Page 1 of 1

Smallbore prone rifle - C of G

Posted: Sun Mar 06, 2011 11:21 am
by Globesmasher17
Folks:

Looking for some advice, hints or tips......

The hand that supports the stock in prone smallbore rifle shooting ..... [I'm a right handed prone shooter so I'm referring to my left arm & hand] ...... where should it be: in front of the Center of gravity (C of G), right on/under the "C of G" or behind the "C of G"?

I read through the 2009 edition of MEC's "Ways of the rifle" and found nothing that mentioned the subject of the supporting forehand placement in terms of the rifle's C of G.

I can also see this as being a very "personal" thing depending on one's body composition ..... long arms would tend to place the supporting hand very far forward on the stock in front of the rifle's "C of G" (more forward towards the muzzle end of the rifle), whereas perhaps short, stubbly little arms (like mine) may lend for the supporting hand to be placed further aft on the stock behind the rifle's "C of G" (for aft of the rifle towards the action).

Initial help for me came from some very helpful individuals who are tall with long arms. I found that stretching my supporting arm and hand as far forward as possible became very uncomfortable leading to quick fatigue and the associated shaking etc .... I've decided to change the composition of my prone position to suit a more natural prone posture for my body type - BUT - I notice that if I do this the "C of G" of the rifle is now quite far forward in front of my supporting hand.

I'm not sure if this a good thing or not.
I'm just wondering if having the "C of G" in front of my supporting hand on the stock is a bad thing or not.
Looking for any advice, hints or tips from experienced smallbore prone shooters.
Thanks.

Posted: Sun Mar 06, 2011 2:33 pm
by RobStubbs
My feeling is that it should be where it feels comfortable for the shooter and the centre of gravity is not so important, although if you're able too, perhaps adjusting so your hand is around the cog might be a good idea (?). In practice the size of the shooter (or their arms) dictates where they put their supporting arm.

Rob.

Posted: Sun Mar 06, 2011 2:51 pm
by KennyB
A natural relaxed position is the way to go IMHO. You can always adjust the balance with weights should you feel the need.

If you have shorter arms, going further forward on the forend will likely lead to a very low position with some possible associated problems as you've discovered...

I know other good shooters who like the C of G slightly forward of the support hand.
My personal preference is to have the C of G pretty much over the support hand. I find that it gets painful if the rifle is too muzzle heavy - I use a tube and have a heavier than normal barrel so I ended up shaving the stock down to get a comfortable balance.

Posted: Sun Mar 06, 2011 3:41 pm
by skylark
Mine's slightly front-heavy, but only slightly. I'm 5'2 and shoot a Walther KK300 without a hook in a not particularly low position, so I'd have thought mine was about as front-heavy as you were likely to get without deliberately adding weight up front.

If yours is very front-heavy, I do wonder if you have got the butt too long (especially if you were set up by a tall shooter who might not have realised), and whether you could shorten the butt and move the handstop forward in sync to bring the CoG back closer to your left hand. What combination of stock and barrel have you got?

Posted: Mon Mar 07, 2011 6:57 am
by Dave IRL
My hand is most of the way to the end of the fore-end and the centre of gravity is certainly behind my front hand. I've found this gives better balance but does make you pay more attention to the pressures around your shoulder, trigger hand elbow and trigger hand in order to retain an exact natural zero. I've a 10" tube on the way from Eric U which should give me just a bit more weight towards the front, which I'm curious to see the effects of.

Posted: Mon Mar 07, 2011 11:03 am
by Globesmasher17
skylark wrote: If yours is very front-heavy, I do wonder if you have got the butt too long (especially if you were set up by a tall shooter who might not have realised), and whether you could shorten the butt and move the handstop forward in sync to bring the CoG back closer to your left hand. What combination of stock and barrel have you got?
Skylark:

I have the butt plate only marginally extended in order to resolve a comfortable position in the right arm and the trigger hand. From pistol grip to butt plate I only have 8.5".

The rifle is an Anschutz 1907 in a 1912 stock with a MEC "Strike" tube on the muzzle. The whole rifle only weighs in at 12.5 lbs so it is relatively light in comparison to some smallbore rigs. The butt plate is the Anschutz 4765 so with all the adjustments I find the right arm and right shoulder to be quite comfortable. The butt hook also offers comfortable upward pressure due to the change in fulcrum (my left hand) placing the CofG in front.

Posted: Mon Mar 07, 2011 11:08 am
by Globesmasher17
KennyB wrote:
I find that it gets painful if the rifle is too muzzle heavy - I use a tube and have a heavier than normal barrel so I ended up shaving the stock down to get a comfortable balance.
Kenny:
Yup, this is what I discovered almost immediately. When I moved my support hand backwards along the stock to a more comfortable position the C of G shifted to now be in front of my hand (muzzle heavy) and suddenly the pressure on the support hand rose appreciably.

This was why I threw the question out to the forum to see what advice I could find.

Seems that if I slide my support hand far forward to be either under the C of G or slightly forward of it - I get marginal pressure on that support hand ... but the position is uncomfortable.

If I slide the support hand backwards (rearwards) into a more comfortable position thus putting the C of G in front of the hand, I get far more pressure coming into the support hand. And, the pressure comes in quickly too!!!!

Posted: Mon Mar 07, 2011 2:02 pm
by KennyB
Globesmasher17 wrote:When I moved my support hand backwards along the stock to a more comfortable position the C of G shifted to now be in front of my hand (muzzle heavy) and suddenly the pressure on the support hand rose appreciably.
Is the pressure/pain on the front part of the hand - between the thumb and forefinger?
I suffered from this for quite a while (to the point where I was considering giving up) but I found a solution which worked for me. I posted some pictures on this thread: http://www.targettalk.org/viewtopic.php ... c&start=20. near the bottom.

Correct positioning of the sling on the forearm and having the right handstop and glove did the trick for me.

K.

Posted: Mon Mar 07, 2011 11:40 pm
by Globesmasher17
KennyB wrote:Is the pressure/pain on the front part of the hand - between the thumb and forefinger?
I suffered from this for quite a while (to the point where I was considering giving up) but I found a solution which worked for me. I posted some pictures on this thread: http://www.targettalk.org/viewtopic.php ... c&start=20. near the bottom.

Correct positioning of the sling on the forearm and having the right handstop and glove did the trick for me.

K.
Kenny:
No - the front part of the hand is good. I use the large black Anschutz handstop - the 4751. It is really good and surprisingly comfortable.

My sling sits fairly high - top of the keeper on a Kurt Thune prone jacket and I use a Kurt Thune glove - the white one with no fingers. It's a Kurt Thune sling too ......

The pain in in the heel of my hand/palm. I tend to "hook" the left elbow a little so the left hand is turned a little. However, it seems now like the entire weight of the rifle now presses squarely into the palm and heel of the support hand.

The glove is fairly new .... so I'm hoping it's not the fact that the padding has been compressed completely .. :(