Canadian Airgun Forum
https://www.airgunforum.ca/forums/

Grouping success
https://www.airgunforum.ca/forums/topic80296-15.html
Page 2 of 3

Author:  MyCrosman [ Tue Aug 14, 2018 8:43 pm ]
Post subject:  Re: Grouping success

Springers can be tough to tame...I use to call them "jump"guns....If they don't jump back to the EXACT spot you shot from...you miss...Every springer should come with a bottle of prozac....

Author:  Carpenter84 [ Tue Aug 14, 2018 9:14 pm ]
Post subject:  Re: Grouping success

Like I said...

Attachments:
tenor (1).gif
tenor (1).gif [ 230.26 KiB | Viewed 402 times ]

Author:  YepYep [ Tue Aug 14, 2018 9:21 pm ]
Post subject:  Re: Grouping success

lol ~

So, actually no need to look for a 'best fit' pellet at the moment, just keep shooting, and build up your close relationship with the gun first ~

Maybe in the period you might need to fine adjust the zero a few times, but just keep shooing...

Sent from my LG cellphone

Author:  Carpenter84 [ Wed Aug 15, 2018 4:02 pm ]
Post subject:  Re: Grouping success

Okay. We start the day off normal. Well, a bit better than normal. I didn't have to zero this time. The same mediocre grouping I've always been getting when things aren't going nuts.

Running low on baracudas again, so I try a few things. Second picture... Nope, that doesn't work...

Attachments:
IMG_20180815_165814.jpg
IMG_20180815_165814.jpg [ 529.32 KiB | Viewed 391 times ]
IMG_20180815_165812.jpg
IMG_20180815_165812.jpg [ 534.74 KiB | Viewed 391 times ]

Author:  Carpenter84 [ Wed Aug 15, 2018 4:11 pm ]
Post subject:  Re: Grouping success

Hold the phone...
Uhhh... HELLO? McFly?!

Wtf is this?
About 25 shots in 3/4". No fliers.

When I first started I only had some kneeling pads and a plastic shoe storage box. I would rest on the barrel. Very mixed results. That was with a different gun i got rid of.
I've always wondered if a lot of the accuracy problems stem from the barrel fit in the forks against the breech. My seal is good, my surfaces are tuned and clean, I re-built the whole washer assembly and seats. I always wondered if the spring in the little push pin that locks the barrel was right enough to keep adequate pressure on keeping the barrel from drooping or moving.
I placed the barrel on the bag just forward of the forks.
Just enough pressure to maybe keep the barrel hard against the breech... Well, I might be onto something...

I'm going to okay with this more, but it's giving me idea. Including, but not limited to, barrel bi-pot, putting a stronger spring behind the push pin thingy, and even potentially adding a barrel release. My polish .177 has a barrel release. It locks shut and I have to push a button that pushes the spring push pin back to release the barrel. I put a stronger spring in that .177 because it has leather seals and it leaks out above the breech. Put a bit stronger spring in and it eliminated that problem. That gun shoots really nice now... It's just hard on the finger to push that release.

If this accuracy issues resides in the barrel drooping I can alleviate that with a stronger spring... But I'll likely need that release right away to not damage anything because the ramp coming out of the locked position on that push pin is very steep.

Hmmm... Need more pellets again....

Attachments:
IMG_20180815_165756.jpg
IMG_20180815_165756.jpg [ 511.4 KiB | Viewed 392 times ]
IMG_20180815_165844.jpg
IMG_20180815_165844.jpg [ 473.67 KiB | Viewed 392 times ]

Author:  Carpenter84 [ Wed Aug 15, 2018 4:47 pm ]
Post subject:  Re: Grouping success

Comments are with the pictures.

Attachments:
File comment: Jsb. Too far up the barrel.
IMG_20180815_172658.jpg
IMG_20180815_172658.jpg [ 445.31 KiB | Viewed 390 times ]
File comment: Jsb 18.1 resting further up the barrel.
IMG_20180815_172529.jpg
IMG_20180815_172529.jpg [ 485.92 KiB | Viewed 390 times ]
File comment: Jsb 18.1
IMG_20180815_172648.jpg
IMG_20180815_172648.jpg [ 491.07 KiB | Viewed 390 times ]

Author:  Carpenter84 [ Wed Aug 15, 2018 4:50 pm ]
Post subject:  Re: Grouping success

Comments are with the pictures.


Tried the 25 grains I got. To see if there gun actually wanted a heavier pellet.

Attachments:
File comment: Nothing to write home about.
IMG_20180815_174430.jpg
IMG_20180815_174430.jpg [ 596.08 KiB | Viewed 392 times ]
File comment: Trying the heavier pellets I got. Resting just forward of the forks.
IMG_20180815_174426.jpg
IMG_20180815_174426.jpg [ 568.2 KiB | Viewed 392 times ]
File comment: Last 5 jsb 18.1 light hold.
IMG_20180815_172654.jpg
IMG_20180815_172654.jpg [ 369.5 KiB | Viewed 392 times ]

Author:  Carpenter84 [ Wed Aug 15, 2018 4:55 pm ]
Post subject:  Re: Grouping success

Interesting how the heavier pellet is higher on the target. Almost like the gun is lobbing the pellet. I'm sure it's range is DRASTICALLY shorter...




I'm not 100% sure what this means yet. It could mean I need a stronger spring. It could mean maybe my seal is either sticking out too far or too squishy. It could mean the barrel frequency or vibration can be dampened with some support or weight.

What it does mean, is if it's the ladder of those options, gaining accuracy while hand holding or hunting would be near impossible unless I maybe put a muzzle break on the end with something in it to absorb the vibration.

What i do know is with the near 1000 pellets I've shot in the past two weeks, my shoulder is quite sore now from cocking... Good thing I see my massage therapist tomorrow...

Attachments:
File comment: Last 3.
IMG_20180815_174559.jpg
IMG_20180815_174559.jpg [ 562.27 KiB | Viewed 392 times ]
File comment: Back to the last of the baracudas
IMG_20180815_174540.jpg
IMG_20180815_174540.jpg [ 490.46 KiB | Viewed 392 times ]
File comment: Jsb monsters again. Different holds then hold under on the bull.
IMG_20180815_174506.jpg
IMG_20180815_174506.jpg [ 504.54 KiB | Viewed 392 times ]

Author:  trickster2000 [ Thu Aug 16, 2018 12:10 am ]
Post subject:  Re: Grouping success

Dont worry its not you but the gun.... The benjamin trail is probably the worst gun in history in terms of accuracy....my buddy bought 2 and it was his biggest mistake.....just watch teds holdover review and you will see what i mean..... He had some pellets miss the whole target completely from a short distance....no offence but the trail is a piece of crap....save yourself the stress and grab something else..

Author:  Carpenter84 [ Thu Aug 16, 2018 12:36 am ]
Post subject:  Re: Grouping success

I can appreciate that. And I will eventually buy something better. But this gun has turned into somewhat of an obsession. And this new barrel hold fiasco has me intrigued. It’s showing me that this rifle actually has a chance of being an accurate gun. I just now have to figure out what it is around the forks/breech/seal/or frequency that’s going to wind up being the smoking gun... so to say...

Author:  leadslinger [ Thu Aug 16, 2018 12:14 pm ]
Post subject:  Re: Grouping success

I wish I could get my spring to group like that. Unfortunately it doesn't. I tried resting the barrel on the rest. And Its the hit on the far right.

I know these pellets are so so, but with my Kral PCP I still could get a 1/2" group not counting the single flier at 20M. With my Diana 240C I'm lucky to get 4" now my scope is suppose to be spring rated. FYI I was aiming at the one I'm pointing at.

Image

Author:  Carpenter84 [ Thu Aug 16, 2018 12:43 pm ]
Post subject:  Re: Grouping success

Uhhg that's frustrating.
I think open sight is a great litmus test. I cobbled together an aluminum ring with a notch in it and threaded the scope locking hole in the top of the barrel and put a sawed off screw in with a notch. Worked at close range but at the 18 yards I couldn't see through it. I was considering getting proper iron sights but never did. It would at least eliminate a huge variable from the equationz being the scope. I realize having a sight on the movable barrel isn't ideal but it COULD help indicate if the problem is in the barrel moving around. If you can secure the barrel like I did, resting on the bag and you get better results it could help narrow down the point of failure.

I've tried to view all this from a mechanical point of view. A piece of machinery will always want to run the same way over and over unless a variable is introduced. Mechanics can be very predictable as long as the conditions remain the same.
Introduce a variable, like a loose or wobbly barrel, and you will get varied results. This had to be taken with a grain of salt when dealing with significant forces like compressed air. Compressed air can make things unpredictable. Usually due to friction. Like a pellet in a barrel. But for the most part, at the ranges we are shooting, that variable will be slight, if not noticable at all. A pellet cocked over in a barrel shouldn't send a pellet 2-4" off over 20 yards, in my opinion. That should only happen if the actual aim point changes to create that.
The frequency that is created by the piston should technically be the same each shot. So, if the barrel is secure, the pellet technically should hit the same point each time at a set distance.
If the force of the piston jars the barrel because there is slack or play, that will be unpredictable based on every force conceivable, from gravity, the angle the gun is held, etc.

Ivr had such a hard time giving up on this springer because mechanically, you SHOULD be able to get the gun to fire accurately. If you can tame the variables....

Often I get wrapped up in what I'm seeing and it's only when I sit down, think about the result, write out my result, look at the pictures, that I can then backward engineer the result to discover the problem. I often talk to myself or write/talk about something to some, bounce my ideas off them, to figure out the problem myself. And the suggestions of others are always helpful too. To introduce another train of thought I hadn't previously considered.

I'm enjoying this journey.

Fyi, I'm not proofreading all this. Deal with the yammering and bad grammer lol x

Author:  jckstrthmghty [ Thu Aug 16, 2018 12:53 pm ]
Post subject:  Re: Grouping success

While I was trouble shooting my umarex surge accuracy inconsistency it was mentioned to me to check for bore tightness before the muzzle. Being tight at the muzzle and loose in the bore while not ideal is ok, the other way around, bad. Very bad. Mine was indeed tight 6" before the muzzle. I significantly increased accuracy by sanding that tight spot out. I re-crowned at the same time.

Author:  Carpenter84 [ Thu Aug 16, 2018 1:06 pm ]
Post subject:  Re: Grouping success

I recrowned, but I only checked the bore once. But I didn't notice anything significant. I should check it again tho.

However, I still feel that unless the pellet is actually tumbling, I don't see how the bore could effect the pellet <20 yards up to 4" like leadslinger is getting. To me, that is either a really loose barrel or something to do with optics.

But... While my understanding of mechanics is relatively advanced I would like to think - I've spent a lot of years in industry operating machinery, in maintenance, and millwright - my understanding of aerodynamics and ballistics is something on the order of null... I can only approach the subject with what would seem as common sense to me.

Author:  jckstrthmghty [ Thu Aug 16, 2018 1:54 pm ]
Post subject:  Re: Grouping success

For me it was 4" groupings at 10m. That's after several thousands of shots to confirm it was not me or the scope. Yup I bought a few scopes to confirm. After correcting the tightness it was 1/4" right away. Shot much better than that at times. I still get the odd flyer but who doesn't? oh yeah, smooth twist x.

Page 2 of 3 All times are UTC - 5 hours
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
http://www.phpbb.com/