FX Crown100yd indoor accuracy Part 2- OUTDOORS

[Ghostranger169]

I shot these groups OUTDOORS using the same procedure and preparation that I used in my original FX Crown100yd indoor accuracy test(see previous post). The conditions were about the same temp(75°) with a slight variable breeze from 0 to 2mph mostly off the left(almost calm). 

One curious thing, the ave. fps were higher in .22 and in .25 using the same settings that I set in previous test. I had 5 fewer shots in .22 before I reached the cutoff of 160 bar? Also, I am using the 700mm slug A liner for the .22 jsb 18g and 600mm pellet liner A for the .25 jsb Kings(surprised no one asked about that in the previous post).

Regulator pressure approx. 145 bar

Jsb 18g setup:

Valve setting- 177/22, Power wheel 4= ave. 983fps

Jsb .25 King setup:

Valve setting- 177/22, Power wheel- 5= ave. 943fps

These groups opened up quite a bit(as expected) compared to the indoor groups.

 

[thomasair]

As a competition rifle builder, I probably shoot indoors more than anyone that reads these forums. It is the only way to figure out what a rifle is doing in a reasonable amount of time.

it is assumed that if you are shooting indoors, there is no wind to deal with. For most indoor places, this is simply not true. The bigger the building and the longer the distance being shot, the more likely it is that their is plenty of air moving around inside. Besides “wind” sources such as heating and cooling systems, there is also plenty of cool floor and hot ceiling to turn the air over...plus drafts from outdoors. Do not assume that there is nothing to affect the pellet because you are indoors. I have seen plenty of poorly designed shooting tunnels that were more frustrating than just shooting outdoors for rifle testing....and plenty of guys trying to test guns in warehouses that had terrible results with outstanding rifles....and this was only 25m.

If it was me...I would shoot indoors at a much shorter distance and be ultra precise about measuring group size. You can then scale up the average group to determine what might be possible at the longer ranges. A gun that will consistently shoot 1 moa at 25y....is not going to improve on that at a longer distance....and there are a great number of factors that can come into play to make it worse at 4x the distance.

Mike 

 

[Exitpupil]

I would cherry pick the top right hand group of the first target and only post that one.

Seriously, thanks for sharing.

 

[JungleShooter]

Mike,

What you wrote is super interesting. Yes, warehouse shooting was on my schedule.

Can you elaborate on ways to detect and avoid these indoor winds (separate post?)?

Matthias

 

[Centercut]

@Ghostranger169 I’d be willing to bet that if you slowed down those .22 pellets to the 880 to 900 FPS range the groups would tighten up considerably. Plus the pellets would be slightly less affected by any wind, since BC lowers with those pellets much past 925. The same can be said for the .25 Kings. 900 to 920 FPS will also tighten up your groups. With diabolo shaped pellets (.22 RD Monsters the exception), speed is not your friend when it comes to accuracy and precision. 

 

[Ghostranger169]

Thomasair,

Thanks for your input. I sure don't have that much experience shooting indoors. I chose 6:00a.m. as a time to shoot thinking that the warehouse atmosphere would be at its most stable(temp, lack of activity/doors opening, sunlight on building, etc.) since 5:00 p.m. the day before. In my setup and testing, I measured the temp at 25 and 75yds away from shooting bench to be 71 and 70degrees respectively. I placed a wind detection box(the kind that emits a smoke/fog) at those same 25 and 75yds distances, then shot thru to the target. At 25 yds, the smoke moved when the pellet went thru it and then a few seconds later(when the air from the muzzle reached it?). At 75yds, only time the smoke moved is when the pellet went thru it. This is what I meant when I listed "no detectable wind" in my original post. I did not have the smoke box in place during the actual test tho. I'm sure I stirred things up a bit with my shooting, walking to change targets, and breathing, but I tried to let thing settle as much as possible. This was as much as I could think to do to check for variables, but there may have been some that I couldn't detect. There were constriction points where more pallets were closer together and a 10yd wide by 15yd long hallway adjoining warehouses which may have been a factor, as well. From my perspective, it was MUCH more favorable shooting conditions than I have experienced outdoors. However, I do have limited experience(especially indoors). Maybe this would have been a more appropriate response to my 1st post since it had pics of targets actual shot indoors instead of outdoors like this one? Just a thought. Thanks again for your input

 

[boscoebrea]

very interesting,good to learn from and will help me.Thanks

 

[Ghostranger169]

Centercut,

Thanks for the input and I appreciate your advice. I will go back and retest them hard at those speeds. 

I had read that the standard is that ~860 to 890fps gives the best accuracy with JSB 18g, so that's where I started. In my intial testing, that standard holds true for the 380mm pellet barrel and the 700mm pellet A liner, but I have to speed them up to get the same(actually more consistently tight) groups out of the 700 slug A liner?? Also, NONE of the barrels/liners like anything "heavy" worth a damn beyond 50 yards no matter how slow or fast I shoot them. I had high hopes of shooting the .22 Monster RDs, but the best 5 shot "group" I've gotten is 6" at 100yds!!? I must not know something or not be doing something right. Sometimes, it's discouraging.

I will take a hard look at those lower speeds again, especially the .25 Kings(I haven't done as much testing in .25 as I need to yet). Thanks again for your knowledge and advice.

 

[thomasair]

I have gotten, by far, the best indoor results by using a half dozen (maybe 8?) pedestal fans placed to the left of the shooting line and at a 45 degree angle on low. Again...this was only 25y and years ago. The fans were just enough to overcome the drafts and currents that I could not see and produce something consistent.


I mostly shoot 12 and 20 fpe rifles. The 20 fpe will shoot well in about any normal indoor condition...while the 12 fpe can be greatly affected by slight air that the the 20 goes right through. Even with a good indoor tunnel, I sometimes have to wait for a time when it’s not blowing 30mph outside to get groups with a 12fpe gun to equal the 20.

Its eye opening.

Mike 

 

[Ghostranger169]

Exitpupil, 

Haha. Yes. I wish I could, but that's not how I roll. It is what it is. No need to give anyone the wrong(or skewed) impression of something they might want to spend their hard earned money on, only to be disappointed later. I think this forum is a great place for fun and comraderie, but also a good opportunity to share and learn.

 

[dmo88]

Wow! That was a great education on indoor shooting for just 15 minutes worth of reading. I've never tried it but I'm going to and I appreciate you sharing your expertise.