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7mm-300 Win Mag with VLD.

01 Apr 2012
@ 09:18 am (GMT)

Nathan Foster

Shifted from blog...

I have a 7-300 win mag also. It has a#5 bartlien cut barrel 1-9 twist.My max is 76.0 h1000 210-p ww cases 003 into the lands.MY MV IS 3150 AV FOR 10 SHOTS ES IS 23 SD 10.Barrel is 26'' long and 168 vlds are used.My problem is i cant get the 180 vlds to shoot better than .595/623 3 shots.T 168 .385 to 450s. ANY COMMENTS???


01 Apr 2012
@ 09:28 am (GMT)

Nathan Foster

Re: 7mm-300 Win Mag with VLD.
Try to experiment with seating depths when you get a chance. The VLD's vary from bullet to bullet by up to 20 thou so if you seat to close, say 10 thou off the lands with your test bullet, some projectiules will actually be engaged in the lands while others will be right off the lands.

Bare in mind, these differences in tolerances of the VLD, do not negatively effect accuracy or long range performance once an accurate load is established. Also, in some instances, individual rifles will sometimes shoot very well with a 10 thou jump, regardless of differences from VLD to VLD- due to barrel timing (timing of when the bullet leaves the bore).

Experiment with 40 thou jump, then 20 thou, then 10 thou if all else fails.

You may have to adjust powder charges due to this, but use your current best load (powder charge) and make observations. If the groups shrink a bit, lets say two shots in one hole but one shot is a little way off, there is a chance that the new seating depth is a good one and that a final tweak of the powder charge will get that wide shot into the the group center.

As always, utilize good the bedding (not 'any' bedding), monitor bore condition (fouling etc) and monitor your own technique. Magnum recoil has to be managed differently than low recoiling cartridges. Use the hold that forend article as a guide. Do not use a bipod for testing loads, use sand bags.


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