Where is that Pellet magic between Transonic and Supersonic?

[2L8]

Long, short story...I want to shoot JSB .25 33.95 MKII somewhere between "Trans and Super", but where? 810, 830, 865...900, 950?

I have an interesting dilemma with a new Bushnell Forge scope I purchased a few months ago that came with a "freebie". It included a free elevation turret custom made for my caliber and scope. I filled out the form the best I could and sent it off to Kenton Industries to have it made. Isaac gave me a call back and asked me a myriad of detailed questions about my gun and I said to him "it is just an airgun and I will be shooting it to maybe 150yds" Isaac said "no problem, we will design it for what you want"...New Fan Boy here!! These guys are incredible. His conversation went into the real core data of sustained FPS, BC and measured pellet drop in 5yrd increments to my target. I told him I would be in touch ...Research time!! I grabbed 4 different "ballistic trajectory" apps/SS and went to work imputing the data I have compiled for the specific pellet I want to shoot from my FX DL Classic in.25 with installed PP. My DL now shoots the 33.95's @810 lights out hole in hole at 25yds and want to tune it with them to my intended max 150-200yds. All 4 trajectory programs gave data that was within a few points of each other at 200yds. I have not tested, nor can I to 150-200yds in 5yd increments here in the city.

Peace , be well and safe.

 

[sonny]

I've shot them(34s) at 920fps with great accuracy as far out as 130yards hitting shotgun shells consistently meaning 5-7 times out of 10 shots and 1 1/2 inch groups at 100 when the wind wasn't blowing. This is with FX Impact original S/T barrel.

 

[vmaxpro]

No problems here at 100 yards at 975 fps

 

[2L8]

I've shot them(34s) at 920fps with great accuracy as far out as 130yards hitting shotgun shells consistently meaning 5-7 times out of 10 shots and 1 1/2 inch groups at 100 when the wind wasn't blowing. This is with FX Impact original S/T barrel.

Have you had similar accuracy at lower FPS?

 

[58Flinter]

AirarmshuntingSA has covered this.



https://youtu.be/HpDKxVuRWto

 

[2L8]

AirarmshuntingSA has covered this.





https://youtu.be/HpDKxVuRWto

Excellent. Thank you...i missed this one.

Do you have a FPS for your ballistic profile?

 

[Guest]

Mr. Sterne did a thread on this topic some time back. I was particularly interested in it at that time. Here is a link:

https://airgunguild.com/ask-bob/velocity-and-wind-drift/msg11277/#msg11277

 

[2L8]

oldspook, That is a great link, thank you so much.

 

[58Flinter]

I am still learning all of this. I am coming from Longbows and Front stuffers. Range finders, ballistic profiles, etc... are all new to Me.

 

[Ginuwine1969]

I shoot them at 855 FPS out of a 600 STX .25 cal Gen 1 impact 8 out of 10 shoots 1 MOA at 1p1 yards. 3 inch shoot n c.

 

[Guest]

oldspook, That is a great link, thank you so much.

Yep, no worries. Mr. Sterne is a pretty sharp fellow.

 

[lenweber2]

I don't think there is much getting around shooting you gun with the slug/pellet you want to have the scope set for. Each gun barrel may shoot differently and to find what speed your gun shoots the best groups is the key. Tune your gun then tell the supplier that speed and projectile data.

 

[tor47]

I resently tried to tune my gen 1 fx crown, with .177 jsb heavys at 880+ speed and could not get them to group well. Tried different pressure also.chrony numbers looked good. Then I lowered pressure, and speed, and ended up at 840, and now shoot very good. Then did the same with my wildcat, which did shoot good at 870-880. Only dropped hammer spring tension on this gun, til velocity ended at 830, and have never shot better, with less flyers. So my "new" speed I will test all my guns at, is at 800-850 range Maybe we often are "stuck" at 880-900, and tries to hard to get the guns shoot good there, while the ansver may be in just going lower