Anyone with M380, TAC Zone, and chrony?

[Roadrunnr72]

Was sighting in my M380. Set my zero at 20yrds. Moved back to 40 yrds. Had the speed ring set to 380. Arrows hitting high. Adjusted speed ring to 390, still high. Thought that maybe, because I stepped off my 40yrds, that the distance was off. Pulled out the tape measure, and sure enough, 40yrds. Hmm, turned it all the way up to 410, and still about 4" high. Weighed my arrows, running about 402gr.
So, anyone here know how accurate the speed ring really is? With 400gr arrows, I was really expecting to be around 350-360fps. Now I will have to figure out my distances, as they are not going match, and can't turn the speed ring any higher.
Any thoughts?

Thanks, RR

[Big John]

You have a PM.

[MTBighorn]

My speed ring is maxed out on my 380 w/TZ scope too..just as touch high all the way to 60yrds...but I like it that way.

If I back the ring out to 278(ish)...my 385gr 18" Zombies are dead on at 100 yards....and if I bottom out the speed dial I am on at 120 yards

When I shoot off a bench I have to be real careful how I hold my bow or I will hit high just from the recoil...and sometimes left and right.

The heavier your arrow is, the more recoil impulse you will have and the longer your arrow will stay on the bow as the bow rises....so it is possilbe for a heavier arrow to actually hit higher than a light(er) arrow at 40 yards.

Just last night it was happening to me because I was letting the grip touch my bench because I didn't bring my shooting bags. I lowered my scope, changed my form and now was hitting 4" low Not sure if this will help you...but it sure makes a difference for me.

[Roadrunnr72]

Thanks Big John for the PM.
MTBighorn, I did have the bow just setting on a rest, and don't think I was really holding it, so recoil may have been a factor. Went back out, and with some tips from Big John, and holding the bow, I almost have it. Will head back out tomorrow for a check.

[wildcatter]

MtBighorn and Big John good work! But let me add this as a lot of people think the scope can give you a fairly accurate idea of the speed you are shooting, and that is impossible, some may be close while some may be way off. Chronographs are made for a reason, they are the only way to verify speed!

Yep consistency requires the same hold all the time. But a scope speed ring will tell you absolutely nothing. On a 380 with 400 grain arrows you are right in the the 360 - 362 fps range, but speed rings are nothing more than a a power ring, a chronograph is required to read the speed of any bow, to get the actual speed. I have seen bows shooting 394 fps have their speed ring set around 360 and seen bows shooting a true 335 fps with speed rings set over 350 fps when properly calibrated.

[Big John]

Wildcatter is also very correct. Seen that many times over. However the starting point is very important. Then how it finish's is anyone's guess.
I think he is good to go now!

Big John

[Roadrunnr72]

Out shooting today, decided to try 60yrds. The center of my bag target is pretty well shot up, but still stops arrows, and I can tell from the sound if I have hit close to center. 3 shots and close to a 2" group, but the last arrow, I could tell from the sound, was off. Low by about 3-4". Hmm, was pretty windy, but didn't think it would affect it by hitting that low, and me thinks it was windy during the first shots. Anyway, went back and decided to shoot the corner circles. Heard one arrow hit low. Went looking, the top 2 were about 4" low and a little off to one side. The 2 lower weren't even on target. Spent about 15 mins before both missed were found. Hmmm something is way off. Checked the bow, and found the factory installed scope mount/ADF screws loose. A little blue loctite and lifted up a little on the front of the mount, and tightened all of the screws. Back to sighting in next time out.
Decided that while the loctite was drying, I would shoot the Phoenix. Went to change the broadheads to field points and cut my finger, good clean cut, cause it didn't hurt a bit. Went shooting and after several shots, and my daughter shooting, found the center serving coming apart. Well at least I have an extra string for this one. Need to get an extra for my 380, just not sure what to get.

Thanks, RR

[Big John]

Go over every single screw, nut, bolt, on the bow and Loctite them! Tight!
Waiting for your post that says your on the money! We're here for you anytime with help.

Big John

Watch the fingers, you need them for control!

[MTBighorn]

Twice when my accuracy went bad all of a sudden it was loose screws that you could not yet feel scope movement... in both occasions I discovered it was the internal screws that hold the trigger and Guardian in place had come loose... You have to remove the 2 screws holding the stock on and remove the stock to access these screws.

I think these 2 screws are often to blame when guys experience a change in there sights from one day to the next. You shoot all dime size groups and then the next day you will be "off". Just a slight scope change and you will be back in the bull for a dozen shots.

[Roadrunnr72]

Out shooting yesterday. 20yrds I was dead on, but 40 seemed to be off a little. Wife checked the mail and I had a new string from 8ptbuk. I was wanting a back up string. A few years ago, 8ptbuk sent me a new string for my Phoenix, free, so I figured the least I could do was buy one for my M380 from him. Besides, he is right here in VA. Installed the string last night and went shooting today. At 20 yrds, I was hitting a little right. 2 clicks to the left, had me back at center. Went to 40 yrds and was on the money, 60 seemed to be a bit high. Now shooting very consistent groups. It will just take a little to dial in the scope to where I'm satisfied. Do love the new string, yellow and orange. Thought it would be a bit slower than my stock, but actually seems faster. No chrony to check speeds.
Thanks for all of the advise.

RR

[Big John]

Good to hear!

Big John