To Fireform or not to Fireform

C

Cherrywood

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I have a new 308 Winchester that has been custom built by Dave Bruno from a Remington 700 action....Hart Barrel, Jewel trigger and a custom made benchrest stock. Dave did everything possible short of a custom made action by Kelby or Borden to make this as accurate rifle as possible. My question is: With new Lapua Palma brass, I am undecided as to load out of the box LAPUA brass and fireform 1st or to full length resize then fireform. What advice can you give? Thanks.
 
Possible answer

Suggest you load and fire form 1 case 3 times.
Then start measuring this case vs the sized case dimensions to determine how much you are sizing die is sizing.
Investment 1 case, 3 primers, 3 bullets, some powder.

Do you have the measuring tools?

Centerfire
 
Cherrywood said:
I have a new 308 Winchester that has been custom built by Dave Bruno from a Remington 700 action....Hart Barrel, Jewel trigger and a custom made benchrest stock. Dave did everything possible short of a custom made action by Kelby or Borden to make this as accurate rifle as possible. My question is: With new Lapua Palma brass, I am undecided as to load out of the box LAPUA brass and fireform 1st or to full length resize then fireform. What advice can you give? Thanks.
Click to expand...

Is this a Turn or No-turn neck chamber? It would be nice to know upfront.

For now, I'll assume it's the easier of the two to work with ... a No-turn neck.

Pull the firing pin from the bolt and see if you can chamber the case. If you can't, resize by pushing the shoulder back .001" to .002". .001" is preferable, but no more than .002". Then see if will chamber. If it will chamber, look at the length of the brass compared the the chamber's length. How long is the brass out of the box compared to the chamber's length? Will it overlap the end of the neck's chamber and present a safety hazard with a bullet seated?

I recommend you look at a few dimensions before you load and then attempt to fireform. You may need to trim the cases first, with a .010" safety zone, even though they normally shrink a little upon fireforming.

Take measurements of the cases length out of the box, after you pushed the shoulders back, after you've trimmed them, if you need to, and after you've fireformed them. That way you'll get a good idea of what's taking place during each step of the process. :)
 
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Custom 308

I have a nice custom 308 (no turn neck) similar to the one that you are describing (trued Remington action) that was built by Tactical Precision Rifles before that company went belly up. I FL size new Lapua brass, trim, skim .002" off the necks, seat to magazine length with 168 or 175 SMK's or Berger VLD's.

The new brass will shoot 3 shots under .25 MOA. I have not gotten any better than that out of the fire formed cases. More than likely I just can't shoot any better than that with the 14X Mk-4 that is on it.

What are your plans for the rifle? Hunt, practice, plink, tactical, varmint? My vote would be to load it up and go for it. Save the components and barrel life.
 
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Headspace

Thank you for all your input. At present I am trying to figure out why I cannot bump the shoulder back enough with my Redding Body Die to close the bolt like I want it to when I chamber a virgin piece of Lapua brass into the rifle chamber.
I feel resistance on the bolt (firing pin removed) when closing. (the bolt does close completely by itself very easily with an empty chamber) I have tried bumping the shoulder back with a Redding Body Die to see if that helps but NOT. I use Redding Competition Shell Holders and have gone through all of them but without any noticeable difference in resistance or measurement when chambering it again. Bolt still closes with same amt. of resistance. What's happening here? Open to your input. Hope I have made it clear what I am trying to accomplish. Thanks
 
Cherrywood said:
Thank you for all your input. At present I am trying to figure out why I cannot bump the shoulder back enough with my Redding Body Die to close the bolt like I want it to when I chamber a virgin piece of Lapua brass into the rifle chamber.
I feel resistance on the bolt (firing pin removed) when closing. (the bolt does close completely by itself very easily with an empty chamber) I have tried bumping the shoulder back with a Redding Body Die to see if that helps but NOT. I use Redding Competition Shell Holders and have gone through all of them but without any noticeable difference in resistance or measurement when chambering it again. Bolt still closes with same amt. of resistance. What's happening here? Open to your input. Hope I have made it clear what I am trying to accomplish. Thanks
Click to expand...

With the above method, if done right, that is pushing the shoulder back .001" [the goal], the bolt should fall about half way, then additional pressure, by you, is required to complete the seating. The bolt should not fall by itself, with a case in the chamber.

A Full Length Sizing Die is the preferred tool since it sizes the entire case and not just a portion of it. Used each and every time you size, the Full Length Die prevents a whole host of problems then when a neck sizing die and a body die are used alternatively. Full Length Sizing with the proper die also prevents over working the brass because it usually sizes between .0005" and .001" or .0015" at the top end.

Is this a Tight-Neck Chamber? A Light-Turn Neck Chamber? A No-Turn Neck Chamber? Or, a SAAMI Specs Neck Chamber? If your Chamber is one of the first two, you're going to have to do some neck turning first and/or some neck trimming too. And may have to trim for the third if the chamber is shorter than your virgin brass length.

What are your reamer drawing specs telling you about your chamber's dimensions? How do they compare to the dimensions of the Virgin brass you are attempting to seat in that chamber? :)
 
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Bruno Action

If Bruno built this as a custom action, my money is on that you are going to have to turn the necks. Did Bruno say what the neck size is ?
 
I have a custom .308 Palma built on a Stiller Predator action, it shoots 5 shot groups sub .150 and has gone as low as .127.

I do not fireform new brass, just fullsize, trim to 1.975" turn the necks so they are even, uniform primer pocket and flash hole then just load and shoot..

I use 44.4gr N150 behind 165gr Sierra Gameking, seems to like the gameking better than match bullets...

after shooting 3 times I measure all cases and they are almost Identical.. .0003 max variation in lenght, no variation in neck thickness.
 
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abintx said:
With the above method, if done right, that is pushing the shoulder back .001" [the goal], the bolt should fall about half way, then additional pressure, by you, is required to complete the seating. The bolt should not fall by itself, with a case in the chamber.

A Full Length Sizing Die is the preferred tool since it sizes the entire case and not just a portion of it. Used each and every time you size, the Full Length Die prevents a whole host of problems then when a neck sizing die and a body die are used alternatively. Full Length Sizing with the proper die also prevents over working the brass because it usually sizes between .0005" and .001" or .0015" at the top end.

Is this a Tight-Neck Chamber? A Light-Turn Neck Chamber? A No-Turn Neck Chamber? Or, a SAAMI Specs Neck Chamber? If your Chamber is one of the first two, you're going to have to do some neck turning first and/or some neck trimming too. And may have to trim for the third if the chamber is shorter than your virgin brass length.

What are your reamer drawing specs telling you about your chamber's dimensions? How do they compare to the dimensions of the Virgin brass you are attempting to seat in that chamber? :)
Click to expand...

1. BOLT......with virgin Lapua Palma Brass out of the box, bolt closes to about where you said it should with a smooth light pressure to completely close.

2. Presently, I have a Redding Type S Bushing Neck Die, their Body Die and their Competition Bullet Seating Die. I have ordered their Full Bushing Die as you and others have suggested.

3. Dave Bruno states the chamber is on the tight side and his chamber dimension is 0.342" Not sure where that fits into a LIGHT TURN NECK or NO TURN NECK... BUT IS DEFINATELY NOT A SAMMI SPEC CHAMBER ACCORDING TO DAVE. Neck thickness of my virgin Lapua brass measures out to about .015". Sound about right?

What I don't get is if the reamed chamber spec is 0.342"... and a seated bullet measures a neck dimension of 0.338", that is a difference of 0.004". Is this too loose for the chamber? Most say that I should use a neck bushing to reduce it by 0.001 Right?
Math: .342 chamber dim - .001 = .341 finished neck dim. of seated bullet. Is this correct?
My dilemma is my neck dimension of a seated bullet measures at .338 Please advise.

4. I don't have any reamer drawing specs to compare anything to. I do have a cut off from the barrel that Dave reamed out for me to the same specs as the rifle chamber. I use this to check bump dimensions of the shoulder.
 
dansig said:
I have a custom .308 Palma built on a Stiller Predator action, it shoots 5 shot groups sub .150 and has gone as low as .127.

I do not fireform new brass, just fullsize, trim to 1.975" turn the necks so they are even, uniform primer pocket and flash hole then just load and shoot..

I use 44.4gr N150 behind 165gr Sierra Gameking, seems to like the gameking better than match bullets...

after shooting 3 times I measure all cases and they are almost Identical.. .0003 max variation in lenght, no variation in neck thickness.
Click to expand...

Thank you for the info.
 
Thank you for all the input fellow shooters. I appreciate it a lot. I will more than likely be asking more questions. Thanks again.
 
Cherrywood said:
1. BOLT......with virgin Lapua Palma Brass out of the box, bolt closes to about where you said it should with a smooth light pressure to completely close. Sounds good so far.

2. Presently, I have a Redding Type S Bushing Neck Die, their Body Die and their Competition Bullet Seating Die. I have ordered their Full Bushing Die as you and others have suggested. Great! The Type S FL die will serve you well. Put the neck and body dies in a drawer and forget about them ... Forever.

3. Dave Bruno states the chamber is on the tight side and his chamber dimension is 0.342" Not sure where that fits into a LIGHT TURN NECK or NO TURN NECK... BUT IS DEFINITELY NOT A SAMMI SPEC CHAMBER ACCORDING TO DAVE. Neck thickness of my virgin Lapua brass measures out to about .015". Sound about right? Sounds like he gave you a tight-sided No-Turn neck. Which is OK since it saves a lot of work. If I remember correctly, .015" is about standard for Lapua coming out of the box.

What I don't get is if the reamed chamber spec is 0.342"... and a seated bullet measures a neck dimension of 0.338", that is a difference of 0.004". Is this too loose for the chamber? In the 6PPC and 30BR world most shooters shoot with .002" total clearance [.001" on each side] although some have experimented with as much as .004". Ask Bruno what his rationale [thought process] was for giving you .004" right off the bat. You might find that he considered a safety cushion, for manufacturing variances in the brass thickness at the neck. At some time, you might see something larger than .015" and since you're not turning you would have no way to compensate for it. The larger clearance will compensate for the + spec changes. P.S. Let's not lose perspective, a piece of copy paper measures .004". Turn a piece on its edge and look at it. You've got 1/2 of that on each side!

Most say that I should use a neck bushing to reduce it by 0.001 Right? Maybe. It depends on what your barrel likes. Try .001" [a .337" bushing], .002" [.336" bushing], .003" [.335" bushing] etc;. Sometimes, if you go tighter, you'll see groups really tighten up. Experiment. Who knows you barrel might like .001" [.337" bushing]. While on the subject of bushings, use carbide. That way you'll never have to lube the outside of necks, except when fireforming for the first time. Here's a source:

Bud Mundy, Director
NBRSA, Mississippi Valley Region
5956 Old Hickory Trail
Hillsboro, MO 63050-3251
Home: 636-797-5786
Cell: 641-425-3397

Math: .342 chamber dim - .001 = .341 finished neck dim. of seated bullet. Is this correct? My dilemma is my neck dimension of a seated bullet measures at .338 Please advise. Neck tension of .001" or .002" etc; with a seated bullet does not affect the Outside Diameter of the loaded cartridge, only how much of a squeeze is being placed on the case neck and the bullet once seated. It does affect pressure buildup within the case.

4. I don't have any reamer drawing specs to compare anything to. I do have a cut off from the barrel that Dave reamed out for me to the same specs as the rifle chamber. I use this to check bump dimensions of the shoulder. Ask Bruno to send you a copy of the reamer's drawing with specs that he used to cut your chamber. They're indispensable. I recommend the Innovative Technologies Digital Headspace Gauge for checking how far you are bumping your shoulder back. Go here, second item down: http://www.larrywillis.com/ Very simple to use; changes in hand pressure are eliminated.

See notations above. I hope this helps. :)
Click to expand...
 
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Needs to be said....again

If bumping the shoulder does not change the "feel" when closing the bolt then some other dimension is at play. A mindset in this direction, left unchecked, will create a dangerous headspace condition. If you feel the shoulder when sizing and the bolt closure does not change....please stop and think about it. Could be as simple as your die has a different shoulder angle than your rifle but to bump further without additional evaluation is not safe.
 
In response to.......

Just a note to thank everyone for their help. I'm still having difficulty understanding it all but far better informed thanks to you.
 
One moer try at writing something comprehensible... If not, ignore it.

It isn't surprising that the dies won't bump the shoulder back on new, virgin cases. All that means is the brass is well below the SAAMI maximum.

It is surprising that such cases chamber with a bit of effort. If that extra bit of effort is due to the shoulder, (1) that's a good thing for fireforming, you will be making cases that fit your chamber very well, but (2) it also suggest that after fireforming, the case will shorten up a bit, and that forecasts bad news for resizing in your current dies.

It is not surprising that the Redding competition shell holder set doesn't help. They are designed to address the opposite problem.

If what is going on is that your chamber is short -- not SAAMI -- you will need a custom die -- also not SAAMI. Alternatively, you can grind a little off the top of the shellholder, so the case will go into the die farther, or, grind a little off the die, so the shoulder point in the die is "nearer" the top of the shellholder.

I might risk a shellholder, taking off 2-4-5 thousandths, but before grinding the die, I would want to know exactly what was going on. At this point,we're (well, I'm) only speculating that the chamber is a bit shorter than SAAMI. Whcih is not particularly a bad thing, given the history of Palma, it kinda makes sense. But I'd want to know what & how much.
 
Cherrywood said:
I have a new 308 Winchester that has been custom built by Dave Bruno from a Remington 700 action....Hart Barrel, Jewel trigger and a custom made benchrest stock. Dave did everything possible short of a custom made action by Kelby or Borden to make this as accurate rifle as possible.
Click to expand...

Once again, ask Dave or Amy to send you a copy of the drawing of the reamer he used to cut your chamber. It's indispensable when it comes to knowing the dimensions you're working with.

If you think you're going to need a custom made die here is the best place to go: http://harrellsprec.com/index.php?crn=207&rn=384&action=show_detail

Lynwood will tell you exactly what he needs, and you're in luck, they make .308 dies. At $75 they're a bargain, and made to use bushings too. At lot of benchrest shooters use Harrell's dies. They're great folks to work with. :)
 
Many years ago I used a simple method to determine what case dimension was impeding the proper fit of a sized case in the chamber of my rifle.
I cleaned the case and chamber with Naptha to remove all trace of lubrication and dirt. I then took a Magic Marker and marked the case with 2 or 3 stripes on the full length of the case. With firing pin assembly and possibly the extractor removed I inserted the case in the chamber followed by the bare bolt to close on the case for fit. If there was excessive pressure necessary to close the bolt a cleaning rod was used to disengage case after opening the bolt. Then.......
By viewing the case, tight fit was exhibited where the Magic Marker ink was rubbed away. This told the whole story and allowed you to correct the setting of your sizing die ...or...choose a different die. I did a lot of Wildcatting in the "60s" and never had a case problem.

Good luck,
Ted
 
I have/had this same problem it wasn't the headspace that was the issue it was the back end. The base of the case might not be sizing enough and you are trying to fix it by sizing the headspace more. As others have already pointed out bumping the shoulder more then needed can only cause problems. I went to a Redding Small base die and then to a custom.
In my case my reamer was cut with a .4700 at .200 up the case. When I fired a round the (new factory brass) which is only .4695/7 expanded to the point where I would get the clicking at the top of the bolt lift. My initial remedy was to bump the shoulder more and more until the base of the case was sufficiently sized. I pushed the brass up into the die so the base would go far enough up the die that it would re-size to .4697 and I didn't have the trouble chambering a round. This lasted all of 10 rounds when I figured something else was at play.
The small base die helped a little but was insufficient in correcting the problem; it wasn't until I got a custom die that I found the problem went away.

As others have stated get a reamer print and go from their.

Trevor
 
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