Others Harder alloys & fouling- your experience?

[wolfmangreg]

Have seen a number of comments, both here & elsewhere on the web, regarding more and/or faster barrel fouling when shooting AEA & JTS pellets vs JSB. Doesn't seem to be the case for everyone shooting them, but common enough to be an interesting topic to this admittedly weird guy.
Both of those brands have quickly built reputations for excellent consistency in weight & dimensions, & my limited experience with them is no exception. Hasn't always translated to excellent accuracy in my rifles, though it certainly did with my Cricket carbine in .25 shooting AEA 33.9 grain pellets.
The caveat is that they lead the barrel in a very short time; ~75 shots or so until flyers start. Past ~100 or so shots, there is clear degradation in accuracy beyond just an occasional flyer. Wouldn't bother me a lick if pulling some patches got things right, but it doesn't- rod & brass brush are required, which means pulling the barrel. Not terribly difficult to pull the barrel on this rifle, but the idea of doing it that often does not give me the warm fuzzies.
The barrel has already been polished by the vendor (Georgia Airguns). Not to say it's 100% smooth & defect free, but I'm quite confident there's little or nothing to be gained by further polishing. Have seen discussions about the positive effect of using a hard wax to treat the bore (reports of much longer cleaning intervals), but have not done it myself. Might be something to investigate.
If I had intentions of winning bench rest competitions involving considerable prize value, it's something I'd live with- no question. No such plans though, so there's always the option of switching to the JSB King Heavy MKII. In my testing when I got the rifle, it was a close 2nd to the AEA in accuracy. That said... giving away accuracy, no matter how small the difference, also does not give me the warm fuzzies.

What's your experience with barrel fouling when using pellets of harder (than JSB) lead alloys? Particulars of rifling, velocity, etc also appreciated. In my case:
- 900 fps
- 12 groove CZ barrel
- 1:17" twist

 

[Danman]

Ahhh I've dealt with this issue all summer as well. The 2 guns in question that suffer from leading and an obvious lack of accuracy: My .22 Brk Ghost and my brothers Diana .177 350 magnum. Both shoot pellets 925-1000fps and the speed does seem to play a factor. Both my Air Arms guns shoot in the mid 800fps range and I can go hundreds (thousands?) of rounds without a cleaning. Polished the Ghosts barrel myself and it's spot on now, but for how long I can't say! I knew it was buggered bc I would clean the barrel and it would be good for one shooting session and then back to again. Lol now I'm concerned, I am shooting JTS pellets out of the S510 as they are proving just as accurate as the 18.13 Jsbs. I'm so paranoid with the that I sight and shoot only 1 pellet choice and run em till gone before trying something else. Also I am lubing the pellets for the Ghost now. As far as accuracy I find both H&N and Crosman pellets to be harder lead and less accurate out of all 3 of my British Airguns.

 

[Pumacarl]

Good topic Greg! I stopped shooting CPD's out of my .22 Gauntlet because they would foul my barrel every 2 tins worth. That may sound like a lot (1000 shots), but, shooting JSB's I usually don't have to clean the barrel anymore. It's so infrequent that I'm not sure the number of shots it takes to effect accuracy anymore. If I had to guess, I'd say somewhere north of 6 tins. I have only cleaned it twice since completely switching to JSB's about two years ago. I have not been shooting the Gauntlet has much so it's hard to pin down a number. As you well know, my .30 Paradigm fouls fast (30-40 shots))using the FX/RMR slugs, which just happen to be it's most accurate ammo, but if I just shoot JSB holds accuracy for a couple hundred shots. From everybody else's reporting on this topic I have never got the impression that it was about barrel type, speed, or twist, but just the lead of the pellets or slugs themselves. Softer lead seems to always be better.

 

[Pumacarl]

Danman, I don't know about speed being a factor because I shoot the JSB 18.13gr pellets at two different speeds, 890fps in my Gauntlet and 925fps in my MA2 and niether ever lead up or foul for many thousands of shots. This isn't the case when I throw in some harder pellets. Have you tried shooting your Ghost in the low 800's and not had any leading, where you had shot fast and it did? That would be interesting to know. I have just always observed problem/dirty ammo to always be a problem, at any speed. Figure out the problem, or don't use it. That's what I did with the FX Hybrids, they're just too accurate to not use. I just pull a patch every time I air up. It's worth it.

 

[wolfmangreg]

@Danman - Glad you brought lubricating pellets for your Ghost. Tried different pellet lubes way back in my early airgunning days, but mostly to see if it could wring out an extra bit of accuracy (it never did, for me). Didn't pay much attention to how it affected cleaning intervals. Certainly a cheap & easy experiment to do- not much to lose in the attempt.

@Pumacarl - Have seen discussion around propensity for fouling with different types of rifling, but don't recall any consensus. Imagine any differences would be easily overwhelmed by the condition of a given bore. A smooth, polished barrel with consistent dimensions, produced with tooling in good condition will always foul less than a sewer pipe barrel with tool chatter, tight spots, pitting etc.

 

[Pumacarl]

Agree on bore condition for sure! Mine are all really good, no tight or loose spots and all my leades are good. I have been using Pledge on the .30 hybrids but still have to run a patch, though one time does seem to be enough.

 

[Grunt64]

Good topic Greg! I stopped shooting CPD's out of my .22 Gauntlet because they would foul my barrel every 2 tins worth. That may sound like a lot (1000 shots), but, shooting JSB's I usually don't have to clean the barrel anymore. It's so infrequent that I'm not sure the number of shots it takes to effect accuracy anymore. If I had to guess, I'd say somewhere north of 6 tins. I have only cleaned it twice since completely switching to JSB's about two years ago. I have not been shooting the Gauntlet has much so it's hard to pin down a number. As you well know, my .30 Paradigm fouls fast (30-40 shots))using the FX/RMR slugs, which just happen to be it's most accurate ammo, but if I just shoot JSB holds accuracy for a couple hundred shots. From everybody else's reporting on this topic I have never got the impression that it was about barrel type, speed, or twist, but just the lead of the pellets or slugs themselves. Softer lead seems to always be better.

I'm not very knowledgeable about this, but when my shots are off, I clean the barrel. With that in mind, wouldn't the tightness of their fit in the barrel also matter?

 

[wolfmangreg]

I'm not very knowledgeable about this, but when my shots are off, I clean the barrel. With that in mind, wouldn't the tightness of their fit in the barrel also matter?

Many moons ago when I hand loaded low power wadcutters for revolvers, learned quickly that bore fit is king! Both for accuracy & to prevent leading.
A poor fit invariably resulted in leading. The common reaction by inexperienced folks (myself included) was to try harder bullets, which in reality just made it worse- sometimes much worse. Softer lead is actually more forgiving of poor fit in that regard, though it would still be a problem.
Getting the bullet to bore fit just right + soft lead = best results.

This is something that puzzles me about what's going on with my Cricket. Fit to bore has to be pretty darn good to have the accuracy it does when clean, yet it's quickly getting fouled enough to degrade that accuracy.

 

[Franklink]

I'm in the harder lead is a $itch, category. And that's based on multiple examples of hard lead (specifically Crosman Premiers) creating issues in barrels.

 

[Centercut]

Greg, I have noticed the early fouling also, even in highly polished barrels and barrels with polygonal or FX liners.

I shot the .30 cal 45 grain all season at various events, and then the 50.5 at EBR. Both are very accurate in a clean barrel (but no more so than a sorted batch of JSB 44.75). I made the mistake after my two 75Y qual rounds (483 aggregate) of not brass brushing well the FX .30 Superior 1:40 twist prior to finals and paid the price with two flyers which dropped me out of the top 10. Totally my fault.

As far as smaller caliber AEA like .25, I didn’t notice better accuracy that the JSB, nor were their BCs any better. In the case of the .25 (haven’t tried the .22), the juice isn’t worth the squeeze. For .25 I’m sticking with JSB Heavy and MK2 Heavy.

I am anxious to try the new .30 caliber 66 grain, but I can only imagine how frequently they must require barrel cleaning. However, if the BC is significantly better than the 50.5 they’ll get the nod for 100Y BR. As far as EFT probably not, since the max speed without exceeding 100 fpe is about 825 fps.

 

[wolfmangreg]

@Centercut - I'm getting virtually identical BC from the MKII & AEA 33.9 as well. The small difference in accuracy was mostly vertical dispersion; suspect that the difference would disappear with weight sorting the JSB.

 

[Grunt64]

Many moons ago when I hand loaded low power wadcutters for revolvers, learned quickly that bore fit is king! Both for accuracy & to prevent leading.
A poor fit invariably resulted in leading. The common reaction by inexperienced folks (myself included) was to try harder bullets, which in reality just made it worse- sometimes much worse. Softer lead is actually more forgiving of poor fit in that regard, though it would still be a problem.
Getting the bullet to bore fit just right + soft lead = best results.

This is something that puzzles me about what's going on with my Cricket. Fit to bore has to be pretty darn good to have the accuracy it does when clean, yet it's quickly getting fouled enough to degrade that accuracy.

have you checked the ammo for inconsistencies?

 

[wolfmangreg]

have you checked the ammo for inconsistencies?

The AEA & JTS pellets I've tried are very consistent in both weight & head size.

Wishing now that I'd held on to a Brinell hardness tester, would be interesting to quantify the difference between brands. And consistency within a brand. Have access to Rockwell & Shore hardness testers at work, but pretty sure none of the indentors are appropriate for lead. Would also have to press the lead into a very flat surface.

 

[jps2486]

I own, or have owned, a lot of air rifles and use them for competition. I think it's safe to say that all choked barrels will foul with lead, especially slugs. The projectile diameter will make a difference too. If it's too large, it will foul faster. Hardness? I haven't found too much difference. I know that various manufacturers use slightly different alloys and have used a number of them. As a rule, I clean my barrels after about a hundred shots and always find lead flakes on the first patch. If I don't clean it at that point, the accuracy gradually degrades. And in competition, it could make a difference between winning or losing on one or two "9s" instead of "10s".