Brass Problem

[Ackley]

I have just had a new Loather Walther barrel fitted to by Nesika action in 7mm WSM mim SAMMi spec,the first problem is the throy is very long and iam unable to get a loaded round into the mag so I may have to send the reamer back and have it reground as the jump from mag length to the lands is 97 thou
anyway the chamber size is .314,a loaded round is .312 Iam using brans mew Winchester brass all fully preped and lightly neck turned
now the gun wont group for sh1t I have found out a fire case measued .310 so it seems i have massive spring back on the brass,I annealed 6 once fired cases and tried again loading just off the lands it did shoot better but still not great the the case measured.311 still a bit of spring back
has anyone else had such a problem or is the neck wall on the brass too thick ????
Oh yea I forgot to add Iam using a 309 bush to neck size

 

[Jason Boersma]

:thumb:Try using Lapua or Norma brass they are more uniform/acurate and should make your rifle shoot better. Also try using a .312 bushing to neck size trim your brass so that your neck thickness is .0145 so when you seat your .284 bullet you will have a loaded round thickness of .313 which will give you a .001 clearance and you shouldn't have hardly any spring back in your brass and your rifle should shoot great.

 

[MSwickard]

Ackley

Based on the info you have supplied, it sounds if your problem is the freebore or leade of your chamber being too long when you load your cartridges to fit your mag. One one around this is to shoot it as a single shot. The other is to rechamber with a reamer with a shorter leade.

As for the neck, I believe 0.002" on a loaded round is fine for a non-hunting gun. That is 0.001" to a side. If this is a hunting rifle I would have the neck clearence at 0.004-0.006" or 0.002-0.003" to a side. If you need more clearence you can turn the necks down some and change to a tighter sizing bushing.

Mike

 

[Ackley]

thanks guys I have loaded it just off the lands approx 8 thou which allows the slight difference in the size of the bulley ogive,the groups hve closed up to .8 Iam going to have to send the reamer back to allow me to re load to the mag as it is a hunting rifle plus theres very little of the bullet in the case case when loaded this far out