Common Mag springs

[at_liberty]

In owning both T9 and T40 and wanting new mag springs for both, I discovered they both use the same spring, one serving for 8 rounds and the other for 7. This suggests to me that the T40 will benefit from the 5% upgrade in spring. Actually the 9mm mag is harder to load full, so I now have my little theory why.

[jocko]

In owning both T9 and T40 and wanting new mag springs for both, I discovered they both use the same spring, one serving for 8 rounds and the other for 7. This suggests to me that the T40 will benefit from the 5% upgrade in spring. Actually the 9mm mag is harder to load full, so I now have my little theory why.

certainly will benefit from the 5% uipgrade. But the 6 round mag and 7 round magazine of the PM9 is a different spring. they are not identical..

[at_liberty]

I have my new springs directly from Wolff. Well, they are about three inches longer...more coils. There was just no way to install the springs free hand. It took a vice to hold the mag case in order to free up a hand to assist capping the spring. The secret was in use of a pin at the lowest hole, after the spring was compressed to about three inches extending beyond the mag. This contained enough tension to allow pretty readily capping the mag.

Afterward, the mag was a real challenge to fully load. As one might expect, the spring is taking up some of the room formerly enjoyed by the rounds. I got them all in there but was almost tempted to forgo that last round. My thumb is sore so I will use that little plastic thumb thingy to help load mags for a awhile. I'm a wimp, I guess. I tried to man up, really! :o

[ripley16]

Well, they are about three inches longer...more coils

Sounds like they might contain a bit more than 5% more energy. :ohmy:

Why did you opt for the heavier springs, were you experiencing feed problems?


But the 6 round mag and 7 round magazine of the PM9 is a different spring. they are not identical..

It's a matter of case diameter, not capacity. The T9 mag holds 8 rounds, but because the .40 is a larger round the mag only holds 7. The spring compresses about the same distance regardless.

[jocko]

My wolff 5% extra strength mag springs sitting on my desk next to a new kahr factory spring for a PM9 has 1 ONE more coil and that is all the difference. If someone got a new wolffs 5% Spring and it is 3 inches longer than a kahr factroy new spering then they sent you the wrong spring.

5% ain't much and u will not notice one bit in loading issues either but that little 5% is sure a nicehelp on that last round in the magazine to help push that mag follower up fast enough and with enough ump to engage the slide lock lever . that is the only reason I ever went to the 5% heavier spring as my factory springs worked great also.

If they made a 10% strength spring I would have um also. I know wolffs made 10% mag sprngs for their kel tecs and they worked super. Nothing wrong with staying with Kahr factory springs, as they are made by wolffs anyhow. I just like the 5% for maybe no other reason that it is supposed to be alittle stouter...but certainly maneagable.

[at_liberty]

Sounds like they might contain a bit more than 5% more energy. :ohmy:

Why did you opt for the heavier springs, were you experiencing feed problems?



It's a matter of case diameter, not capacity. The T9 mag holds 8 rounds, but because the .40 is a larger round the mag only holds 7. The spring compresses about the same distance regardless.

Refer to http://kahrtalk.com/t-series-pistols/223-slide-will-not-lock-back.html

I don't believe I had a choice of standard springs on the Wolff site...ICBW. It was 5% or 10% as I recall. I chose 5%. I was expecting just heavier, stiffer wire, not more of it (longer).

I disagree about the space taken up by 8 rounds of 9mm versus 7 rounds of .40 in the same length magazine. There clearly is useful headroom left when inserting that last round of .40. The 8th round of 9mm though can be aggravating sometimes, especially with the small round that wants to squirt out of there before seated. It might not be much but certainly seems to change the loading experience.

[jocko]

AT LIBERTY: I THINK THEY ONLY OFFER 5% for the kahr magazines. and yes ur right, jwolffs only offers 5% springs, not exact factory strength..

[at_liberty]

It's a matter of case diameter, not capacity. The T9 mag holds 8 rounds, but because the .40 is a larger round the mag only holds 7. The spring compresses about the same distance regardless.

9 mm = 0.35433071 OR 45/127 inches

Using only the diameter of the bullet, not the casing, I see that I should agree that 8 rounds of 9mm and 7 rounds of .40 come out very close, with the 9mm taking only about .04 more space. All that remains is the different mag loading experience between the two, perhaps as simple as the fatter round being noticably less inclined to squirt around under tension.

[jocko]

9 mm = 0.35433071 OR 45/127 inches

Using only the diameter of the bullet, not the casing, I see that I should agree that 8 rounds of 9mm and 7 rounds of .40 come out very close, with the 9mm taking only about .04 more space. All that remains is the different mag loading experience between the two, perhaps as simple as the fatter round being noticably less inclined to squirt around under tension.

rigth there to. Not sure magazine springs are rocket science either..:001_tt2:

[at_liberty]

If someone got a new wolffs 5% Spring and it is 3 inches longer than a kahr factory new spring then they sent you the wrong spring.


I found that old and new T9-T40 mag springs have the same number of coils. The older one is simply more compressed. The issue is fatigue, so it stands to reason. Those mags have been constantly loaded, springs completely compressed for five years, with not that much range time cycling ammo and exercising the springs.

The single mag of the three that now has a new spring can be loaded successfully, but for now it is quite a task getting that last round or two in the mag against all that tension. It'll work.:)