220 swift

[ragsflh]

1in 9 twist on 220 swift.will it shoot 60 to 70 grain bullets with out exploding

[35Whelenshooter]

Yes it will shoot those bullets, you will be able to shoot 75's and 77's I like 68's and 69's myself and my go to bullet is 55's


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Respectfully
Mike

[darkker]

Rather than just using the bullet weight, although it likely pre-supposes this, consider construction.

Here is the math you need:
MV = Muzzle Velocity. TR= Twist Rate
MV * 720 / TR = RPM

I did a thread a some years back, when I called all the major MFGR's, save Berger at the time. Here are the stated RPM limits for .224 cal bullets of various construction. **Remember** That your particular barrel smoothness will play a large roll, in the final RPM possible.

Light Jackets = 230-260,000 RPM
Think of the Original TNT's, SXSP, Dogtowns, Hornets, etc

Most everything else = 275 - 290,000 RPM
This is the V-max, A-max, SP's, SMK's, etc.

The monsters = 320,000 RPM
These would be the Nosler BT's and the BlitzKings. While I don't know this, suspect the Berger Tactical line.