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Discussion Starter · #1 ·
I am just getting into some prone rimfire shooting, what is the preferred technique for the use of the handstop and sling? Is it possible to have it too tight? I am getting some pulse or heartbeat transmitted throught the sling,I have the sling as high on the shoulder as it can go. What are the things I should be looking at to correct this? Thanks! Joe S
 

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Yes is it is possible to have the sling set too tightly, both around the arm and in length.

Firstly what sling/rifle combination are you using? A single point sling and target rifle (possibly with jacket as well) or a two-point sling and a sporter style rifle?

With a single point target sling; I have always been taught, and practise this, that there should be sufficient room to fit a couple of fingers between the bicep and sling. This prevents the sling from acting as a tourniquet. I don't ascribe to the idea that having a completely numb supporting hand is good.

If you are using a well-fitting shooting jacket, this can help to support the sling, so it need not be really tight around the arm to stay in place.

I would also avoid having the sling too tight at the handstop. This can put too much pressure on the wrist, and also jam the butt to tightly into the shoulder.

A sucessful prone position is balanced, everything should feel comfortable and "right".

As to technique; the supporting hand should be snug against the handstop, and the handstop must fit comfortably into the web of your hand, not too big not too small. With your hand like this, the rifle should lay across your palm; not over the thumb muscle or the fingers, as these will hurt or strain the hand. Expensive handstops can be adjusted laterally to fit.

The sling should pass over the back of the wrist and hand, and fix as near to the the hand as possible. Having the swivel well ahead of the handstop will place pressure on the hand and wrist.

The wrist joint should be straight. If the hand is bent this will strain the joint, target shooting gloves provide suport here.

I would advise you to find an experienced shooter to look over your body position and technique, for feedback. Also buy a good book on prone and positional target shooting. "The ways of the Rifle" is highly though of, written by international level shooters.
 

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Joe,
Glad to hear that you are giving prone a try. There is little that can be done to totally eliminate the pulse. It is possible to minimize it, however. If you are planning on getting real serious about this, you will eventually need a shooting jacket and a shooting glove. Assuming that you are not at that stage yet, a heavy sweatshirt some atheletic knee pads (for the elbows) and a work glove or mitten with some padding in it will suffice. Get into position without the sling. Adjust the location of the forend stop so that when you are supporting the rifle in the shooting position, your left forearm makes about a 30 degree angle with the ground. Your hand should be firmly against the forend stop. The left hand should not be cramped or in an unatural position. The gun should be resting on the heel of your palm and the back of the hand should be relatively straight. Your left elbow should be slightly to the left of the center line of the stock. Now attach the sling. The sling should be around the arm above the bicep. The loop of the sling should be drawn tight enough to prevent the sling from slipping down the arm but not so tight that it cuts off circulation. The length of the sling should be such that you can feel it hold the rifle without any effort from your right hand. It helps if you have someone helping you make your initial setup. You should not really be able to see your pulse with iron sights. With a scope, you will always see a little pulse. You just have to ignore it, hold center and squeeze. Hope this helps.
Al
 

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Discussion Starter · #4 ·
Thanks Al and Tim

I am shooting a Rem 40X with a heavy shooting jacket and a single point leather target sling. I also want to shoot my BSA MkII, but the handstop is not on a sliding rail like the 40X, so I cannot get the handstop up tight against the left hand. Will be shooting mini-palma for the first time in a few weeks, and was thinking about using two rifles, but I might end up bringing just one and switching sights to shoot Iron and scope. So my original question was how to eliminate the pulse, which is being transmitted, apparently I have too much tension on the sling, will back it off a bit and see what happens,I am using the sling hook on the shooting jacket to keep it from slipping. Will also double check the tightness of the sling loop.
I havent decided what to do about the handstop on the martini, either shoot as is or figure out a way to mount it closer to the butt. I do not want to modify the rifle unless I know there will be substantial gain from doing so. How much difference do you think it will make? Thanks! Joe
 

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Reducing the pulse may just be a matter of adjusting sling tension and finding the right place on the arm for the loop. If your pulse is such that you can keep the cross hairs in the ten ring, that is good. If you can keep them in the x ring, that is better. It will never totally go away.
I shot the Mini-Palma twice in the past 2 days. Managed to get a 445 with the irons. You will need a very small front aperture. I use a 0.3 diopter in my front sight with a 40 inch sight radius. I used a 3 mm aperture for the whole course but probably should have used a 3.1 or 3.2 on the 800 target. Line of white around the bull was a little thin. If you shoot it in block time, take a break after the 900 bull. By that time you will be throbbing. LOL Have fun with it.
Al
 

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I quite agree about the Mk II, the tapped plate is a nuisance. You might want to try packing the back of the BSA's handstop so that your hand does fit snuggly, or bringing out the metal file if it's the opposite.

While checking the sling hook, make sure the jacket fits. If it is loose around the chest and shoulders the sling will slip. With the jacket on and fastened raise your elbows to shoulder height and try to touch them together. If the jacket fits properly they shouldn't meet.

You are right to let the jacket support the sling; the sling shouldn't be too tight around the arm. Do you wear a sweater under the jacket? This extra padding can help deaden pulse.

The body position also contributes to heartbeat, rolling slightly left (for right-handers) and bringing the right leg up will raise the chest from the ground reducing the felt effects.

Good shooting.
 

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Since you are using a jacket with a sling hook, get the parts of the sling that are in contact with the inside of your bicep off of it. The sling should be tight enough that when you completely relax your arm, you're still on the target (as this is how you will shoot it). It should be very taught going to the rifle, but the part that wraps around your bicep should only be putting pressure on the back of your arm, with very little on the sides.
 

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Discussion Starter · #8 ·
Thanks everyone for your help. I just bought a set of Lee Shaver's front sight inserts for the Redfield Olympic sight, they are unmarked but I am measuring the size of the apertures. I recently read that the aperture should be 2-2.5 times the size of the bull. Does anyone know what that translates to for the 800 and 1000 yd targets? Al D. suggested 3.1 or 3.2 mm for the 800. I will give that a try this week to see how it works. Is there a formula for computing the relative size of the bull at 100 yds? thanks! Joe
 

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Actually, 2-2.5 might be a little big. 1.5-2 is a little more like it. If you are not using a lens in the front sight, you will probably want to go down to 2.5 on the front aperture. The way to calculate the apparent diameter of the bull in your front sight goes like this. Dont worry about the trig nomenclature.
tan a = y/x where y= 1/2 the diameter of the bull and x= the distance between your rear sight and the bull. tan a is going to be a very small number.
The diameter of the bull at your front sight = y'= 2(x'tan a) where x' is the distance from the rear sight to the front sight.
Hope this is not too confusing... good luck.

Al
 

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Joe,
Hoo boy! Ask the right question and the flood gates open! I had forgotten about Bryan's table. It is a great piece of work and can be quite useful. It will probably give you larger aperture sizes than the method I described. That is not all bad. In defense of my method, however, I ran some numbers. Since I did not have the diameters of the MP bulls at hand before, I used the ones in Bryan's table. As I stated before, I used a 3.0 mm diameter front aperture with 0.3 diopter forward of the aperture (i.e. not magnifying the aperture) and a sight radius of 40 inches. I also use a corrective lens in my glasses that is on the order of 1.75 diopter plus some correction for astigmatism. I have severe presbyopia (in other words, can't read a paper, or this computer screen for that matter, without my glasses). Anyway, I calculated that the aperture range for my set up for the front sight would be 3.1-4.1 mm for the 800 bull; 2.7-3.6 for the 900 bull, and 2.5-3.4 mm for the 1000 bull. As I said in my original post, the 3.0 was just right for the 900 and 1000 but a little tight for the 800.
Now, how does my method compare to Bryan's? Without any corrective lenses but staying with the 40 inch sight radius, I would suggest 2.4-3.2 mm for the 800 while Bryan suggests 3.1-3.3 mm (if I have read the table correctly). For the 900, I suggest 2.2-2.8 mm and Bryan suggests 2.9-3.1 mm. And finally, for the 1000, I suggest 2.0-2.6 mm and Bryan suggests 2.7-3.0 mm. Again, If I have read his table correctly, you can see that they are a bit larger. So, you now have a whole lot of info to chew on. Good luck.
FWIW, in case you did not know, we can blame Bryan for creating this monster we call the Mini Palma. It is a demanding target and course of fire. It is too bad that it has not caught on more as a competition.
Al
 

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A little aperture background theory ..... !

Hi Al and Joe,

Just for reference I have uploaded an extract from my files ... an old text on the subject .... original author long forgotten, at least by me ... but hopefully it will supply an explanation as to how the prior work by Karas and myself was derived.

http://chatrifleclub.org/apertheory.pdf

In essence the concept is based upon the ability of the individual eye sensors - many thousands of them per eye - to define an "edge" - (ie: that demarcation line between "white" and a "black" areas of the vision picture). Naturally it assumes the posession of "perfect" eyesight in which case each sensor cell can detect to an accuracy in the neighbourhood of 1 MOA. Hence one must make slight adjustments for personal satisfaction for those not blessed with such vision.

Over the years there has been a fair amount of discussion between myself and several other leading coaches and "opthalmic specialists" as to the validity of the data ... to date there has been no major dissension !

Al, thanks for the thoughts on the Mini-Palma game .... as you say it is quite challenging ... yet if I had to do it again I would utilise a larger "black" .... one more in keeping with, say, the current Metric bulls. No changes would be made in the scoring ring sizes. All the tests and matches we ran in the early days of the game produced scores by actual Palma competitors comparable to those they shot on the full-size LR targets. Brooks Harris is still, I believe, the highest ever scorer to date, losing out on a "possible" on his final shot of a match when an unexpected Hi-Power rifle was fired on an adjacent range.

Regards,
Bryan - The Fuzzy Limey :rolleyes:
 

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Discussion Starter · #13 ·
Mini palma report

Thanks for all your help everyone. I ended up making a wooden handstop for the BSA MkII with a detachable sling swivel, worked out quite well. Also ordered a set of Lee Shavers inserts for the iron sight aperture. I had an old Vari-X III on the BSA and used a CMP 40X for the iron sight match. I shot 411 with the irons, the aperture size was OK, but I had difficulting finding the correct bullseye on the target. Do not think I had any crossfires. It started to rain during the scope relay, so I shot as quickly as possible due to the difficulty of removing the BSA stock to dry it out. Ended up with a 437 with 14Xs on that relay. Raindrops on the front lens did not help, I am looking for a sunshade for the scope, do not think the new Leopold sunshades will fit the older scopes, can anyone let me know if sunshades are available? The scope height got to be a bit of a nuisance, neck got sore after a while, will try to get a lower set of rings, I think I can bring it down about 1/8" without interference. A good learning experience for sure, and very compeitive. My friends son won the State Championship with a 422 and about 20Xs, Oh to have the eyes of a 15 yr old again! Thanks! Joe S
 
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