Impact Compact The perfect Storm

Let me explain, I bought sampler pack from NSA Speciality amo .22 slugs ,and at the same time had a new in the box Hawk Compact 4x16 IR scope, plus did a retune for the slugs in anticipation ,for more power and my tune yielded a spectacular tune with way more power and an incredible three magazine shot count from the FX compact 300cc cylinder.

So mounted the new scope. Tuned my Compact with Superior liner to 945 fps with JSB 15.89g pellets.

Then as my wife and I was about to go out of town the slugs arrived and decided the shoot four each of 2165, 17.5g and four 2175 17.5g slugs over the chrony before leaving, I got 900 for the 2175 and 910fps for the 2165 and thought that should be great from what I've read.

So latter on I tried sighting the scope with the pellets and was really bad, so then changed the scope thinking that was the problem but no! So I mounted a third and reliable scope and had the same shotgun results at 50 yd.

Ok must be the wrong tune and after cleaning the barrel and re-seasoning many times I still had the shotgun results. Returned my compact to close to previous tune that provided excellent accuracy but yet the accuracy was still shotgun results at best and I'm talking one and a half inches to two inches at 50 yards what the heck?

So after 3 weeks of frustration changing scopes changing the tune on my compact I now know the problem. I ordered a new Superior liner and guess what my accuracy and groups have returned to what was expected.

So my conclusion is that slugs will destroy the accuracy of a superior pellet liner not designed for slugs just giving my thoughts as to those who may be experiencing this issue.

Thats why I say the perfect storm (of disaster).

Don
 
I know from personally experience the .22 superior liner will shoot both slugs and pellets with laser precision. I would get that barrel warrantied! 


before you getting it replaced, look into light with the liner out. You might have piece of lead stuck in there, Clean out with bronze brush if that’s the case.


This is good info as I had the same problem and while doing a thorough cleaning. I pushed out a half inch long piece of lead from my liner. The gun then shot great again afterwards. I also polished the barrel after that and have not had the problem since.
 
Interesting read. I asked the question last year, whether slugs would damage a pellet liner, and the response was an overwhelming "no". That, and I have not seen any warning from any manufacturer stating that they do. But - apparently they can, as in your case. Please keep us updated in the event you either confirm or find out otherwise.
 
Lead is so much softer than any steel used in an airgun barrel that any "damage" is more likely "leading" in the lands and grooves than actual physical damage to the barrel.

People tend to read so much into the difference between slugs and pellets in a given barrel. Given similar weight and diameter, both should shoot fine in any barrel...however a choked barrel will tend to make a difference with some slugs and pellets, depending on projectile diameter. 

Further, not all barrels are created the same. There are variables...ie: Smooth Twist, choked, unchoked, fully rifled, quality: LW vs. generic, etc...

Hot subject, but that's been my personal experience. Everyone's mileage will vary on this one!



Kindly 'Ol Uncle Hoot
 
Yeah I read where Yo said if you shoot slugs in you pellet barrel it will never shoot pellets good again and most everyone scoffed at him and I too said Phooey.

But none the less it stuck in the back of my mind and as a last ditch try bought the new liner and I'm back in pellet heaven!

I examined the liner off the gun with a bore light multiple times, clean the barrel multiple times and re-season with pallets however I never used polish or a boar brush but did use hope's #9 bore cleaner to no avail.

Also tried different pellet probe, change probe oring, liner to shroud orings and oring inside liner retainer.

Checked picatinny rail mount screws couple of different times, tried different pellets, removed the thin camo wrap on my shroud.

Bought new liner cleaned, lubed, recleaned, shot over crony while seasoning the new liner until consistent velocity was obtained shot after shot and then the final try shot groups at 50 yards first thing and dime-sized groups had finally returned.

As someone suggest bronze brush and polish may do the trick on the old liner , but I feel the FX liners to be a little to delicate for that but have no experience to back that up.

I'm just going to shoot my pellets and later on will reinstall the old liner and revisit the Nelson slugs.

Oh and as I said in OP I only shot 4 each of the two different sizes.

This post is not intended to be a pellet versus Slug comparison or anything like that just the perfect storm of disaster when one thing has changed and all your accuracy has gone out the window and for the life of you you're just trying to figure out what happened is it me? Is it the barrel? Is it the scope? Is it the tomb? Are the screws loose on the scope mount? Is the picatinny rail screws loose? You get the idea thanks Don
 
From personally experience I switched between pellets and slugs countless times and many times during the same tuning or shooting sessions in 3 barrels and 5 liners with zero issue. In fact I haven’t even cleaned my Fx barrels at all except for one time when I first got my impact. Subsequent barrels and liners have not been cleaned, not even initial cleaning when new. If Ted bier doesn’t clean his barrels then neither will I. YMMV 
 
Here's a couple pics the pic with the dime is with the new liner and a random only 3rd shot group I just shot a few minutes ago @ 930 fps with 16 grain JSB plus seven shot group with some swirling wind. 

THE other pic with the quarter is with the old liner @ 50 yards and is hand cherry picked best of the very best after shooting the slugs through the old liner.

Its a 500mm .22 superior liner in both cases.

Others post excellent results swapping back and forth, I have no reason to disbelief, but my experience is my experience and no one can dispute because it's my experience. I'm only giving my results and experience AND THE SLUGS DID IN FACT RUIN THE ACCURACY IN MY particular liner for pellets and nothing I've tried could restore the accuracy for pellets.

Thanks Ernest for your reply and thoughts.

20210113_175550.1610585110.jpg
20210113_175512.1610585111.jpg

 
The only thing I can think of, and this is highly unlikely, is the slugs, fitting more tightly, and much more bearing surface would have caused the barrel, (Being so thin) to actually swell slightly while trying to extrude the slugs down in size. Particularly in the start of the choke area. But the barrel would have to have been unusually soft. 

As I said, highly unlikely. But possible. 

Never, Ever use a Bronze brush in a polished barrel. Not even in a precision PB barrel. A very bad habit! All top barrel makers of pb Benchrest barrels forbid it. As does Larry Potterfield of MidWay USA.

Being of a metallurgist background, I concur. And before someone stated that I have done it and haven't seen any damage, (Where is you bore scope), there are people walking around perfectly fine after playing chicken as a teen or playing Russian roulette and surviving. I wouldn't recommend either.

On a side note, if using a brush and cleaned from the muzzle, more than likely the metal core of the brush damaged the crown. It is easily damaged, and even damage not visible the the naked eye can damage a crown. The Crown is extremely delicate. Treat it like a sore peter and dont touch it while cleaning!. 





Knife
 
Hey Knife

Oh no I would never try any of some the suggestion I've gotten, the most severe attempt I made was trying,(with the liner out) was using Hope's #9 bore cleaner. I have never used any type of brush, nylon or brass, the only method I have ever used on any of my airguns is pull through crown saver and 99.9 percent of the time dry patches at that. That is all I ever needed to restore degrading accuracy.

I haven't yet pushed any pellets or the slugs through that liner yet but would be willing to bet the pellets will practically fall through.

Din
 
Sir, I had a similar problem with my impact. Loss of accuracy after shooting slugs. Close inspection of liner with magnifier and bright flashlight revealed heavy lead fouling by way of choke. Normal pull through cleaning or polishing would not shift it. I resorted to copper brush of correct diameter, in from choke end and only a couple of inches. That got rid of the fouling and the accuracy returned to normal. If you believe your liner is already damaged by shooting slugs then surely it can do no further harm to use a copper brush of the correct diameter, just at the choke and see what happens. It won’t make it any worse. It may well surprise you and return your liner to original. Go on, give it a go and let us know your results. By the way, these impact liners have a fairly tight choke. Pellets are hard to push through. Slugs are even harder! No wonder they leave debris behind.
 
Ok guys lm big enough to admit when I'm wrong,,, well not completely wrong.

And to Jonjo and others that had same experience and suggested heavy lead fouling, GIVE YOURSELF A PAT ON THE BACK!

I've yet to completely removed it but upon closer inspection there it is, heavy fouling at the choke end of the liner.

I pushed a pellet through the liner and was difficult especially at the choke then examined the pellet and it had some very strange wear marks especially on the head so that's when took a much closer look. I pushed eight pellets through and each time was easier and the pellet would become more uniformed, I don't get it but pushing pellets through is cleaning the heavy lead out but then not when shooting? I suppose it's dragging it out slowly but shooting just leaving more behind.

So yes the slugs did cause my problem but probably not permanent damage if I can safely remove the rest of the lead deposits? I can still see a couple of areas where the lead is refusing to come out by just pushing pellets through.

Jonjo suggested a copper brush of the correct caliber, I'm a little afraid of this but may be the only way?

So at this point I can't say100% my accuracy in that liner will return but I absolutely think so.

Don