I have a FX M3, 25 cal, 700mm barrel with a superior heavy liner, carbon sleeve dual transfer port, shooting NSA 34.9 grain slugs. I am having no luck at all getting them to shoot well. Anyone have any settings that could get me close? I have tried any where from 890 FPS to 980 FPS. I am luckey to get a 2" group @ 70yds with flyers. I can achieve very go SD of 2.3 with ES of 7. Had same experience with NSA 33.6.
NSA 34.9 slug tune
- Thread starter Stealth
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It could very well be that your barrel doesn’t like the size of the slugs. I dont think NSA has different sizes available in .25 caliber. Have you slugged your barrel ?
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Try the 43.5 grain NSA at 900 FPS. If those and the others you’ve tried don’t shoot it could be a poor liner. Have you tried the 34.9 with the Superior liner that came with the gun?
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No clipping.34.9 are what I am shooting now. I have 10 boxes of them LOL. The heavy liner does shoot FX 34 grain mark 11 very well.
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Slugging your barrel will determine if your groove diameter is larger than your slug diameter. That is a no go for slugs.
you need to drive a slug that is bumped up a few thousands over your barrels Id. Pellets do not work well for this and you have slugs on hand that will work. I lightly tap mine with a small hammer. you will need to push them, the expanded and lubed slug, down the bore from the chamber end, and out the muzzle.
if that slug you pushed down the muzzle is larger than the slug your shooting, you will never get good accuracy. I home cast and have for 50 years and shot cast slugs in airguns for a decade, I try to match my slug diameter to .001 over groove diameter, ie, a .253 slug in a .252 groove diameter barrel. Groove diameter is the space cut out of the interior of your barrel when the rifling is cut in manufacturing. Pushing that over sized slug the first two inches nay be hard to do, but it is important to have thar slug completely fill the bore.
Regards,
Roachcreek
you need to drive a slug that is bumped up a few thousands over your barrels Id. Pellets do not work well for this and you have slugs on hand that will work. I lightly tap mine with a small hammer. you will need to push them, the expanded and lubed slug, down the bore from the chamber end, and out the muzzle.
if that slug you pushed down the muzzle is larger than the slug your shooting, you will never get good accuracy. I home cast and have for 50 years and shot cast slugs in airguns for a decade, I try to match my slug diameter to .001 over groove diameter, ie, a .253 slug in a .252 groove diameter barrel. Groove diameter is the space cut out of the interior of your barrel when the rifling is cut in manufacturing. Pushing that over sized slug the first two inches nay be hard to do, but it is important to have thar slug completely fill the bore.
Regards,
Roachcreek
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I'd agree with others that some further testing on your liner is needed. I generally find the 34.9's accurate from 940 up to around 980fps in little bands of fps range.
I'd try the superior that came with it and see if it's any better. I generally have not had the 'best' performance with the .25 heavy liners--I'm a slug a liner guy when it comes to 25 cal.
I'd try the superior that came with it and see if it's any better. I generally have not had the 'best' performance with the .25 heavy liners--I'm a slug a liner guy when it comes to 25 cal.
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I second that on the 700mm Slug A liner. The Superior Heavy in .25 seems to have a tighter bore and choke than the Slug A. I'm shooting the NSA 43.5 at 900 FPS and its as accurate as any gun I have. I'm currently in the process of testing the ZAN BT slugs, one Hollow Point (44 gr) and one Round Nose (46 gr). The BC of the NSA 43.5 is approx. 0.105, but the ZAN Boat Tail slugs are about 0.135 for the HP and 0.150 for the RN. A SIGNIFICANT difference in wind resistance... Haven't gotten too detailed on the accuracy yet, but will over the next couple of weeks. Currently shooting the RN at 880 FPS, may need to jack it up a bit...
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Do you thing installing a slug probe will help with accuracy. Dubber talks about slugs having the need to be well seated in the l & g to shoot well.
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Put the reg superior liner in and run her from 950-980. That will shoot better than most sluggers out there. The 33.5’s will shoot damn good also with that liner. The 25 heavy liner isn’t that great unless you shoot the 43’s and that isn’t magazine friendly. Or sell me your remaining slugs cheap
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The 34.9g nsa shoots very well without even a fine tune out of my 700mm MK2PP with superior heavy with carbon sleeve, MOA at 200 yards. What’s your reg pressure? I bet it’s about 100-110 bars.
Also at that power level the impact is very hold sensitive and parallax is also a major contributor to inaccuracy sometimes.
Also at that power level the impact is very hold sensitive and parallax is also a major contributor to inaccuracy sometimes.
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Regulator pressure is between 120 and 125. I reached velocities with maximum hammer spring in the 990s. Can I use the valve to bring down the velocity into the 980 to 940 range slowly decreasing the velocity and shooting groups. Not much luck had good accuracy
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for heavier slugs try 150-160 bars, it is much easier to tune starting with max regulator pressure.
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Tried the superior liner with same results. Took it all the way up yo 980FPS and back. Groups settled a little at around 870 FPS, but still to many fliers. Loaded up with FX 34 grain @ 905 and its lights out. I'm done with slugs LOL. Heavy liner and NSA 34.9 (8 boxes) will becoming up for sale. Are there any more slug A barrels in 25 cal left?
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the most advisable thing is to test with a variety of weights and diameters, not to test just one, in my case, I tested with 14 different types of slugs with my red wolf hp .22
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