[xPaw]

Code involved:

Reload for M3:

    void CM3::Reload()
    {
        if ( m_pPlayer->m_rgAmmo[ m_iPrimaryAmmoType ] <= 0 || m_iClip == SHOTGUN_MAX_CLIP )
        {
            return;
        }

        if ( m_flNextPrimaryAttack > UTIL_WeaponTimeBase() )
        {
            return;
        }

        switch ( m_fInSpecialReload )
        {
            case 0 : 
            {
                m_pPlayer->SetAnimation( PLAYER_RELOAD );
 
                SendWeaponAnim( M3_START_RELOAD, UseDecrement() );
                m_fInSpecialReload = 1;

                m_pPlayer->m_flNextAttack = UTIL_WeaponTimeBase() + 0.55;
                m_flTimeWeaponIdle        = UTIL_WeaponTimeBase() + 0.55;
                m_flNextPrimaryAttack     = UTIL_WeaponTimeBase() + 0.55;
                m_flNextSecondaryAttack   = UTIL_WeaponTimeBase() + 0.55;
            }
            case 1 :
            {    
                if ( m_flTimeWeaponIdle > gpGlobals->time )
                {
                    return;
                }

                m_fInSpecialReload = 2;
 
                SendWeaponAnim( M3_INSERT, UseDecrement() );
 
                m_flNextReload     = UTIL_WeaponTimeBase() + 0.45;
                m_flTimeWeaponIdle = UTIL_WeaponTimeBase() + 0.45;
            }
            default :
            {
                m_iClip += 1;
                m_pPlayer->m_rgAmmo[ m_iPrimaryAmmoType ] -= 1;
                m_fInSpecialReload = 1;
 
                m_pPlayer->ammo_buckshot--;
            }
        }
    }

Reload for weapons (I used ak47 as example, they mostly equal to each other):

void CAK47::Reload()
{
    if ( m_pPlayer->ammo_762nato && DefaultReload( AK47_MAX_CLIP, AK47_RELOAD, 2.45 ) )
    {
        m_pPlayer->SetAnimation( PLAYER_RELOAD );

        m_flAccuracy   = 0.2;
        m_iShotsFired  = 0;
        m_bDelayFire   = 0;
    }
}

DefaultReload which is being called from any weapon reload (except shotguns)

BOOL CBasePlayerWeapon :: DefaultReload( int iClipSize, int iAnim, float fDelay, int body )
{

    if (m_pPlayer->m_rgAmmo[m_iPrimaryAmmoType] <= 0)
        return FALSE;

    int j = min(iClipSize - m_iClip, m_pPlayer->m_rgAmmo[m_iPrimaryAmmoType]);  

    if (j == 0)
        return FALSE;

    m_pPlayer->m_flNextAttack = UTIL_WeaponTimeBase() + fDelay;

    //!!UNDONE -- reload sound goes here !!!
    SendWeaponAnim( iAnim, UseDecrement(), body );

    m_fInReload = TRUE;

    m_flTimeWeaponIdle = UTIL_WeaponTimeBase() + 3;
    return TRUE;
}