ODL UTU2 User guide

Use and Maintenance of the ODL UTU2 45 Cal Pistol Suppressor
Overview
The UTU2 suppressor is a monolithic titanium suppressor designed with a Neilsen which allows it to be used
with most of the common John Browning tilting barrel designs including linked (1911) or cam operated (Glock)
pistols. The Neilsen is an assembly in the aft end of the suppressor that allows the gasses to push the suppressor
forward while allowing the unimpeded rearward movement of the barrel and slide assembly using a stainless
steel spring and titanium piston.
As such, the suppressor is able to function well with a wide range of ammo although it will perform best with
subsonic ammo.
Since the suppressor is a sealed unit ahead of the Neilsen, it is designed only for jacketed or plated ammo and is
not intended for use with cast lead projectiles that are not plated or jacketed.
The UTU2 45 Cal suppressor is designed to be run wet or dry and provide hearing safe sound levels at the ear
with ammunition tested. Initial sound testing was performed using a 10 shot average, recorded on a BK2209
with a 4136 mic 1.6M above short grass and 1m left of the muzzle along with chrono data. Dry numbers
averaged low 135.4 dB(A) at muzzle with an average speed of 826 FPS using 230 grain on an FNX 45. Sound
at the shooters right ear 133 dB(A) for a 27db noise reduction at the muzzle and at the ear.
Installation on the Pistol
First, ensure pistol is unloaded and lock the slide back. Thread the suppressor onto the barrel ensuring that it
is not cross threaded. There should be no difficulty or resistance in the threading process. The pistol can be
tilted with the barrel up to make this process easier.
Tighten the suppressor very firmly by hand. Do not use a wrench to tighten the suppressor onto the pistol.
Once the suppressor is tight on the pistol, pull the suppressor firmly away from the pistol until the spring
compresses fully and rotate the suppressor until the top is parallel with the top of your pistol and release the
suppressor. It should return to the normal position and be even with the top of your pistol within 4 degrees.
The last 2 degrees can be obtained by rotating the suppressor one more tooth or slightly tighten the can further.
Test that suppressor is tight before every string of fire. If suppressor gets loose, baffle strikes can occur. Also,
test that the back nut is tight (you can use a spanner on this) after every 60 to 100 rounds.
The suppressor and pistol are now ready for use either dry or wet. Shoot the pistol as you normally would using
both eyes open to pick up the target with the weak eye while the strong eye picks up the front sight and aligns it
with the rear sight and the target. While the front sight is below the top of the suppressor, your dominant eye
will focus on the front sight while your weak eye will focus on the target allowing you to see what you need to
see to shoot fast and effectively.
The Neilsen on the suppressor returns the can to the ready position in approximately 2 milliseconds (.002
seconds) while the cycle time of the slide is approximately 48 milliseconds (.048 seconds). This allows normal
pickup of the front sight as the slide is returning to battery before the full recoil pulse is finished, allowing split
times suppressed as quick as unsuppressed.

Disassembly and Cleaning
The Neilsen should be cleaned and lubed after every 500 rounds and no more than 1000 rounds. Since the
Neilsen is a moving part, proper maintenance will ensure optimum operation of the host pistol.
Remove the aft nut with a 20mm spanner using a counter clockwise direction (standard right hand thread
removal –lefty loosey). Remove the spring and clean off excess carbon with a brush and carbon remover.
With the nut off, inspect the O-ring inside the nut. It is a 16x1.5 mm Viton O-ring that reduces the amount of
gas that escapes past the piston. If it looks smooth and has no ragged edges hanging off, it is good to go for
another cycle.
Remove the piston by pulling straight out . With the piston free of the suppressor, spray a carbon cleaner on the
piston and brush off all carbon with a brush. Make sure you run the bore brush and cleaner down the bore of
the piston to remove all carbon. Brush off excess carbon with any type of mild cleaner and a toothbrush Simple
Green is recommended.
Neilsen disassembled.
Use a sharp dental pick or die file to scrape the hard carbon deposits that foul the indexing ridges in the
aft portion of the suppressor where the piston slides. This is the most important area to clean as the carbon
in the ridges can impede the movement of the piston. If you have compressed air, blow out any residue from
the suppressor while using safety glasses or just wipe dry or let it drain out.

Clean thoroughly around ridges.
Assembly and Lube
Use Mobile 1 motor oil (or similar) to lube the parts prior to assembly. Use a liberal coating of oil on the inside
of the housing and the entire piston and spring. If Mobile 1 is not available, any grease or thick motor oil will
work but Mobile 1 does not smoke.
Piston in place.
Install the piston first. Next insert the spring and wind the back nut in place. Use the supplied 20mm spanner to
firmly tighten the nut.

Suppressor shown with aft nut tightened properly flush with back of suppressor and the correct amount of
piston visible from the nut. Thread on barrel and actuate the piston several times and check for correct
operation and distribute oil on working surfaces.
With the Neilsen assembled onto the suppressor, wipe off any excess oil that is visible. The Suppressor is now
ready for use or storage.