Anti-pulse slings - do they work?

[Cumbrian]

There has been some recent discussion here about slings but not specifically, I think, about the merits of anti-pulse slings. I seem to be having problems with pulse, even though my sling is placed high on the arm and pulls from the outside, so I wonder if an anti-pulse sling would help? I can't quite see how even a fancy mechanical link can prevent the pulse being transmitted down what is still, by definition, a very taut link. If such slings do work, which is the best one? All thoughts and experiences gratefully received.

[Tim S]

The basic idea of anti-pulse slings is to ensure the strap is pulling from the back of the arm, with no bias to one side, and for the cuff not to compress the arm. Both the Centra slings have a separate cuff and strap; the cuff is double thickness at the front, and the strap is attached to the outer strap in a way that it will self-centre. The Gehmann sling has a split strap that anchors on either side of the cuff, again to ensure an even pull.

Anti-pulse slings seem to be a bit like marmite; some shooters love them, and some gave up in disgust. The main complaints about the Centra sling are weak strap material that tears, and the metal gubbins breaking/coming loose. I have also seen one Centra sling where the cuff elongated under tension, and changed form and o to an 0 during a match, so the shooter was practically flat at the end of the detail.

Before you go spending £100+ on a new sling, it may be worthwhile checking whether you can eliminate, or just lessen, pulse issues by traditional means. Firstly is your sling cuff loose enough around your arm? You should be able to fit at least three fingers between the cuff and your arm, any fewer and the cuff can be pinching the brachial artery. I use an ESE sling and have the cuff completely open; I removed the clamp and pinned the straps together with Chicago screws. Do you have enough padding under the jacket? It may not be comforatble to wear a thick jumper and jacket in the summmer, but if a t-shirt doesn't give the necessary padding, you may have to live with the heat. Have you tried altering the height of the sling? Most British Prone shooters prefer a high sling as it gives maximum leverage, but small differences in exactly how high can make a big difference to the pulse. Maybe try having the sling pull against the back of your arm, not the side, so the strap projects from the front of the arm when you are in position. Finally make sure the sling tension is not too great; a tight position is good, but you can easily go too tight, especially with a synthetic sling. Because synthetic slings don't stretch, they will bite the upper arm and wrist/hand in a very uncomfortable manner if over-tensioned.

You can make your own anti-pulse sling. Forum member (and current British champ) Ken B made his own from a Kurt Thune sling. His design also works with ESE slings; I tried it, but preferred a standard configuration. Ken is normally quite happy to help with enquiries.

[Cumbrian]

Tim,

Thank you very much. That looks like a comprehensive and definitive reply, unless someone can come along with experience of the latest Truttmann and Bleiker anti-pulse sling. I seem to remember seeing a photo of Ken B.' s sling, which he had altered quite a lot, but I didn't realise the effect was to produce an anti-pulse sling. I must look it up as I too have a Thune sling.

[Peter_Scant]

The recent discussion got me thinking as well. I’ve always used a simple sling like the KT UIT1 with the cuff completely open but since the newer “anti-pulse” slings came out I’ve been looking at them but hadn’t convinced myself that they are technically better.

After digging through old posts, looking at world cup photos and the various slings on the market I saw that there were three basic designs:
- Open cuff where the cuff doesn’t go completely around the arm. For instance slings like the KT UIT1 and Anschutz constant.
- Closed cuff pulling from the centre where the cuff goes completely around the arm and the sling pulls from the centre of the cuff. For instance slings like Martynov’s and Jenson deluxe rifle sling.
- Closed cuff pulling from side where the cuff goes completely around arm and the sling pulls from the sides. For instance the MEC sling and Creedmoor No-Pulse Sling.

It was looking the Jenson deluxe sling and Creedmoor no-pulse sling that tuned me into the differences when comparing the others in there.

I can see that depending how you set up any of the above sling designs you can mimic another.

The only other difference I noticed is some designs ensure the pull of the sling is through the centre of the cuff by coupling the two ends of the sling via a sliding mechanism. For instance slings like MEC, Martynov’s and Jenson deluxe rifle sling.

So for me I wonder:
Is there an advantage of having cuff going around the arm?

Is the key element of the “anti-pulse” sling that the pull of the sling is always through the centre of the cuff?



Also Cumbrian, a photo of the modified sling by KennyB can be seen here http://www.targettalk.org/viewtopic.php?f=3&t=33285

[KennyB]

I should put a new picture up as that was how my sling was 2 years ago. It now has a Thune fine adjuster (ATL) and the buckle has moved. I wouldn't describe it as entirely Pulse Free though.

What I HAVE done is to try and introduce a twist into the cuff so that the bottom edge doesn't dig into the inside of my bicep quite so much. This means that the thing isn't self centering anymore because of how I've had to do it, but it's slightly more comfortable. I'll post a pic later.

I know Warren Potent has posted elsewhere that pulse free slings aren't... I tried HIS sling configuration a while back and quickly changed back.

K.

[Cumbrian]

I'm very grateful to Peter for his careful and thoughtful piece of research - and for the very useful link to the photo of Ken B.'s modified sling. Likewise to the owner of the latter sling for his contribution. Looks a bit like, as I suspected, that there is no easy answer to pulse problems. I had already incorporated most of Tim's recommendations, though maybe my sling could go an inch or two higher, and I will certainly think on Ken B.'s original sling model. Perhaps I need to get my pulse rate right, right down to give me a sporting chance; it's not particularly high on the whole, but it's all too easy for the heart to start racing on the firing point. Who is it that has pulse reducing techniques - free divers? yoga meditation specialists?

One further thought/question: if the hand supporting the rifle goes numb, which seems to happen to people, including me on occasion, will that help to nullify the pulse?

[Tim S]

I don't think a numb hand will help your pulse issue, and I'm not sure that it's desirable. For me my hand will normally only go numb towards the end of a long match. If it does go numb when shooting a 10-bull it's when my position is uncomfortable (usually the result of an ill-advised tweak) and the sling is too tight, or there's somehow too much pressure on my hand.

[KennyB]

Here's how my sling currently looks - see the way the fine tuner is angled to push the bottom of the cuff away from the inside of the arm :



K.

[ABoyd57946]

Re a numb hand I purchased a small Anschutz compatible handstop which solved the problem. FYI thanks Tony

[Cumbrian]

Following Tim's excellent advice and that of a very experienced fellow shooter I met recently, I have pulled and fastened my sling much more round to the outer side of my left arm, so that it sticks out pointing forward from my jacket when not attached to the rifle. It effectively shortened the whole sling and I had to let it out a couple of notches to be comfortable. First results in use are encouraging. To prevent the sling from slipping down and round the upper arm I use a sling keeper as well as the strap from the shoulder on a Kurt Thune jacket, if anyone is interested.

[Tim S]

I fixed my sling onto the keeper many years ago. A bolt and butterfly nut with two washers did the trick. If you go this route it is very important that the sling is fixed at the right point, or it can pull the jacket off the shoulder.

[higginsdj]

I assume people haven't forgotten about the second pulse point - the wrist.....

Cheers

David

[Cumbrian]

I assume people haven't forgotten about the second pulse point - the wrist.....

Cheers

David

I must confess I have never heard of this, though I can easily believe that I ought to have done. Where is it exactly and how do I avoid putting pressure on it through the sling?

[HWN1011]

I assume people haven't forgotten about the second pulse point - the wrist.....

Cheers

David

Do tell more??? :-)

Also has anyone tried the Truttmann/Bleiker anti pulse sling? Thoughts no it?

[higginsdj]

The sling wraps around the front of the wrist to the handstop. Think about it - where do doctors take your pulse from and why? If the sling is really tight not only can you see the pulse through the wrist in the sight but you can feel it as well. I have elimiated all pulse from the upper arm in my fullbore setup (thanks to a heavy/stiff jacket) and in most cases the padding on the wrist of the shooting glove + jacket cuff will eliminate the wrist pulse - but not everyone shoots with a glove and/or jackets cuffs that cover the wrist!

On hot days shooting out in the summer sun, pulse is a real issue. If you can minimise it under those conditions you will all but elimiate it for any other shooting conditions.

Another less common point is the jugular. If you have a chunky stock with a high stock postion that efectively runs along the side of the neck then applying any pressure by the head (ie to get the head in the right position behind the sight) can allow pulse to be transmitted down the stock.

Cheers

David

[Peter_Scant]

I’m still thinking about this and still don’t see the technical advantage of the “anti-pulse” sling....

I’ve come to the conclusion that the only reason to have a totally enclosed cuff is to prevent the cuff from sliding down. But with good grip material on the sling and jacket, and a properly set up sling keeper the additional grip of an enclosed cuff isn’t needed for this.

KennyB, what is your rationale on the screw positioning of the cuff?

David, thanks for the reminder about the pulse from the wrist!

[KennyB]

KennyB, what is your rationale on the screw positioning of the cuff?

Hi Peter.
OK - originally I had the screws above each other and that allowed the fine tuner mechanism to self center on the cuff in a similar fashion to the MEC & Truttmann/Bleiker. However, I found that the bottom edge of the cuff still dug into my bicep on the inside of the arm and occasionally I suffered bad pulse which I thought may be caused by this.
By angling the fine tuner mechanism so that the top is towards the outside of the arm and the bottom is towards the inside of the arm I found that the bottom inside edge of the cuff didn't dig in quite so much - so I fixed like that by moving the screws to permanently maintain that angle.
I then angle the strap so that it runs across the wrist with an even pressure. As the Thune sling was configured when I bought it, the bottom edge would dig into the wrist quite painfully. Having a single thickness of strap was better, being able to twist it to achieve an even pressure was better still.

I still sometimes get pulse but I've worked very hard at releasing the shot in between beats - which is part of my technique now. When I can hear the heartbeat in my ears I'm no longer anxious about it (like I was 3 years ago) because I know exactly when in the cycle to let the shot go. When I can't hear it, I still get a sense of when the pulse is - but it's not so exact and I occasionally get it wrong.

Ken.

[Peter_Scant]

Thanks Ken, you've confirmed some of my thoughts. I'm currently using a KT UIT1 sling and find that I have to be really careful how the sling goes around the back of my hand otherwise I get a pressure point on the boney point of my wrist causing pain.

My current plans are to change to a KT ATL for the twist mechanism of the fine adjuster and change the strap to the handstop to a single thickness leather strap. I'm then going to do testing with sling height and pull direction.

The problem I have with my pulse is that while it is small, typically well within the 10 ring, the speed of movement is quite quick which I suspect is throwing the shot out of the 10 ring.

Thanks again Ken.

Peter

[KennyB]

Hi Peter - my sling was originally a Thune Mk 2 sling but I was able to buy the ATL bit separately and incorporate it.

I agree with your observation about speed of movement - there is a great article about it on the SCATT website. I think that adding mass to the rifle in the right places to increase it's inertia might have helped me but it also may have aggravated my aging joints... My rifle was over 7Kg last year - now it's back to 6.6Kg.

Good luck.
Ken.