Is it possible to shoot slugs too fast?

[MoeHofer]

I have been shooting 26 grains NSA slugs out of my edgun at 950 fps. 

But yesterday I had a little time on my hands so I began to tinker a bit with speeds, just to see what would happen. 

I turned the hammer spring back about a quarter turn which slowed it down about 10 fps and a saw a marked improvement in the groups! I shot several groups that stacked dangerously close to 5/8" even at 70 yards!

I only shot 2 groups before the wind and rain began to pick up and it got rather miserable to be outside. But I'm really intrigued by this! I was under the impression speed is king! The more speed the better the spin stabilization effect! 

But perhaps not!? What are your guys' thoughts?

Sorry no pics. Will do more testing soon and give more feedback. 

 

[mercado]

Since is all a learning curve..my best guess is that it has something to do with the twist rate of the barrel..some twists with aloud us to use the improper ammo n still work .. if we maintain a reasonable speed...

 

[Kaeokini]

Aloha,

I know that speed of the slug(s) being shot at different FPS and different guns will differ a lot. I have several guns with different slugs at different speeds and some of my guns shoot better at slower speeds. Also no 2 guns will be the same, I have a cricket in .25 and my friend has one too. My gun shoot 30 FPS slower than his but we both get the same accuracy at 50 yards using the same slugs. Its a lot of testing to find the right slug and speed for the gun.

Aloha, 

Keone

 

[TNT19]

It is absolutely possible to shoot slugs too fast or too slow in an airgun. Like it has been called out in previous posts it will vary depending on a multitude of factors. Gun, type of barrel, twist rate, etc. I have a 22 cal kral that shoots the 17.8 nsa slugs at 930 fps and is sub moa at a 100 yards. My brothers won't group with the same slugs shooting any higher than 900 fps. My prophet loves the 26 gr fx hybrids but I have to sling them at 960 to 980 fps otherwise past 50 yards they won't group. I shoot the Nsa 26.8 at no more than 940 fps otherwise they won't group either. So in short just need to find that sweet spot like when you hit a golf ball and it just feeeeellllss good.

 

[Odoyle]

There is a sweet spot in velocity in any given barrel with any given projectile.

 

[vmaxpro]

Ive often wondered if its speed related, or when you start crankin on it the harmonics get worse. I was shooting these light but long .30 cal 29gr at 1196fps and were slightly over an inch at 100. Explosive little suckers on birds inside 30 yards. Switch over to 65.5gr dial down to 700fps and scary accurate. Push them to 940 ( maxed out, harsh shot cycle) and accuracy went down the drain.

 

[davidsng]

With my Edgun R5M in .22 I have been using slugs for two years now. I found that accuracy is pretty close between 940 to 1020fps. I would say that around 940fps is a little more accurate than 1020 for most slugs, but the flatter trajectory has its benefits too. So, I feel it is a wash. Not all guns are like that either. Some guns shoot beautifully at a tight window, if you increase/decrease by 20fps you loose it all. My Huben is like this.

 

[EDventure]

Ive often wondered if its speed related, or when you start crankin on it the harmonics get worse. I was shooting these light but long .30 cal 29gr at 1196fps and were slightly over an inch at 100. Explosive little suckers on birds inside 30 yards. Switch over to 65.5gr dial down to 700fps and scary accurate. Push them to 940 ( maxed out, harsh shot cycle) and accuracy went down the drain.

I was wondering the same thing and how the FX harmonic balancer might help that. 

 

[bigHUN]

.........ow the FX harmonic balancer might help that.

You still need to do your 98% part finding the best tune for your projectile in relation to a barrel and twist rate,

and no shortcuts, this could take you several hundred shots and weeks and months of tweaking and tinkering until you get the most tightest groups for a given projectile and distance,

and only then the tuner may give you those extra 2%.

I believe if you change the pellets/slugs you can start over again, but this time the process could be faster because you already know what you looking for.

 

[SteveKralsAround]

The way I do it is start with the highest speed possible then keep slowing them down till the group closes up .

 

[Airgun-hobbyist]

The way I do it is start with the highest speed possible then keep slowing them down till the group closes up .

This is the best way to do it and have all available down range power.

 

[oncall-50]

Yes, it definitely is possible to shoot slugs too fast. You have to realize the slugs are going at just under the speed of sound. There is a "transition zone" at 0.8-1.2x the speed of sound. Above and below this zone projectiles are stable in flight. Slugs travel on the lower end of this Transition Zone. As air travels over the surface of the slug, there are micro points where the air speeds up and travels closer to the speed of sound. This causes turbulence in flight and can result in target point of impact (POI) spacing. Slowing down the MV under the transition zone will do away with this turbulence and yield increase slug POI accuracy. .... So, yes, there is a maximum speed for accuracy which just above will cause "wabble" and inaccuracies.

 

[Ranchibi]

There is definitely a sweet spot for spin stabilization whatever that speed may be! LOL!

 

[delooper]

If you shoot the slugs at close to the speed of light, it'll trigger an explosive reaction and ignite the atmosphere around it. The explosion would likely kill you, and if not, the gamma radiation given-off might give you cancer.

 

[dizzums]

likely it goes through 'phases' of speed it will work good with a particular config up to the point the mechanics of the gun reach a point theyre banging to much .. theres several factors involved in other words .. more than just speed, but generally a slow anemic setup will print better in anything simply because the mechanics are moving more gently ..

 

[thomasair]

As someone already pointed out….going fast requires a lot more air than going slower. It also requires a heavier hammer strike. Both of these things can impact accuracy very heavily.

Mike

 

[rigbymauser]

The limitation for shooting slugs would be like any other leadbullets limitation. Going faster means harder alloy. Harder alloy means more power to push it down the barrel. Harder bullets is harder to expand on impact.
So for every step upward in speed a new parameter must be considered into account.

 

[Motorhead]

Yup, reading this thread yesterday, knew in time someone with powder Burner experience & LEAD bullets would share the connection that has been a FACT for well over a century now .... LEAD and even hardened / alloyed has a threshold of speed where the friction / surface speed against the barrels bore creates transfer. That of the lead projectile deposits a lead smear as it passes by, each sequential lead projectile doing the same. End result a Lead Fouled barrel !!
Thus why copper gilding was introduced ( Think .22rf ammo ) and in more recent years a lot of pistol bullets for reloading. Faster yet ... Copper Jackets over the lead core. All because of SPEED in which we in the High Power realm of PCP's have already well exceeded that speed of transference of lead to bore. Yet we're still shooting pure lead or only slightly harder alloyed.

FYI ....