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100 yards with a Thomas

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thomasair

thomasair

Member
Manufacturer
Nov 6, 2016
2,187
2,731
Colorado, United States
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I recently built a gun for a customer that is high power for me compared to the normal 25m BR and FT guns I build. Over the last week I have been tuning and testing it at 50 and 100y. This has always been a real challenge for me because I had to drive to a range where I could shoot further than the 75 yards available at my shop. I moved last year, so now I can step out the back of my shop and have all the distance I need. It’s an awful lot more efficient for testing purposes.

Anyway, I’ve actually had a pretty good time fiddling with barrels and setups.


I live in the high desert of Colorado, and it’s usually very windy here... so there is no shortage of good test conditions for that sort of thing.

I have tried 22, 25, and 30 caliber from this rifle in many iterations. I have narrowed down the 25 caliber setup shooting the 34gr MK IIs at 880 to be my favorite in the wind thus far.

I’m a believer in 25 shot groups to determine if a rifle is working right. Here are some in winds ranging from 5-25mph. You will be able to tell which are which I suppose. I’m not holding for wind drift, but aiming in one spot to observe the drift over 25 shots. I’m looking for a group that is fairly consistent and shows small vertical dispersion. I don’t care how wide the group is as long as it’s mostly not very tall. Most of the wind comes from the 1:30 direction here.


The target boxes on the 25m cards I’m shooting are a little under 2” x 2”.

I think it’s doing well.

Mike


 
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If you figure 25-18...that’s 7 mph....times .7 for the wind vector...equals 4.9 mph....times maybe .75” of drift per mph at 100y....that’s about 3.75” possible drift if I shot at each end of the spectrum. Looks like I probably did not actually experience the full 7 mph variation in wind that my meter was telling me was there since the group is only 2.5” or so wide.


I would shoot a few sample shots, then click the scope over to a place near where the samples landed...then commence shooting the group. I’ve clicked around so much that I really don’t know where zero is right now.


I don’t think it’s really drifting any more or less than it’s supposed to....but it is shooting pretty tightly in the vertical plane during heavy wind. That’s the part I like.


Mike 
 
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At the present tune it was holding a SD of 2 over 10 -15 shots. I was happy enough with that short term test that I didn’t worry about doing a long string. It’s not particularly miserly on air at this tune, but it’s enough to get 45-46 good shots before it hits the reg setpoint if I fill to 3400. I think the tube is about 375cc. Reg is at 1800. I’m certain I can improve air usage, but it’s not that high on my list at the moment. 

Here is a few more 25 shot groups from today since I already posted the best ones. What is posted so far is the best and worst from today.

I forgot to say that I was trying different velocities ranging from 835-890. The best performance was at 880 for me.

Mike 
 
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Intriguing! Those pesky winds, I know all about them in the mountains where I practice here in the PNW. 

Question for you - are you shooting straight from the tin or are they sorted? I had the best 20+ shot group a little while back around ~115y with sorted 50.15gr in ~10-15mph winds. Left a small ragged hole, unfortunately I didn't have more of that head size to shoot 😭

It's nice to see that you're building long range shooters 😎
 
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Hello... thanks. I’m not a pellet sorter. I have not seen any evidence in long term testing that proves it does anything.


I always tell people that when they sort pellets....do not throw away the culls. Keep them and interject them into a group once in a while and see if they produce the flyers that they are supposed to. Of probably a dozen guys that have actually tried this...none have ever reported that they could produce a flyer at will by shooting a culled pellet from the sorting process.


I’m not saying that one die of pellets won’t shoot better than another....I just have not found that I could make a good shooting tin of pellets shoot any better by sorting it...or take a crappy shooting tin and make it shoot great. I’m also not saying that I’m going to load an obviously damaged pellet and shoot it in a competition....but I don’t look for them prior to shooting.


In some instances I have found that weighing pellets to remove very heavy, or very light pellets has improved the vertical spread at 55y for FT. That being said, I rarely have done it....even for bigger national events.


Over the last few months I have delivered a few BR rifles to guys down in the Phoenix area that were big into pellet sorting. As I was testing their rifles here I sent them pics of the groups and cards I was shooting. They could not believe that it was possible without sorting. I’m happy to report that these guys have duplicated the results I was getting with pellets straight from the tin. They are pretty happy, too. 😀


I could probably write 10 pages about why I don’t sort, and why I think guys gravitate to sorting. I’ll leave that to another time.

The bottom line is that almost all things can be proven helpful or hurtful in short term testing....or flawed process testing.

Mike 



 
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Mike, looks like its shooting well. I like the first group photo in the original post, its shows excellent vertical dispersion, That's what we're all looking for, since the horizontal is on us as shooters when we shoot for score. I always have a laugh when I read (or see) about 100 yard + groups shot in varying winds, like 18 to 25 mph for example, yet the groups show no horizontal dispersion despite the 7 mph difference. We know this is physically impossible if shooting at the same aim point as is commonly done to shoot groups to check for gun accuracy. Pellets (and slugs) drift with the wind, can't get around that. Its refreshing to see real (very good) groups posted on AGN. Could you tell us more about the barrel choice you made for the .25 to shoot the Mk2s? Thanks,

Mike
 
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One 30 shot group in 5-12 wind coming at 4:30-5:00 while taking a break from working on a frustrating item.

The upper 5 shots on the group all came in succession which I thought was interesting. 

Shot one row of 7 for “score”. Took center from bull measurement....deducted .175” and doubled the number to compare to the EBR target rings which I believe are .500”, 1.25”, and 2” for 10, 9, and 8 rings. I think that is right.

Actually I see I screwed up the far right bull...that should have scored a 9 instead of 8. I think I had 1.125” in my head instead of 1.25.

Mike
 
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@thomasair I hear you. Shooting from the tin can be an honest representation of the rifle / barrel. 

Sorting doesn't seem to matter as much at shorter range targets, but there are some pellets that clearly perform better when sorted by head and skirt diameters in specific barrels I have owned. In those cases, it was the reproducible difference between ragged holes and a few inches at 100 and beyond.


 
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I have done very little shooting beyond 55y to be truthful...so I can’t say I have tested sorting at those ranges beyond the 55y mark.


Mike...here is my attempt at the card you posted here. Wind is 6-13 crossing over center and flipping the flags every 30-45 seconds. I was just waiting till I got a definite indication of direction before trying to do anything. The mirage is quite heavy, and it’s honestly very difficult for me to see a pellet hole if it lands in the red....and a lot of them did. I’m using a Sightron 36x bench scope. I can see that a mil dot type reticle would be handy. I have a Leupold 40x with dots at 2.2 moa on my FT gun. I will try that when I get a chance. It’s more clear than this one, too. Maybe that would help.



Mike 
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Those swirling winds can be a beatch. I think I added wrong on the above target. Should be 218. Math is not my friend.

Your technique with 100Y is totally different than 25M. Some guys single load but it’s a disadvantage. But it can be done Nicolay won EBR single loading.

Im going to change the maroon to a light yellow on the targets to make shots easier to see.
 
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I feel you on that wind thing. Here in Texas I've been the last 3 times with very tricky winds. But, at all the matches, there is going to be the same kind of wind. You gotta practice in the kind of wind you are trying to win in. :)

And thanks C'Cut for the target. It is my new favorite. Printed 50 yesterday on card stock. Let me know when you have the yellow one. I think it will be easier to see.

Crusher


 
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