More seating questions...

[Dougan]

I'm just starting to load for a 6.5 x 55 Mauser - So made a couple of dummies to try out the new dies, and test the rifle mag and action:

The one on the left is Win brass and an unknown cheap bullet (magnet tested ) - the OAL to the tip is 2.955 (ogive - 2.452). The one on the right is Lapua brass and scenar bullet, with an OAL of 3.034 (ogive -2.455). The diagram that came with the dies shows a max OAL of 3.150...so both well under.

The only guide to seating depth I used was to seat them so that all of the inside of the case neck was in contact with the bearing surface of the bullet - with the cheap bullet, that took the neck upto the cannalure (though not crimped), which seems natural, and the round looks about right...

...But with the Lap bullet, the boat tail is so long, that when seated with the full bearing surface in the neck; the boat tail goes down slightly beyond the bottom of the shoulder...

So first question: As long as the bullet isn't touching the powder, is it ok for the tail to go so far into the case?

And: If you wanted to seat them a bit further out, this would lessen the amount of contact between the bearing surface and the inside of the case neck - How much contact is recommended? Is there a minimum ratio?

[John25]

before I ever bought dial calipers, chamber tools and half a million quids worth of other 'essential' kit, my first rifle loads were measured by simply putting my round (made long) between two factory rounds and putting a steel rule across.Moving the die down by quarter turns until they were level. It produced surprisingly consistent loads.

Then making a batch of ten the same, then ten a couple of thou longer,/ shorter until the best results were obtained.

As long as you don't compress the powder (or seriously under-fill) and keep the loads within limits, assuming you use the correct powder and chart, all will be well.

Eventually you will find your sweet spot, bullet jump etc.

Let usk now how you get on.

Good luck



P.S.Remember to change only one element of your procedure at a time.

[Dougan]

Cheers for your reply John sign92

I loaded my .303s last year by doing the same (copying factory rounds) - I did measure the jump, but it was so big it wasn't worth bothering with. I will measure the jump on the Mauser too (have some cases comming) - but my main concern with my milsurp reloading (as opposed to .308 TR) is that I shoot rapid and snaps (so using the mag), and as I don't crimp, want to make sure that they have a good neck tension...

I havn't used anything like these long thin Lapua bullets before, so I might try a few different seating depths...as long as it doesn't compremise safety.

I havn't got any factory to compare with - So would very much appreciate it if anyone could post the measurements of theirs (especially the OAL to the ogive).....?

[Alpha1]

I think you will find that you have the same problem with your 6.5 as you had with the .303. Milsurp rifles dont tend to have tight chambers and your COL is limited to the size of the magazine.

[Dougan]

Yes, I think this will be the case. I havn't actually shot the Mauser yet, so it's going to be intersting to see how it compares to the smle in different competitions - I have a feeling the Mauser will be more accurate, but that it won't be as good as the Enfield action for rapid - so there is scope for experimenting with single fed precision rounds...as long as I don't mix up the batches!

[Alpha1]

The other thing to take in to consideration is the sights on the 6.5x55 swedish mauser they are normaly set up for long range shooting I have never had much luck with them under 300yds.
I have a swedish mauser I dont use it because I normally shoot at 100yds and I have never had any luck getting it to shoot at that distance.

[nicklm]

not wishing to hijack this thread but is this a correct thought re oal and bullet jump.

If we use a stoney point case or who ever makes them these days, and that gets stuffed in the chamber, what we are
actually measuring is the relative distance from the shoulder of the case where it makes contact with the chamber.

? if this is non foreformed brass
ie: might be a few though short etc when the round is loaded it will now have a larger jump to the lands, in the split second of ignition does the case expand to the chamber (there by setting our jump to the lands) or has the projectile already left the case before this expansion has occured.

regards

nick

[ovenpaa]

Regarding the second half of your question, if it does expand it will be mostly sideways so probably not a lot of help. So in theory the jump you are measuring at say .010" is when the shoulders are jammed against the chamber shoulder but when you chamber the round with the bolt they could be .016" back (Extreme but possible) however whatever the measurement of jump/jam you have arrived upon gives best accuracy in your rifle with your load soin theory you could be measuring in ants knee caps and as long as you stick to that measurement you are shooting with the optimum length.

Until you set the shoulders back, then in theory things could be wrong again. In my opinion the true reference distance is the bolt face which is as close to a constant as you can get, to the point at which the Ogive for your bullet engraves the lands. This is the true length and nothing else can ever be as accurate. The problem is emulating this measurement.

I make OAL gauges and have struggled with concept for a while and will occasionally sit down and make something to emulate the bolt face. My neighbour has a very different approach to the problem and Mik @ Dolphin offers yet another alternative.

Interesting stuff and the sort of thing that can consume many hours of discussion over a glass or two of red.

[Dougan]

The other thing to take in to consideration is the sights on the 6.5x55 swedish mauser they are normaly set up for long range shooting I have never had much luck with them under 300yds.
I have a swedish mauser I dont use it because I normally shoot at 100yds and I have never had any luck getting it to shoot at that distance.

You can solve this problem by either putting a taller front post on, or lowering the rear sight - On my smle (which isn't as original), I've filed the metal down under the rear sight so that it sits lower.

With the Mauser I'm starting with a scout scope; but if I end up using it with open sights instead I'd go for a taller front post, as it is all original...

[Dougan]

not wishing to hijack this thread

Not at all...good question