  Chromium (Cr) is a transition metal element with 3$d$ orbital electrons. In
most compounds containing Cr, due to the correlation effect, twofold features
of localization and itinerancy are expected. The localization gives rise to a
magnetic moment, while the latter exhibits as the effective coherent weight for
conductivity. Here we report the physical properties of Cr$_3$Ru compounds with
bcc or A15 phases by using multiple experimental tools. The resistivity
measurements show sharp superconducting transitions at $T_{\rm c}$ = 2.77 K and
$T_{\rm c}$ = 3.37 K for the bcc and A15 structures. A high residual
resistivity exists for both samples with the mean-free-path about 2 nm.
Magnetization measurements also show rather narrow transitions, with a clear
hump structure at high temperatures around 150 K, which may be ascribed to the
remaining antiferromagnetic spin fluctuations. The specific heat coefficient
reveals a clear jump at $T_{\rm c}$. We find that s-wave gaps can be adopted to
fit the low temperature specific heat data yielding ratios of about
$2\Delta/k_{\scriptscriptstyle B}T_{\rm c}$ $\approx$ 3.6, indicating a
moderate pairing strength. Interestingly, the Wilson ratios are 3.81 and 3.62
for the bcc and A15 phases, suggesting a moderate correlation effect of
conducting electron in the normal state. Besides, for samples with A15
structure, another specific heat anomaly occurs at about 0.85 K and is
sensitive to magnetic fields. By applying high pressures, both system exhibit
an enhancement of $T_{\rm c}$ with a rate of about 0.019 K/GPa and 0.013 K/GPa
for the bcc and A15 phases. We also conduct tunneling spectrum measurements and
found that the coherence peaks are strongly smeared out. The strong suppression
to the coherence peaks may be ascribed to the strong scattering. Our
combinatory results point to an unconventional superconductivity in these Cr
based compounds.
