Rifle Scopes mst 100 users I need help!

[codyb]

When I get set up (focus and parallax) it seems I get about 10 clear shots and it becomes so blurry I have a hard time seeing the 1" black dots on the white side of an IPSC at 100 yards.

I don't think it is my eyes (fatigue) because I don't have a problem with any of my other scopes.

Not sure what to do?

 

[nolo263]

Re: mst 100 users I need help!

I am pretty sure that it is your eyes. The focus is probably not set right and it is giving you eye fatigue. The MST-100 is extremely hard to set up paralax..

 

[LoneWolfUSMC]

Re: mst 100 users I need help!

from the MST-100 thread:

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">
Loosen the lock ring 1/4 to 1/2 turn (no more)
Turn the focus ring 1/4 turn then snug the lock ring back down.
Check for parallax. If it's still present, then repeat.
If you get to 1/2 to 3/4 turn and observe no change, then you are turning the ring the wrong way. Dial it back and start over.
Make sure you are snugging the lock ring after every adjustment otherwise the objective lens could "float".

It goes without saying that when you do this you should be on a target at your desired range. The Marine Corps suggests 300 yards for shooting to 1000 yards. If you won't be shooting that far, then set the parallax at a closer range (100-200 yards).</div></div>

Make sure you have adjusted the ocular focus first then adjust the parallax. Take your time and get it right.

 

[codyb]

Re: mst 100 users I need help!

Have done the above I seen no changes when adjusting the ocular focus it always appears clear to me. Have made the changes with objective all the way in to a few revolutions out. Never seem to be able to completely get rid of the parallax so I am just stopping when it seem it is at the best point I can get.

Will try again in smaller increments.

Thanks for the pointers.

 

[tansinator]

Re: mst 100 users I need help!

Could it be mirage from heat off barrel? How fast are you shooting the 10 shots?

Eddie

 

[codyb]

Re: mst 100 users I need help!

<span style="font-weight: bold">Could it be mirage from heat off barrel? How fast are you shooting the 10 shots?</span>

I considered it, but it didn't get better by letting it cool.

I played with it again tonight and think it is better. I spent about 45min fine tuning it and I seemed to stay acceptable through my entire session. I notice now that the edges of the the scope are not a sharp as the center is, but it is all within reason.

My question now is, after adjusting the parallax should I see any movement in my crosshairs as I move my head?

 

[doc76251]

Re: mst 100 users I need help!

Ocular focus has NOTHING to do with parallax.

FWIW it takes me several trips to the range working with a particular scope to get the ocular focus correct. According to the optometrists I have spoken to it's because even at the ripe old age of 41 my eyes are still better than 20/20 and this screws me over because I can recognize the error in my eyes even if my brain won't register it.

I have discovered that after a few minutes to a few hours behind a scope my groups will suddenly open this is indicative of a non-focused ocular and the resulting eye strain.

Once you do hit upon the correct ocular focus, parallax is the next thing that will screw you. Any scope that has side focus will have some bit of "backlash" in the knob. You cannot engineer it out of the system because if you do the knob won't turn. I believe it was a poster here by the name of "Catshooter" that had a detailed method of dialing out parallax.

The short version was to take the parallax to infinity and dial down to no parallax w/o EVER turning "back". If you did all solid adjustment was lost and you had to begin again. I have followed that guidance for many years and believe it to be spot on.

MST-100's faithfully reproduced by year 2000 technology are still simply re-creating 1960's technology..........

Cheers,

Doc

 

[Lindy]

Re: mst 100 users I need help!

Here's the long answer, Doc:

Kittywhacker on Parallax

Pablito knows his stuff.

 

[Turk]

Re: mst 100 users I need help!

I read it twice! Thanks, great info.

 

[doc76251]

Re: mst 100 users I need help!

That's the one Lindy!! Some day I will build a web site with all the info that everybody asks over and over for. Or at least make a list of links that I can cut and paste to.

Cheers,

Doc

 

[LoneWolfUSMC]

Re: mst 100 users I need help!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: doc76251</div><div class="ubbcode-body">Ocular focus has NOTHING to do with parallax.</div></div>

Doc, I don't believe I ever said it did. I simply said to adjust the ocular focus first. That's the way I was always taught to setup a scope and the way I have always done it. I have never heard a credible reason not to. When you have an issue with the setup it's usually better to go back to square one and start over.

Lindy.....that was a great read. I am going to have to start trying that with my parallax knob on my scope.

 

[doc76251]

Re: mst 100 users I need help!

LW,

Didn't think I was calling you out or contradicting. If taken that way it was not my intention. I concur with all that you have said on this topic.

The USMC scope is a finniky buzzard to say the least. I think that's half the reason snipers get so tweeked with somebody handling their rifle. It takes a month of Sundays to get it set up

That and I have never seen one "correctly" set up that didn't involve duct tape and rubber biotch or packing foam from an ammo can.

Cheers,

Doc

 

[LoneWolfUSMC]

Re: mst 100 users I need help!

Aint that the truth!