Strelok users: Actual 22LR bullet BC?

[TresMon]

Morning,

I know what is reported in general on the 'net and I know what is in the library of Strelok Pro, But what actual bc values are you having to use to make your predicted data match real world data?

I shoot Lapua Center-x for short range, Midas+ for longer range and Lapua X-act or Eley Tenex for the longest range.

These Lapua offering I mentioned all have the same bullets and I am having to use a really low bc of .119 for my data to work, which is WAY lower than advertised.

I have not actually worked out real world BC data for the Eley Tenex yet.

Any body have a working BC for Strelok with this Lapua and Tenex bullets?

Big Thanks,
TM

 

[ScottDWallace]

I use between .131-134 with my kestrel with good success.

 

[TresMon]

I use between .131-134 with my kestrel with good success.

For which bullet? and thank you.

 

[beetroot]

.120 seems to be about right with CCI Std and SK Match for me, have confirmed it out too 150m.

Not done enough testing past that too know if it holds true further out.

 

[barronian]

@TresMon So far at 50m, 100m and 200m i find Strelok Pro's BC to be very accurate for center-x and tenex, i haven't tried midas+ yet, nor have i tried further than 200m.

I do have to adjust them by 0.6 mil when i put a silencer on though.


How far out are your hits from the predicted aim point ? what gun are you using ? Are you sure that your scope is tracking correctly ? have you tried hold over instead of twisting the elevation turret ?

 

[10ring1]

@TresMon So far at 50m, 100m and 200m i find Strelok Pro's BC to be very accurate for center-x and tenex, i haven't tried midas+ yet, nor have i tried further than 200m.

I do have to adjust them by 0.6 mil when i put a silencer on though.


How far out are your hits from the predicted aim point ? what gun are you using ? Are you sure that your scope is tracking correctly ? have you tried hold over instead of twisting the elevation turret ?

Out to 200 yds, strelok is within .1-.2 at least out to 100. What BC is everyone using for Center X? I know mine may be high but I use . 172. I adjusted the BC to get the dope correct with reality and all the others fell into place.

 

[DownhillFromHere]

I'm showing .148 for Lapua-sourced Wolf Match Extra and .152 for Lapua Center-X, "trued" at 150 yards. I put the word in quotes because the mildest of breeze or the day of the week or cosmic rays can move that point of impact.

Concentrating on precise placement at 100 yards, the BC falls to .131 or so. But, for the matches I shoot the most, win or lose is decided at 150 yards. Going out to 300, the higher BC seems to work best. At least it did last tie out. Next time may be different.

Because .22.

Vudoo V22 with 20" Ace/Kukri, 50-yard zero.

 

[TresMon]

Thanks everyone. My data is closest to real world using an RA4 drag curve of .119 out to 500 yards.
But it's only "acceptable," being off 3" at 300 yards. But this is rimfire: Good enough for a rimfire I guess seeing as how at that range even a shadow will scare the bullet off to somewhere else.

 

[Spblademaker]

.132 for Eley Wolf Extra Match

 

[barronian]

@TresMon i assume you are you using G1 as the drag function ?

 

[billmeek]

I calculate the BC for each rifle / ammo combination:

https://www.snipershide.com/shooting/threads/ballistic-coefficient-calculating.6924581/

 

[ScottDWallace]

For which bullet? and thank you.

SK Standard Plus, SK match, and Lapua Center X.

Cheers

 

[TresMon]

@TresMon i assume you are you using G1 as the drag function ?

I was and have been, but have now found using RA4 better matches my real world com-ups.

 

[barronian]

@TresMon hummm, i'll have to give RA4 a go !

 

[Mech_eng]

I'm running a .155(G1) with Center X and a 22" barrel at 1092 FPS. I'm using Strelok pro. I first checked actual MV with my Magnetospeed and then adjusted BC to match actuals at 100 and 200yds. Have had hits out to 340 with this setup..

 

[TresMon]

Thanks for the reply everyone! Yeah, RA4 ballistic model was specifically created for skirted, 22 LR round nose bullets. Most ballisticians say that RA4 and G1 are identical UNDER 1350 fps, but my Strelok pro app seems to disagree. RA4 gives me better modeling that matches my real world better.

 

[barronian]

@TresMon here is an interesting description of the differences between some of the BC models

Long range 22LR trainer - how to get best out of it?

22LR rifles have always been very popular. Most of us have one sitting in safety. Some of us have also spent quite a bit hard-earned money to make their small rimfire feel and look similar to favorite big center-fire. All in sake of realistic low-budget training. It is also not too uncommon to...

finnaccuracy.com

it looks like some of the confusion in the answers above, over BC numbers, is people not stating if they are using G1 or RA4.

I tried RA4 in Strelok after your comment and agree that it matches better, although i'm finding that it very weather sensitive ?

 

[beetroot]

@TresMon here is an interesting description of the differences between some of the BC models

Long range 22LR trainer - how to get best out of it?

22LR rifles have always been very popular. Most of us have one sitting in safety. Some of us have also spent quite a bit hard-earned money to make their small rimfire feel and look similar to favorite big center-fire. All in sake of realistic low-budget training. It is also not too uncommon to...

finnaccuracy.com

it looks like some of the confusion in the answers above, over BC numbers, is people not stating if they are using G1 or RA4.

I tried RA4 in Strelok after your comment and agree that it matches better, although i'm finding that it very weather sensitive ?

Are you using Strelok + or Pro?
I have + and can't see a way to change from G1.

 

[barronian]

@beetroot Strelok Pro

 

[beetroot]

@beetroot Strelok Pro

Bugger.
I really struggled to get the ballistic data to match my real world data on one of my 22s, was hoping this would help.

 

[spartan67]

I talked to Mike at Eley. He said all Eley ammo is .150.

 

[Country]

I was and have been, but have now found using RA4 better matches my real world com-ups.

Ra4 is for the 22 rimfire bullet shape .

 

[barronian]

I talked to Mike at Eley. He said all Eley ammo is .150.

@spartan67 .15 C1 or .112 RA4

 

[spartan67]

@spartan67 .15 C1 or .112 RA4

G1

 

[Emerson0311]

I’m struggling with the apparent drop off of BC after 200yds with CCISV. Using my dope drop at 200yds, my predicted 300yd solution is not enough up to match my dope on target. I have had to guess and experiment with multiple BCs based on velocity to make Strelock Pro live up with my action 30rnd groups on target.

 

[DownhillFromHere]

I’m struggling with the apparent drop off of BC after 200yds with CCISV. Using my dope drop at 200yds, my predicted 300yd solution is not enough up to match my dope on target. I have had to guess and experiment with multiple BCs based on velocity to make Strelock Pro live up with my action 30rnd groups on target.

Fwiw, Strelok Pro has a 3-tier truing function. Most people are aware of the single-value function, which is accessed by tapping the lower-right icon on the home screen. To access the 3-tier function, press and hold the icon for a couple of seconds and then release. Presto.

I don't know if the ability to enter three values will help - I use the Lapua drag function, which does pretty well with Center-X out to 400, which is as far as I've ever seen targets in a match. Also, CCI SV typically gets more and more inconsistent the farther out one shoots.

 

[Boxerglocker]

I’m struggling with the apparent drop off of BC after 200yds with CCISV. Using my dope drop at 200yds, my predicted 300yd solution is not enough up to match my dope on target. I have had to guess and experiment with multiple BCs based on velocity to make Strelock Pro live up with my action 30rnd groups on target.

Have you actually verified muzzle velocity ES and SD with CCISV in your gun? YMMV, but I have never found a lot of CCISV with decent enough
numbers to bother attempting to true it beyond 200 yards. Bear in mind at 300 yards an ES of 30 alone is a difference of 6-8 inches of elevation.

 

[Emerson0311]

Have you actually verified muzzle velocity ES and SD with CCISV in your gun? YMMV, but I have never found a lot of CCISV with decent enough
numbers to bother attempting to true it beyond 200 yards. Bear in mind at 300 yards an ES of 30 alone is a difference of 6-8 inches of elevation.

Yes I have. I use 30 rnd groups out that far and discard the half dozen highs and lows. The ES and SD are no worse than my lot of SKRM, which is reflected soundly in the targets at 100 and 200. This is a bit of a training exercise for me to understand full use of the App and start to wrap my head around the effects of environmentals, especially wind, on the 22LR out there. I’ve got a 1/12 to put on soon, but that will preclude the use of CCISV, which I’ve got a lot of. No sense burning up good ammo learning to basics of 22LR at distance.

 

[Emerson0311]

Fwiw, Strelok Pro has a 3-tier truing function. Most people are aware of the single-value function, which is accessed by tapping the lower-right icon on the home screen. To access the 3-tier function, press and hold the icon for a couple of seconds and then release. Presto.

I don't know if the ability to enter three values will help - I use the Lapua drag function, which does pretty well with Center-X out to 400, which is as far as I've ever seen targets in a match. Also, CCI SV typically gets more and more inconsistent the farther out one shoots.

Thank you, I didn’t know about the ability to enter 3 values. It lines things up much better. Yes, CCISV is the beater car to learn long range 22 with. I typically discard the 1/2 dozen highest and lowest out of 30 to get a group to use for data. When I break a decent shot, my crosshairs move < 1 1/2” @300, so the shot that goes 8” high or low isn’t me. Consistent, round groups are required to beat other shooters, but at this point I can disregard the crazy impacts and keep learning for cheaper.

 

[Gleedus]

Generally the further out you true your drop the lower your BC. I use Strelok pro almost exclusively now.

Couple notes. In no particular order. A testing session for me is (yards) 50, 100, 200, 300 all on paper. 50 and 100 are 10 shot groups 200, 300 are 20. I also regularly shoot 400, 500 with some longer stuff occasionally. When calculating drop it is important to mathamatical calculate the group center not just measure the ES and split in half if you want very repeatable results. Especially with larger vertical groups.
It is EXTREMELY important to factor wind velocity and direction accurately if trueing drop.
1- RA4 and G7 are generally better for 22lr then G1
2- Normally if you true at 300 yards with RA4 you will be good to 450-550 ish
3- if you true at 400 you will be a 0.05-0.2 mil high at 200 depending on the drag model used.
4- I've found the best results getting actual velocity then true the BC.
5- increasing your sight height will lower your mid range calculations if hitting high. But it will also lower your BC to true.
6- truing your drop at 100 yards simply will not work. 0.1" difference in POI is aprox 0.010 bc points plus other issues.
7- if you true at 300 yards you may find POI low at 100-150 depending on ammo velocity. (Still testing/ working on that)
8- scope tracking test is important to know actual scope values.
9- its all in the little details that will get you messed up when truing drop.

Couple Rule of thumbs
BC 1-16 twist
1- SK bc 0.113 RA4 0.133 G1
2- Eley 42 gr round nose 0.113 RA4 0.133 G1
I dont have Eley EPS BC handy in 1-16 but if memory serves its about the same.
3- Trueing drop at 200 yards if with RA4 add 0.0-0.05 mil to drop
4- if using G7 add 0.05-0.1 mil
5- if using G1 add 0.1- 0.15 mill
Then you'll be good 450-550

Anyhow lots of rambling hope its food for thought. I also tend to get better BC with 1-12 twist depending on the bullet.

Ending thought is for PRS, NRL22 you dont have to be so worried. Shoot 200 yds throw out "fliers" if you have big groups. Then split your remaining group in half and true your BC well using actual velocity. Be sure you have accurate BC based on temp and go win a match.

If you dont have access to 200 yards for testing use the BC above with actual velocity and you'll be "good enough". Good enough is all that matters.

 

[Gustav Jimny]

I use between .131-134 with my kestrel with good success.

Much belated reply, I know....
Exactly what I found yesterday, shooting Yellow SK Standard Plus, at 200m, 1008fps measured with a Magnetospeed.
Rifle is a CZ455 Supermatch, 20" barrel.

 

[NewsShooter]

I've got .123 for Sk plus, it's been accurate out to 400 yards.

 

[Gustav Jimny]

Mmm, I will test out to 300m Saturday, thanks

 

[JG26_Irish]

I have been using the G1 (0.137) BC with CX ammo that is 27speed lot in my Sako out to 400y. It is not perfect but enables hits on steel at 200/300/400 out our range. It is important to adjust my atmospherics to the actual temps each day and adjust them thru the day as it warms if shooting really long. Some of the posts above are very good and make me want to get more detailed in my efforts. Might try some of your suggestions when I have time. You guys are good.

 

[Deputy Dan]

A bit late to the thread but what the heck --

Using Strelok Pro, Bergara B14R. Initially used G1 and Strelok's BC of .142 (at least I think that's where I got .142!) for Eley Tenex. Everything Strelok gave me beyond 50 yards out to 206 was a bit high (.1 at 122, .3 at 206). I adjusted to RA4 and it brought my 122 yard down to true, but the 158 and 206 are still a bit high (shooting silhouettes!). Next I put in the .150 BC mentioned earlier (as from Eley) and it came out to my true numbers at 122 and 158 yards - but not 206 . Changed the BC to .133 Gleedus mentioned and now 122 and 206 are right on, but 158 is a bit high.

I've also got a profile for SK Standard Plus and also changed it to RA4; initially at .132 (again, not sure where I got that!); RA4 also brought the Strelock settings closer to true. Changed the BC to .123 as mentioned by NewsShooter above, and brought everything still closer to true. Dropping the BC down to the .113 mentioned by Gleedus actually made things a bit worse so I'm going to leave it at .123 for now.

And - as an afterthought- all my dope is BEFORE I added a tuner. I don't think the tuner is supposed to affect the dope - but I guess I'll see at the next match!

Still a work in progress - but this thread has been VERY helpful! I haven't yet had an opportunity to use my new chronograph - when I do I'll see how/if the true MV changes things.

 

[Gleedus]

A bit late to the thread but what the heck --

Using Strelok Pro, Bergara B14R. Initially used G1 and Strelok's BC of .142 (at least I think that's where I got .142!) for Eley Tenex. Everything Strelok gave me beyond 50 yards out to 206 was a bit high (.1 at 122, .3 at 206). I adjusted to RA4 and it brought my 122 yard down to true, but the 158 and 206 are still a bit high (shooting silhouettes!). Next I put in the .150 BC mentioned earlier (as from Eley) and it came out to my true numbers at 122 and 158 yards - but not 206 . Changed the BC to .133 Gleedus mentioned and now 122 and 206 are right on, but 158 is a bit high.

I've also got a profile for SK Standard Plus and also changed it to RA4; initially at .132 (again, not sure where I got that!); RA4 also brought the Strelock settings closer to true. Changed the BC to .123 as mentioned by NewsShooter above, and brought everything still closer to true. Dropping the BC down to the .113 mentioned by Gleedus actually made things a bit worse so I'm going to leave it at .123 for now.

And - as an afterthought- all my dope is BEFORE I added a tuner. I don't think the tuner is supposed to affect the dope - but I guess I'll see at the next match!

Still a work in progress - but this thread has been VERY helpful! I haven't yet had an opportunity to use my new chronograph - when I do I'll see how/if the true MV changes things.

What twist rate is your barrel?

 

[6.5SH]

A bit late to the thread but what the heck --

Using Strelok Pro, Bergara B14R. Initially used G1 and Strelok's BC of .142 (at least I think that's where I got .142!) for Eley Tenex. Everything Strelok gave me beyond 50 yards out to 206 was a bit high (.1 at 122, .3 at 206). I adjusted to RA4 and it brought my 122 yard down to true, but the 158 and 206 are still a bit high (shooting silhouettes!). Next I put in the .150 BC mentioned earlier (as from Eley) and it came out to my true numbers at 122 and 158 yards - but not 206 . Changed the BC to .133 Gleedus mentioned and now 122 and 206 are right on, but 158 is a bit high.

I've also got a profile for SK Standard Plus and also changed it to RA4; initially at .132 (again, not sure where I got that!); RA4 also brought the Strelock settings closer to true. Changed the BC to .123 as mentioned by NewsShooter above, and brought everything still closer to true. Dropping the BC down to the .113 mentioned by Gleedus actually made things a bit worse so I'm going to leave it at .123 for now.

And - as an afterthought- all my dope is BEFORE I added a tuner. I don't think the tuner is supposed to affect the dope - but I guess I'll see at the next match!

Still a work in progress - but this thread has been VERY helpful! I haven't yet had an opportunity to use my new chronograph - when I do I'll see how/if the true MV changes things.

You can't just change the drag model from G1 to RA4 without converting the value. Ex; SK Standard+ is a G1 of .132 and RA4 of .107 for me.

JBM - Calculations - Drag Function Conversion

www.jbmballistics.com

 

[Gleedus]

You can't just change the drag model from G1 to RA4 without converting the value. Ex; SK Standard+ is a G1 of .132 and RA4 of .107 for me.

JBM - Calculations - Drag Function Conversion

www.jbmballistics.com

I'm assuming your using G1 in your solver? If you used the jbm to convert its close but my experience is that with strelok a G1 of 0.132 will actual work out to a RA4 of 0.112-0.113

There are some variation lot to lot but to date I havent seen SK lower then RA4 of 0.111.

But having said that you made a very good note on there are real differences between G1 and RA4 many people think they are interchangeable which they are not in subsonic.

 

[6.5SH]

I have profiles for both, the numbers actually came from analyzing a 100 shot LabRadar session out to 100 yards.

Geladen | Labrabaco

ETA:
Tikka T1x 16" bbl with 1:16.5 twist

 

[Gleedus]

I have profiles for both, the numbers actually came from analyzing a 100 shot LabRadar session out to 100 yards.

Geladen | Labrabaco

ETA:
Tikka T1x 16" bbl with 1:16.5 twist

Super interesting! Never heard of labrabaco I have wondered about using the labradar to create out own PDM basically but figured we would want it to read out to 200 yards forsure to work.
I will say if I true at 100 with RA4 I get a lower BC.
Thanks for posting.

 

[Deputy Dan]

What twist rate is your barrel?

1:16, length 18"

You can't just change the drag model from G1 to RA4 without converting the value. Ex; SK Standard+ is a G1 of .132 and RA4 of .107 for me.

I appreciate that - and I recognize I'm only looking at one variable. Just changing to RA4 and leaving the original BC I had in there at G1 brought the Strelok a little closer to true, but it took changing the BC to get even closer - or right on - true. I trust I'll get still better numbers once I've got MV locked in closer to actual as well.

 

[DownhillFromHere]

Fwiw, guys, I have been using the Strelok ".22LR Lapua Center X 2.59g" drag curve, available in the selection list where G1, G7, RA4, etc. curves are found, for quite some time. It should be applicable to most if not all SK/Lapua labels. It gives me good solutions out to 415 yards, which is as far as I've seen targets in matches.

I just checked to make sure the curve is still there on the list... uh, yeah, there are five of them, all with same name. I'm not messing with my setup because it works... it would be interesting to know why there are five of them but there is coffee to be consumed and newspaper to be read...

 

[Gleedus]

Fwiw, guys, I have been using the Strelok ".22LR Lapua Center X 2.59g" drag curve, available in the selection list where G1, G7, RA4, etc. curves are found, for quite some time. It should be applicable to most if not all SK/Lapua labels. It gives me good solutions out to 415 yards, which is as far as I've seen targets in matches.

I just checked to make sure the curve is still there on the list... uh, yeah, there are five of them, all with same name. I'm not messing with my setup because it works... it would be interesting to know why there are five of them but there is coffee to be consumed and newspaper to be read...

The reason you have 5 is you loaded it 5 times.

 

[DownhillFromHere]

The reason you have 5 is you loaded it 5 times.

"Loaded" how? I remember selecting it from the pick list (where it appeared once as I recall but that was three years ago) to use, but nothing more. That's not to say I didn't mess with it later - I don't remember. No worries for me, but others may find the info useful. Thanks.

 

[Gleedus]

"Loaded" how? I remember selecting it from the pick list (where it appeared once as I recall but that was three years ago) to use, but nothing more. That's not to say I didn't mess with it later - I don't remember. No worries for me, but others may find the info useful. Thanks.

Yup when hit the button for lapua drag functions you then select the one you want to load. That then goes on your mail list of drag functions where you can the edit if you wish.

 

[Gustav Jimny]

As promised, I used the G1 BC of 0.133 in my Kestrel on Saturday out to 300m, and I was hitting a 12" target repeatedly.
Rifle is a 20" CZ 455, Ammo was Yellow SK , Magneto Speed 1006 fps

 

[bostonbullit]

I have profiles for both, the numbers actually came from analyzing a 100 shot LabRadar session out to 100 yards.

Geladen | Labrabaco

ETA:
Tikka T1x 16" bbl with 1:16.5 twist

Thank you for that link! I was thinking of building a similar app but will gladly use this one and spend my time at the range instead

 

[oldfatjonwick]

Bugger.
I really struggled to get the ballistic data to match my real world data on one of my 22s, was hoping this would help.

me too. it works out best when i use the hornady 4DOF app with the drag model function.

 

[drglock]

RimX
Green Mountain @ 22”
Center X

I zero at 50yds then true my velocity at 150yds(1101fps) and true my BC at 250yds. Don’t have my Kestrel in front of me but I believe it trued out at .134 . 300+ I use a BC of .118.
Most matches I shoot are 250ish and under and this has worked well for me.