A general dynamic model and differential equations for an unsymmetrical projectile traveling in a flexible, increasing twist rifled bore gun tube are developed.

建立了非对称弹丸在挠性渐速膛线身管内的弹丸一般运动动力学模型和运动微分方程组。

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At last, acquired conclusion is that band cut is not only in relation to gun bore wear and bore pressure, but also to length of heavy wear section.

最后得出结论：弹带削光不仅与内膛磨损量和膛压大小有关，还与严重磨损段的长度有关。

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Gun sights introduced early in the nineteenth century consisted of fixed front and rear sight points so adjusted that the line of sight across their tips was parallel to the bore of the gun.

十九世纪初的火炮瞄准具由炮身前后两个尖点构成，视线通过两尖点顶端就得出与火炮炮膛平行的瞄准线。

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These moves may seem small-bore compared to gun laws in many other countries, but they are a very big deal here, and it is hard to see how the ban on assault rifles will get past Republican (and indeed some Democratic) opposition in Congress.

BBC: President Obama's next campaign - against the gun lobby

The Sports Council for Wales has recognised the need for an Olympic standard range for air gun, air rifle, and small bore rifle shooting.

BBC: Youth airgun marksman

The prosecution also alleges the defendant handed Mr Duggan the gun in a shoebox, 12 to 15 minutes before he was shot and that the box bore the fingerprints of Mr Duggan, Mr Hutchinson-Foster and his girlfriend Desire Cox.

BBC: Mark Duggan