H & K Recoil Spring

Mods and Fixes by P-64 users...
Post Reply
mikethewreck
Member
Member
Posts: 172
Joined: December 3rd, 2005, 3:34 pm
Location: Chattanooga, TN

H & K Recoil Spring

Post by mikethewreck » February 12th, 2006, 8:28 am

I am trying to do the H & K recoil spring mod on my P-64. I have one question and a "condition".

Question: should the H & K spring be trimmed until it is the same length as the P-64 spring?

Also, the current recoil spring in my P-64 just drops into the slide when I put it in. The H & K spring scrapes the sides of the slide slightly (looks JUST a little wider than the current spring). Is this a problem?

So far I have not been able to get the P-64 back together with the H & K spring on it, and I think it may be because of the size of the spring.

jbailey
Member
Member
Posts: 90
Joined: November 26th, 2005, 12:39 am

H & K Recoil Spring

Post by jbailey » February 12th, 2006, 10:49 am

Mike - see my post under Walther recoil springs. There's no way to determine if, or by how much, an H&K spring should be trimmed. However, if it's gonna scrape the sides of the slide, there's gonna be trouble, sooner or later (no way to predict) Spring steel, subject to constant abrasion at one point, will develop a stress concentration there, and that's where it usually snaps. Not being able to get it back together seems to indicate too many coils, the spring 'coil binds' before you can get the slide far enough back to reassemble. Me, were I determined to do it, I'd take off one coil at a time, until I could get it back together, making sure I was able to pull the slide completely to full stop, not just back together, and then one more to be safe. If the spring coil binds at full recoil, it surely will be damaged

mongo
Member
Member
Posts: 141
Joined: December 15th, 2005, 12:02 am

H & K Recoil Spring

Post by mongo » February 12th, 2006, 1:40 pm


saands
Senior member
Senior member
Posts: 263
Joined: November 17th, 2005, 12:09 pm

H & K Recoil Spring

Post by saands » February 19th, 2006, 11:31 am

Having done this one ... I'd heed jbaily's warning about stress concentrations ... I think that he's right. I would, however, ignore his comments about cutting a coil at a time and removing one more. Here's why: If you remove 1 full coil at a time, you will almost assuredly (well, you have about a 75% chance, anyway) remove too much, as the coil pitch is pretty long. As you get close, to the right length, I'd recommend going .25 coils at a time. As for removing an extra coil, the constraint that you have to meet with reassembly requires MORE than full slide travel already, so by meeting that, you are automatically about 0.2" from full compression of the spring, so this is not an issue.

Saands

jbailey
Member
Member
Posts: 90
Joined: November 26th, 2005, 12:39 am

H & K Recoil Spring

Post by jbailey » February 20th, 2006, 12:55 am

After some thought, I agree with saands comment about NOT cutting a coil at a time and going one more for good measure. If you can get it together, you've got the thickness of the slide stop lug as a margin.

hawkerjim
Junior member
Posts: 20
Joined: April 8th, 2006, 3:21 pm

H & K Recoil Spring

Post by hawkerjim » April 22nd, 2006, 9:22 am

Re-assembly after HK spring installation

I cut off 6.75 coils.When I tried to put the slide back on the frame the slide jammed at the where the barrel is starting to come through.

Slide is at a 20 degree angle to the frame.

I have gently pried from all angles. Stuck firm.

Advice please.

Hawkerjim

hawkerjim
Junior member
Posts: 20
Joined: April 8th, 2006, 3:21 pm

H & K Recoil Spring

Post by hawkerjim » April 22nd, 2006, 1:26 pm

H-K recoil spring re-assembly.

What a great website. within a couple hours I had help and advice.

All is OK. Page 9 calls the spring around the barrel the recoil spring.

Just too much H-K 44325 spring both in strength and volume at that stage of the project and not enough strength in these old hands. Finally got it.

Cleaned up the slide channels with a point file and greased them. Polished the ramp with Flitz and a Dremel buffer.

The H-K spring ended up being about the same length as the original,slightly longer.

I should have been more "SPRING SPECIFIC".

Hawkerjim

Post Reply