Accuracy issues

[RBD2]

Hello need a little help I have a brocock bantam hi lite in .22 and having issue with grouping I don't have a chrono. So at 25 yards when I shoot jab 18 grains maybe 3 pellets will hit close to point of aim the I'll get pellets shooting to the right about mil dot. I cleaned the barrel and the pellets still do the same it didn't use to do this before. When I switch to low power it seems to group better . Any suggestions

I fill the gun to about 200 bar should I be filling to to 250 could that be my issue

 

[Yo]

Have you ever changed the breech o-ring before? Maybe it's about that time...

 

[Yo]

Driving without a speedometer huh? I have this one and works like a charm everything you need is included. Included Shooting lights are a must. I have used 5 different brands of Chronys including 2 broken Shooting Chrony brand.

 

[Yo]

Don't fill past 200 BAR even if it's capable. You get better shot curve since its unregulated and easier on the seals too. Ideal start pressure for yours at 190-195 BAR.

 

[RBD2]

Never changed the breach seal how do you know when it needs to be changed ? Is that one of the symptoms I had a chrony lol but I shot it like a dummy lol I'll get another one that one looks cool

 

[Yo]

Daystates are notorious to go through breech o-rings which is normal and you got a Daystate in Brocock's clothing. Buy an o-ring pick and go fish it out. You don't have a working chrony to tattle tale on an erratic shot string so this is all I can think of as being your problem unless your magazine is being temperamental. You state that it shoots fine on low power so it must be blowby through a worn or damaged breech o-ring at higher power. Match it with one from ACE HARDWARE for now Buy couple just to get you going for now and you can order better longer lasting ones online if you choose to do so but changing that o-ring is easy peasy with an o-ring pick so go buy one and a CHRONY.

 

[AirNGasman]

Though I don't know what is causing your accuracy issue, Yo explains where to start looking for the problem. Lay a light tissue over the breech area and fire a shot with a pellet chambered to check for breech seal problems. 

FWIW, I consider my .22 Bantam Hi Lite not only extremely accurate, but one of the best air rifles I've ever owned for consistently holding a zero. I also consider the Slingshot hammer/valve system nothing less than FANTASTIC.

After much chronograph testing to eke out all possible consistent-velocity shots per charge, mine returns over 70 shots per 250 BAR fill with a 32 FPS extreme spread; this only after thousands of rounds of break-in. Before that I could only charge it to 235 BAR, for about 60 shots per fill. From my testing notes-

.22 Brocock Bantam Hi-Lite bolt-action pre-charged pneumatic repeater

18.1 grain JSB, 250 BAR fill, 73 shot powerband- Low= 834, Hi= 866, ES= 32, SD= 8, Average= 850 FPS/29.0 FP

10/4/2018- Six consecutive 5 shot groups at 50 yards with 16 grain Air Arms pellets averaged .50” c-t-c.

4/14/2020- Seven consecutive 5 shot groups at 50 yards with 18.1 grain JSBs averaged .59” c-t-c in windy conditions.

6/2/2020- Four consecutive 5-shot groups at 100 yards with 18.1 JSBs averaged 1.18” c-t-c. The smallest group measured .55” c-t-c; the best 100 yard group I’ve ever gotten with an airgun.

Though Yo might be correct in stating that lower charge pressures might be easier on some seals, charging to less than 200 BAR will lower your shot count considerably. FWIW, I now not only routinely charge mine to 250 BAR, but often leave it charged that high for months with no ill side effects.

Mine shoots 15.9 JSBs as well as 18.1 grainers at 50 yards, but the 18.1s return a few more shots per charge, do better in wind, and shoot tighter groups at 100 yards.

 

[Rj]

What scope are you running and Does it have parallax adjustment ? 

Might be worth a scope swap to see if that's the problem. 

 

[RBD2]

Thanks for all the helps I'll try all listed . 

Using a hawke 4-18-44 with AO don't think it's a scope issue but after I do all of the above I'll try the scope last. 

 

[oledawg]

Keep your troubleshooting simple, both the suggestions above are along those lines. Great idea using the tissue to test for breach leaks. Have you recently tightened your scope rings?
good luck

 

[elh0102]

You didn't mention how you cleaned the barrel, or how many shots fired since cleaning. If less than 100, shoot it some more. If no better, I would remove the barrel, clean carefully with rod and brush, then lightly polish with JB paste. At that point, you should have a truly clean barrel. Do your testing again, and realize it may take some shots to season the squeaky clean barrel. A dirty or dry hammer can cause this issue, but without a chrono run, it's really hard to even guess. If velocity is consistent, then it's probably a barrel issue. If velocity shows a wide spread, then I would look at some internal servicing. And yes, the above mentioned simple test for a torn breech O ring might disclose the problem. 

 

[Yo]

Though I don't know what is causing your accuracy issue, Yo explains where to start looking for the problem. Lay a light tissue over the breech area and fire a shot with a pellet chambered to check for breech seal problems. 

FWIW, I consider my .22 Bantam Hi Lite not only extremely accurate, but one of the best air rifles I've ever owned for consistently holding a zero. I also consider the Slingshot hammer/valve system nothing less than FANTASTIC.

After much chronograph testing to eke out all possible consistent-velocity shots per charge, mine returns over 70 shots per 250 BAR fill with a 32 FPS extreme spread; this only after thousands of rounds of break-in. Before that I could only charge it to 235 BAR, for about 60 shots per fill. From my testing notes-

.22 Brocock Bantam Hi-Lite bolt-action pre-charged pneumatic repeater

18.1 grain JSB, 250 BAR fill, 73 shot powerband- Low= 834, Hi= 866, ES= 32, SD= 8, Average= 850 FPS/29.0 FP

10/4/2018- Six consecutive 5 shot groups at 50 yards with 16 grain Air Arms pellets averaged .50” c-t-c.

4/14/2020- Seven consecutive 5 shot groups at 50 yards with 18.1 grain JSBs averaged .59” c-t-c in windy conditions.

6/2/2020- Four consecutive 5-shot groups at 100 yards with 18.1 JSBs averaged 1.18” c-t-c. The smallest group measured .55” c-t-c; the best 100 yard group I’ve ever gotten with an airgun.

Though Yo might be correct in stating that lower charge pressures might be easier on some seals, charging to less than 200 BAR will lower your shot count considerably. FWIW, I now not only routinely charge mine to 250 BAR, but often leave it charged that high for months with no ill side effects.

Mine shoots 15.9 JSBs as well as 18.1 grainers at 50 yards, but the 18.1s return a few more shots per charge, do better in wind, and shoot tighter groups at 100 yards.

0.55" AT 100 YARDS? WITH AN UNREGULATED GUN? REALLY?

 

[RBD2]

I cleaned with a patch worm ran through until it came out clean . I have maybe 100 rounds through since cleaned . I did the breach seal test and don't notice it moving much maybe I'll order a chrono just to rule all out it was accurate for the first 500 pellets then accuracy started to slip so I cleaned the barrel.

 

[Simplyhooked]

I'm sorry for not contributing to this post earlier but I played with my Bantam Sniper Lite earlier this evening and I noticed that while shooting with the magazine and 18.3 pellets, my shots were not lining up either. Normally, I enjoy using the single shot tray and that's where I find all of my shots ending in one ragged hole at 25 to 30 yards. My gun shoots very well, I have no complaints as to how well it performs and it always leaves a smile on my face once I've had enough.

 

[elh0102]

I cleaned with a patch worm ran through until it came out clean . I have maybe 100 rounds through since cleaned . I did the breach seal test and don't notice it moving much maybe I'll order a chrono just to rule all out it was accurate for the first 500 pellets then accuracy started to slip so I cleaned the barrel.

Just to be sure I understand, your accuracy deteriorated before you cleaned the barrel, not as a result of the cleaning. If so, I suggest you might need a more aggressive cleaning,by removing the barrel and using a rod and brush. 

 

[AirNGasman]

"0.55" AT 100 YARDS? WITH AN UNREGULATED GUN? REALLY?" Yes, but don't get too excited.

As I stated, that is the best five-shot, hundred-yard group I've ever gotten with an airgun... of hundreds of 100 yard groups fired from dozens of hundred-yard-capable air rifles. It now bears repeating what I've written in several books; I put little credence in ONE group, Rather, I rely instead on the average group size of several groups before making judgements about a given gun's accuracy capabilities. Even then, the more accuracy-testing sessions logged with any gun, the clearer emerges its accuracy potentials. 

All that said, I consider the 1.18" AVERAGE of four consecutive five-shot groups at 100 yards with the Bantam Hi Lite just as impressive as the single .55" group, as that 1.18" average is among the best average I've ever achieved at 100 yards with an airgun.

I consider regulated guns over-rated. 

 

[tommyb]

All that said, I consider the 1.18" AVERAGE of four consecutive five-shot groups at 100 yards with the Bantam Hi Lite just as impressive as the single .55" group, as that 1.18" average is among the best average I've ever achieved at 100 yards with an airgun.

1.18” is an excellent average group size for 20 shots at 100 yards with any air rifle. Darn close to MOA and although I don’t know if you shot these groups in any wind, your rifle seems to be quite accurate.

Have you ever recorded a larger sampling size at 100 yards to obtain average group size to assess your gun’s accuracy? I.e., 50 shots or more? I ask because I frequently shoot my rifles at 100 yards ( RW .25 cal and RAW .30 cal and RAW .22 cal ) and my average group size is probably more like 1.5 to 2.5” range (approximately); and that’s over a year of shooting between 50-150 shots per outing at paper targets.

I would be thrilled with 1.18” average CTC group size at 100 yards or anything close to that with my rifles. 

OP - others are providing good suggestions for your question on improving your accuracy, and not trying to derail your thread. Just trying to get a better understanding about the Brocock platform and associated accuracy from AirNgasman. Good luck solving your issue. 

 

[AirNGasman]

Answers to Tommy's questions that might be of interest to others, in hopes it's not taken as a hijack.

"I don’t know if you shot these groups in any wind, your rifle seems to be quite accurate." My .22 Bantam Hi Lite producing only 29 foot-pounds, the groups mentioned were fired in still wind conditions and could not have been achieved in any (felt) winds. However, I've found more "energetic" power levels still capable of achieving their best accuracy in light winds, provided those light winds are not gusty or varying in direction. In fact it sometimes seems .25 caliber rifles producing 60+ foot-pounds with 33.95 grain JSB pellets have posted their best group averages in afore-described light wind conditions.

"Have you ever recorded a larger sampling size at 100 yards to obtain average group size to assess your gun’s accuracy? I.e., 50 shots or more?" Due to the extreme levels of concentration, shooting technique, stable rest, ammo consistency, and rifle capabilities required for gratifying results when stretching pellet guns to the extreme range of 100 yards, like my concentration, each additional shot in any group becomes exponentially more difficult to keep from straying. Hence, I feel several consecutive five-shot groups more realistically indicative of practical accuracy capabilities; six-shot groups with my .25 Sumatra and .22 AR6 Hunting Master (pistol) six-shooters. To paraphrase, by testing pellet guns to 100 yards I might admittedly be masochistic; but not masochist enough to shoot ten (or more) shot groups at such extreme distances! And fifty-shot groups... think I'd rather spend as much time in a dentist's chair.  No offense intended; to each his own. BTW, Rapid Air Weapons totally ROCK! (Love my .177 TM1000)

 

[elh0102]

I consider regulated guns over-rated. 

Yes, they may be. I know they are highly rated by many people for the wrong reason. If the shooter closely manages the sweet spot of the rifle's power curve in a non-regulated rifle, he will gain no practical advantage in accuracy by using a regulated rifle. A regulated rifle should make that job easier, because if it's properly tuned, the accurate shot count should be higher, maybe considerably so. I guess the question, is the added variable of maintaining a regulator worth its advantage? I like them, but, if I were interested only in the rifle's limited, but peak performance, then I might lose some enthusiasm for it.

 

[bandg]

I consider regulated guns over-rated. 

Yes, they may be. I know they are highly rated by many people for the wrong reason. If the shooter closely manages the sweet spot of the rifle's power curve in a non-regulated rifle, he will gain no practical advantage in accuracy by using a regulated rifle. A regulated rifle should make that job easier, because if it's properly tuned, the accurate shot count should be higher, maybe considerably so. I guess the question, is the added variable of maintaining a regulator worth its advantage? I like them, but, if I were interested only in the rifle's limited, but peak performance, then I might lose some enthusiasm for it.

My weevil brained thoughts exactly. I went through this process with my Condor. It could be managed with charge pressure but it has become an excellent reliable performer with a better more usable shot count after adding a TT 3600 psi bottle and regulator. No more fiddling with pressure curve, just pick it up and shoot. Also, the pull length with the regulator and shorter CF bottle is almost identical to stock, and I like a shorter LOP.