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Need new zero


72stick

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My latest dilemma - Zero my rifle for Mo3 Gun Championship March 21st/22nd w/350, 500 & 600yrd stage.

I have a new load to test for those 600 yrds shots with no DOPE for a 69g SMK on top of 24g Re15. I've used this load in my service rifle for HI Power, but it's a 20 inch White Oak barrel. With this sub freezing/sub zero weather, how do I get an accurate chrono test & zero on my JP 15 with a 16" barrel w/o access to a 100 yrd target board? With temps below freezing all day, my Chrony is only accurate down to 32 degrees. My rifle's currently zeroed for Fed/American Eagle .223/55g FMJ @ 100yrds. I have access to a 25yrd indoor range. I could chrono/zero it there, but I don't think that zero would tell me much, unless may be, I use a reduced range target. I have some JP benchrest targets calibrated @ 100yrds with a 200 yrd zero windage & elevation line & hash mark above the 1 inch zero box.

What do you guys think about extending the line below the zero box on the target? The center of the Burris Mtac is 2.5 inches above the bore. Wonder if it would tell me anything useful other than windage @ 25yrds?? If the weather breaks, I might have one day at the 100yrd target board above freezing on the 14th. If I at least have it on paper before I go, it might be the only day I have before the match to get a useful zero.

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Not sure if this helps but if you chrono your load, when I go back to the shop I can tell you where you need to hit on paper @25 yards to be zeroed at 100 or whatever range you want. Of course any error at 25 is greatly magnified at longer distances so it is preferable to zero at the range you want your zero. Anyway, if that's what you need, shoot me a PM.

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Not sure if this helps but if you chrono your load, when I go back to the shop I can tell you where you need to hit on paper @25 yards to be zeroed at 100 or whatever range you want. Of course any error at 25 is greatly magnified at longer distances so it is preferable to zero at the range you want your zero. Anyway, if that's what you need, shoot me a PM.

Thanks!

PM inbound.

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I try to set my zero where my bullets are hitting. :ph34r::ph34r::ph34r:

In actuality, I don't have a good answer for you. Short of getting a solid velocity number indoors, getting a rough zero and checking raw accuracy potential, then allowing some time the day before the match to fine tune it there. You can calculate the rest if you know your scope height over bore

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I like to run an absolute zero.

I had to read it a couple of times, I thought you were saying to drink Absolute and zero the rifle.

For the OP, if I had a known zero with a proven load and were headed to a major match, I would take it to the match. I would not take a new load that I did not have any time with and expect to be able to hit at 600yds. Just my opinion.

Hurley

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While I don't know, I estimate that your 69g SMK load is running at 2600 MAX. If you were shooting some variety of 55FMJ 5.56 factory FMJ, then from a 16" barrel, that's 2800 FPS max.

If you go into a ballistics program you can run a program for a 200 yd zero and you will see what your NEG is at 25 yds. It should be -1.5 to 2-2.25" low at 25 yds. You will need to be as precise as possible in measuring your scope to bore height and precise in drawing the point on the target. Zero so that your bullets strike the -1.5 to -2.25 at 25. You are going to be pretty close provided you measure your scope to bore well.

Aside from that, its about all you can do. Any zero is going to be better then no zero. You should be looking for 5 rds on top of each other and making small adjustments. Remember 1/4 off at 25 is 1" at 100.

For the record I have had mostly good luck zeroing my M4 1" low at 25M and hitting out to 300 M.

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-459.67 or there about

That would be awesome. SD and ES would be "0", but then so would your velocity. :devil:

I'm going to need some hand warmers if we are going to shoot in that kind of weather.

Doug

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With the help of this thread I finally figured out the true meaning of this video. The guys just trying to figure out his zero........I feel so enlightened.

To the OP, I feel your pain. I've got a 77gr load put together, but I'm not sure if I'll be able to get in enough range time to feel comfortable using it in the match. Worst case scenario, I have to use my 55 grain loads and pray for no wind.

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New wrinkle. I have a Burris MTAC 1.5-6 with ballistic Plex QC 5.56 reticle. I use the Istrelock app for ballistic calculator. I noticed that at 6x the bottom dot only goes out to 473 yrds. I have to reduce the power to 4x to get the dot out to 600.

Anybody using the Burris MTAC 1.5-6 that can confirm the 6x isn't calibrated out to 600?

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New wrinkle. I have a Burris MTAC 1.5-6 with ballistic Plex QC 5.56 reticle. I use the Istrelock app for ballistic calculator. I noticed that at 6x the bottom dot only goes out to 473 yrds. I have to reduce the power to 4x to get the dot out to 600.

Anybody using the Burris MTAC 1.5-6 that can confirm the 6x isn't calibrated out to 600?

NO BDC is calibrated to anything in reality, unless you have the exact same theoretical ammo at the exact same theoretical atmospheric conditions.

The MTACs are true to the reticle subtensions at the high magnification.

Strelok is showing you where to hold for your load on that reticle.

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