New rifle, new load development, new brass, what’s wrong??
- Thread starter ta6ppc
- Start date
DaveTooley
Gold $$ Contributor
And that will tell you what?
This is my thought, if he has a slightly larger reloading brass compared to a factory round then he may have a tighter bolt lift hence the marring issue.
This is from your post #10.
What is your baes to ogive measurement compared to your jam and/or lands measurement? I don't think you have posted that measurement in the thread. ( I may have missed it) All I saw was the overall and from your comment ...should be off .010 to .020".... Does that mean off the lands or you are guessing the over all by measuring without a caliper.
I colored a bullet with a very light neck tension and closed the bolt gently and got the oal to the point of a jam. Then I turned my wilson seater down .020 from that which does not engrave or leave a mark on a sharpie painted bullet. It takes some patience but it has always worked well for me on every other rifle
I went and shot some today, with the hornady brass I loaded from 38-40.6 in .3 incriminates of the same H4350 I have been loading with the Berger hybrid 140 and I have zero pressure signs on this 10 pieces of brass.
I loaded 50 with 37.0 grains of H4350 and I have ejector marks. The bottom of the seirra manual is 39 grains for H4350 and a 140. I’m almost to the point that I’m gonna have ejector swipe on Peterson brass no matter what I load.
Just for the curiosity of it I loaded the seirra accuracy load which is 36.8 grains of Varget with a 142smk and all I got to say about that load is it leaves an ejector mark but Damn that’s a nice load for sure 5 in a single hole with one barely out of the first 4 mostly because my wife stopped me and need help for a second. (We just shot at 100 today because I was just looking at my cases)
What if you try the Peterson brass and start .020 off of already reduced .020. In other words you are .040 off of jam. Going .020 may put you right at touching lands. Of course every barrel is different.
I have heard from multiple thread that Peterson has different brass construction and probably has thicker walls, hence less volume to the case and more pressure if you stay with the same grain weigh as with Hornady case,
On a none marred same way prepped Peterson case seat the bullet (without primer or powder) chamber the round with the same intensity as you do and lock the bolt. The with the same intensity eject the round. See if you get marring.
I am just thinking out loud with my limited experience. As always if I go off track and if does not make any sense somebody will set me straight.
Without a doubt the Peterson brass is a smaller case volume, I am at 2 full grains under the minimum recommended load for H4340 and still getting a swipe.
My next outing I’m going to load the same way and seat 5 bullets with a 40 jump and a 60 jump and see what that does perhaps I’m just in too much of a jam, however I have never had that issue in the past when running a short jump.
With Peterson brass?
I am just curious and It probably won't make a difference, but try the dummy round test and see if you get any marring.
Why are you anchoring to a specific powder charge? Lower your charge, tune it and move on.
Also, did you actually measure your lands or are you guessing? Unless you know this number, you could be loading a dangerous round...
Also, did you actually measure your lands or are you guessing? Unless you know this number, you could be loading a dangerous round...
LVLAaron
Gold $$ Contributor
Just curious why that would matter?
Nick Caprinolo
Gold $$ Contributor
I don't know what source you are following for you loading data but you are using Berger bullets in Peterson brass. Peterson brass is, as you know, thicker and will cause higher pressure, than normal.
Now the Berger book lists maximum powder load for H4350 at 40.7 gr at 3634 fps and minimum at 36.5 gr at 2378 fps.
No bullet maker recommends the same powder load as others because of the thickness of their jackets and the shape of their bullets, among other factors.
It has been my experience, to start on the low end and work up. Generally speaking, .2 grs above minimum and increase by .02 grs increments.
The most important factor is finding the correct velocity for you barrel. Velocity will allow you to time the harmonics which affect the bullet leaving the barrel during the center point of the harmonic. All loading components involved determine the point at which the bullet leaves the barrel. High velocity does not mean accurate shooting.
Now the Berger book lists maximum powder load for H4350 at 40.7 gr at 3634 fps and minimum at 36.5 gr at 2378 fps.
No bullet maker recommends the same powder load as others because of the thickness of their jackets and the shape of their bullets, among other factors.
It has been my experience, to start on the low end and work up. Generally speaking, .2 grs above minimum and increase by .02 grs increments.
The most important factor is finding the correct velocity for you barrel. Velocity will allow you to time the harmonics which affect the bullet leaving the barrel during the center point of the harmonic. All loading components involved determine the point at which the bullet leaves the barrel. High velocity does not mean accurate shooting.
so your saying an chronograph can estimate barrel length and give new velocity reading for pressure?
This has always been one of the dumbest answer I have seen. You can not go by velocity. The test barrel was likely a 22-24” barrel.
You are using a 28” barrel. So your saying once I reach the speed of the 24” barrel I need to stop because I have reached max pressure??
Where is any information for shooting a 180gr bullet in a 284 with a 30-32” barrel? What will velocity show me with anything with pressure?
The only indicator we have of pressure is the speed we get the bullet to leave the barrel unless we use some sort of pressure trace equipment, if he is shooting a 24” barrel Creed and getting say 2800fps with that 140gr and his 38gr load its obvious his running into “pressure” at his start load, if he has a 30” barrel and his getting “pressure” signs at 38gr with the same speed obviously the marks are coming from something else. Then there are many programs on the internet that will simulate or give him a rough idea of his pressure if he has his actual speed. Fighting a problem that you think is pressure related without knowing the actual speed is like starting my car and listening to the engine to figure out why the car wont outrun any other car imo
That is quite obvious and profound but he specifically made a statement that is absurd and dumb and is always used without knowledge.
Velocity does not dictate pressure.
That statement says no matter the barrel length, if you reached the Max velocity then you have reached max pressure. That is absurdly false.
I never said it wasn’t a tool but with some common sense you can figure out pressure issues without a chrony.
I never had one, and almost always started in the middle and worked up with any rifle data..
Update I shot 36.5 grains of h4350 with the 140 hybrid, and I got the same ejector swipe.
I also shot 42.5 of H4831sc in a hornady case with no swipe.
I bought a box of lapua at the range today thought I’d try it and see if I get the same results.
I’ve seen two and heard about 4 more what seems to be identical issues with multiple mpa rifles/ba’s. I just saw Curtis for the action and thought maybe.....
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