loading WSM close to rifling
Is it just my two rifles, 270 WSM by Savage and a 25 WSSM by Browning, or do these type of rounds like to be loaded about .005-.007" off the rifling. That seems to be the best accuracy in mine with hunting type bullets.
The other calibers I've loaded for don't seem so critical, my 204 Ruger doesn't seem to matter and my dad's 257 Roberts, Rem 722, doesn't seem to care ether.
I was just going through all my range notes and noticed that the gap seemed to be a much bigger deal than most other components.
The other calibers I've loaded for don't seem so critical, my 204 Ruger doesn't seem to matter and my dad's 257 Roberts, Rem 722, doesn't seem to care ether.
I was just going through all my range notes and noticed that the gap seemed to be a much bigger deal than most other components.
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Most of my rifles, up to this point, have liked to be seated about .005 off the lands...I'm now experimenting with seating into the lands... 0 -
skyfish,
"...or do these type of rounds like to be loaded about .005-.007" off the rifling."
Purely a function of those particular rifles and the way their chambers are cut in the barrels in relationship to the individual bullets. That's why we tell posters that they have to do the testing of loads and bullets simply because each rifle is considered to be an individual. There are very few generic rules that apply to every situation.
Best.0 -
skyfish,
I find that generally, it depends on the bullet first and then it's relationship to the chamber. Several years ago when I was introduced to seating into the lands I found that Bergers always seemed to shoot best that way. Now that they also have tangent ogive bullets I find I can seat them off the lands like a Sierra, Nosler, or Speer and still get great accuracy. Some bullets, with tangent ogives of not-all-that-steep of a radius will shoot .5 MOA .125" off the lands. My .30-06 target rifle is one such case. I bought it as a Rem 721 w/heavy barrel and Olympic style sights. I was initially going to rebarrel it to 7mm-08 with a long throat for 180 Bergers. Since it's been shooting .5 MOA @ 300 I don't want to take it apart. So, I shoot Nosler Cust. Comp, Sierra 168/175 SMK's and M118LR bullets through it. All about .125" off the lands. Truth was, I couldn't even reach the lands with those bullets.0 -
Interestingly, an article in the March 2009 issue of Guns & Ammo discussed this very topic with regard to the testing of a .270 WSM in a Browning A-bolt.
The author, Steve Gash, noted: "It is an article of faith that the best groups are obtained by seating the bullets very close to the lands--.010 inch, or even .005 inch off--but for the .270 WSM, this is not the case. I first tried seating bullets .010 inch off and got mediocre results. Most .270 WSM factory loads have a bullet jump of about .030 inch; with some the gap is as high as .100 inch. I switched to .030 inch off the lands for all bullets except the Barnes Triple-Shock X and the Nosler E-Tip, which were seated .050 off, and accuracy improved dramatically."
But, of course, it depends on the individual rifle, etc.
This writer notes in the article that he got a 3-shot group of .47 inch using a 130 grain Nosler Partition and 71 grains of Reloder 25.0
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