Forend Rifle Strap for Support Hand

One Day...

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As to turn bolt extraction, bruce moulds is correct. CRF or PF has nothing to do with it. The camming (operating word: camming) extraction power comes from the fact that when a turn bolt handle is lifted, an angled camming surface engages either against a lump inside the rear bridge, or against the rear bridge rear face, to converts some of the lift force of opening the bolt into a rearward force, therefore an extraction force. Because this force is leveraged by the camming function, it is a superior force to a straight pull force.

1605390447970.png

Straight pull actions by definition do not have a rotational bolt handle movement, hence no extraction camming power. Admittedly, this is not required until a case gets stuck into the chamber, in which case any straight pull action will provide less extraction power than a typical well-designed turn bolt action.
 
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Dr Ray

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interesting comment on the video re extraction.
he comments on the lack of extraction camming of straight pulls compared to turnbolts.
bruce.

I have never used a straight pull action rifle bit when I think about it, it would not have the canning power of a bolt action.
Hmm something to think about but

I don’t think a hunter would be using ammunition that was not “perfect”.
I mean by test it would be correctly sized.
 

bruce moulds

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Understanding the physics of it...

Hmmmm............. as much as I hate to be raining on Norma Academy's parade, the reality is that a hand loop like this is entirely useless, and BeeMaa's conclusion "another piece of gear that would end up in a drawer" is correct...

Here is why:

When shooting a rifle, the butt rests on the shoulder. This contact point is also the pivot point upon which the stock rests, relatively stably, as the muzzle wobbles.

The support hand that holds the rifle forearm is also attached to the same shooter's shoulder that holds the rifle butt. Therefore, the rifle and the support hand are free to wobble together because they only have one shared attachment and pivot point at the shoulder. Tying the hand to the forearm with a hand loop does not change any of this.

When a shooter uses an elbow rest, whether it be on the ground when shooting prone, on the knee when shooting kneeling or seating, or on a support (e.g. tree branch or rock) when shooting standing, a second contact point is created half way between the butt and the muzzle. However, the elbow itself being flexible, it constitutes another pivot point, and this allows the muzzle to still wobble, although less than if the elbow is not used, because the second pivot point is now closer to the muzzle.

The purpose - and the physics - of the shooting sling, whether it be a competition sling wrapped around the bicep close to the shoulder joint, or whether it is a military or hasty sling wrapped under the bicep close to the shoulder joint, are:
  1. to use the relatively stable shoulder as the first point of a support triangle for the rifle forearm;
  2. to use the fairly stable elbow anchor point as the second point of a support triangle for the rifle forearm;
  3. to create a mechanical link between the shoulder and the sling attachment point so that the third point of the triangle, the sling attachment point, is stable, being forced into a fixed position at the end of the fixed-distance arm and the fixed-distance sling.
With a sling under proper tension, the butt of the rifle is at a relatively stable point on the shoulder; the elbow is at a fairly stable point on the ground, on a knee, or on some form of support; and the support hand is a fairly stable support point at the end of the arm and the end of the sling.

This is why, as BigSteve57 and Nyati rightly emphasize, the sling must be properly tensioned. If it is too long and loose, it does not retain the support hand from moving forward and does not stabilize the third point of the support triangle; and if it is too short, it bring the third point of the triangle too close to the second point and reduces the stability of the support triangle.

View attachment 375650

Once the physics of the application of forces in the sling technique are understood, it is easy to conclude that:
  1. Using a sling without an elbow rest is virtually useless, save for the psychological placebo effect;
  2. Using a hand loop that only involves the support hand is completely useless, save for the psychological placebo effect.
In both cases, the rifle and support arm still wobble freely around the shoulder pivot point...

And obviously, as previously noted, attaching the sling to the barrel defeats the purpose because a properly tensioned sling will flex even competition bull barrels...

:)
one day,
you saved me a post, and you did it more eloquently than i could have.
the sling thing in question is more of a hindrance than an asset.
it puts the hand in a fixed position when that might need to be varied with conditions.
when you see "norma acadamy" you instantly know ADVERTISING.
to do this they need cred, and including this sling implies a greater understanding of this subject.
further thought however reveals that they have avoided the importance of basics, so often done in modern times in the shooting industry.
bruce.
 

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