Various Stringing Groups

slinkylegs

slinkylegs

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Hudson Bay, SK
Alright, I'm hoping someone can help me figure out what is going on with my gun.

I'm using a CZ 452 Varmint with a Leupold VX-II 3-9x33 EFR, Talley low mounts torqued to spec. I was at the range today making sure it was still sighted in at 25 yards, and used CCI Subsonic HP (shot off sand bags). It shoots great, with my first group pretty much in one ragged hole.

After it was too my satisfaction and the remaining rounds were fired, I decided to fire off four additional types before I left. I only did 5 shot groups for each, but the results were interesting.

The first group was CCI Standard, and they shot very well (as expected). No issues with that.

Secondly, I used CCI Quiet's. These strung horizontal rather dramatically, with nearly an inch of variation.

I then shot some CCI Quiet Segmented, and while they were not that accurate, the group looked fairly typical.

Finally, I fired off some CCI Mini-mag Segmented rounds. These had a slight horizontal stringing, so I did 5 tree shots, and these were all in line vertically, but with some horizontal stringing.

I did shoot a final 5 round CCI Standard group and they were wonderfully accurate, just as before. So why is it that the Quiet's string vertically, but the Mini-mags horizontal (although not as dramatically), while the Standards and Subsonic HP's are very accurate. It was breezy, around 25-30 km/h, but wouldn't that affect the bullets the same? Is it just that each gun handles bullets differently?
 
Hi,
Grauhanen (among others), one of the members here has posted extensively about 22lr ammo accuracy. Based on that info, my understanding is that several things come into play:

  1. Consistency of the ammo manufacturing process. Amount of primer, how evenly is it distributed, and the same for the powder. Bullet seating and crimping, etc.
  2. Consistency of the bullets themselves. Is each bullet the exact same weight and dimensions?
  3. The general specs of the ammo in relation to your rifle. Some rifles just won't shoot some specific ammo well. My Marlin semiauto shoots reasonably well (usually about 1" at 50 yards with a scope) when using CCI SV. The groups opened to 1.5" or more, when I used CCI Blazers.
  4. The condition of your rifle barrel, crown and chamber. If they are worn or damaged, you're more likely to get weird results.

Cheers,
Neil
 
Even though your barrel is relatively heavy, it will still be susceptible to different harmonics with variations in ammo. I have the same rifle and see similar results. Try the Norma Tac stuff. It shoots like a dream in mine.
 
Quiets because they were slower so will have a different POI than the SV you shot. Plus more acceptable to wind due to the slower speed.

25kph winds would effect it as well. Then the faster HV ammo normally have a different POI as SV. I can see up to a inch with my guns switching from SV to HV.
 
Marlin989 said:
Hi,
Grauhanen (among others), one of the members here has posted extensively about 22lr ammo accuracy. Based on that info, my understanding is that several things come into play:

  1. Consistency of the ammo manufacturing process. Amount of primer, how evenly is it distributed, and the same for the powder. Bullet seating and crimping, etc.
  2. Consistency of the bullets themselves. Is each bullet the exact same weight and dimensions?
  3. The general specs of the ammo in relation to your rifle. Some rifles just won't shoot some specific ammo well. My Marlin semiauto shoots reasonably well (usually about 1" at 50 yards with a scope) when using CCI SV. The groups opened to 1.5" or more, when I used CCI Blazers.
  4. The condition of your rifle barrel, crown and chamber. If they are worn or damaged, you're more likely to get weird results.

Cheers,
Neil
Click to expand...

Thanks Neil, those are helpful variables to consider. I assumed the Quiet's wouldn't shoot great, but I was floored to see a vertical string of 1" at 25 yards. The gun itself shouldn't be the problem, it only has a few hundred rounds down the barrel and is in very good shape.

propliner said:
Even though your barrel is relatively heavy, it will still be susceptible to different harmonics with variations in ammo. I have the same rifle and see similar results. Try the Norma Tac stuff. It shoots like a dream in mine.
Click to expand...

I knew it wouldn't shoot great with everything, but this much variance at 25 yards is surprising, and the different stringing is not what I expected. I may need to check out TAC stuff if the local-ish shop has it
 
OkayShooter said:
Quiets because they were slower so will have a different POI than the SV you shot. Plus more acceptable to wind due to the slower speed.

25kph winds would effect it as well. Then the faster HV ammo normally have a different POI as SV. I can see up to a inch with my guns switching from SV to HV.
Click to expand...

Yes, the different point of aim was expected. The Standards shot more to the right than the Subsonic HP, but the Mini-Mag's were about a 1/2" higher. I'll see if I can post a picture
 
All the ammo tested is the culprit...

if you want to shoot groups, (other than the CCI std) try shooting some decent quality match versions of Sk, ELey, Lapua or RWS. ...and shoot at 50 or 100y/m

All will have different POI... even different lots of the same ammo can have a slightly different POI. The segmented hollow points are also going to spin slightly weird through the air... similar to when regular round nose can get lead 'shaved off' when chambered from magazines that might be slightly off. Also the CCI quit that I've shot seemed to be pretty inconsistent, you could almost call the high and low POI just by the feel/sound of the shots.
 
I know what causes vertical groups with a scope and low right shots, but not horizontal groups.

Goofle is your friend - "reading rifle shot groups" You might find your answers there.
 
Horizontal: If it's not the wind or your shooting technique, it's the (lack of) ammo quality.

Vertical: At 25 yards, it's unlikely the muzzle velocity spread of the ammo is going to show up in a meaningful way. This type of stringing is what happens when the load properties of the ammo do not suit your barrel. Since we can't handload, the only option is to try a different ammo until one is found that shoots well in your rifle, then buy as much of that lot as you can afford. There's nothing wrong with your rifle, welcome to rimfire :)
 
sk8snwmx said:
All the ammo tested is the culprit...

if you want to shoot groups, (other than the CCI std) try shooting some decent quality match versions of Sk, ELey, Lapua or RWS. ...and shoot at 50 or 100y/m

All will have different POI... even different lots of the same ammo can have a slightly different POI. The segmented hollow points are also going to spin slightly weird through the air... similar to when regular round nose can get lead 'shaved off' when chambered from magazines that might be slightly off. Also the CCI quit that I've shot seemed to be pretty inconsistent, you could almost call the high and low POI just by the feel/sound of the shots.
Click to expand...

I'm not looking for the smallest groups possible, this is just a plinker and varmint control gun. If the local range had a 50 yard berm I'd give that a go, not looking to shoot at 100 yards lol. But interesting info about the segmented rounds. I'll have to try the regular Mini-mags to compare, although the MM Seg. are acceptable for close to mid range gophers.

Leuchtkafer said:
Horizontal: If it's not the wind or your shooting technique, it's the (lack of) ammo quality.

Vertical: At 25 yards, it's unlikely the muzzle velocity spread of the ammo is going to show up in a meaningful way. This type of stringing is what happens when the load properties of the ammo do not suit your barrel. Since we can't handload, the only option is to try a different ammo until one is found that shoots well in your rifle, then buy as much of that lot as you can afford. There's nothing wrong with your rifle, welcome to rimfire :)
Click to expand...

Yes, the rimfire stuff is such an enigma to me! So many variables and such, but it keeps it interesting for my casual self. One day later this summer I'll go for the day and have an extended session of shooting multiple strings from each type
 
Vertical stringing is usually the ammo or the bedding, horizontal stringing is usually the wind or the shooter. There is nothing wrong with your gun.
 
Two things come to mind. The first is that a five shot group with any ammo isn't reliably representative. It's too small a sample.

The second is that if the groups shown were shot with the same ammo, it might be said that the different group shapes were the result of inexpensive ammo doing what it often does, which is to be inconsistent.
 
slinkylegs said:
Alright, I'm hoping someone can help me figure out what is going on with my gun.
Click to expand...

Nothing abnormal is going on. Like all others, your gun shoots different kinds of rimfire ammo, especially cheap ammo, differently. You need bigger samples to make any meaningful comparisons.
 
slinkylegs said:
It was breezy, around 25-30 km/h, but wouldn't that affect the bullets the same? Is it just that each gun handles bullets differently?
Click to expand...

No. Wind is almost never constant. If you're stringing ONLY horizontally (not diagonally or vertically) then the wind is almost always the culprit. The only exception would be some kind of front rest / cheek pressure, etc issue.

Barrel harmonics can be a factor in ammo selection, but if that were the issue, it would throw shots out radially, not straight to one side or the other.

Assuming the rifle is in good order and shooter knows how to be consistent/repeatable in his grip, rest position, cheek and shoulder pressure, etc, then:

Vertical stringing = crappy ammo or head/tail wind
Horizontal stringing or diagonal stringing in one direction = practice reading wind flags
groups not tight enough, but not in any one direction = wrong ammo for your rifle or inconsistent grip/rest position, etc etc.

That's been my experience anyway

Just a suggestion - if target shooting is what you're into, the ammo you're using really isn't the right stuff. Try SK Yellow at minimum, Red would be better, or Lapua. Eley, etc. I bet you see the biggest improvements just by picking the right ammo for your intended purpose.

Good luck - it's always fun when everything finally comes together, but it ca be a real process finding the perfect combination
 
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