New rifle, new load development, new brass, what’s wrong??

[ta6ppc]

I’m kinda wondering if the fact that a hornady case has right about 55 gr h20 and Peterson is 50

should one consider a max book load -5 grains as max published data? Because if that’s the case I’m far over max with where I started my work up.
I took my old load that shot well, reduced by 1% and worked up in .2 incriminates, if all is equal then I should had started even lower..

I know I need to speed check it..

 

[ta6ppc]

If you have a place where you can shoot to 400yds or more you can zero at 100 and shoot dead on at 400 and measure bullet drop. Put all the data in to a ballistics calculator and keep changing the speed till the amount of drop at 400 matches the program and that will give you the speed. Check the OAL of the cases and check to see if the necks are too long. When the lead pinches the neck down on the bullet pressure goes up fast. Good luck

Good point I didn’t trim these, they measured good I figured I’d trim after fire forming

 

[Fast14riot]

Did you clean your chamber and barrel before firing? Any oil left in the chamber can contribute to swipes with increased bolt thrust.

 

[ta6ppc]

I did clean it, I also ran some isso paste, followed with some bore tech, dried it out with 3-4 patches and put one oil patch with 2 dry patches and fired it, shot 3 ran a patch of bore tech, dried it out shot 3 , repeated till 12 shots and then ran a string of 5. I shot 26 rounds day 1. This last Tuesday I shot 50 rounds I did clean it before shooting but it cleaned up easy and the cold bore wasn’t out of the group over .2” I’m guessing this Peterson brass is the cause of the pressure sign, we and I started at 38 grains and went to 40. Every single case has a ejector swipe. 40.6 grains I started to get a heavy bolt lift but it wasn’t as stiff as I’ve seen in the past with something that was over pressure

 

[Bill K]

From those pictures and the ejector marking, you are on the edge of pressure. Back off and if your still get the good grouping, be happy.

 

[Ranger188]

Take one of your fired cases and see if a bullet will drop into the neck
easily or with some force.

 

[Chedward]

I agree that having a chronograph would help with a lot of answers. Just guessing on how fast you are shooting will keep you chasing your tail throughout that barrels lifespan. But I don’t agree with just going off of a different calibers load data. Every barrel and gun will like a different pressure or load. And it will probably change throughout how many rounds you have down the barrel.

Secondly, if those are your 200 yd groups, I would stop chasing something unless you know something is terribly wrong with your velocities. Those groups are pretty damn good.

 

[INTJ]

I’m kinda wondering if the fact that a hornady case has right about 55 gr h20 and Peterson is 50

should one consider a max book load -5 grains as max published data? Because if that’s the case I’m far over max with where I started my work up.
I took my old load that shot well, reduced by 1% and worked up in .2 incriminates, if all is equal then I should had started even lower..

I know I need to speed check it..

A few years ago I was working a 338 Win Mag with 225 grain Hornadys. The manual said 2900 fps was the max velocity with the max load. I achieved 2900 fps with the min load. No pressure signs. I stopped load development, took apart the remaining rounds, and started with a lower powder charge with my testing.

I consider the max published velocity in the bullet maker manual for a given powder and bullet, corrected for barrel length, to be a good guide to what the max velocity can be without exceeding SAAMI pressures. This is probably plus or minus 50 fps.

So at whatever powder charge I reach the max published velocity, assuming no other pressure signs, I consider to be the max charge.

Realize the first pressure sign, often a primer starting to flatten, usually doesn't show up until past 65,000 PSI. I know one fellow, a ballistics consultant for the US Army, saw as much as 80,000 PSI with no pressure signs on one lot of brass as measured by his Oehler 43 PBL strain gauge.

So anyway, I think a chronograph is one of the best tools available to help determine max loads. There is no ballistic free lunch. If we are getting 100 fps over what the manual shows, we are likely well over pressure, regardless of how much below max our powder charge might be.

So get/borrow a chronograph and your questions will be answered.

 

[ta6ppc]

I agree that having a chronograph would help with a lot of answers. Just guessing on how fast you are shooting will keep you chasing your tail throughout that barrels lifespan. But I don’t agree with just going off of a different calibers load data. Every barrel and gun will like a different pressure or load. And it will probably change throughout how many rounds you have down the barrel.

Secondly, if those are your 200 yd groups, I would stop chasing something unless you know something is terribly wrong with your velocities. Those groups are pretty damn good.

They are indeed 200 yards shot Tuesday this past week. The first one was the center diamond 38 grains of H4350 small fed champion primer, Peterson brass oal was 2.904 Berger 140 hybrid and believe it or not 38.0 left ejector swipe. Which has me scratching my head.

 

[Tokay444]

I would load all the brass up to just over min, and fire form it. Then start your desired method of load development.

 

[JFrank]

I would load all the brass up to just over min, and fire form it. Then start your desired method of load development

Me Too

 

[DaveTooley]

Brass hardness/toughness varies from manufacture to manufacture. Even lot to lot from the same manufacturer. Consider the Lapua VS Hornady comparison. Sometimes it's difficult to read pressure from the primer on these SRP cases. If a bullet goes back into a fired case then there maybe too much powder.

 

[mgunderson]

The above makes a good point about the brass. It does not all handle pressure the same.

 

[Chedward]

They are indeed 200 yards shot Tuesday this past week. The first one was the center diamond 38 grains of H4350 small fed champion primer, Peterson brass oal was 2.904 Berger 140 hybrid and believe it or not 38.0 left ejector swipe. Which has me scratching my head.

you also have to remember that Peterson brass has less volume inside the case because it has thicker walls. I’ve noticed about 5 to 10 percent less capacity than other brands of brass. I have 3 6.5 creeds. Two shoot lapua brass at about 42 to 43 grains of h4350, and my third i shoot Peterson and it only shoots about 39 to 40. Just something to think about when you start comparing your loads to others.

 

[WEL]

This is why having a chrono is an essential reloading tool. Charge weights will vary but the max velocity equals max pressure in most cases.

 

[Chiquita]

Just for comparison, have you tired another brass for this rifle and see if it has same issues.

 

[ta6ppc]

Just for comparison, have you tired another brass for this rifle and see if it has same issues.

Had a mild load of 42.5grains of 4831 that went 2550 in hornady brass and had a heavy bolt lift.. slight ejector mark this was worked up in another rifle I had. Which 4831sc book max is around 44.8 or so.

 

[ta6ppc]

I’m wondering what a factory loaded round would look like.. I haven’t shot a single one.. to bad you can’t just buy a box somewhere! Smh

 

[Chiquita]

Had a mild load of 42.5grains of 4831 that went 2550 in hornady brass and had a heavy bolt lift.. slight ejector mark this was worked up in another rifle I had. Which 4831sc book max is around 44.8 or so.

Try different brass in this rifle, but keep everything else the same (same seating, same shoulder bump, same freedom seed, same powder...) except the brass. and see if you still the same marring results.

when you installed the barrel what do you set your NOGo measurement to?

If I am off base on my questions someone will set me straight.

 

[ta6ppc]

Try different brass in this rifle, but keep everything else the same (same seating, same shoulder bump, same freedom seed, same powder...) except the brass. and see if you still the same marring results.

when you installed the barrel what do you set your NOGo measurement to?

If I am off base on my questions someone will set me straight.

The barrel was gunsmith installed and I’m gonna do exactly what you’ve suggested with some hornady brass, of course it’s been shot and neck turned but I’ll break 10 or so down and load them.