H1000 variance in powder or chrono?

[jrock]

Had something happen to me yesterday that I haven't seen in my 10 years of reloading. Took a new gun out to break it in and followed a 5 single shot between cleaning and then 4 sets of 3 shots between cleanings. I was using the same powder charge the whole time. Temperature was 67 degrees that day. Then yesterday, 60 degrees, I did some scope dialing testing and leveling with the same powder charge and my F1 chrony said I was 100 fps slower than the previous outing. I did open a new can of powder for the last outing but I have never seen a 100 fps variance between lots of any other powder I use. The weather was very similar, sunny and warm and I used the diffusers over the sensors both times. Seems to me that it would be a chono issue vs powder. Anyone run into this before? Maybe the chrono needs a new battery??

I've been frustrated with the F1 but can't bring myself to pay a whole lot for another system or the magneto speed which is trading accuracy information for velocity. Been toying with getting another F1 and putting them back to back.

 

[RockyMtnMT]

Get the Mag Speed and don't look back. We shoot far less ammo now with it than we did using sky screen chrono's. Depending on the time of day and the angle of the sun you can see the 100fps easy. Could be a bit of difference in the lots of powder in the equation as well. Hard to tell without a good chronograph.

Steve

 

[Mikecr]

So now your brass is fire formed?

 

[jrock]

So now your brass is fire formed?

No, I am still working on the 100 new sized cases. One thing I forgot about before posting was that I am using a neck tension of 0.001" and thought I dry lubed the inside of the necks on the first set. That was to simulate carbon build up. Didn't do it on the second. I'll check my reload data when I get home. Wouldn't think a dry lubed neck would produce higher velocities than virgin brass.

 

[Pdvdh]

Been toying with getting another F1 and putting them back to back.

No sense doubling up on two inaccurate light sensing chronographs. You'll still end up not knowing much more than whether or not a bullet crossed through them.

 

[Mikecr]

So you changed powder lots AND case capacities?
These would be two major potentials at the same time..
Also, neck lube does not affect velocity.

 

[jrock]

So you changed powder lots AND case capacities?

The first outing finished off one can I had. The second outing was off the second can. Sorry if I wasn't clear on that. I bought both the cans at the same time but I don't keep track of lot numbers as I never have had an issue between cans.
As far as case capacities, shouldn't have changed. Still virgin brass with each shot. I've shot about 30 of the 100. I shoot them all before reloading to keep the same number of firings on each.

 

[Mikecr]

Ok, I misunderstood. It's hard to believe that much change in powder lots alone.
Was there barrel cleaning between?
Was the barrel up to fired temps with second MV measure?

 

[Garycrow]

I saw about 100 fps change in velocity between two different lots of H1000 also. I was in the middle of trying to work up a load for an elk hunt and it blew my load work up out the window. I bought an 8 lb keg & that took care of the problem.

H1000 isn't the only powder I've seen lot to lot changes from, it's more common than many know. I've started buying powders I know I'll be using a lot in 8 lb jugs to keep things consistent.

 

[Jerry M]

Another recent thread on H 1000:

https://www.longrangehunting.com/threads/7mm-stw-h1000-issues-or-is-it-me.191648/#post-1342676

Good luck

Jerry

 

[Greyfox]

I would be highly suspect of the optical chronograph. Even using diffusers, lighting variations can easily produce a 100FPS variation. I'd bite the bullet and get a Magnetospeed. My problems with precise velocity measurement ended when a I bought my MS several years ago. Yes, POI can be effected by the MS. IMO, running separate velocity readings that are "accurate" will cost you a lot less in the long run.

 

[RockyMtnMT]

I would be highly suspect of the optical chronograph. Even using diffusers, lighting variations can easily produce a 100FPS variation. I'd bite the bullet and get a Magnetospeed. My problems with precise velocity measurement ended when a I bought my MS several years ago. Yes, POI can be effected by the MS. IMO, running separate velocity readings that are "accurate" will cost you a lot less in the long run.

This exactly matches our experience. We shoot much less ammo now that we use the Magspeed. I would say that accuracy is still good with the Magspeed on but the poi is different. So I can see if the load workup is looking like the rifle likes it or not. Once done collecting vel data then the bayo is removed and I move on to zero etc.

Steve

 

[Wedgy]

The latest batch of H1000 has been faster than the previous ones, I call it H950.
An F1 can raise more questions than it can answer, get an MS or Labradar

 

[HARPERC]

I agree with the F1 being less than helpful, I suspect cumulative +/-. A few FPS here and there with the chrony being the bulk of it.