Has anyone found that their gun shoots different slug diameters equally accurately with the same settings?

[TheDaleness]

I'm trying to decide between the .217 or .218 Jav Gen 1 30gr for my Impact M3. Would appreciate any input.

I describe my experience below, but I’m just generally curious if anyone else has not found a significant difference in velocity or accuracy when switching between slug diameters, regardless of your brand of gun or slug, accessories, gun features, etc.

Is this common or rare?

I’m shooting an FX Impact M3 .22, 700mm, with heavy slug liner and carbon fiber liner sleeve and barrel tuner. Shooting Javelin Gen 1, 30gr .217 and .218 slugs at 990fps.
1st Reg: 200
2nd Reg: 150
Valve: fully open
Macro Wheel: 16
Micro Wheel: 2

I’m shooting 1” groups at 100y with both the .217 and .218 Javelin Gen 1, 30gr slugs. I often come across people reporting a dramatic difference in accuracy and velocity when changing slug diameters, but maybe thats because these people are more likely to post their “dramatic” experience.

 

[Long_Gun_Dallas]

My recommendation. Use the smaller ones. Less fouling, I would think. Can't say I've experienced this however.

 

[iAMzehTOASTY1]

Yeaaaa I only have a few kinds of slugs. But none close enough in weight or size to compare them against one another
I do notice that with the bigger ones comes a louder muzzle report downrange.

 

[TheDaleness]

Thanks Long Gun, I'm brand new to air gunning. Now that I've found a slug brand and weight that I like, I'm trying to figure out which diameter to go with. That helps me make the decision.

 

[TheDaleness]

Yeaaaa I only have a few kinds of slugs. But none close enough in weight or size to compare them against one another
I do notice that with the bigger ones comes a louder muzzle report downrange.

Ah, interesting. Curious why it'd be louder as well. But Another vote for the .217s. Thanks Toasty!

 

[dgeesaman]

I'm trying to decide between the .217 or .218 Jav Gen 1 30gr for my Impact M3. Would appreciate any input.

I describe my experience below, but I’m just generally curious if anyone else has not found a significant difference in velocity or accuracy when switching between slug diameters, regardless of your brand of gun or slug, accessories, gun features, etc.

Is this common or rare?

I’m shooting an FX Impact M3 .22, 700mm, with heavy slug liner and carbon fiber liner sleeve and barrel tuner. Shooting Javelin Gen 1, 30gr .217 and .218 slugs at 990fps.
1st Reg: 200
2nd Reg: 150
Valve: fully open
Macro Wheel: 16
Micro Wheel: 2

I’m shooting 1” groups at 100y with both the .217 and .218 Javelin Gen 1, 30gr slugs. I often come across people reporting a dramatic difference in accuracy and velocity when changing slug diameters, but maybe thats because these people are more likely to post their “dramatic” experience.

Do the slugs actually measure .001” larger?

David

 

[TheDaleness]

Do the slugs actually measure .001” larger?

David

I just measured ten of each and they were all the correct diameter.

 

[Nico5999]

I would say to shoot them both in the most adverse conditions you can find and pick the ones that do the best in that case.

In my Air Arms S510, it shot the .249 and .250 38gr HN slugs just about equally. When the wind started blowing though, the .250s were definitely the winner. Almost seemed as if the .249s were destabilizing or something?

Not sure...all I know is that I THOUGHT they shot the same...they didn't

 

[madeintheuk]

I agree with long gun Dallas. I’d go smaller for less fouling. Less fouling means less cleanings, and less accuracy losses.

 

[Chukar60]

how do they compare at closer ranges?

 

[dgeesaman]

I would say to shoot them both in the most adverse conditions you can find and pick the ones that do the best in that case.

In my Air Arms S510, it shot the .249 and .250 38gr HN slugs just about equally. When the wind started blowing though, the .250s were definitely the winner. Almost seemed as if the .249s were destabilizing or something?

Not sure...all I know is that I THOUGHT they shot the same...they didn't

Years ago I bought a set of golf clubs but I tested several over several visits. My method came down to choosing based on which set created the fewest flyers. So yeah I’d test again at different ranges and choose the winner that way.

Another parameter worth considering is real world bc. If you don’t have a LabRadar, shoot side by side at distance and take the one with less drop (and the tightest groups).

 

[jps2486]

I've tried JSB KO slugs in my Crown 600 mm. It definitely likes the .216 slugs better than the .217. I kind of have a rule of thumb that if it requires a significant push against the bolt to chamber the slug, then it's too big. I know this is subjective, but it works for me. As someone else said, the larger slugs tend to foul easier.

 

[Ranchibi]

You're very lucky indeed! I shoot NSA 17.5gr .2175 accurately but .217 does not group! .218 do well......

 

[TheDaleness]

UPDATE:
It seems that I may have gotten a container of .218s that was mislabeled .217s, or something else was off. Or maybe it was some sort of user error on my end. During the shoot this thread is based on, I finished off that container of .218s. Yesterday I opened a new container of .218s. Those are the ones that I measured with the calipers in the photo.

I shot the new container yesterday and immediately noticed a difference before I even fired: I needed to push harder on the lever to seat the slug into the barrel. All of the shots were 20-30fps slower, and the groups opened up considerably in comparison to the .217s. I'm guessing that the .218's decrease in speed is a result of the increased friction in the barrel. Some people have reported the .218s shoot faster than the .217s. Not sure why that would ever be the case, unless their barrel diameter is so large that air is escaping around the .217s?

I wish I hadn't shot the whole container of the previous .218s. Would have liked to have measured their diameters.

An anticlimactic ending to the "phenomenon".

Thanks guys. I appreciate all your input.

 

[Jungle_George]

I have an AT44 in 22 the shoots 217 and 218 equally poorly.

It shoots pellets well, but I have tried easily a dozen different slugs and they all sucked. Recently I bummed some 216s off a friend and there was a noticeable improvement. I going to purchase some 2155s from NSA as a final attempt before giving up and sticking with pellets in that gun.

 

[TheDaleness]

I have an AT44 in 22 the shoots 217 and 218 equally poorly.

It shoots pellets well, but I have tried easily a dozen different slugs and they all sucked. Recently I bummed some 216s off a friend and there was a noticeable improvement. I going to purchase some 2155s from NSA as a final attempt before giving up and sticking with pellets in that gun.

I've heard that from other people as well. I didn't even know they made 2155s diameter. I was talking to a guy at Saber Tactical and he said for one of his guns he wasn't having any success until he went down to .216.