Gemtech HMR User manual

TM-HMR/WMR
OPERATION AND MAINTENANCE
OF SOUND SUPPRESSOR
MODELS HMR and WMR
Before using this suppressor,
be certain you have read and
understand this manual.
Manufactured by
GEMTECH
Div. of Gemini Technologies, Inc.
P.O. Box 140618
Boise, Idaho 83714
ISSUED:April 2, 2015

WARNING 
Because sound suppressed weapons make less
noise than non-suppressed weapons, it is easy to for-
get that they are still firearms. It is of vital importance
to remember that a sound suppressed firearm is just
as dangerous as a non-suppressed one, and the same
safe handling requirements apply.
TM-HMR
FIRSTEDITION October2004
SECONDEDITION May2010
THIRDEDITION APRIL2015
Published by:
ATI Star Press
Antares Technologies, Inc.
P.O. Box 140618
Boise,Idaho83714
Phone:[phone]
COPYRIGHTNOTICE:
©2015 Gemini Technologies, Inc.
All rights reserved. The contents of this publication may not be reproduced in any
form or by any means in whole or in part without the prior written permission of the
copyright owner.

TM-HMR/WMR
OPERATIONALMANUALFOR
SOUNDSUPPRESSORMODEL
HMR™(.17rimfire)and WMR™ (.22 Magnum)
Manufacturedby
GEMTECH
Division of Gemini Technologies, Inc.
P.O. Box 140618
Boise, Idaho 83714-0618
Phone: [phone]
FAX: [phone]
GEMTECHPROPRIETARY
This document contains proprietary information of Gemtech and is sub-
mitted to the receiver in confidence. Any reproduction, use and/or dis-
closure of this and/or any portion thereof is expressly prohibited with-
out the express written permission of Gemtech
CONTENTS:
GeneralDescription ......................................................................... P. 2
AmmunitionRecommendations ....................................................... P. 2
InstallationInstructions .....................................................................P 3
Maintenanceand Cleaning............................................................... P. 4
Physical Specifications .................................................................... P. 4
Limited Warranty.............................................................................. P. 5
Repair Policy.................................................................................... P. 5
ThreadingSpecifications .................................................................. P. 5

SOUND SUPPRESSOR MODEL HMR and WMR P.
 WARNING 
Failure to follow installation and maintenance instructions
detailed in this manual can result in potential for serious
injury to the user and damage to the weapon. Firearm sound
suppressors are user attached firearm muzzle devices, and as
sucharesubject to improper attachment unless the proper proce-
dures outlined in this manual are followed.
MANUFACTURER’S DISCLAIMER
The manufacturer is not responsible for improper usage of this
product. This product is potentially dangerous, and as such it is the
user’s responsibility to understand and implement its proper use. If
you do not understand the instructions in this manual, please con-
tact the manufacturer for further clarification.
GENERAL DESCRIPTION
TheHMRand WMR are highly advanced suppressordesignoptimized
for maxi-mum accuracy and minimal back pressure in a compact envelope.
They are 100% constructed of 300 series stainless steel. No packing mate-
rial or wipes are used in these units. Designed to meet requirements for a
compact, highly efficient muzzle suppressor, they have been optimized for
maximumefficiencydry, maximum accuracy, and minimum first round “pop”
(theamountthe firstroundislouder than subsequentrounds).TheHMR and
WMR suppressors are engineered to reduce the sound level of the muzzle
blast significantly below the bullet flight noise and makes the weapon hear-
ingsafeunder the requirementsofMIL-STD-1474Dand OSHA.
TheHMRisintendedonlyforthe.17HMRand.17HM2rimfirecartridges.
The WMR is intended for the popular .22 Magnum rimfire cartridge.
Dueto thefragileand highly frangiblenatureof theultrahigh velocity.17
rimfire bullet, grease, water, or other coolants in the suppressor may cause
the bullet to fragment within the suppressor.
AMMUNITION DISCUSSION
Both the .17HMR and .17HM2 cartridges were introduced by Hornady.
The first was the .17HMR, which was a .22 Magnum cartridge necked down
to.17 caliber with a unique 17 grainHornadyV-Max projectile.Itbecame an
instanthitwith small varmint huntersduetoitsflat trajectory and devastating
effecton smalltargets.Althoughthe bullet has negligibleweight,thevelocity
ofaround 2,600 fpsassuredessentially totalfragmentationofthe bulletinthe
2

SOUND SUPPRESSOR MODEL HMR and WMR P.
target resulting in clean kills. The .17HM2 is a necked down .22LR cartridge
with the same .17 caliber projectile as the .17HMR. Non-suppressed, both
.17 caliber cartridges and the .22 Magnum are loud (at 155 dB) and can
causesignificanthearingdamage.
Because this is a muzzle suppressor, there is no velocity control of the
projectile.Thesecartridges are supersonicandwillgeneratea ballistic crack
(sonic boom) outside the weapon system. Subsonic ammunition does not
exist in these calibers, nor is it practical to even consider a ported integral
suppressor to reduce velocity. Considering the projectile weights, any sub-
sonic treatment would end up with the accuracy, range, and terminal ballis-
tics of a pellet pistol. The HMR and WMR are designed only for rimfire
ammunition, and must not be used with any type of centerfire ammunition.
 WARNING 
Failure to follow installation instructions detailed in this manual
can result in potential for serious injury to the user and damage to
the weapon.
INSTALLATION
Beforeinstalling (orremoving)thesuppressoron theweapon,becertain
to remove the magazine, open the action, and visually ascertain that the
weaponisunloaded.
Remove the thread protector from the end of the barrel and screw the
suppressor tightly by hand onto the barrel threads.
For proper alignment, the muzzle threads must be absolutely concen-
tric with the bore and must have a 90° rear shoulder perpendicular to the
bore.Wewillguarantee alignment only on barrels threaded byusorgauged
by us if threaded elsewhere.
As a general rule, the weapon will need to be re-sighted in after each
removal and replacement of the suppressor. For this reason, it is fairly nor-
mal to not remove the suppressor at any time during a hunt (or even the
season).Personally owned HMRandWMR suppressorsatGemtechare not
removedduringthe entire prairie dogseason.
 WARNING 
Before performing any maintenance operation, always remove
the magazine from the firearm, open the action, and visually
ascertain that the chamber is empty and the weapon unloaded.
Failure to do so can result in potential for serious injury to the user
and others in the vicinity.
3

SOUND SUPPRESSOR MODEL HMR and WMR P.
MAINTENANCE
Cleaningisoptional. The design oftheHMRand WMR allows for main-
tenance without disassembly. Nothing will dissolve the carbon buildup, but
rinsing out powder residues and unburned powder particles may be done at
regular intervals of 1,000 to 2,000 rounds. For this purpose, it is suggested
that the suppressor be submerged in an appropriate solvent such Kroil®,
WD-40, or a 3:1 mixture of mineral spirits and automatic transmission fluid.
Allowtheunitto soak as long as possible andthendrainthreaded(rear)end
downfollowedbyblowing with compressed air.Althoughthesuppressorwill
notbedamagedby water based cleaning agents, we see no benefit inusing
them as residual water can cause rusting of the underlying firearm.
 CAUTION 
Always read the warning label on any cleaner or solvent, and
remember that virtually all solvents are inherently dangerous and
potentially toxic. Always use adequate ventilation and both skin
and eye protection when using organic solvents.
We discourage any attempt at disassembly of the unit. Internal parts
orientation is critical to the efficient operation of the suppressor, and reas-
sembly requires special tooling and jigs available only at the factory. Any
attempt at disassembly will void the warranty.
PHYSICAL SPECIFICATIONS (HMR)
Length 5 in. (133 mm)
Diameter 7/8 in. (22 mm)
Weight 5 oz. (150 g)
Caliber .17HMR,.17HM2
PHYSICAL SPECIFICATIONS (WMR)
Length 5.3 in. (135 mm)
Diameter 1 in. (25 mm)
Weight 7.5 oz. (213 g)
Caliber .22Magnum,.22LR
4

SOUND SUPPRESSOR MODEL HMR and WMR P. 5
LIMITED WARRANTY STATEMENT
Gemini Technologies, Inc., dba Gemtech warrants to the initial retail
purchaser that Gemtech products will be free of defects in workmanship or
material and that the product meets manufacturing specifications at the time of
manufacture. This warranty is limited to the repair or replacement of the product.
This express limited warranty is exclusive and no other express or implied
warranty is otherwise provided.
GEMTECHMAKES NO WARRANTYOF MERCHANTABILITYOR FITNESS
FOR PARTICULAR PURPOSE. Product technical specifications and/ or designs
may be changed without notice. This warranty does not cover negligence,
misuse, careless or improper handling and/ or operation, abuse, unauthorized
adjustments or modifications, improper mounting / installation, ordinary wear
and tear, the failure to follow manufacturer instructions and/ or the use of
inappropriate or defective ammunition.
Gemtech shall have no liability for incidental or consequential damages
and under no circumstances will Gemtech be liable for personal injury,
property damage or economic loss. This warranty and disclaimer is subject
to all applicable laws some of which may limit these terms.
REPAIR POLICY
Gemtech maintains complete repair facilities for all suppressors manufac-
tured by them. Return authorization and shipping instructions must be obtained
prior to return. Contact Gemtech for this information.
ATF no longer requires transfer on a Form 5 to the manufacturer for repair.
However, they do require a letter accompanying the weapon detailing the re-
pairs required as well as proof of ownership. This requirement is satisfied by a
photocopy of the front of the owner’s Form 3, 4, or 5.
NOTE: ATF prohibits transferring the serial number to a new outer tube in the
case of damage to the tube. Tube damage will require a new suppressor.

All Gemtech products are
100% manufactured in the
United States of America.