Odd results, low and right

[ryanmattes]

So I cast up a bunch of 401-175-TC for my P229. Coated with Hi-Tek, they ended up 178.7 (give or take .5 gr), and got sized to .401. Loaded those on 5gr Unique, with Fed #100 primers. All win headstamp brass, all within a couple thousandths of .845. OAL was 1.100.

This is almost exactly the same load I do with j-words. 180gr XTP, 5gr unique, Fed or CCI SPP, Win brass trimmed to .845. only difference is I was using 1.115 for the OAL, based on Lyman load data.

With j-words I get nice enough groups at 7yd off hand. With the cast, I'm getting very similar groups, but they're all low and right. Almost like my sights are off. But if I switch back to j-words, it corrects itself. I'm also seeing leading in the last 1/3rd of the barrel.

I need to fix both issues, but the low and right confuses me. Anyone had something like this happen before?

https://uploads.tapatalk-cdn.com/20210214/70313286008a3dbdeafb5b3ca4ac5e51.jpg

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[onelight]

Do you know if the shots closest to point of aim were the first shots ? Perhaps the leading is moving the point of impact.

[ryanmattes]

No, the closer-to-center shots were later, and were most likely caused by me. The started out near the middle of that group.

As a reference, I shot this group right before the .40, with a new .45 I got recently. Again, the high and left shots were towards the end of the group, and probably related to fatigue at shooting 20 round sets.
https://uploads.tapatalk-cdn.com/20210214/f57853c78c91fdc104db61ab2400e3e0.jpg

[jimb16]

Not an unusual situation at all. Happens all the time. Cast frequently shoots to a different spot.

[ryanmattes]

Not an unusual situation at all. Happens all the time. Cast frequently shoots to a different spot.That sucks. I don't want to adjust my sites for cast. What can you do? Faster/slower? Heavier/lighter? Harder or softer lead? Will different bullet shapes have different points of impact?

I hadn't noticed this in any of the other handguns I cast for, so this is my first time trying to work around it.

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[onelight]

That does not look normal to me at 7 yards with same weight bullets and powder charge in my experience they normally hit so close to the same spot it's hard to see any difference.

[jim147]

Try larger boolits.

[Jal5]

What about a little smaller OAL? If you are not at the max charge you could go for a little more pressure and move the group up. Just a thought.


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[ryanmattes]

Is there something that makes you say it's too small and not too large?

I mean, I slugged that barrel at .4000 exactly, so I assumed .401 would be about right. But maybe it would do better with a .4005?

I'll get my hands on another Lee .401 push through sizer and open it up a bit. I can give it a shot at .4015, and then open it up to .402 if that doesn't work.

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[popper]

The recoil will be slightly different but groups should be same at 7. Leading is lube/alloy or size problem. Right handed and left/low is anticipation. Cast is faster for same load.

[ryanmattes]

What about a little smaller OAL? If you are not at the max charge you could go for a little more pressure and move the group up. Just a thought.


Sent from my iPhone using TapatalkThey're seated pretty much right at the edge of the bearing surface now, I don't think I could seat much deeper.

The load is light, though, the Lyman data says 4.7-5.8 and I loaded it right at 5.0, so I could probably push it a bit hotter to see if that helped.

I'm thinking size is what's causing the leading problem, so I'll have to modify a push through die to address that.https://uploads.tapatalk-cdn.com/20210214/4d9f2252e47cc5b38cefc8257a422cc4.jpg

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[ryanmattes]

The recoil will be slightly different but groups should be same at 7. Leading is lube/alloy or size problem. Right handed and left/low is anticipation. Cast is faster for same load.It's not anticipation. I did 9mm and 45acp in the same session, and those both grouped around the bullseye I was aiming at. The lead in the barrel could've affected POI, but it was low and right from the first shot out of a clean barrel.

I think I probably need to speed it up and try some different sizes.

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[Dusty Bannister]

It is normal for the bullet impact to move at a diagonal on the target as you change the powder charge. There is a significant difference in bore friction between cast bullets and jacketed bullets. Looks like you also complicated the results by introducing powder coating. You need to regulate the load and bullet to shoot to the sights. This might require a different burning rate powder. Is that a wasp waisted cartridge or just camera distortion?

Try the existing powder and shoot a ladder from the suggested starting load up to where you start to see pressure signs, like erratic or wild ejection. The results of that test should indicate to you if you need a faster or slower burn rate. Single load these test rounds so the weight of the gun does not influence recoil movement. I have not had to do this for years so do not recall all the details as to direction of movement on the target. Barrel time and recoil are factors that influence the impact on the target.

[ryanmattes]

Is that a wasp waisted cartridge or just camera distortion?

It's the phone camera with zoom cranked up, it doesn't look like that when you look at them.


Try the existing powder and shoot a ladder from the suggested starting load up to where you start to see pressure signs, like erratic or wild ejection. The results of that test should indicate to you if you need a faster or slower burn rate.

Good info, thanks, that's where I'm headed next. I'll ladder the load and clean between sets until I can get a die to open up so I have some sizing options, since the Lee push through sizers only come in .401.




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[jimb16]

I would load it down just a bit and see if that doesn't correct the problem. Cast bullets move faster for the same loading. That means less barrel time so they tend to hit lower. Slower/lighter loads mean more barrel time so they hit higher due to the barrel having more time to move under recoil, hence higher and slightly to the side of where they hit with a heavier load. Its worth trying and might just be what you are looking for.

[rintinglen]

Jimb16 has the handle on this one. A little slower, a little more time in the barrel and the impact will rise. You might try a charge of 4.8 grains to see if it doesn't get you closer to the elevation you are shooting for. It may or may not fix the "right" part of the miss-match though.

[gnostic]

Leading at the muzzle end of the barrel, usually means your bullet lube failed. I'd try some different powders before I did anything radical. The faster the bullet goes, the lower they'll land on the paper...

[mdi]

Groove diameter .400"? I'd try at least .402"...

[ryanmattes]

Leading at the muzzle end of the barrel, usually means your bullet lube failed. I'd try some different powders before I did anything radical. The faster the bullet goes, the lower they'll land on the paper...I'm using Unique right now, and all the other pistol powders I have are faster (HP-38 and Titegroup).

If there's a slower pistol powder you can recommend I'll look for it, but you know what powder availability is like right now. I know a few other loaders in the area, I might be able to trade with one of them.

I'll do a ladder starting from 4.7gr to 5.4gr in 1/10th increments and see if I can see a pattern. The cast load data in the Lyman manual puts 5.8gr as the max, so I'm a good way under the max.

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[ryanmattes]

Found another .401 push through sizer available online, so I ordered it and went about opening up the one I currently have to .402. I used a length of .375" diameter oak dowel chucked into my drill, with 600 grit and then 1000 grit sand paper (with a tiny dab of oil) taped and wrapped to the end. Since I've already sized the few hundred I had cast, I'll need to cast and coat more before I can try it out. The throwback slugs I pushed through it came out right at .4020.

Meanwhile, I'll do the ladder on the ones already cast and sized, and see what I see. I'd have done it already, but it's been 6 degrees (in Texas?!?) and no power the last few days, and I'm loading in an unheated garage, so I haven't really wanted to stand out there long enough to put those sets together.

[ryanmattes]

After opening up the sizer I cast some more to test, and as I pushed them through the sizer I realized: they were barely touching the sides. The mold drops at .402. I probably didn't need to put them through the sizer, but I figured it couldn't hurt in case they were slightly out of round.

So I've loaded up a ladder at .401 starting from 4.7gr up to where I started before, and I'll load another ladder at .402 from 4.7 up through all the charges I already tried in .401.

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[popper]

4.5 hp38, 401 cast is my recipe.

[ryanmattes]

Update:

I need a bigger mold, to stop the leading. The .402 sized that barely touched the sides of the sizer still left lead, although less. If I can get a good .403+ slug and size to .402, that may do it. I may try going unsized and adding an extra layer of coating to see if it tames the leading.

Also, reducing the load brought the point of aim closer. Best results were around 4.8gr unique. Lower than that started to spread, higher than that and the POA started going down and right.

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