Need an answer for 243 Lapua brass mystery

[pmarauder]

I recently annealed 50 of my .243 Lapua brass. they had about 5 firings on them each. I then full length sized them all. I noticed that after full length sizing, I had .006 to .008 run out on the necks on my concentricity gauge. I traced the problem back to a bent expander shaft in the die. So i removed the expander shaft and then re-sized them all... now back to near perfect concentricity on the necks.....I then ran them through my K&M expander and skimmed all the necks to a perfect .0145 thickness. I then ran the brass back through my .270 neck bushing die.... primed..... powdered and seated the bullets. Now..... Here is my question that i cant figure out.... I went to the range and shot 21 shots with one fouling round. shot some good 3 Shot groups in the .130 to .250 range . I get home and measure the necks on my shot cases...... The neck on my fouling shot measured .2755 like they usually do. ... all the other 21 shot cases measure only .270.... every one of them..... How is this possible??
Any help would be great

 

[pmarauder]

One more piece of info i left out is....with only .002 neck tension, maybe the pressure didnt get great enough to expand all the way to the chamber before the bullet left the case? Also, the fouler round that did expand was a mess up and was seated way back on accident. .075 off the lands. and that is the only case that the neck expanded to .2755 which is my chamber dimension. all the others were touching the lands, and the necks measured .270
Thanks
Derek

 

[CPorter]

The fouler was the only one seated enough to build enough pressure. Even though the others were seated in the lands the friction & swaging forces had to be low enough to let the bullet move. Where did the powder fouling stop on the fouler and the other cases? I bet only the neck was dirty on the fouler and the other cases it went down onto the shoulder.

 

[pmarauder]

After further inspection..... you are correct. Looks like the shoulders are dirty about .150 down on to the shoulder as where on the fouler round, just the neck itself is dirty. So, do i change to a smaller bushing? (.269) or do i just load the same way? If i change bushings, do i need to back my powder charge back down? and start over??
thanks
Derek

 

[TheBlueEyedBear]

Hey neighbor!! You came to the right place for answers. There's a lot of knowledge on this site.

Barry

 

[jo191145]

I ran into the same issue using N-135 in a 204 Ruger. Huge jump to the lands in that particular set up.
This was not a wimpy load either. Going well past book recommended velocitys for bullet weight the necks would reliably expand. Unfortunately the accuracy deteriorated. Jamming into the lands solved the problem but my 204 did'nt like long pills anyway.
I eventually discontinued using Viht powders in the 204.

Sounds like you have a very light load in your 243 but sometimes................

It would help if you tell us exactly what your load consists of.

 

[pmarauder]

The load was getting up there.... 50g of VV560. Average speed of 3475 with the Berger 71 BT (Discontinued bullet) with a Fed 210m primer

Thanks

 

[jo191145]

How'd I know it would be a Viht powder?? FWIW 133, 140 and 530 also failed to expand my necks in that 204. Other powders no problem. "The Viht Curse" is back.
This was a load I developed starting with fresh brass. An extremely accurate load too. By the third firing of the brass I noticed accuracy going south. Discovered some of the necks we're not expanding, some were. I annealed the brass. No help.
Eventually I chucked that brass and bought Nosler. Accuracy was back necks expanding nicely until the third loading or so things went downhill.

Judging by the prep work you did on the brass theres no question your an expierienced reloader.
How far did you bump back the shoulders? I don't think thats the "real" problem here but its what will take the blame

I would try more neck tension and jam hard into the lands. See what happens.
You might want to blow that brass back out with a different powder too. Your call.

I shot half my barrel life out in that 204 trying to correct this issue with different brass,annealing etc.
I never did try increased neck tension :-[ Jamming was not an option. I swore off Viht powder in a 204 until I could reach the lands in a custom chamber. I have that chamber now but still haven't tried Viht again. Good luck.

 

[pmarauder]

Thanks for all the info. with this 71g Berger BT, I am .005 off the lands. I cant seat it any further out or else it will fall out of the case. where it is seated as of now, im just barely getting .001 of neck tension just at the very top of the neck.
Since they dont make this bullet anymore, i may just try the 95 vld or the 88. I think my chamber has more free-bore than the shorter bullets like. I think i can still stabilize the heavier bullets with my 1-10.25 twist. Do you guys have any info on a new load i might try next?

Thanks

Derek

 

[TheBlueEyedBear]

Here is some info for loading the 90gr Nosler Ballistic Tip and the 87gr V-Max.
These bullets work well on varmints.

Barry

 

[pmarauder]

Hey Barry..... Thanks for the load data. I will have to pick up some RL 17 and give that load a try....

Derek

 

[jo191145]

Pm

Be advised the Berger 95 VLD has a very short bearing surface length. I've never had any 88VLD's but I would'nt doubt they also have a short bearing length. Obviously the short bearing length will make it hard to reach the lands.
My lot of 95VLD's has .350" of bearing surface. You can compare that number to your 71's to get an idea on how they'll fit your throat.

Now the 80gn Berger is an excellent performer. Not the greatest BC but it shoots darn accurate very easily. Jam it .010" and put some powder behind it and sit back and smile. Bearing surface on my 80 Bergs measure .455".


Barry. I'd be interested in what distance in/from the lands you found worked best for you with the 87's. I've been having a rough time getting them to shoot in my 243.

 

[TheBlueEyedBear]

I have plenty of RL17 if you want to try some of mine first,, just knock on my door. Watch out for the 'guard dog' though.

Barry

 

[pmarauder]

Sounds good Barry..... thanks for the help.

Derek

 

[CPorter]

How much of the bullet bearing surface is in the neck? You're saying they almost fall out of the case when you seat in the lands. I seat further in the neck to get one bullet diameter in the case and use a .002 or .003" under finished diameter bushing.