PCP RAW cut barrel .22 slug accuracy

[Mubhaur]

I was thinking of testing Knockout 0.216 dia slugs in unchecked cut barrel of my BM500X .22 after installing the barrel on my HM1000X for many days.

This is because my HM1000X is highly modified for power, tuning capabilities and consistency.

The twist rate of cut barrel is somewhere around 1:27" to 1:30".

Here are the pics of my HM1000X with cut barrel.

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Initially I zeroed the gun in my house using JSB Knockout 25 grain slugs at around 950fps.

My gun is capable of shooting the same slugs at around 1000 fps at 150 regulator pressure.

Following is 10 shots group of Knockout slugs at 24 yards where I sighted in the gun.

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Then I moved to the boundary wall of my society. It is around 85 yards. Pic below.

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I shot a 12 shot group from inside the car with same slugs at 950fps. Gun was not very stable and wind was around 14km.

Following is 12 shot group at 85 yards on pre cast wall from inside the car.

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There is one flyer. I don't know whether it's my fault, slug fault or the gun needs tuning.

Anyhow I am positively surprised that during this casual shooting, the unchoked cut barrel performed well with slugs even with slow twist rate.

Bhaur

 

[jps2486]

Please explain what you mean by "cut barrel". Has it been cut to shorten it or does it have cut rifling?

 

[Mubhaur]

Please explain what you mean by "cut barrel". Has it been cut to shorten it or does it have cut rifling?

There are three major procedures of making barrels.
Button drawn
Hammer forged
Cut rifled

I hope you already know about the 1st two methods. In cut rifling each groove is cut individually by removing the material. There are least chances of stresses in the barrels made by this method. It's a classical method and requires more skill to make barrel.

A good barrel maker by cut rifling method does great job.

 

[jps2486]

That's what I thoiught, but just making sure. Thanks.