Re: Minimum impact velocity for 300 gr SMK?
There are several theories about this and many dedicated extreme range BR shooters do not want their bullet bases below the case neck/shoulder junction to prevent any bullet deforming.
My opinion is that in one of my rifles built for extreme range shooting, The neck of the chamber will be roughly 0.001" over loaded neck diameter, The throat will be 0.0002" to 0.0005" over bullet diameter and thus there not much room for bullet deformation.
Now if the bullets are seated very deep into the case, there may be an issue like this but again, I have not seen it so far even in my Allen Magnums which are running in the +3500 fps with extremely long bullets with a large portion of bullet below the neck shoulder area.
I may have not seen this because I use Wildcat Bullets that have a very think jacket, at least the ones I am using and this may prevent this problem.
I do know that every bullet that is fired will be deformed to some degree from the pressure driving it down the bore. This is needed, if it did not happen, accuracy would suffer because this bumping up of the bullet seals the bore and provides an accurate fit to the bore.
This is why Match bullets generally are more accurate then big game bullets. Sure they are held to tighter specs as far as consistancy but just as important is their relatively thin jackets bump up much better to fit the bore and groove diameter better then a big game bullet.
This is why hard bullets can be so tricky to get to shoot very tight groups. Take the X bullet for example. If you have a bore that matches the diameter of the X bullet perfectly, they are amazingly accurate, if your bore is a bit tight or a bit loose, consistancy will suffer because the bullet will not conform as well to the mismatched bore diameter.
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