Assistant creating array?

Hi,

I'm a Powershell Amateur! I've written some code to import data from logfile.txt and export the results with export-csv to a weapons_date. I'm replicating each line but I'm sure I might be able to do this better, perhaps with an array or loop or something?

I did some basic research but don't fully understand arrays

Clear-Host 
$TestPath = $null 
$sourcefile = "logfile.txt" 
$dest = "weapons_" 
$date = (Get-Date -Format "%d%M%y-%H%m%s") 
$target = $dest+$date+".csv"

if (Test-Path $destinationfile) {Remove-Item $destinationfile}

Get-Content $sourcefile | Select-String -Pattern "weapon_sks" | Measure-Object -Line | Add-Member -MemberType NoteProperty -Name Weapon -Value SKS -PassThru | Export-Csv -Path $target -NoTypeInformation

Get-Content $sourcefile | Select-String -Pattern "weapon_rpk" | Measure-Object -Line | Add-Member -MemberType NoteProperty -Name Weapon -Value RPK -PassThru | Export-Csv -Path 
$target -NoTypeInformation -Append 

[System.Windows.MessageBox]::Show('Parsing Log File complete','Logfile Outcome','OK')

Hoping to build array to make file much shorter so I can perhaps just read from a string or csv with list of names?

Cheers!