I am very skeptical of these Wolff 'standard' weight recoil springs...So I thought up a test...
I stripped the Nambu down and stripped the bolt of all but body & recoil springs...Old & new...
I attached my spring tension gauge to a loop of wire around the bolt knob...Clamped the pistol in my vise...And checked initial weight to get bolt moving, and weight when fully retracted (or just before)...
Here's what I got...
Old springs - 4# initial, 19# fully retracted
New springs - 6# initial, 19# fully retracted
Here's why I'm skeptical - 73year old springs have the same draw weight as brand new springs??? I don't buy it...
I don't want to test-load up a number of cartridges with 3.5gr of powder while using an underpowered recoil spring...In fact, I noticed that when dry cocking, the new springs would not always force the bolt closed...The bolt stopped about a quarter inch from closed...
I'm going to order the Wolff
'Recoil Spring Pak (Stock No. 16960) contains 2 extra power recoil springs' and check those the same way to see if they are actually 'extra power'...
