how fast is to fast?

[20X11]

You can?t mix metric & SAE. So that would be 1,371 MPS. The conversion factor is M X 3.281 = Feet. So, 1,371 x 3.281 = 4498.031 FPS.
At about the second shot, your barrel is spitting out molten Copper & lead.......

Hopefully you aren’t shooting tracers.......

Wait...you still have SAE in there with the 18 INCH barrel length?

[normandinpatriot]

Wait...you still have SAE in there with the 18 INCH barrel length?

Still havent got there yet... this weekend I chronoed Sig Sauer Elite performance 175gn OTM, Lake City M118LR 175 gr Sierra OTM , and Lapua 167gr Scenar OTM...
Temps were 88-91f relative humidity was near 50%, ... Yes i know that hotter temps equal faster velocity...
rifle: CMT matched upper/ lower DPMS patter LR308, Ballistic Advantage .308 18" 1:10 barrel about 200rds on this barrel, Odin Works ADJ gas block, SureFire brake/ adapter...
Distance to chrono.... 10 ft measured...
Sig ammo average is not comprehensive, as I got radically different readings from 2 boxes of the same lot.... first 20rds average about 2530... second box measures much higher... about 2625...
Lake City M118LR 175gn Sierra OTM average... 2695..10rds
Lapua 167grn Scenar OTM 2704..10 rds
best accuracy from the Sig ammo.in the 2600fps range..
All cases except the M118 looked acceptable.. the M118 had cratered and 2 popped primers...

groups were shot with a minimum of 5 minute cool down between each 5 shot group... and for some reason the photo of my painfully average 100yd target wont load...

As far as my shooting ability goes, I am able to generally shoot pretty well. I have never had any formal training, but have shot both pistol and rifle or about 35+ years