Best FX Slug Caliber for long range Hybrid or Slug Insert ?

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Shooting Targets

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Jan 7, 2017
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Any consensus what is the best caliber for long range shooting of hybrid with and withtout dedicated slug liner in the FX impact 3 rifles ?

So from the hybrid slugs we are looking at .22 BC .08 , .25 is .09 BC and 30 Cal is .102 BC. 

Has anybody used these calibers with the Impact M3 as is and with the slug liners ?

I am seeing matt duba from SAAir Arms saying he thinks the .22 call has some of the best ballistics for long range ??

Curious what on paper should be the best is the .30 cal with a BC of .102 but not sure what the reality of these guns really are ?

I want to shoot out past 100 yards with accuracy?

Jay 
 
Interesting! The 31.2 NSA has BC of 0.095 VS 43.5g NSA with BC of 0.11, guess the extra 100FPS really helped. 

I will trying to see how fast I can push the new 34.9g NSA because it also has BC of 0.11, if I can get them to go 950 or higher I don't see how the .22 31.2g slugs can compete. The .25 NSA 34.98 grain has a 20% increase in BC. On a different note I got .25 NSA 29 grain to shoot at 1000 FPS in my Impact MK2PP, it has BC of 0.93 so I would suspect it will be just as good as the .22 NSA 31.2 grain slugs. 



Granted I found heavier and higher BC slugs still performs better in the wind or at least more consistent/predictable in the wind compared to faster with lighter slugs. Could be my tune though, plus heavier slugs at lower speed is heck a lot easier to tune for. 
 
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I'll mention this, having shot a thousand of the 25 cal 29gr NSA slugs at 922 fps average, a couple hundred of which I spent hours using "actual" come ups with holdovers and dialing using expensive rifle scopes, the advertised BC is not .093, it's .075-ish. 

I first checked my zero, then velocity on my expensive Oehler chrono, then targets at 125Y, 150Y, 175Y, 200Y, 230Y and 300Y, distances verified using my Vectronics RF, using actual DA/Density Atltitude, and correct parameters in my SHOOTER ballistic app. Also testing was done in near calm conditions. The short story is NO the BC for these is not correct. If I put in .093 into the app the dope is significantly off at father distances. The farther away the worse it got. Too the tune of 1.9 mils difference at 300Y! That is about 20" difference.

I'm guessing the rest of the BC's for the other slugs weights and calibers need to be tested for actual verified BC's.

And BTW at closer to medium distances you won't be able to tell as easy because the closer the target is the harder it will be to tell. The difference in drop at 100Y for the .093 BC and .075 BC at 922 fps is (ONLY .1 mil, or .36" !!!) Which of course would not bother most shooters.

Coming from my perspective, which 99% involves shooting steel at long range, I would like to see slugs made that don't have a huge hollow point which induces more drag and lowers the BC.
 
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The BCs listed on the NSA site are not verified or tested. Just guesses. I’m pretty sure if actually measured the heavier .22 would come out higher than posted. I know my NSA 43.5 have an ACUTAL BC of between 0.100 and 0.105. But you are correct, It was easier to tune the gun for the lower speed…
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Good ol' saying that the last 1% is most difficult. I have 600mm barrel on my crown and 700mm barrel on my impact, I know every barrel length has it's max velocity even with maxed out regulator pressure. From my testing the compact 300mm barrel has MV of ~750-760fps, 380mm is about 780-800fps, 500mm is about 860-880fps, 600mm is about 900-920 and 700mm is about 920-940fps. Anything above those speed I experienced much higher air consumption and muzzle blast and slugs are very muzzle blast sensitive. IMOH to get slugs flying around 1000FPS we need the 800mm barrel to do it comfortably. My crown seems to shoot slugs most comfortably and consistently with the 600mm barrel right at 880-900fps tops, at 920fps I can hear the sound of the gun/muzzle blast change and the groups would be more erratic, just my personal experience and maybe you can chime in with your experience since you have shot far more slugs than me. For me it's easier to tune to be about 20-30fps lower than the max velocity of the barrel length, timing the valve closing AND harmonic right at the edge of max velocity is a pain because the margin of error is just so little. 
 
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I'll mention this, having shot a thousand of the 25 cal 29gr NSA slugs at 922 fps average, a couple hundred of which I spent hours using "actual" come ups with holdovers and dialing using expensive rifle scopes, the advertised BC is not .093, it's .075-ish. 

I first checked my zero, then velocity on my expensive Oehler chrono, then targets at 125Y, 150Y, 175Y, 200Y, 230Y and 300Y, distances verified using my Vectronics RF, using actual DA/Density Atltitude, and correct parameters in my SHOOTER ballistic app. Also testing was done in near clam conditions. The short story is NO the BC for these is not correct. If I put in .093 into the app the dope is significantly off at father distances. The farther away the worse it got. Too the tune of 1.9 mils difference at 300Y! That is about 20" difference.

I'm guessing the rest of the BC's for the other slugs weights and calibers need to be tested for actual verified BC's.

And BTW at closer to medium distances you won't be able to tell as easy because the closer the target is the harder it will be to tell. The difference in drop at 100Y for the .093 BC and .075 BC at 922 fps is (ONLY .1 mil, or .36" !!!) Which of course would not bother most shooters.

Coming from my perspective, which 99% involves shooting steel at long range, I would like to see slugs made that don't have a huge hollow point which induces more drag and lowers the BC.
Click to expand...





Good to know! The biggest issue is the testing condition for the published BC! NSA was in socal but testing right at sea level is impossible so my assumption is they are testing at higher elevation which is a good information to have. As long as their test environment/condition is consistent then their published BC is relatively reliable and can easily be adjusted to. Like you said at closer ranges I found their BC to be pretty darn close or within 0.1 mil, guess it's best to get a labradar one of these days. 
 
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I'll mention this, having shot a thousand of the 25 cal 29gr NSA slugs at 922 fps average, a couple hundred of which I spent hours using "actual" come ups with holdovers and dialing using expensive rifle scopes, the advertised BC is not .093, it's .075-ish. 

I first checked my zero, then velocity on my expensive Oehler chrono, then targets at 125Y, 150Y, 175Y, 200Y, 230Y and 300Y, distances verified using my Vectronics RF, using actual DA/Density Atltitude, and correct parameters in my SHOOTER ballistic app. Also testing was done in near clam conditions. The short story is NO the BC for these is not correct. If I put in .093 into the app the dope is significantly off at father distances. The farther away the worse it got. Too the tune of 1.9 mils difference at 300Y! That is about 20" difference.

I'm guessing the rest of the BC's for the other slugs weights and calibers need to be tested for actual verified BC's.

And BTW at closer to medium distances you won't be able to tell as easy because the closer the target is the harder it will be to tell. The difference in drop at 100Y for the .093 BC and .075 BC at 922 fps is (ONLY .1 mil, or .36" !!!) Which of course would not bother most shooters.

Coming from my perspective, which 99% involves shooting steel at long range, I would like to see slugs made that don't have a huge hollow point which induces more drag and lowers the BC.
Click to expand...





Good to know! The biggest issue is the testing condition for the published BC! NSA was in socal but testing right at sea level is impossible so my assumption is they are testing at higher elevation which is a good information to have. As long as their test environment/condition is consistent then their published BC is relatively reliable and can easily be adjusted to. Like you said at closer ranges I found their BC to be pretty darn close or within 0.1 mil, guess it's best to get a labradar one of these days.
Click to expand...

I forgot to mention that I test at 6640 ft altitude which would allow the slug to drop less because the air is thinner up here, but I did account for DA which should give a fairly predictable trajectory when all the parameters are put into the ballistic program.

The drop is what it is so I have to adjust the BC and velocity in the ballistic program to fit the actual trajectory as close as I can otherwise I would be off enough to miss a smaller target past about 150Y.

I need to order the NSA 34.8gr to test them because these 29gr do blow a lot in the wind.


 
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In my own testing of the NSA 34.9 … I came up with a BC of about .08 and it may well be less. Other NSA’s I tested had lower bc’s. 


i too want to know which caliber nsa has the least wind drift. The theoretical charts I see in StrelokPro and other places says that wind deflection increases with additional speed. As U drive a pellet from 850 to 1000 fps… the pellets launched at 1000 fps are supposed to have more drift. 


id love to know the definitive answer. It’s complicated because the slower pellet may have less drift but is impacted by more time in flight. 
 
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@Steve123: I found NSA data very very consistent and accurate, I was shooting @my local range and zeroed are 50 yards. Used strelok and got the drop for 200 yards and it’s pretty spot on minus the changing wind deflection which was unpredictable, then i shot at stuff at 325 yards with strelok data and I was right there so any difference in BC data at anything over 100 yards might have more to do with environmental, gun and shooter variables. Not say NSA data is exact right and even if it is the data will be slightly off due to environmental variables especially at that distance for low weight and low BC subsonic/slow projectiles. As long as NSA data is consistent then it’s easy to adjust to and produce consistent which equates to accuracy. 
 
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This is a funny thing! It's that we have the BC's split right now.

Brad and I are close in BC's for NSA, he states this "In my own testing of the NSA 34.9 … I came up with a BC of about .08 and it may well be less". Me - Which would be close to what I have at .075 for the NSA 29gr.

Then Qball and Skidoo are close together in BC's which are higher than Hearkins and I.

Are you guys using station pressure or altitude when you test for BC? For example my app shows a correction at 6000ft DA for 300Y as 21.1 mils, but at 1000ft DA it shows 23 mils. That is a 20" difference of drop if accounting for Density Altitude.


 
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I’ve used altitude and station pressure. I’m at 4,800 feet and not sure what’s best.
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Station pressure is better but using altitude is better than putting nothing in your ballistic program.

Density Altitude/DA is what I have used for the last 12 years with my firearms for long range, also for the airguns. It's a combo of station pressure, temperature, and humidity. 


 
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I think it is better me to repeat my question here, the other post got drifted and buried :)

.........................

Beside the fact I have a decent porting mod in my .25 MK2 PP for pellets (slotted the transfer hole also enlarged the valve + peek poppet), I just started shooting slugs very recently.

The current speed is more then plenty for JSB 34gr pellets, on a calm day :)

but the ZAN 37 gr slugs feels a bit hungry for more speed, currently 958 fps @ 145 bars.

Last 2-3 range days I was tuning for these 37gr slugs, but ...my place is well known that no calm days and always windy. Not very windy that I would go surfing instead, but enough to toss around the POI (the group shape) for about 2". And this will get worse all the way until May-June next year.

I am not saying the MK2 is under-powered, but if I would really want to jump to some heavier like 41-45 gr slugs I assume this current power maybe on borderline?

Would be (or could be) a larger 720 cc FX plenum a wisely spent money? or better don't think about investing further into MK2?
 
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Are you guys using station pressure or altitude when you test for BC? For example my app shows a correction at 6000ft DA for 300Y as 21.1 mils, but at 1000ft DA it shows 23 mils. That is a 20" difference of drop if accounting for Density Altitude.

Click to expand...




there are 2 ways to approach this:

1. If you zero the day of at the range then set the weather same as current weather then DA doesn’t matter at all. 
2. if I zero at a different location and time then I always make sure I record my zero whether/which includes DA. Then I make sure my ballistic solver has the current weather and zero weather then it’s pretty spot on. 


funny thing is I was at the range zeroed at 50 yards the. 325 yards with 29 grain .25 nsa at 1000fps is exactly 21.1 mils! depending on how you factoring delta from wind the NSA published BC is spot on or 0.5 mil off at worse. 
 
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