UPDATED: Head scratching day at the range

[med358-boise]

I know many people think that all book data has been "lawyered downward" and I hate to be Captain Obvious but just in case you didn't look it up - Hodgdon shows 58.1 as the max for H1000 and the 143 ELD-X and that it is a compressed load.

 

[Eric Musgrove]

That is so true about load work. At the AMU ammo shop I was talking to the shop boss how they develop their 600 yard ammo for service rifles. Typical matches the barrel would have 20, 30, or 66 rounds before the 600 yard event starts.

Their load work will have the barrel with that many rounds to make sure the system is stable fouled up.

I shot with and trained with the AMU a lot when I was stationed in GA and then of course competed against them also at Interservice and the Nationals. Retired in 2014, miss it but not laying there in the heat wearing that sweatshirt and coat.

 

[Eric Musgrove]

I know many people think that all book data has been "lawyered downward" and I hate to be Captain Obvious but just in case you didn't look it up - Hodgdon shows 58.1 as the max for H1000 and the 143 ELD-X and that it is a compressed load.

That's is one reason I started at 57.0, that and based on previous loads with the 156 gr Berger, which Berger claims max is close to 62, but like others I hit pressure long before that, for me it was at 59.8 I did have an accurate load at 59.5, so it would seem the 143 should be in the ball park. Heading back in the morning before the heat to retest.

 

[Rick Richard]

That's why is one reason I started at 57.0, that and based on previous loads with the 156 gr Berger, which Berger claims max is close to 62, but like others I hit pressure long before that, for me it was at 59.8 I did have an accurate load at 59.5, so it would seem the 143 should be in the ball park. Heading back in the morning before the heat to retest.

Here is another thought. I ran into this when I had my 6.5 SAUM and that is you may question hitting pressure. I found the Hornady brass to be on the soft side and would give me erroneous signs. I am not saying this is for sure for you, but something to think about. I usually depend on bolt lift rather than reading brass. Good luck.

 

[bamban]

I shot with and trained with the AMU a lot when I was stationed in GA and then of course competed against them also at Interservice and the Nationals. Retired in 2014, miss it but not laying there in the heat wearing that sweatshirt and coat.

Awesome.

I was a civilian volunteer at height of the war helping AMU in the SDM classes on Easley Range and other places.

Them boys are hard holders.

 

[Mike Matteson]

Watching!

 

[BCMAG2]

I have had problems with brass hardening after a couple max pressure loads. I never had a sticky bolt on the first or second loading, but by the third all the pressure signs were there with the exact same load. I have learned to back off my powder charges to just the point where I get good speed but don't ruin the brass, and no longer have pressure problems.

 

[Harry Knutz]

Did you use 2 different lots of powder?

 

[JAYgs8163]

Get another Chronograph, those MVs you are getting in the 3100 range would indicate a very HOT load and it leads me to believe your Chronograph is way off. The ones in the 2950 area are more indicative of where you should be. Back off, start over, and work up after you get a new one. I've not seen anyone in the MV area you are reporting without being way over pressure. I run the 144 Berger right on the edge and I'm at 2945.

 

[RidgeTop]

Did your ammo get overheated sitting in the sun? High temps,I take my ammo to the range in a cooler with a cool pak. Just saying.

 

[26Reload]

Yup...hang the rifle up....return the elk tag...
That settles that......

 

[RockyMtnUT]

Did you use 2 different lots of powder?

same 8# jug of powder and same box of bullets

 

[bassassassin104]

Not sure about your particular chronograph, but mine has a good bit of variation based upon light conditions. It is consistent as long as the light doesn't change. As for the pressure signs, you stated same box of bullets, same lot of powder and you were using resized brass for both loadings. I assume same primers. Is it possible you accidentally seated the bullets a bit longer and are now jammed, creating a spike? Was the brass weight sorted prior to the loading that showed pressure?

 

[emp1953]

I helped a friend develop a load for a .270win model 70. We came up with a dandy, loaded up 200 rounds and on the day we finally zeroed it in it was 80 degrees and overcast. We came back the next week, firing the same batch, all the same conditions, with 1/4 moa groups opening up to over 1 moa. The only difference being bright sunshine. The ammo was exposed to the sun and heated up. Changed things dramatically. Had nothing to do with the rifle, or the shooter, or actually none of the components, it was the environment that had changed. We had signs of over pressure too. There were 20 rounds left from the original loading session which we brought out several weeks later. We kept the ammo out of the sun, and went back to 1/4 moa groups. Just goes to show there is always something unexpected to bite you in the ***.