6PPC Case Length

[Ghansen]

I have a question re brass length;

Although the answer to this may be self evident, I had a run of some brass that were over trimmed 5 thou, and I know that this will affect the seated bearing surface on the projectile by that measurement.

What I was wondering if someone here has run the accuracy numbers, and therefore if the brass are worthwhile keeping, or all ?

Reject brass is 1.485" trim instead of 1.490"

Thanks, Geoff

 

[tenring]

No problem, but you may get more carbon plating in the throat.

 

[Tim Singleton]

Keep them and separate in the same lot of lengths and shoot
The 1.485 will be fine just keep them separate. They will catch up after a few firings

They will shoot just as well as the 1490. Just keep them seperate

 

[artbosco]

Trim them ALL back to 1.485" and keep shooting. As long as all of your box of 50 [for example] is the same you're good to go. If you want them longer let them grow as you use them for practice. You do practice ... right?

 

[savagedasher]

Drill out the back of the brass like a chamber all brass is .Push it all the way in and use your bore scope to check how long it can be. Larry

 

[Ghansen]

Well, I tested the shortened cases with positive results after my maiden comp match this morning. (Targets attached) Firstly I will post the comp result:-

1st Place, me (it may never happen again, but a small reward for my testing)
conditions, A & B targets almost no wind, picked up through to 7mph gusts and shifting the next targets with a rising temperature.

I tried to include the comp targets, but the document size wouldn't come down enough for all.

Chosen load for this comp. 29.0 grains N133, Berger Column seated to jump .010. Fed205M

Target A .212
Target B .251
Target C .355
Target D .200
Target E .194

If you have any comments on the attached targets, I would be pleased to read your feedback.

The short cases will be set aside for practice, and hopefully my preparation will be closer to optimum than less! I am fire forming new brass for my future comp efforts (fouler's and barrel warmers this match), and look forward to some good consistency.

Geoff