Shooting Slugs at Slower Speeds

[Gear_Junkie]

Shooting JSB KO Mk II slugs out of a .22 RAW at 825fps produces fairly good groups out to 50 yards. The groups average no larger than 1/4" at 25yds and 5/8" at 50yds. Since this is a fairly low speed for slugs, is there good reason to believe that the slugs will destabilize, and therefore accuracy decrease, as I approach 100yds? Or would they remain stable and produce groups roughly twice the size of what I get at 50yds? Or is there no way to really tell unless I actually shoot at 100yds? The reason I ask is because I don't really have a way to shoot up to 100yds anywhere near me.

Thanks.

 

[thammer]

No way to tell until you try.

 

[JaceSpace1369]

Shooting JSB KO Mk II slugs out of a .22 RAW at 825fps produces fairly good groups out to 50 yards. The groups average no larger than 1/4" at 25yds and 5/8" at 50yds. Since this is a fairly low speed for slugs, is there good reason to believe that the slugs will destabilize, and therefore accuracy decrease, as I approach 100yds? Or would they remain stable and produce groups roughly twice the size of what I get at 50yds? Or is there no way to really tell unless I actually shoot at 100yds? The reason I ask is because I don't really have a way to shoot up to 100yds anywhere near me.

Thanks.

If you aren't able to shoot a hundred yards, does it really matter? Are you able to see the slugs midflight to determine whether they are stable or not?

I would say that if you can lower the speed to replicate what the slugs would arrive at a 100 yd.But shooting at fifty yards, then test it out.

You won't have the same amount of wind and gravity working against you.But you will be able to determine whether or not your slugs are stable at said speed.

 

[Ranchibi]

That's awesome accuracy! As long they they keep spinning to the yardages you are shooting, your accuracy should be good. When the spin slows is when slugs de-stabilize and go off line. That's pretty cool that you can get that accurate at slower speeds with slugs

 

[6gun]

Shooting JSB KO Mk II slugs out of a .22 RAW at 825fps produces fairly good groups out to 50 yards. The groups average no larger than 1/4" at 25yds and 5/8" at 50yds. Since this is a fairly low speed for slugs, is there good reason to believe that the slugs will destabilize, and therefore accuracy decrease, as I approach 100yds? Or would they remain stable and produce groups roughly twice the size of what I get at 50yds? Or is there no way to really tell unless I actually shoot at 100yds? The reason I ask is because I don't really have a way to shoot up to 100yds anywhere near me.

Thanks.

This is a function of stability factor. Rpm of projectile for it's construction, diameter, length etc. Typically as velocity decreases, twist rate increases depending on intended purpose.

 

[thomasair]

The spin will not decay at the same rate as the speed...so shooting them slower will not replicate their behavior at longer distances.

My guess is they will be fine at 100y.

Here's a couple 25 shot groups at 50y using 40gr slugs going 791 fps. The furthest I have shot them is 265 yards and they did extremely well....although at that time I think I was around 830fps.

Mike

 

[Gear_Junkie]

That's awesome accuracy! As long they they keep spinning to the yardages you are shooting, your accuracy should be good. When the spin slows is when slugs de-stabilize and go off line. That's pretty cool that you can get that accurate at slower speeds with slugs

Yeah, it's a pretty sweet barrel that Scott machined! It shoots quite a few pellets and slugs with 1.5 MOA accuracy up to 50yds. A couple different pellets shoot under 1 MOA. I've been trying to find a slug that will get close to this. the JSB KO Mk II's are the best so far. I just need to find some space where I can stretch the distance out.

Thanks for all of the help guys!

 

[Gear_Junkie]

View attachment 523406View attachment 523407The spin will not decay at the same rate as the speed...so shooting them slower will not replicate their behavior at longer distances.

My guess is they will be fine at 100y.

Here's a couple 25 shot groups at 50y using 40gr slugs going 791 fps. The furthest I have shot them is 265 yards and they did extremely well....although at that time I think I was around 830fps.

Mike

Wow, that's awesome!!!

 

[6gun]

Wow, that's awesome!!!

Check out some of the theory on 8.6blackout (as an extreme example).

You have to be doing something very very out of the ordinary to run into issues ime.

I enjoy just going out shooting and taking data these days after building a gun on paper that slowly lost its fun and became a highly focused tool. Take your biggest projectile and group it as fast and as slow as you care to send it to find the limits.

 

[Ballisticboy]

Slugs, just like every other spin stabilized projectile, get more gyroscopically stable as range increases, not less. This is because the spin decays at a much slower rate than the forward velocity. The gyroscopic stability increase may lead to yaw increases at longer ranges, as the slug will be less able to turn into the airflow and follow the trajectory. This is much more likely to occur with pellets rather than slugs.

Thus, if your slugs are stable at short range, they will not become gyroscopically unstable at longer ranges, no matter how long the range.

 

[woogie_man]

I have shot a few of my guns at slower speeds and they work great. To many people are stuck on speed being the ultimate thing. Speed isn't everything, and some guns just don't want to be fast. Much like a lowrider.... they like going slow and showing off

 

[Troy Bakel]

Purchased a used but never shot 30 cal FX M3.

Left the first and second regulators as set.

Set the air valve to 4, Macro to 8, Micro to 3.

Reduced the Macro to 1 and tested 3 different diabolos and 1 slug at 20 yards indoors.

The slug truly sucked but the FX 44.8 grain domed diabolo produced 5 round groups of 0.3XX" Edge to Edge at 440 fps. The other diabolos grouped > 0.4" .

I kept testing at 20 yards indoors and advancing the Macro 2 clicks at a time and the 44.8 grain FX grouped the best over the full range of testing.

My final tune sends the FX 44.8 grain domed diabolo at 50 fpe and ~ 710 fps.

This tune is accurate outdoors to 60 yards with 10 sequential rounds striking head on within a 2" tip to tip diamond shaped Bullseye.

By 70 yards all 10 pellets are keyholing and not grouping within the Bullseye.

I did increase the Macro setting to 16 and opened the air valve to 4. This ended the keyholing but didn't improve the grouping much if any.

I reset the tune and dropped back to 60 yards. 10 round groups/accuracy returned to normal.

Ballistically a lot is changing when a projectile has dropped past the apex of its trajectory and its forward velocity is decelerating at an increasing rate.

 

[Ballisticboy]

Ballistically a lot is changing when a projectile has dropped past the apex of its trajectory and its forward velocity is decelerating at a decreasing rate.

Corrected it for you.