What's up with my lapua brass

[GhengisAhn175]

Just shot this group with remington brass.

WHY THE FUCK CAN I NOT REPEAT THESE RESULTS WITH LAPUA BRASS.....

I'm going to tear my hair out.

Before y'all ask, yes I did the following:

1. Play with charges and chrono for fps. (Lapua needs additional .7~ grains to meet same speed as remington brass).

2. Seat depth played with but found my best one .

3. Multiple groups to offset shooter error.



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[MajorHeadTrauma]

What caliber?
Bullet?
Seating depth?


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[BLDTYLRY]

What's your fired Neck ID, Loaded Neck ID with Remington and Lapua Brass?

 

[shoot4fun]

What's your fired Neck ID, Loaded Neck ID with Remington and Lapua Brass?

This.
Lapua brass is normally thicker in the neck. Neck tension on your bullets is going to be different.

 

[GhengisAhn175]

sorry guys was raging but will clarify.

dont know what neck ID or loaded neck ID is.

260 remington
berger 140 VLD's
seat depth/CBTO: 3.180" (using sinclair hex tool and accounting for the hex tool length also, which is 1").

with my remington brass I have used 42.0 (this firing) and also 42.9 (near max load). Both of these loads shoot what I posted above (with the 42.9 shooting slightly bigger groups or it couldve been fundamentals).

With the lapua brass I need to load a bit hotter (somewhere around .4-.7 grains to get same FPS).

The weird thing is I have Neil Jones custom dies and I sent him my 3x fired lapua brass so its formed to lapua. I just happen to use the remington in the same FL resizing/seating die for it and it works. I have to admit, I think I may feel a slight difference when I seat in remington vs lapua. Remington seating seems "easier/smoother. I feel like I may be able to pull the bullet out where as with lapua it feels more of a sure seat.

 

[BLDTYLRY]

Take your calipers and measure the diameter of the neck this is the Outside Diameter. Measure a fired case and a loaded case. Get measurements for both Remington and Lapua brass. My guess is the loaded Lapua brass is big for your chamber.

Your reference to the custom die should give you an idea of what's going on. The neck thickness is different between the two brands, Lapua being thicker. Say you sized your neck using your custom die to a OD of .295" for both brands. The neck tension will be the difference because of the neck thickness. The neck tension is also releasing the bullet differently when fired. Your die maker took your fired case and measured the Neck OD" and probably subtracted .002" to ream out your custom die.

My 260Rem has a fired Neck OD of 0.297" which was specifically sized for Lapua brass. My loaded round using a 140gr Amax has a .295" Neck OD. I'm current running 43.5gr of H4350 at 2850fps and can run as high as 44.6grs at 2950fps.

 

[GhengisAhn175]

I received two bushings for my sizing die. How can I tell by
The numbers on the side which size is bigger?

Will changing my bushing (to better match neck tension of remington) possibly solve my issues if seating depth/powder charge don't?


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[dauntedfuture]

Its your neck tension difference between rem and laupa brass for sure. What do the lapua groups and chrono results look like compared to the lapua groups? What is the ID of the fired lapua brass? If your rifle has a small neck then you might need to neck turn the lapua brass to ensure a consistent release of the bullet. The Fired case ID should be at least .309 or so, if there is not enough clearance you will get pressure issues and inconsistent velocities from the thicker then average brass. I suspect the REM brass is thin enough that there is no issue.

 

[GhengisAhn175]

Still unsure what the neck ID is fellas.

As far as chrono data, the rem brass (at .8 grains lower than lapua) achieved 2898 average on oehler 35 (43.2).
ES was 20 and SD was 7
Or 8.

Lapua on the other hand at 44.0 was 2940 fps with an ES of 40 and an SD of double digit (below 20 can't remember ).

Thinking I need to drop charge but I've redone my charges since Then.

The only thing I haven't tried is change the bushing on my resizing die, which I think I'll do now.


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[dauntedfuture]

ID is inside diameter. It's going to be close to bullet diameter but slightly less to provide neck tension after sizing the case. A .260 rem bullet is .264 bullet, -.002 should be .262 or so. The fired ID of the neck should be .265-.266, if its smaller then that on some cases then your brass is not able to let go of the bullet and send it on its way; a very rough quick measure is that you should be able to put a new bullet into a fired case without much effort. Provided there is enough neck clearance, you will need a bigger bushing with lapua brass to get the same neck tension as the rem brass.

 

[GhengisAhn175]

What's up with my lapua brass

I have two bushings as stated. The one I currently use is 292X20SX457SD

The other is 291 first 3's then the rest is the same.

I'm assuming the 291 is tighter and is what I should use for the lapua brass (for more neck tension) IF the rem brass has a tighter neck?

Not sure what I can do here as I currently use the 292 for both brass.

Also, don't have any brass to compare ATM. Should I use once fired of each to determine neck diameter?
If I find that the rem brass is tighter than the lapua, that would mean I need to continue using the 292 for the remington brass and switch the lapua brass to the 291 (assuming 291 resizes a tighter neck by .001?)

However, if the lapua is tighter than the remington from the get go, I should not use the 291 For lapua as that will make it tighter ?

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[MitchAlsup]

There are 2 major differences:
a) neck thickness
b) case capacity

For a) you will need to uniform the necks, or use a different bushing to size the neck.

For b) you will have to find a different power charge. In 308 Lapua cases take 0.4 gr less powder than Win cases take for the same MV.

 

[MajorHeadTrauma]

Hi,

I appreciate your frustration. I think you are getting some good advice.

If I am allowed to make a suggestion, you may consider investigating if you have an issue with a donut at the junction of the shoulder and neck. The wall thickness of Lapua brass in the body is rather thick. As you fire the brass, the metal/brass flows up and into the neck after to resize the brass.

BFD MHT, what does this mean? Good question. The neck wall thickness at the shoulder neck junction IS thicker than at the case mouth. Where the brass may be .015 near the mouth, it may be closer to .020 near the shoulder. Yes, this is truth.

But MHT, why doesn't everyone have this issue? Is it just me? It isn't you, the God's at Lapua only mess with those they think are OCD, type A, Alcoholic, or good shooters. Ok, this was all BS. I'm bored at Starbucks.

But really, WTF? If I recall you are using bushing dies (as do I). If the base of the neck has thicker walls, as you size the necks, the brass pushes inward. Any variation in the walls gets pushed to the inside. The OD from the mouth to the shoulder will be consistent (i.e. .291"). But, yes a big butt, the ID will not be consistent. It may be .261" at the mouth but may be .250 near the neck.

So MHT, how can I confirm this is my issue? This is easy but work slowly. When you seat a bullet with about .002" neck tension, slowly slowly, repeat slowly, raise the ram and seat a bullet. If you feel the bullet slide in smoothly and then get a pop feel on the arm of your press, this is the bullet passing the donut.

This only happens with bullets that are seated deep in the neck and/or past the shoulder. This will not happen with 80 grain bullets but will with 140g VLDs etc.

If donuts are the issue, how do I solve it Lord MHT? The easiest way is not to use bushings but I think this is just hiding the issue. I resolve this by the following:
Full size with a non-bushing die no expander ball. (Expander balls are evil.)
Use a expander die mandrel to size the ID of the necks. (You can stop here if you are not OCD)
Grab your buddy's neck turning lathe and turn your necks from the mouth to the shoulder.
Resize with your bushing die.

Do I have to do this every time I size my brass. Nope. After a few firings, you can revisit steps 1-4 and find and eliminate that pesty donut. But, when this isn't required, just size normally but don't adjust the neck bushing down the the shoulder. Leave about .020" play in the bushing.

I hope this helps


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[GhengisAhn175]

Lol I appreciate the info from EVERYONE. Still a novice reloader. It just irks me how my lapua brass isn't performing as well as my Remington brass, more so that my custom dies were formed from 3x fired lapua brass (oh the irony).

I never thought I'd have to deal with turning necks (as I don't have that tool or capability yet).



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[FCS]

View attachment 48640

Just shot this group with remington brass.

WHY THE FUCK CAN I NOT REPEAT THESE RESULTS WITH LAPUA BRASS.....

I'm going to tear my hair out.

Before y'all ask, yes I did the following:

1. Play with charges and chrono for fps. (Lapua needs additional .7~ grains to meet same speed as remington brass).

2. Seat depth played with but found my best one .

3. Multiple groups to offset shooter error.



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Lapua needs 0.7gr more then RP for same velocity? You sure?

What distance did you shoot the ammo with RP brass?

Lapua isn't the end all, be all brass but typically will outperform RP.

Lapua has slightly thicker necks then RP, use larger bushing with Lapua and smaller with RP.

Probably need to anneal brass if when you seat bullets the RP is smoother then the Lapua. How many firings on the RP?

RP or Lapua, isn't going to matter on brass sent to have die set up. Chamber of rifle is what is going to dictate that more then brand of brass used. When you change barrel, get a different chamber then the die may or may not be a good match to new chamber.

 

[dauntedfuture]

to determine proper bushing size: load bullet in Lapua case, load bullet into REM Case. MIC outside diameter of both. The Lapua will be .001-.003 larger then the REM case. Take the total OD and -.002 for each case, this will give you the bushing you will need for each king of brass. The REM brass will need a SMALLER bushing then the Lapua brass by .001-.003 or so. If you want to use the same bushings turn the necks on the lapua brass to match the REM brass. Each brass has a different thickness. Lapua is thick, FCC is thick, LC is thick, REM and WIN are about the SAME, I think BH and NOZ brass is actually WIN brass so its about the same / the same as WIN/ REM.

Charges needed to get the same velocity will be close in Lapua, LC and FCC cases. You will need about .5-.7 more in WIN/REM cases.

Laupa cases should be more uniform out of the box then other brass. You can uniform other brass to make it as good or almost as good as Lapua Brass.

The thick necks on Lapus will allow you to turn the necks to your chamber and in theory provide better accuracy, they have to start out thicker then some others to do this.

Check your velocity numbers when you shoot groups; your Nodes should correspond on target and on the crono. You will also identify velocity variation issues that might not appear at 300 yds or so but will show up further out.

 

[oldfatguy]

I never thought I'd have to deal with turning necks (as I don't have that tool or capability yet).



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Not to rain on the Lapua parade, but I have measured as much as .002" difference in neck thickness on the same piece of new Lapua 260 brass. That is why I neck turn every piece of new PR brass. On the good side the flash holes are GTG out of the box.

OFG

 

[Victor N TN]

I used to hear this saying a lot. "Sometimes the wind and other outside forces will push a couple INTO the group". Maybe...?