Lube for Slugs NSA .22 24.8gr .218

[ddnzf]

I just want to provide some of my findings. I have been exclusively trying to get these slugs to work in a 22 700mm FX maverick. I am shooting them at about 1000 ft/s 160 bar/125 bar shooting on PW 7 with 11gram hammer. I have shot many groups unlubed and lubed. I find that the lube really does help and shrink the groups. I would shoot a day of unlubed, and then another day of lubed and another day of unlubed, about half a box each day. 

I believe the reason it helps is because the .218 is tighter and so I am guessing a little lube helps. It might have less of an effect if you use a smaller diameter slug that is more loose in the liner. I just use silicone spray lube. 

I know some say lube doesn't do make any differences, but for me it definitely shrank the group at 86 yards, probably shrank about an 1/2 inch to 1 inch. 

 

[nplez1]

Did you notice any difference in fps with lube? I’ve been wondering if a thin layer of lube would fill gaps between the barrel and the slug yielding higher pressure behind the slug before it exits the barrel. 

 

[ddnzf]

I have noticed a few strange things. 

1. Like the first shot after leaving the gun for a while is completely different. It is probably be regulator creep.

2. It takes few shots (5 or so) of the new ammo to "lead" the barrel before things settle down.

3. There is a better consistency with the speeds when I lube vs when I do not lube. 

4. I seem to get more of the odd flyers when I do not lube. 

5. I do not notice a consistently higher speed with lube, but that is because my chronograph is not that good and measures in M/S. Also I think the difference in speeds would be small maybe 1 to 2 m/s and so I would not really notice on my chronograph. I was more paying attention to group sizes than speeds. 

I think for what you are asking, testing the .217 slugs would probably be able to get an answer. With the .217 being looser in the liner, the lube might help seal? The .218 already seem already tighter. I have the unlubed JSB KO in .217 and they seem to get faster speeds than the unlubed .218 NSA 24.8gr. But I would need to test more to make sure of that conclusion. 

 

[Solo1]

you want to find out just how well your gun will shoot? It’s very simple take your barrel off and push a slug down the barrel and measure its diameter then try a slug that diameter and 1 just slightly larger you will see your velocity go up and with proper tuning groups will shrink

 

[Kgphotos]

I have also been shooting the same NSA 24.8 .218” slug in both my Impact MK2 and Crown MK2. Impact is the older FX slug liner and the Crown is the new Superior liner. I am also lubing them; but I’m using Balistol for my lube. I did a lot of testing with .217” also but for my rifles the .218” was best. In both guns I’m using a mid level tune, not pushing the guns too hard and they both shoot absolutely fantastic groups. The Impact shoots them at 950 fps and the Crown at 945 fps. A good friend of mine shoots a Dreamline 600mm superior and it also loves the lubed 24.8 .218” at 915 fps. If you are still experimenting you may want to try slowing them down to the 950 fps range and see what you get. The 24.8 slug at 950 fps will still expand well all the way out past 100 yards on squirrels. Here is a post I made a while back when I just had the Impact. It shows the expansion testing I did using actual squirrels.

https://www.airgunnation.com/topic/nsa-slugs-and-fx-impact-ballistic-testing-tuning-and-lots-of-photos-to-share/?referrer=1

 

[ddnzf]

you want to find out just how well your gun will shoot? It’s very simple take your barrel off and push a slug down the barrel and measure its diameter then try a slug that diameter and 1 just slightly larger you will see your velocity go up and with proper tuning groups will shrink

What about the choked fx liners? What's the process for them?

 

[Solo1]

that’s exactly why you shove 1 thru. you will see how tight the choke is. 

 

[ddnzf]

that’s exactly why you shove 1 thru. you will see how tight the choke is.

the 700mm STX superior barrel in 22 using calipers, not micrometer and going in a circle around the slug. slug is 5.52mm-5.54mm before. After it is 5.42mm to 5.45mm. Is that about right? It was quite hard to get that slug through. What NSA slugs size can I use, the smallest they make is .216. I would need like .2135 or .214. 

 

[Solo1]

well try 216 or 2165 mine had higher velocity with 216 23gr nsa but 2165 seemed to be slightly more accurate. with only slight loss of velocity. To me this is the problem with forming the barrel from the outside you never have an exact measurement close but not exact so every barrel is slightly different

 

[Thach2264]

I do notice that the jsb ko fly a bit faster than the nsa 24.8. Even though the jsb is heavier, might be because the jsb have skirt and the nsa just concave. 


nsa more accurate at 940ish in my fx Maverick 600