.300 win mag high pressures?

[Matches Malone]

I'm putting this in the stupid questions area because i probably survived war just to blow myself up with my own gun. My .300wm when using factory 180 gr federal fusion which i use for long range yote hunting has for awhile being shooting at screaming hot velocity. It's hot where i am...about 100 degrees but to be honest but lets put a pin in that and get to the point.
I've chronoed with a light sensor chrono and it gives me about 3200 fps....for a 180gr pill. Not a huge deal for a 26 in barrel. But when using a calculator...and ive used a few...my poi is pretty high. a few mils high. no worries. Trued it out increased bc still high, increased muzzle velocity and reaching somewhere at 3400. On all the calculators. Ok but that doesn't mean anything, what about the chrono. I chrono'd that data in the winter, with a sd of 13 fps.in one string and 23 on another string on another day. I dont look at the ES because it was grouping fine at the target at 100y behind the chrono, not a method that everyone will agree with but at least i can say it wasnt flying all over the place. groups are in the 3/4 moa at 100y. No deviating super significance in cold bore shots. Chrono works fine. I did a work up last weak for my girls .308 and it worked just fine at 10ft away and hour and a half before the sunsets like I normally do. Got some base line dope fast tweaked everything on the solver and it was good. So its not the chrono.
Further more, no pressure signs on brass or primers whatsoever. No sticky bolt. Nothing. Just shoots.....really fast for 180gr pill...all the time.

Suspicions: There is some copper build up, but...its not that bad...no precision run off with groups.
Any thoughts?

 

[...]

some barrels are just fast.......ive got a fast barrel on a 16" 308 thats giving me 2600 fps out of FGMM 168gr........

so long as you are having no pressure signs like bulged brass, flattened primers, or sticky bolts, i really wouldnt worry about it.....especially if you are running factory ammo.

 

[tnichols]

some barrels are just fast.......ive got a fast barrel on a 16" 308 thats giving me 2600 fps out of FGMM 168gr........

so long as you are having no pressure signs like bulged brass, flattened primers, or sticky bolts, i really wouldnt worry about it.....especially if you are running factory ammo.

Agree ^^^ Shooting buddy of mine has a 20" Obermeyer on his GAP built 308 that puts out crazy fast numbers with nary a pressure sign. Enjoy it.

 

[Matches Malone]

Alright cool. Yeah thats been my thought my process. I just wanted to verify that that wasnt uncommon. Apparently it is more common then I thought. Thanks!

 

[SubOptimal]

If extraction is still easy and smooth and primers are still in the pockets and not cratered, you are not seeing over pressure. A chronograph measures bullet velocity, not chamber pressure. Yes, the two are related but I use a chronograph to evaluate various loads, seeking small SD and ES and then go looking for something that will get me good groups around that number. I often find that max velocity does not necessarily correlate with the best groups.

 

[Matches Malone]

It's is what it is. The billet doesn't like, if it is obly .4 mils to 500y w/ a 100y zero, using hunting soft points, it's going fast. I'm aware of the truing and the chrono. It's always shot fast, and the numbers are true for most things in application. Yes the pressure is concerning to me as well hence the post, but there have been no indications of pressure signs either on the brass or the bolt, no sticky bolt, and throat erosion has been pretty much at a nominal rate. Whatever the anomaly, if it even really is one, no gun smith or armorer (to include myself) has noticed anything relevant.
about the only thing I haven't done and maybe I should thinking about it now is to pull one of the bullets from the factory loads that this problem occurs and weight it on my powders scale. Make sure that lot is 180gr and not something else, however unlikely.

 

[Fishkat]

Check out this link on pressure signs, it's a good read.
http://www.primalrights.com/library/articles/understanding-pressure

 

[SubOptimal]

I looked at Federal's data for the 300 WM 180g Fusion ammo and there is no way, fast barrel or not, you are seeing 3400 FPS and I would be skeptical of the 3200 number. I suspect something else to be wrong and my spidey sense tells me it is in your input to your ballistic calculator. If you are accepting a couple of mils high as your 100 yard zero, that would explain it. If you target is just a touch higher than where you are shooting from and you haven't compensated for this change in angle of bore, your ballistic calculator won't return accurate data.
No, the bullet does not lie but, calculators with bad input data can.

 

[FatBoy]

When I chrono my 300WMs I put the 35P at 15' if I'm not running a can. I find the results to be more consistent.

When is the last time you did a tall target tracking test with your scope? The adjustments may be off. As long as it's repeatable, and you have a good log, no big deal but I'd find out. Many years ago I had a NXS that moved 4.5" off a 3 MOA adjustments at one spot in the elevation range. Up and down.

 

[rpk762]

I am getting 3015fps with a 220gr SMK. I do run a 3 grove tube and hbn on the bullets.

 

[SubOptimal]

The thread seems to be abandoned but I would like to make one more comment here.
Is it possible that your 100 yard zero was established with a rising bullet? It may even be likely with a 300 WinMag.
I suspect you are extrapolating data about bullet velocity from the come up on your scope which could also be wrong.