I've just started reloading for my Ruger #1 (7MMX08). How important is overall length? It looks like an OAL gauge is about $50 including the cartridge, tax etc. Is it likely to make a significant difference in how accurately the gun shoots?
You don't really NEED an OAL gauge to properly load for the Ruger Number 1. For that matter, you don't need one to make accurate loads for bolt actions or any other actions either. The OAL guage simply makes it easier to determine that maximum length for reference. An inexpensive dial caliper does the same thing.
Simply start by loading the bullet out so that it touches the lands, and then seat bullet deeper in 0.010" increments and develope the load that is most accurate in your rifle. For most rifles/chamber throats, this means keeping the bullet ogive just short of touching the lands.
John is 100% correct. I only use dial calipers when checking case OAL and loaded round OAL.
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The closer to the lands the bullet is, it is generally conceeded, the more accurate the round is.
The further from the lands the bullet is the higher the velocity for the same round. Weatherby chambers are cut specifically to take advantage of this phenomenon. They are not known for being tack drivers but they are perfectly adequate to hunt with.
The pressure also goes up as you decrease the jump of the bullet from start to lands.
If you are into extreme bench type accuracy then closer to the lands makes sense. These, from what I have seen, also tend to be loaded well under maximums.
If you are into hunting and want to get the longest point blank range trajectory for your purposes then you may move back from the lands a bit to let the pressure be generated by your load and to let the velocity come up a bit.
Hi there Old Crow,
O.A.L. is mainly max length so that the round will feed through a magazine for mag feed rifles. When loading for accuracy set projectile just to touch land, NOT fully engraved. Work your loads up safely. The #1s that I own have large chambers and fire forming brass then neck sizing gives me best results