How Equipment Accuracy Affects the Bottom Line |
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britrifles
Senior Member Joined: February 03 2018 Location: Atlanta, GA Status: Offline Points: 6539 |
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Posted: March 13 2021 at 2:30pm |
I was looking for pointers on a stable Sitting Position for Service Rifle shooting and came across this video. If you are curious about how much the accuracy of your rifle and ammo combination affects your ability to hit the center of the target, watch this video. Stick with it. For many of you, it will have some very non-intuitive conclusions.
This will be of interest to those who shoot in our Lee Enfield Forum Virtual Match in the Service Rifle Class.
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Goosic
Senior Member Joined: September 12 2017 Location: Phoenix Arizona Status: Offline Points: 8792 |
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My main question is, why does this person deem it necessary to fire off 4800 rounds of ammunition to establish where a particular rifle is shooting in regards to its MOA capabilities?
If I averaged out the cost of my 308W ammunition at $1.25 per round, I would need $6000.00 worth of ammunition to duplicate his spreadsheet. The other factor would be barrel life. I personally have fired 275 rounds out of my faux L8A5T. Add the additional 4800 rounds as this gentleman suggests and I am at 5075 rounds and I have a barrel that is now at 50% of its usable life expectation. The MOA would enlarge regardless of how well tuned the rifle and ammunition is after that many thousands of rounds have been fired through that barrel. I have one rifle that is my go to target rifle. The trigger has been adjusted for optimal let off with a wide cantilever trigger shoe added for consistent let off. The barrel was cryogenically frozen prior to installation. It has 7 groove micro rifling with a 1-10" twist rate. The initial three shot test group fired from it produced a tiny triangle shaped hole measuring .325" The ammunition used is a 168grn SMK bullet sitting on top of 40.0grns of N202 and seated to an O.A.L. of 2.755 ". It has had 500 rounds through it to date. My groups for each target is ten rounds apiece using five targets only. I then add up the five individual horizontal and lateral spread of each group, do the math and get my average. 50 rounds total for every range session with this rifle. That is ten times at the range to date and the averaged MOA was established after the first 50 rounds. I think I very well might have missed what was being expressed in the video. I found it very counterintuitive...
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britrifles
Senior Member Joined: February 03 2018 Location: Atlanta, GA Status: Offline Points: 6539 |
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Not sure when he did that work. There were several shooters and rifles involved to collect the basic data. I’m certainly not going to repeat that experiment.
I think he used that data to develop distributions of the basic variables involved and then ran Monte Carlo simulations with these distributions to develop the statistical conclusions.
I’m really not surprised by this, I know from my own experience that shooter skill is the single largest factor in what happens on the target. That is obvious from the data collected. But what is not so obvious is the very small, if any, gain made for increasingly accurate rifles and ammo. An improvement from 1 MOA to 3/4 MOA rifle and ammo combination has no effect on the scores. The 10 ring on the MR target is 2 MOA. Only 2 points out of 200 possible (20 shot sting) were gained with improving the rifle/ammo accuracy from 2 MOA to 1 MOA. The reason for this is that the rifles are not fired from a bench rest and most are shot with aperture sights. So, there is considerable error in holding steady, repeatable sight picture and aim, trigger release, etc. The Monte Carlo simulation will show that sometimes a less accurate rifle will be an advantage as an error in holding or sight picture will be countered by an opposite error in rifle/ammo accuracy. I.e an aiming error to the left is countered by a shot that would have otherwise gone to the right of the group. So when these probabilities are included in the analysis, rifle/ammo accuracy has only a minor effect. What I got out of this is that you can be very competitive with a 2 MOA rifle/ammo. And this is at 600 yards on the MR target which is the least forgiving target in Service Rifle shooting (smallest score rings in MOA). The rifle/ammo accuracy will not limit you in Service Rifle match shooting unless of course it is not capable of holding 2 MOA. Our No. 4 rifles will easily hold 2 MOA off the bench, perhaps even 1 MOA with handloads. My average 10 shot group size off the bench with a scope was about 1.5 MOA with my Long Branch with handloads. None of this really apples to bench rest shooting with high power scopes. Here, the rifle and ammo accuracy dominate. The conclusion here is that if you are not able to hold the 10 ring on the SR target (3.5 MOA) in prone slow fire, don’t expect ultra precise match loads will fix that. If your Lee Enfield won’t hold the 10 ring off the bench with a scope, it’s not likely a problem with the ammo either. Quality match bullets will have an inherent accuracy of less than 1/2 MOA. I hear it time and time again from the top Service Rifle shooters, spend your time developing your skill in position shooting, not at the reloading bench. That is good advice, except now, we can’t get powder and primers! You can develop position shooting skill by dry firing. I find that rather boring to do, but it does work. |
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Goosic
Senior Member Joined: September 12 2017 Location: Phoenix Arizona Status: Offline Points: 8792 |
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You initially stated that you were looking for a stable sitting position. The sitting position I was taught and that I have taught to my teenager produce positive results. All of the horizontal and lateral movements are controlled with the non shooting hand. The elbows are employed as a rear bipod setup with the stock resting on anything of sufficient substance. Your body position is almost 90° to the rifle as well. Short of locking the rifle into one of those bench rest devices, this is as steady a position as it gets. The picture shown here has my teenager demonstrating the described sitting position. She wanted to try using the pictured sandbag but pushed it away after the first shot because it didn't let her control her X&Y axis of movement. This was the first time my daughter had fired this rifle. It was still chambered in 303B, and still had the No32Mk1 reproduction scope. Every shot hit the X ring after her initial sighting in was done...
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britrifles
Senior Member Joined: February 03 2018 Location: Atlanta, GA Status: Offline Points: 6539 |
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Sorry, should have explained better. The “Sitting Position” in Service Rifle competition is not the same as bench rest shooting. You sit on the ground with legs or ankles crossed, elbows supported on the knees. No support under the rifle other than your hands. A sling is used to help hold the rifle into your shoulder and steady the rifle. This is shot at 200 yards on the SR target in rapid fire. 70 seconds starting with an unloaded rifle and a magazine change required after the first 2 shots (mags are loaded 2 and 8 rounds each).
I had this awful rocking motion that I could not stop that was in time with my pulse. It ran at least the full height of the 10 ring, and sometimes into the 9 ring. I had to try and time my shots, which worked fairly well, but I would always throw one or two into the 9 ring in a 10 shot rapid fire string. Sometimes more if I was rushing too much. Yesterday, I sat down on my living room floor and tried all kinds of combinations of feet, leg, elbow and support hand position. I came up with a position that dramatically reduced the rocking motion. It was dead steady except for some slight twitching I could see thru the scope. I plan to dry fire practice every day until the Service Rifle match next week. It’s all about finding a position that you can completely relax into, and maintain a natural point of aim without muscling the rifle into position. |
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Zed
Special Member Donating Member Joined: May 01 2012 Location: France Status: Offline Points: 5585 |
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To improve my prone position; I need to get longer sling's. I'm not comfortable enough to get the regularity required.
The 1903 types that I have are at there longest on the No4 rifle; which is probably one or two holes off correct for me. But the No1MkIII* is longer between the sling attachements than the No4; with the No8 being even longer. So none of my 1903 type slings are comfortable on these two rifles. Even the Turner Biothane 53". The standard British made replica sling is only 47" on the long strap. That's much too short on the No4. I reckon I need 56" to be comfortable on the No1 and probably 58" for the No8.
I may try and get some leather slings made locally and I'll make the metal parts. |
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It's nice to be important, but it's more important to be nice!
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Goosic
Senior Member Joined: September 12 2017 Location: Phoenix Arizona Status: Offline Points: 8792 |
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Try this position. It has never failed me...
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Shamu
Admin Group Logo Designer / Donating Member Joined: April 25 2007 Location: MD, USA. Status: Offline Points: 17603 |
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See if you can find a Bren gun sling!
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Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)
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britrifles
Senior Member Joined: February 03 2018 Location: Atlanta, GA Status: Offline Points: 6539 |
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Sham, the 1903 sling works great for prone and sitting. Rules are kinda particular...
Goosic, the magazine on the AR makes that position pretty difficult. I tried adjusting the length of the butt stock and can’t get a comfortable stable position. Looks like what I figured out yesterday will work for me, it’s incredibly stable. My boots are supporting lower legs (right boot under left leg, left boot under right leg). I have direct contact from both elbows to my knees to my lower legs and boots to the ground. Firm grip on pistol grip, pulling back with moderate pressure. Support hand is held with wrist straight and a “V” is formed between thumb and first finger for the supporting the forend, held well back on the hand guard, a few inches in front of the magazine. I can completely relax my body into the sling, not using any muscles to stay in position. And no body movement, that’s the most important part. I’ll find out this week at the 800 aggregate Service Rifle match how well it works... We don’t shoot the sitting position in the CMP Games events (M1, Springfield, Vintage Military bolt rifles, and Modern Military), so this is something I’ve had to sort out since I started shooting Hi Power / AR Service Rifle. |
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Shamu
Admin Group Logo Designer / Donating Member Joined: April 25 2007 Location: MD, USA. Status: Offline Points: 17603 |
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I have the same problem with my SMLE. the sling is actually on hole #1, the last one!
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Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)
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britrifles
Senior Member Joined: February 03 2018 Location: Atlanta, GA Status: Offline Points: 6539 |
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I’ll get someone to take a picture of my sitting position. That’s if it works out for me on Thursday. I don’t see why it should not. Way more stable than it have ever been for me.
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Shamu
Admin Group Logo Designer / Donating Member Joined: April 25 2007 Location: MD, USA. Status: Offline Points: 17603 |
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Sitting was always my weak spot. I did better kneeling if it was permitted.
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Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)
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Zed
Special Member Donating Member Joined: May 01 2012 Location: France Status: Offline Points: 5585 |
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Shamu, I switched to the 1903 type slings in 2019. Got 2 from Turner Saddlery in the USA; one Leather and one Biothane. Both are longer than the standard British made 1903 type for the No4 Sniper kit.
I bought a British made leather replica1903; it looks the part; but is only 47" on the main strap. It's too short on the last hole for the No4; and no chance on the SMLE or No8. I'm looking at contacting a French saddlery to see if they can make longer straps to a similar pattern. If they can do that for a reasonable price, I may get a few made up. I reckon a 10 " addition will be enough for the No8 and SMLE. I'm certain it will make a huge difference to the prone position. Our service rifle competitions are shot prone; except the trainer .22 class which has both prone and standing.
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It's nice to be important, but it's more important to be nice!
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Shamu
Admin Group Logo Designer / Donating Member Joined: April 25 2007 Location: MD, USA. Status: Offline Points: 17603 |
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I got mine from a guy who makes them here exactly "to Spec" but the spec for the 03's & the Garnds is about 6~8" shorter than is comfortable with the SMLE.
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Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)
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Zed
Special Member Donating Member Joined: May 01 2012 Location: France Status: Offline Points: 5585 |
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Shamu, could you measure your sling's main strap length please?
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It's nice to be important, but it's more important to be nice!
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britrifles
Senior Member Joined: February 03 2018 Location: Atlanta, GA Status: Offline Points: 6539 |
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The Turner Saddlery 1903 Biothane sling works brilliant. I’ve got 4 of them and have used them for 5 or 6 years now. You can’t break them. The long version needed for the No. 4 and M1. Short version OK for AR.
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