Rule of thumb - 12 GA Spring Lengths - Is there one?

[lmar]

Hi,

Just purchase a +1 Remington 870 magazine extension from S&J Hardware.
It comes with a new oversize spring to replace the factory 4 rounder.
It is a very nice piece of kit and the oxide finish matches the new 14" Remington factory 870 barrels that were just released.

However, I don't recall ever seeing an answer to the following question.

What is the correct free length of the spring that is used for

a) +1 Extension
b) +2 Extension
c) +3 Extension

P.S. I emailed Simon this afternoon to get an answer but the 3 hour time difference meant he was home (or Xmas shopping).
Figure the guru's on this site would be able to supply me with an answer.

L

 

[enefgee]

I don't think the spring can be too long, due to the nature of the feed path. Stronger is better.

 

[45Carbinedude]

I would think the answer is in the question...

Take your stock spring length as is, then add the number of inches to the spring as is your extension.

 

[EL34/6L6]

Spring should extend 4-5 inches past the end of the magazine extension when fully extended.

 

[HuntersStand]

Cut the spring long and go by feel taking one link out at a time until it's not too hard to squeeze in the max amount of 2 3/4" shells of the longest variety you can find of slugs,buckshot,and birdshot.