M40A1 Unertl/MST-100 10x Parallax Question

[BullGator1]

I recently aquired my unicorn M40A1 from @gregv and understand there is a lot of nuance to using the Unert/MST-100 10X scopes. Being that I don't have readily available access to ranges over 300 yards, I do most of my shooting at 100-300. I know the suggested parallax setting is either 200 or 300 yards, and I know that if set to 300 the site picture at 100 is blurry as hell (which it currently is), but my question is: If I set the parallax for say 100 or 150 (I have a Redfield Revolution Tac 3x9 on my SSA M40 that is fixed parallax at 150y and is clear at all ranges) will the site picture be blurry at further distances? 300 yards and beyond? I have not had the opportunity to go to the range to try adjusting the parallax yet, so thanks for any help in advance.

Follow up question,
Does anyone know the correct Butler Creek caps that fit this scope?
Thank you,
BG

 

[B y r o n]

Not an answer to your question but may assist in setting your scope up.

 

[HarryBC]

USO used to sell Butler Creek caps with the MST-100, so call their sales number and see if they still carry them, or will tell you the sizes…..

 

[corsairpilot62]

For the bulter creek covers.
It should be obj #25 for the objective and the multiflex eye piece 19&20

 

[ODCMP]

I recently aquired my unicorn M40A1 from @gregv and understand there is a lot of nuance to using the Unert/MST-100 10X scopes. Being that I don't have readily available access to ranges over 300 yards, I do most of my shooting at 100-300. I know the suggested parallax setting is either 200 or 300 yards, and I know that if set to 300 the site picture at 100 is blurry as hell (which it currently is), but my question is: If I set the parallax for say 100 or 150 (I have a Redfield Revolution Tac 3x9 on my SSA M40 that is fixed parallax at 150y and is clear at all ranges) will the site picture be blurry at further distances? 300 yards and beyond? I have not had the opportunity to go to the range to try adjusting the parallax yet, so thanks for any help in advance.

Follow up question,
Does anyone know the correct Butler Creek caps that fit this scope?
Thank you,
BG

You shouldn’t have to compromise on the parallax setting. I set the parallax on mine at about 300 yards and it is in focus from 100 and 1000 yards. I run 2 MOA steel plates from 100 to 800 yards with no focus or parallax adjustment, just elevation adjustments and windage holds.

If yours is that blurry at 100 yards then I suspect that the parallax is set way off or the eyepiece focus is not set right for you.

I also recommend setting the parallax before you go to the range. All you need is an open view and some known distances. I picked out signs at 300, 600, and 1000 yards.

 

[BullGator1]

You shouldn’t have to compromise on the parallax setting. I set the parallax on mine at about 300 yards and it is in focus from 100 and 1000 yards. I run 2 MOA steel plates from 100 to 800 yards with no focus or parallax adjustment, just elevation adjustments and windage holds.

If yours is that blurry at 100 yards then I suspect that the parallax is set way off or the eyepiece focus is not set right for you.

I also recommend setting the parallax before you go to the range. All you need is an open view and some known distances. I picked out signs at 300, 600, and 1000 yards.

I appreciate that vote of confidence. Going to give it a go this weekend.

 

[ODCMP]

One thing to remember when trying to adjust the parallax is that the adjustment ring only pushes the lens assembly rearward. To move the lens assembly forward, you have to pull it forward using the locking ring. If you go to far past the parallax sweet spot, then you need to pull it forward and try again.

The post (#31) in this link describes it well:

Unertl Scope Question. Zeroing

I have received my scope back from the repair shop and would like to get my m40a1 up and running. Upon reading the Technical Manual on the rifle and related optical equipment, and without a 300-yard range at this time, what is the best way to zero the scope? Should I use the FIELD EXPEDIENT...

www.snipershide.com

 

[BullGator1]

One thing to remember when trying to adjust the parallax is that the adjustment ring only pushes the lens assembly rearward. To move the lens assembly forward, you have to pull it forward using the locking ring. If you go to far past the parallax sweet spot, then you need to pull it forward and try again.

The post (#31) in this link describes it well:

Unertl Scope Question. Zeroing

I have received my scope back from the repair shop and would like to get my m40a1 up and running. Upon reading the Technical Manual on the rifle and related optical equipment, and without a 300-yard range at this time, what is the best way to zero the scope? Should I use the FIELD EXPEDIENT...

www.snipershide.com

Thank you for the info.