New brass question

[foxpig]

Hey all

Can anyone answer this one.

Why would a rifle shoot superbly with new Virgin brass out the box. And on the second loading of that case throw flyers?.

Got me stumped .

Would full length sizing cure this problem as they are only neck sized?

Cheers

[MrCetrizine]

It's worth a try.

I recently replaced my full length dies as I started getting poor results on the second loading. I guess dies can wear because new dies fixed my problem.

[Montey]

Does any one ellse clean thier dies? I use brake cleaner this mite be the cause as I had a simler problem and found it worked. Full length RCBS in 243.

[gunner]

Iv recently bought dies for 2 calibers 2nd hand - they come pretty filthy tbh , i strip clean and lube where necessary and definitely clean them on a regular basis especially the shoulder bump / FL dies . The amount of lube/wax build up is astonishing

[The Gun Pimp]

Hey all

Can anyone answer this one.

Why would a rifle shoot superbly with new Virgin brass out the box. And on the second loading of that case throw flyers?.

Got me stumped .

Would full length sizing cure this problem as they are only neck sized?

Cheers

I always say "nothing shoots like new brass'. Why? because new brass is 'straight'.

 

Once you fire it in a factory chamber it is ever so slightly distorted and, if you don't at least attempt to restore the brass by full-length sizing, you are putting a distorted case back in your rifle.

 

Some factory rifle chambers are truer than others. Some are awful.

[simonl]

Did you load develop with the new brass?

If you're only neck sizing I'd consider the case volume to be different with fired cases vs new. My stance is that if you change any variable then you can expect to have to go through a load developing exercise again. Keen to see what some of the gods say..

[Andrew]

If it shot well with new (FL sized) brass, why would you not try to duplicate the conditions of the initial loading?~Andrew

[rem700]

Could it be down to the neck tension being tighter on virgin brass compared to your brass after sizing??

[Brillo]

In every rifle I've owned, including custom and factory, the new brass has always been smaller than subsequent firings. I have two custom rifles where the cases will fit each chamber if I decide to neck size, but this is unusual in my experience.

 

I had one factory rifle where the case expanded so much and out of shape because the chamber was not concentric that I had to full length size just to get them to re-chamber.

 

Again, in my experience, new brass is marginally smaller than even full length sized brass through my dies.

 

As TGP says "nothing shoots better than new brass" , and I can only put this down to their uniformity.

 

If your rifle chamber is similar to the one I mentioned it sounds like full length sizing is a must.

[gbal]

Foxpig,the replies make good points-

Is this a factory chamber?

Has this just started,or did the rifle shoot consistently before-if so with what?Any component changed?

What's the sample size-how consistent were the 'superb' groups....and crucially what is a 'flyer' in that context-one shot in five that is 1/2" out of group....or just one that nudges a .4 group to a .5 group? for example-actual sizes are not the central concern.

 

You might try reloading a 'flyer' case and firing it again,noting if it produces another flier from the group.....and much better yet,several such 'flier cases'....Why would only one in 5 (or whatever) new brass shoot differently-either a brass flaw or just maybe aligned in a non uniform chamber in the 'worst' way...though I'm not sure we know just how much extra dispersion that causes-and yes,some have tried aligning the case the same way in the chamber next time....eg by marking the flier case head at 12 o'clock before removal,and reinserting it loaded in the same orientation.....but you'd need quite a decent size sample...as ever (with so many potential differences between packet and target,twice ) :-)

 

 

 

Full length will do no harm (Full or Neck are indeed only for one reload,then can be changed).

 

Maybe such better detail of symptoms will help diagnosis....

 

gbal

[foxpig]

As suspected great replies cheers all.

I did kind of realise that I needed to get them back to as close to new as poss . So full length will have to be tried.

Having never done this it will be another learning curb.

In all my other rifle's neck sizing and bumping the shoulder back every now and then has always been great.

Just not for this one. And this brass is very expensive ..

This is a custom chamber. Built on a factory action..

And by superb I mean nigh on same hole shot after shot if I do my bit. And by flyer I mean the odd one goes where it should . The other's randomly scatter up to an Inch off at 100y.

I'll try the full length dies and hope and pray that that is all it is.

I very much Dout that it is anything to do with smithing as I used the best there is . If I have to keep buying new brass I will as it's just so good with it. And really boosts confidence to take anything on.

What's a really good full length sizing die to go for then??

Cheers

[simonl]

Have you taken any measurements of new brass vs fired?

[onehole]

Hi Foxpig how you doin? Take care even full length sizing can be done badly,,,choose your dies wisely or at least ensure your case is entering the die dead concentric/true etc ,,,You should see a uniform sort of marking around the fls case ,,,if it looks uneven you may have fls,d out of true?,,,,best wishes,,,,,D

[simonl]

Hi Foxpig how you doin? Take care even full length sizing can be done badly,,,choose your dies wisely or at least ensure your case is entering the die dead concentric/true etc ,,,You should see a uniform sort of marking around the fls case ,,,if it looks uneven you may have fls,d out of true?,,,,best wishes,,,,,D

How do you control how the case enters the die? Are you just talking about ensuring it's snug in the shell holder, or are we talking a bit more precise than that?

[onehole]

How do you control how the case enters the die? Are you just talking about ensuring it's snug in the shell holder, or are we talking a bit more precise than that?

Hi Simonl,,,,,In the greater "majority" of resizing regimes all will be just fine but consider the press and the dies and the infinite number of variables in working tolerances of both and in particular the fit of the die assembly into the press.Its a pretty sloppy affair really and I,m sure you can waggle your dies around in the thread a fair bit and if one can assume that the dies are well made and true then fit in the press must be considered to complete a linear action.....What I tend to do before locking up the die is to leave it in the correct screwed in postion but loose and place a case in the shell holder and gently raise the case to the die whilst jiggling the case around a little whislt it self centres in the die then lightly tighten up the die lock nut.This will ensure that at best you would not have tightened down the die slightly off centre.Presses and dies do have an element of play in them and for good reason that some of this self centering can take place.As I said most of the time there is,nt an issue but if your chasing a reason for unexplained flyers or bad grouping then the press and die fit and use could be brought into question.I,m pretty sure serious benchresters and of others seeking the ultimate don,t go for Wilson straight line/type or custom reamed die sets for no good reason.....Concentricity all the way,,,,,,,O

[John MH]

I usually find I get better results on the second firing of new brass.

[gbal]

Just to support onehole's point-the well thought of Forster Co Ax press does not tighten down dies,butallows some 'wiggle room'....actually difficult to find if that is THE factor of course.....

 

I'd hesitate to recommend a new press on the -to me-still uncertain information so far-("hole on hole'-for how many shots-"flyer means the odd one goes where it should " (??) then the rest are random up to an inch away...."

 

Strikes me as odd-a string of perfect shots,then a string of wild shots-that does not sound random at all-as you would expect,if it's a chamber/brass thing....you'd get hole/hole,then flyer(s),then back to 'hole' then flyer....and so on. Unless the sample is very small-3shots ,say,in which case there is not enough data to comment....nor throw money at..yet.

To continue my medical analogy,we need more tests before diagnosing an expensive cure...

 

Carridge is probably not too relevant, make of brass likewise(they can all have a poor QC batch) but why not give it.

I'd still shoot the 'flyer' brass again and see if it was still 'flyer'-if it reverts to 'hole on hole',that's informative,and if it remains 'flyer' so is that....

 

I agree that Wilson hand/arbor dies are prettty much the best,but to change to that set up is pricey-for screw in dies,Redding (get the best options-something else might need fiddling with) and Forster are pretty good....or is that what's being used already....and making 'hole on hole' ammo until it isn't?

 

"Hole on hole' strings of shots really is critical-as above-consistency that goes off is a whole different ball game from erratic....or 'only 1 moa' etc.....(consistent but disapponting)....especially in a custom chamber/barrel...so long as we have a decent sample of data.

Note this applies to almost everything-bullets,brass.reloading proceedures etc etc-ten perfect shots ,then 5 fliers is VERY unlikely to be due to inconsistencies there...such inconsistencies would pop up/out

..well...'randomly' ,not in distinct string,then go away....with perfection restored.

 

(as would happen eg with an overheating barrel,for example....can we exclude such possibilities....?)

 

If you just want to hope and pray and pay,upgrading dies is very unlikely to make things worse,and removes that possible factor not least in the mind...if it don't fix,then see above....

 

gbal

[Brillo]

I'm going to throw an 'out of the box' idea into the mix. The OP was about the second firing of brass, but the way foxpig described the group anomalies yesterday doesn't sound like a brass problem to me.

 

It reminded me of a perplexing experience I had in a comp earlier this year (and it had to be in a comp didn't it?).

 

At a practice shoot a few days before, at 200 yards, everything was fine and I started the comp with a bit of confidence, but the last few shots at 300 yards went a bit wild. There was no wind shift, so I put that down to 'the nut behind the butt.'

 

At 600 yards I couldn't hit the V and some shots went high and low. By now I was getting a tad perplexed as the load I was using was tried and tested and from a batch of cases that had given good results before.

 

At 900 and 1000 yards it was the same. The conditions on the day indicated a good days shooting but my performance, and the rifle's, was disappointing.

 

My squad partner who knows my capability was equally puzzled.

 

When I got home and started to clean the barrel, as I picked up the gun by the end of the barrel and stock to place it in the cleaning station, I thought I slight detected movement. On close examination I found that the bedding bolts were not tight, by as much as a quarter of a turn. I don't know how this happened as the bolts were torqued up OK before (or at least I was sure they were).

Was I pee'd off or what? This had never happened before or since.

 

I tightened them up and the nice groups returned the next time I shot that rifle.

 

It's a long shot (sorry about the pun) but it would be worth checking those bedding bolts.

[onehole]

I usually find I get better results on the second firing of new brass.

Same here MJH,,,,,,

New Brass,,,,whilst I respect TGP,s new brass is best mmmm yea but ,,,, you may still have to fiddle with this too!! New lapua brass in particular can exhibit huge neck tension from new ripping jackets to shreds deforming bullets and inconsistent OAL,s/ogives,,,,Minimum requirement would be to mandrel neck size and then resize for comfy fit.

Foxpig,,,,only a suggestion,,,,re check your seating depth using a fired case as this may have changed from a new brass situation,,,ie your cases have blown in and changed to true chamber dimensions now?,,,,,atb D

[gbal]

Just another a bit like Brillo's.

 

My first competitive BR match was going well (not really so hard at all) for the first two 5 shotters,but then the next two had one flyer each-maybe two,I was too traumatised to remember exactly-then a final good one.Intermittent failure...

Explanaton was a very fine severed crack in one scope ring,almost imperceptible,but there.Cured by new ring (it's still not that easy,though!),

Had the aluminum cracked badly,there would probably have been immediate catastrophic failure,not intermittent lapses (over only ten shots)...another reason,like Brillo's experience,when a decent sample is helpful.

 

"on the blink" is the tricky diagnostic condition-eyes wide open or wide shut simplifies it !

 

gbal

[foxpig]

Ok so here's what I do.

Buy new lapua brass

Open box

Trim to uniform length

Shamefer neck

Run through expand mandrel

Neck size (le wilson)

Prime

Charge

Seat (le wilson)

Fire

Perfect accuracy better than I could of imagined.

Go home

Repeat but I stead of expand mandrel I deprime and ultrasonic clean cases.

Check for case stretch ect.

Go to shoot group and my confidence vanishes.

I'll try a few things what you've all advised and will let you know.

Cheers

[foxpig]

Surely if it was the dies then the first firing would be crap aswell??

All my other rifle love fire formed brass best.

[Brillo]

Yup, sounds like it's something other dies.

Did you check bedding bolts and, like gbal's experience, scope rings?

 

BTW are the rings still snug in the rings and on the rail? A tiny creep will cause irrational grouping.

[foxpig]

But how does the rail now when it's new brass or not ?

[gbal]

Exemplary prep and reloading-thanks for that,foxpig. No wonder you are wondering.

At least we have a clear idea of the dies etc now,and no need to reinvest ! I'll assume it's not a big cartridge with very hot loading...though that wouldn't fit really,just it might stress the brass.Something clearly happens after first firing....and too ALL exvirgin once fired brass-or just some of it (and if you know,does the unreliable fired brass continue to throw fliers-if so,then we need to focus on tthose cases...if not....we're getting into Sherlock Holmes territory,but there has to be an explanation in this world!

If we can eliminate finally the 'brass' ,then attention reverts back to something about the delivery system-scope,maybe overheating....though can't be that IF you get fliers straight away on second firing...sorrry to keep on,but it's this steady chipping away based on evidence that holds the best chance of a diagnosis of the problem and thence it's solution.....random 1 inch fliers in an otherwise screamer rifle are ulikely to be caused by slight imperfections.....which are not there on first firing...obviously,keep the brass meanwhile,even if you use more new stuff.....over many years I've found that having hundreds,nay even more, brass is no inconvenience,once you get all sorted and load en masse....I would not want to have less then say,300 of any one cartridge ( .470 nitro express etc excluded). :-)

Hang on in,a hole on hole rifle is a rare joy.

g