Help me understand slugs better

[madeintheuk]

Am I correct in thinking that the a slug going the same speed as a similar weight pellet, has a flatter trajectory?

School me some on slugs please. I’ve always thought that if I could shoot slugs even at slower speeds from my pcp, I could have less holdover than shooting similar weight pellets.

 

[dgeesaman]

A slug vs pellet of same weight and caliber will have different ballistic coefficients, with the slug being higher.
Therefore if they are fired with the same energy/muzzle velocity, the one that slows down less gets to the target fastest. Flatter trajectories come from shorter time of flight. High BC means less loss of velocity, resulting in shorter time of flight. The slug's will have a flatter trajectory.

Wind effects are also reduced with a higher BC projectile design. Wind drift is proportional to the velocity loss between muzzle and target.

In my experience the flatter trajectory means little if the slug veers inches off the intended target. I've tried at least two dozen slugs in two different PCPs and only a couple of them showed any promise at hitting more targets at long range. Most were much less accurate than a good pellet. My testing was with a 70-100fpe .30cal PCP and a couple of 30-50fpe .22cal PCPs. Going slower did not help. Based on what I've read here, none of them were pushing the slugs fast enough to be optimal. I may try slugs again in the future. For now I'm focused on pellets which have been consistently more accurate.

 

[UDABEGGER]

Yes they shoot flatter !

 

[bigHUN]

Lessons what I learned is, in same calibre and weight category not all slugs to pellets is better BC, or that BC number is irrelevant when you focus on POI.
A longer slug - has a better BC that can perform better on POI.
Longest possible you can feed in will win.

 

[Scotay42]

Mainly depends on the barrel. Slugs need to spin faster to stabilize. Some guns just wont. If it ahoots slugs, they are better, if it doesnt, then they are not. Pretty simple. My impact m3 likes hybrids but put a 40g .25 in there and not so great, but hybrids will outshoot pelkets long range. The delta wolf i just traded had an unchoked lothar walther barrel and it would shoot anything. I also recently had a snowpeak p35x .177that would hammer slugs at range as well. Had plenty that jjst dont like them also.

 

[delooper]

As mentioned by Scotay42, if you want to get advantages out of a slug you'll need to have a properly set-up gun. A non-choked barrel, proper twist rate, proper power levels, etc.

 

[Ta-Ta Toothie]

Negative, choked barrels work just fine. You just need the right one.

 

[WorriedMan]

Pellet design is self-stabilizing in flight, like a badminton shuttlecock, preferring choked barrels, minimal spin and speeds around mid to upper 800 fps. Similar to a football, slugs need spin and speed to stabilize. Slug-designed airguns use increased power, unchoked barrels and faster spin rates, as Delooper stated. Many slug-design airgun owners still face a daunting search for preferred slugs but long range accuracy and increased downrange energy is possible. WM

 

[Ta-Ta Toothie]

Again negative that airguns barrels need to be un-choked in order to shoot correctly. I'm not talking about twist rate. It's been done for years now.

 

[Ta-Ta Toothie]

For one is the FX heavy liner.

 

[Ta-Ta Toothie]

It's just false information. It will scrub speed and will agree to that.

 

[Scotay42]

Again negative that airguns barrels need to be un-choked in order to shoot correctly. I'm not talking about twist rate. It's been done for years now.

It is not that choked barrels dont work, they just dont like many slug varieties. Typically only fx hybrids and griffins for choked barrels. I have tested many, many guns.

 

[JimD]

I mess around with slugs sometimes and lately have found two slug/gun combinations that work (both guns have choked barrels). My P35-177 shoots Nielsen 12.5 grain slugs pretty well but not as well as it's favorite pellets. It shoots JSB knockouts horribly, however. Other users of SPA guns get great results with knockouts.

My Caiman X likes all the different weights of H&N slugs. 21, 23, 25, 27, 30 grain all will produce 1/2 inch groups at 30 yards consistently. The 31 grain are going 900 fps and the 30 grain at 765. I've shot the 21 grain at three different speeds starting at 820 and groups were all about the same size (5/16 to 9/16 inch). I think speed probably matters but not nearly as much as finding a slug a gun likes. In my experience finding a slug/gun match is a lot harder than finding a gun/pellet match.

 

[JimD]

My point of impact with slugs is significantly lower with both guns at 30 yards where I sight in. I am sure they have a better bc but that doesn't control point of impact at short range. Chairgun says the slugs will carry 1000 yards or more. 2 to 3 times as far as pellets. Something to think about for back yard shooting.

 

[Ta-Ta Toothie]

It is not that choked barrels dont work, they just dont like many slug varieties. Typically only fx hybrids and griffins for choked barrels. I have tested many, many guns.

I think that goes both ways, choked and un-choked. Others have removed the choke just to find out it performed better with the choke. I tried many different slugs on my heavy 1:16 and nothing stood out as unacceptable. H&N's Jalvins, Zans, NSA's all worked very well. Also swage my own, stated with a Thor press and now a Corbin with great results. Either your barrel can do it or not. Some more picky then others.

 

[Ta-Ta Toothie]

And just using a pellet pusher isn't going to do the job.

 

[Franklink]

Am I correct in thinking that the a slug going the same speed as a similar weight pellet, has a flatter trajectory?

School me some on slugs please. I’ve always thought that if I could shoot slugs even at slower speeds from my pcp, I could have less holdover than shooting similar weight pellets.

Yes, slightly flatter with the slugs. These are screen grabs from actual setups that I shoot a lot of.

100 yard comparison first...relevant data is bottom right. Projectile data is listed too (JSb 15.89 versus NSA 18.9)

200 yard comparison

In this particular comparison they're going nearly the same speed. This slug has about double the BC of this pellet.

Personally, I feel like the big win for slugs isn't so much the "flatter" trajectory, but the minimized drift, versus pellets.

The true big jump in air powered projectiles is to go to what I call the second generation of airgun slugs, the boat tailed type. Think Altaros. They double again the BC of my little .20/18.9NSAs, and quadruple that of even a high BC small bore pellet. But then you're in rimfire territory, in power levels and downrange danger, etc. Rimfires are simply the cheaper and easier way to get to that level of performance.

As others have noted, choked barrels CAN shoot slugs accurately.

And as others have noted, with 1st gen airgun slugs, expect the journey to find an acceptably accurate combination of gun/slug/barrel to be long and expensive. From my journey, you're looking at about a +95% failure rate with small bore 1st gen slugs. Mighty sweet to eventually find a magic combination though. There's a really cool happy medium of cost/benefit/performance ratios if you can stumble upon an NSA slug that performs well.

 

[DesertSilver]

Lessons what I learned is, in same calibre and weight category not all slugs to pellets is better BC, or that BC number is irrelevant when you focus on POI.
A longer slug - has a better BC that can perform better on POI.
Longest possible you can feed in will win.

As long as you have the twist rate for the length of the slug to stabilize it. If not the slug will not fly straight which will increase drag.