surprising results at 100 compared to 50

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super7

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I was shooting at 50yrds with Laupa club, Laupa Master M and Win dynapoints. At 50 yrds, the Laupa club was shooting the best for me, shooting 1/2 inch groups. The master m was a close second and the dynapoints were not surprisingly 3rd, shooting about 3/4 to 1 inch. I was curious what these ammos would do at 100 yrds. Surprisingly the Laupa club which was the best at 50yrds
(1/2 inch groups) was the worst at 100 shooting 3 shots into about 4 inches :eek:. The dynapoints were second with a respectable approx 1 inch (not much different than at 50 yrds) and the Laupa master m was the best, shooting 3 shots into about 3/4 of an inch (again just slightly worse than at 50yrds). I was very surprised that the ammo that was shooting the best at 50 would open up so much at 100. This was the only target I shot at 100 so perhaps it was just fluke? Anyone have similar results?
6p2e10.jpg
 
.22's can do some strange things if they go super sonic. High velocity ones will hit turbulence as they go supersonic when they leave the barrel & depending upon the range they will hit more turbulence when they slow down & go subsonic.

That was according to an article I read a couple of months ago & it sounds logical.
 
I would suggest that a 3-shot group with those ammos is not very representative of what the ammo really shoots like. Try 10 - 5 shot groups with each at 100 in very calm conditions, and then you will have a better idea of what really is happening. I once had a single group with Winchester HV plated ammo at 100 that went into ½". The following 4 groups were all bigger than 2½", with one group at 5". Things will "click" occasionally, but the long haul tells the tale. Regards, Eagleye.
 
Eagleye said:
I would suggest that a 3-shot group with those ammos is not very representative of what the ammo really shoots like. Try 10 - 5 shot groups with each at 100 in very calm conditions, and then you will have a better idea of what really is happening. I once had a single group with Winchester HV plated ammo at 100 that went into ½". The following 4 groups were all bigger than 2½", with one group at 5". Things will "click" occasionally, but the long haul tells the tale. Regards, Eagleye.
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X2, you need to shoot a lot more targets before you draw any conclusions.
 
The bullet that has to break sound barrier will have to deal with 'breaking' thru it, as mentioned above; and in your case, it'd do it twice - speeding up and slowing down.
Every time bullet breaks speed barrier, is like going thru an obstacle (like a few pieces of paper) that will def cause bullet to wobble and change its direction a little bit (or quite a bit) depending on it's shape, weight and so on.

Below is a pic of a plane breaking sound barrier for illustration:

SoundBarrier.gif
 
CeeZer said:
The bullet that has to break sound barrier will have to deal with 'breaking' thru it, as mentioned above; and in your case, it'd do it twice - speeding up and slowing down.
Every time bullet breaks speed barrier, is like going thru an obstacle (like a few pieces of paper) that will def cause bullet to wobble and change its direction a little bit (or quite a bit) depending on it's shape, weight and so on.
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Not quite accurate. The first time a supersonic load breaks the sound barrier, it will be inside the rifle barrel, so no effect to exterior ballistics. A bullet does not speed up after leaving the barrel. However, when it drops through the sound barrier while slowing down, then the instability is apparent. With a Rimfire HV round, that is somewhere between 65 and 90 meters, depending on initial velocity. With a centerfire, it may be well beyond 1000 meters. Regards, Eagleye.
 
You are right in the sence that supersonic bullet will reach and break sound speed before it leaves the barrel, but as it travels thru it - it's constantly accelerating (unless the barrel is veeeery long, then gas pressure behing bullet may drop below outside-barrel pressure and create drag) and as it leaves the barrel it suddenly looses the barrel drug (= wobble), thus will accelerate for a little longer (thou already travelling above sound speed).
 
CeeZer - Being a novice at this ballistic stuff, can you explain how a bullet will continue to accelerate outside the barrel if the gas pressure dissipates so quickly. I recall seeing hi-speed footage of the gases actually accelerating past the bullet due to their rapid expansion and dissipation. Surely, the bullet reaches terminal(maximum) velocity at the muzzle,no? Unless the barrel is so long to induce drag.
 
Here are some good "guidelines" for ammo-testing: they make sense, and work!

1) State the particulars (i.e. distance, target types, rifle, scope, rests - and ammo type, of course! ). Added things like wind speed and temp are nice, but a bit show-offy, perhaps!

2) Ensure you are testing the ammo you are testing (i.e. test by first firing "clearing shots" to acclimate the barrel to the particular ammo, and only then "print" your shot patterns. The clearing shots are to remove any lubrication/schmutz left over from previous bullets, or to build up lubrication that is on the test bullets ).

3) Added-point: Two swipes of a boresnake between ammo-types is recommended.

4) Shoot 3-4 groupings with each ammo type.
 
The idea that some funkiness happens to the flightpath when a bullet goes from supersonic to subsonic is debatable. In fact, you could debate it for years, and it has no effect on what the bullet actually does. In fact, it has been debated for years, and then a dude in the states starts ringing gongs at a mile with a .223 on a regular basis and the whole theory is compromised. From the above pictures, I find no conclusive proof of loss of accuracy due to a sonic transition. Both Lapua breeds are subsonic loads, hence they would not be affected by the theorized transonic dance that supersonic loads are thought to do. Dynapoints, however, do leave the tube rockin' Mach 1 and a little... just a little... depending on the temperature. Therefore, if this transonic theory is right, they should shoot the worst, which, by a long shot, they do not. Lapua Club is the anomaly, as it performed significantly worse than expected.

In my experience, as distance increases, the ability to aim small miss small lessens, resulting in augmented misses. As well, rimfire tends to be finicky to no end. A certain brand might shoot 3/4" today, and open up to 2" tomorrow (100y). At some point in time an acceptable average should be reached and accepted.

+1 on shoot more per group- your average becomes more accurate.
 
Oh right, and F=m*a... no F, no a... once the bullet leaves the muzzle, the F active is air drag, causing the slug to decelerate, not accelerate, however cool a trick that would be.
 
cyclone said:
Here are some good "guidelines" for ammo-testing: they make sense, and work!


2) Ensure you are testing the ammo you are testing (i.e. test by first firing "clearing shots" to acclimate the barrel to the particular ammo, and only then "print" your shot patterns. The clearing shots are to remove any lubrication/schmutz left over from previous bullets, or to build up lubrication that is on the test bullets ).

3) Added-point: Two swipes of a boresnake between ammo-types is recommended.
Click to expand...
How many "clearing shots" would be enough?
 
dryfire said:
CeeZer - Being a novice at this ballistic stuff, can you explain how a bullet will continue to accelerate outside the barrel if the gas pressure dissipates so quickly. I recall seeing hi-speed footage of the gases actually accelerating past the bullet due to their rapid expansion and dissipation. Surely, the bullet reaches terminal(maximum) velocity at the muzzle,no? Unless the barrel is so long to induce drag.
Click to expand...

Since you saw the footage of gases going past bullet would it be correct to think that the gas is still pushing the bullet forward then for a split moment that would translate to futher acceleration for the same split moment and lasts may be 2-3 feet past the muzzle?

I did a little research before making such a 'rediculous' claim...
 
super7 your tests are not sufficient to make any kind of conclusions or to base your ammo choice on. Listen to cyclone - he gave you by far best way to really test ammo-rifle combintaion. Just to sum up

- boresnakes between ammo brands is a must
- fouling shots are a must
- suffient number of groups is a must
- your scope should be good and sit on a rifle tight, adjusted for parallax at 100 yards.
- no rain

things like that
 
I'm certainly not making any conclusions based on this one poorly executed test. Actually, it wasn't even a test, I just shot a few rounds at 100yrd for sh*ts and giggles before I packed it in at the range....though I did find it interesting to see that 1 brand had performed so poorly compared to its norm at 50yrds.

Next time I make it up to the range, I'll test the laupa club properly and see if it really does open up that much at 100 (in this particular rifle) or if it was just a result of poor/insufficient testing.
 
That Lapua ammo is interesting and like all other 22 types of ammo, they perform better in some rifles than others. I had bought a Browning model 52 that is a real beaut of a rifle and I thought for sure that Lapua ammo and it were going to be a magic combo. There was a $150.00 lesson learned. Couldn't get it to group worth a damn at 25 meters, never mind 50.
Turned out that my old Win 60A target rifle just loved the Lapua. i have some BRNO and CZ's to try it in later when it isn't minus 29 out. FS
 
super7 said:
Next time I make it up to the range, I'll test the laupa club properly and see if it really does open up that much at 100 (in this particular rifle) or if it was just a result of poor/insufficient testing.
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Sounds good. Realize that you're probably testing a box (50 shots) per cartridge-type.
 
Ceezer
As I mentioned I'm a neophyte in ballistics . Can you refer me to your research material. All my research indicates projectile velocity is highest at the muzzle. The powder gases lose their energy quickly because of their rapid expansion in the atmosphere. Within a few inches of the muzzle. This may be why muzzle breaks are designed as they are, to take advantage of this rapid expansion, and are not more than a few inches long.

'boresnakes between ammo brands is a must'
22LR Would a couple of passes with clean dry patches be a suitable substitute for the boresnake ?
 
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