Questions. Bumping shoulders back.

[Alpha1]

I re measured several times using different makes of brass to see if they made a difference. I finally selected 6 once fired PPU cases.
The first case was sized normally and measured 1.760. I then sized the other five cases in turn trying them in the rifle and recording the measurements. Actually in this set the no 4 shell holder was the best fit the bolt closed with a slight resistance on the bolt close using my thumb to close the bolt.
So normal sized case = 1.760
Number four shell holder = 1.764. so I get that to .004.

The new lapua cases average = 1.763 so I will just leave them as is and they should be Ok. So I had a enjoyable couple of hours with my new Wamadet press learning about setting shoulders back. I just need to double check my trim length's.

If I set my seating depth correctly I should be good to go.

Next I'm going to try resizing the fired cases with a redding body die setting the shoulders to 1.763 then sizing the necks with a L.E.Wilson neck bushing die. hmm what's next. Oh yeah I suppose I better shoot it otherwise I wont have any cases to play with. I need to buy another 100 Lapua cases I will probably chuck the ones I have messed with. I might treat my self to one of ovenpaas 6.5x55 measuring thingys as well while Im at it. Just for the hell of it.

Neck turning now whats that all about. Hmmmm

[Martin]

In the OP you mention not having reloaded any of the cases. You seem to be FLS new Lapua brass? If the new brass fits your chamber, as it should, why not load a few new cases first, then shoot them and you will then have a fired case from which you can take measurements to assist future FLS. You have measured a new Lapua case at 1.763 - I query why you would resize to 1.760 (see "normal sized case" above). Given there ought to be case expansion after firing, the fired case ought to measure more that 1.763. The absolute minimum measurement after FLS a fired case would therefore be 1.763.

Martin

[Alpha1]

If you read my previous post you will see that I have stated that I finally used 6 once fired PPU cases. Yes I messed about with lots of new lapua brass thats now been confined to the bin. This exercise was about learning about shoulder bumping full stop. The problem is new brass does not all ways fit my chamber and factory rounds definitely not.
But that is another story and its been flogged to death so I do not want to go back there.

I query why you would resize to 1.760

I will check my measurements to morrow but I believe that is the case length of the once fired PPU case after re sizing. Unless I have got it wrong and thats quite possible.

[phaedra1106]

So, at the end of the day if you're happy with the cases shoot them and fire form them, measure the shoulder datum point of the fire formed cases and then set your die to resize with a 1 to 2thou" decrease.

Regardless of what measurements you have now the correct shoulder position is between 1 and 2thou" shorter than that of a case fire formed in your rifles chamber, anything more and you will create excessive headspace.

[Martin]

[quote="Alpha1"]The problem is new brass does not all ways fit my chamber and factory rounds definitely not.


There are potentially 2 quite different issues based on that statement. New 'out of the box' brass not fitting the chamber indicates a fundamental chamber problem necessitating gunsmith assessment. Factory rounds not fitting the chamber can simply mean a tight match chamber often with minimal freebore necessitating projectiles to be seated deeper in the case when compared to a factory round - and potentially also requiring neck turn. My match rifles for example will not chamber factory ammo, new brass will chamber 'out of the box' however require neck turning from the first loading in order for there to be adequate case neck/chamber neck clearance.


Martin

[Alpha1]

There are potentially 2 quite different issues based on that statement. New 'out of the box' brass not fitting the chamber indicates a fundamental chamber problem necessitating gunsmith assessment. Factory rounds not fitting the chamber can simply mean a tight match chamber often with minimal freebore necessitating projectiles to be seated deeper in the case when compared to a factory round - and potentially also requiring neck turn. My match rifles for example will not chamber factory ammo, new brass will chamber 'out of the box' however require neck turning from the first loading in order for there to be adequate case neck/chamber neck clearance.

My response to your questions are probably miss leading.

Factory rounds not fitting the chamber can simply mean a tight match chamber often with minimal freebore necessitating projectiles to be seated deeper in the case when compared to a factory round - and potentially also requiring neck turn. My match rifles for example will not chamber factory ammo, new brass will chamber 'out of the box' however require neck turning from the first loading in order for there to be adequate case neck/chamber neck clearance

The above statement probably sums up this rifle. My problem is I have shot milsurp rifles all my life this is totally alien to me. Getting it to shoot has been a huge learning curve.

[Alpha1]

Neck turning is my next learning curve. I have ordered a neck turning tool and a suitable mandrel.
I would be intrested to learn how you reload for your match rifles. If you could describe the process that would be good.

[phaedra1106]

There's also one other "quirk" with this rifle to add to the mix, it's a 6.5x55 chambered barrel fitted to a 308 action (short), generally 6.5x55s are used on a long action to take advantage of its preference for long heavy bullets with a 1:8 or 1:9 twist rate, the long action gives more room for feeding the rounds.

[Alpha1]

There's also one other "quirk" with this rifle to add to the mix, it's a 6.5x55 chambered barrel fitted to a 308 action (short), generally 6.5x55s are used on a long action to take advantage of its preference for long heavy bullets with a 1:8 or 1:9 twist rate, the long action gives more room for feeding the rounds.

Yes I had forgotten about that an important point. The answer would be to re chamber it in 6.5x47.

But for now I will just shoot it (May be. May be not)

[phaedra1106]

Or 260Rem, an excellent calibre, or even .308Win if you're not shooting competitions beyond 600m or so :)