!

Now,if someone "Ackleyed" your factory chamber without setting the barrel back one thread,then there likely is a problem.
Ackley did not intend the improved reamer just be run in a factory 7-08 chamber.There is no good reason to believe the juncture of the neck and shoulder will hold the case head tight to the bolt.

The bullet in the rifling trick can be a way to cope,and form virgin brass.No factory loads necessary.

Another way COULD be just running 308 brass through your Ackley Imp die,necking it down a bit and creating a trace of shoulder...but I hesitate to recommend it.Mistaken identity,you get used to shooting .308 headstamp ammo in your 7-08,could be bad.I doubt you could close the bolt on a .308 round....you make up your own mind on that one.

 

[603Country]

Yes, it is semantics. I was trying to make the point that the shoulder can be set back too far, depending on the die setup and the size of your rifle chamber. Of course, if a fellow is only going to be using the brass a couple of times, it won't matter. If going for max case life, it will matter.

 

[F. Guffey]

Of course, if a fellow is only going to be using the brass a couple of times, it won't matter.

I wonder if the members on this forum actualy form cases or just talk about it. A friend built 5 fine rifles, he used 03 actions. When fire forming he had 5 case head seperations out of the first 10 cases fired. I told him I could have checked for that problem before he left the shop, I informed him I could have fixed the problem before he left the shop and I suggested he have me drive to the range, had I been at the range I could have 'fixed' the problem long enough for him to form his case.

Then I suggested he allow me to form his cases first to eliminate fire forming.

F. Guffey

 

[HiBC]

Mr Guffy,pardon me,but it would seem if your friend with 5 fine 03 Springfield rifles had one of three potential issues.

1)Some incompetent ,careless gun butcher did an unacceptable job of chambering the rifles,or,at best he bought rifles and failed to gauge headspace
2)He used range pickup or brass fired through a Browning 1919 with the headspace set poorly,so the cases were near separation.No forming helps this.
3)He set the shoulders back,creating a excessive head clearance condition.His own incompetence created a condition.Case forming is not the answer.Competence is
Or,yes,as you have described many times,its no mystery,he could have stretched .270 brass up over a 35 Whelen die while swinging a dead chicken over his head under a full moon then necked it back down.
Fireforming Ackley Improved s does not need to be that complex and time consuming.

I simply load 100 virgin .257 Roberts brass,go to the ranch,and shoot rocks and prairie dogs till I run out of ammo.

After that,I have 2 boxes of 50.I keep One of them full.I shoot out of the other till its brass.I have another box of 50 to fall back on till I load.

I buy 500 at a time,new brass,use 100 at a time till they wear out.

I do not have time or inclination to put 15 or 20 minutes into each piece of brass. Neck up,neck down anneal,trim,a few hours shot to get 15 cases out of 20 that are useable.NO!

I start with using a "go" and "NO go " headspace gage,and I get it right or set the barrelback.People who do otherwise have no business working on guns.

What else is new?

 

[F. Guffey]

Mr Guffy,pardon me,but it would seem if your friend with 5 fine 03 Springfield rifles had one of three potential issues.

As I have stated before, there is not much more boring than listining to a story that starts with "Hatcher said". I told my frind I could have determined if case head seperation was a possibility, I said I could have fixed the problem at the range long enough for him to form his cases.

He ask "HOW?", that is different, he did not tell me everything he knew about the Springfield 03 and head space.

F. Guffey

 

[std7mag]

I'm doing the chambering myself.
Was hoping to be able to turn the action 1 turn more onto the barrel, but alas no. So barrel will go to the smithy to have 1 thread removed so I can ream to the improved chamber.

What I should probably have asked, was should I go ahead and load all of my new brass to SAAMI length, and shoot to fire form as like buying/shooting off the shelf cartridges?
OR
Would it be better for me to wait till I get the barrel turned, and reamed, then measure the gun for COL, to load to? (the chamber now allows me to load 140gr. Nosler BT's to a length of 2.900"). Hence the question.

I sometimes get antsy with things like this, and want to put the cart before the horse, but in this case I would prefer to do a better job.

 

[HiBC]

If you are chambering it after setback
,I suggest you get your hands on headspace gages specific to AI.

Heres a crazy idea.If you must put something together,and you have virgin brass,take between one and three rounds of brass,and load one to three dummy rounds with no primer and no powder.Is maxmagazine length 2.800?Try that .You can set them deeper later,based on rifling,if you choose.
Now you have something to fiddle with,and try without risking a bunch of components.I'd partial size them to tune the necks,but don't touch the shoulder.

And then,as you get your chamber done you have try rounds that won't go "bang"

Then you have some masters to set up dies with.Put one in your die box.

 

[F. Guffey]

[/QUI'm doing the chambering myself.
QUOTE]

I will assume no one has asked what rifle you are using, I can only guess it does not matter to them. I would suggest you get paper and something to write with, I suggest you compare the difference between the 7mm/08 and the 7mm/08 improved.

By design fire forming was suppoase to be easy, not complicated. The few that has compared the difference between the improved and standard case know the neck on the improved version is longer. This means nothing to most but I know when I chamber a standard case in an improved chamber the short neck on the standard head spaces on the neck shoulder chamber juncture. MEANING! When I chamber the standard case in an improved chamber I size part of the shoulder when I chamber the case, The rest of the shoulder is formed when the case is fired along with the case body.

For the few that measure case diameter and length before firing, it is no surprise the case after firing is shorter. Shorter? From the mouth of the case to the head of the case. The length of the case from the case body/shoulder juncture to the case head will be longer and the length of the case from the neck/shoulder juncture will be shorter. The case got shorter when the case body and shoulder was formed.

I have formed cases for 30 Gibbs that shortened .035", because it was my 30/06 chamber I used 280 Remington cases. I added .051" to the length of the case from the shoulder to the case head and for reasons no one canunderstand I did not finish with cases with short necks. The neck of the 30 Gibbs is supposed to be .217".

F. Guffey