Tuning Would you consider this an accurate rifle?

[Arzrover]

I've been working on two 20 cal barrels for a couple of months here and there. This is one fitted to a Red Wolf.

The first pic is 6 - 5 shot groups @30 yds w 13.7s and 5 - 5 shot groups w 15.89s. The center group on the left was first so I took a couple of clicks off and all remaining are from the same zero. The top left shot was 1st after the scope adjustment but hold was in the same place. The 13.7s are sub 20 ft lb. The 15.89s are about 30 ft lb. I did not hold for wind in any group but was a fairly light breeze.
The second pic is @ 50 yds with 15.89s. I shot 3 below the target to find holdover, then group of 5.
The third pic is @ 100 yds w 15.89s. I shot 5 off the target to find holdover, then group of 5.
So basically- its 73 consecutive shots with only one I'd consider a flier but maybe two or three that are outliers.
What do you think?
Bob

 

[Sqwirl57]

I think you have an accurate rifle

 

[Bbailey]

If that were my project I’d be very pleased with how its shooting. Nice work!

 

[JaceSpace1369]

I've been working on two 20 cal barrels for a couple of months here and there. This is one fitted to a Red Wolf.
View attachment 404450View attachment 404451View attachment 404452
The first pic is 6 - 5 shot groups @30 yds w 13.7s and 5 - 5 shot groups w 15.89s. The center group on the left was first so I took a couple of clicks off and all remaining are from the same zero. The top left shot was 1st after the scope adjustment but hold was in the same place. The 13.7s are sub 20 ft lb. The 15.89s are about 30 ft lb. I did not hold for wind in any group but was a fairly light breeze.
The second pic is @ 50 yds with 15.89s. I shot 3 below the target to find holdover, then group of 5.
The third pic is @ 100 yds w 15.89s. I shot 5 off the target to find holdover, then group of 5.
So basically- its 73 consecutive shots with only one I'd consider a flier but maybe two or three that are outliers.
What do you think?
Bob

Quick question, why did tou measure the second one corner the corner while the others were measure center to center? Great groups either way.

 

[Long_Gun_Dallas]

Looks good enough that the group size is largely due to user error. (Or environmental deviances) And they're still small groups.

So, that would be a yes.

 

[bdzjlz]

Absolutely!

 

[Arzrover]

Quick question, why did tou measure the second one corner the corner while the others were measure center to center? Great groups either way.

I measured all the paper from the outer pellet marks, then subtracted the caliber (.200) to give ctc group size. The splatter on the steel makes that difficult and the center of the pellet shows, so I just measured ctc on it. The 50 yd group would be 0.312.

Thanks to all but I wasn't really looking for any accolades with this... just an idea if you would stop or keep working on it. My pre benchrest accuracy goal was ALL shots inside of a 1/2" circle at 30 yds for FT... a Troyer factor of 60. Now in that era, I never had a 100% rifle but was really close. I didn't shoot benchrest so small holds for wind and shooting over wind flags would likely have done it. This was NO holding for wind but I don't feel that the outliers are wind related... mostly.
People post a lot of single groups but I was more looking for fliers than smallest group, though I DID try to be very consistent. I've shot lots of individual groups from this and my other 20s that were in the zeros at 30. Just not given a motivated go at this many.

My key takeaway is that 73 consecutive shots with two different ammos were both decent with virtually zero real fliers. Now I know that Mike N has posted some spectacular high count groups and these would not compete, but maybe he's just that much better?

The project has been inspired by the Sterling project barrels that @Franklink has documented and trying to get a CURRENT 20 barrel to do as well. This is close but the slugs I've tried so far haven't been as good as his rifle does with them.

Will anyone post some comparisons... 5 - 5 shot groups consecutive @ 30 ? Would love to see em.
Bob

 

[Long_Gun_Dallas]

Unfortunately, it's been a long time since I went shooting. Too much family stuff going on, and working like crazy. Climbing the proverbial ladder. Trying to buy a good bit of land within the next few years. For many reasons. One benifit of which will be plenty of space to shoot/hunt.

What slug shooting I have done seems to rely on proper projectile diameter in relation to bore size. Appropriate twist rate for said projectile. A choke that isn't too aggresive (or a barrel that's good enough it doesn't need a choke), plenty of testing and tuning, and a fair bit of luck. Sounds like your friend may have tested several barrels, and simply found one that's happy with the rest of the variables. ?

 

[Bbailey]

Will anyone post some comparisons... 5 - 5 shot groups consecutive @ 30 ? Would love to see em.

Are you wanting only .20 cal or can these groups be shot with .177 & .22 ?

 

[Lewis]

The results are excellent.
I am excited to see what happens with ,20 slugs. Both NSA and Zan are now making some.

 

[thomasair]

Bobby, maybe have a look at the 30y challenge. It’s essentially 24 shots at 30y shot by all kinds of rifles. 30 is kind of an odd distance for me.

30-Yard Challenge

Getting tired of shooting groups? Try this game out. You shoot all 24 bulls once at 30 yards. Next, eliminate your two lowest pairs. Then, add up your score, with a Max of 200. My best target using my Vet Long is below, as is the target I used. It would be a really great shooter who could get a...

www.airgunnation.com

Mike

 

[Franklink]

Since we're talking Sterling Lothar .20s.....

Late night at work so just barely shot this..
And I got all kinds of excuses, 38 degrees, night time shooting is hard to center the eye in the scope, jittery from being at work all day and drinking caffeine, etc.

5, 5 shot groups with the Vet .20 and 5, 5 shot groups with the Ghost .20. all at 30 yards. 50 shots in a row, all seen here. Shot in the order I wrote on the bull. No "flyers" per se, but the lowest one from the Vet (#4) was waving grass blades as the pellets went past. And I did pull the 25th shot on the Vet, in group 5, pulled just a bit right. That shot bumped up the average from the Vet .20 quite a bit. I think the somewhat and slightly wandering poi is from parallax issues (again, eye centered in scope in the dark is tricky).

Only used the .20/13.73s. Both guns average 800-805ish, and both have fairly tight extreme spreads. Vet is a bit tighter, 8-10fps spreads usually. Ghost is more like 15fps extreme spreads. Those ES aren't a factor for 30 yards.

The written group size is how they measured from outer edge to outer edge.

 

[JDGriz]

Wow - old Mitutoyo!

 

[Arzrover]

Any caliber is fine... just looking for references. I planned to try my wifes 177 barrel asap. It's probably the best in our collection or very close. Or maybe my USFT... The reason for the 20 cal is that at 20 ft lb, the bc is the best.

Thanks Mike I considered that but just haven't downloaded the targets.

THAT'S what I'm talking about, @Franklink ... so your Ghost averaged 0.119 ctc and the Vet averaged 0.137.... This one averaged 0.302 w 13.7s and 0.320 w 15.89s.

The question is: is there more to be had on this barrel?

Bob

 

[thomasair]

This is often regarded as nit picky, but is actually important when trying to compare groups of different calibers or projectile types.

To obtain a valid ctc distance based on a groups outside to outside “daylight” measurements…you must use the “daylight” measurement of a single hole to deduct from the outside to outside. Using the raw caliber as the deduction results in optimistic numbers…especially when the group is already smallish. .177 holes from round nose pellets on reasonably decent paper are about .135”-140” but can produce even smaller “daylight” measurements than that with variations in paper and backer support.

Mike

 

[Solo1]

Something else to consider in your calculations is the difference in measured bc between poly and rifled barrels. I have no crono data to verify this but using strelock i had to bump the bc to .040 to get it to match where my 13 gr jsb 177 pellets were landing @ 55 yds when sighted @ 40 yds. Just some input from me. Rainy today or id go out and shoot will do at first chance

 

[ocedummy]

Those look decent for thirty yards. Every time when I am comparing pellets, slugs, wind deflection, gun velocities I shoot at 50 yards. I have been using a 27 yard zero for 20 FPE testing. When I shoot at 25-30 yards everything looks good.

 

[Solo1]

Ok bob here are 5 - 5 shot groups from my 177 ghost and my m3 22 Winds light but variable and i think i need to clean the ghost barrel. Lol

 

[Arzrover]

Thanks @Solo1...
Using your measurements, I get a 3/8" average for both.
Looks like we both have some work to do to match @Franklink

Bob

 

[Franklink]

This has me wanting to try it out with a few more of my ft rifles.

I've used the International Field Position as a metric for a couple years now, but this might be even better. The IFP is more a measure of the gun+the shooter, since it's shot from a ft position. Whereas this 5x5 @ 30 from a bench is more a measure of the raw accuracy/precision potential of the barrel/pellet combo.