Weak recoil spring results.

[praecorloth]

Hey peeps, I haven't posted here in a long while. Back when I did, I made a post about buying a matching USP .45 for my wife. It was a very beat up USP, lotsa holster wear and a noticeably weaker recoil spring.

http://hkpro.com/forum/showthread.php?t=57592&page=2

I didn't want to resurrect the thread since it was from so long ago, but there it is for reference.

We haven't had a whole lot of opportunity to hit the range in the time between that post and this one, but the last time we hit the range, The Warden was forced to use my USP due to lane limitations and the number of friends we brought shooting with us.

She had fired her USP previously, then my friend went, then I went, and she got back up to the firing line, threw her target down range and shot at it with my USP. She did remarkably better. Probably the best shooting from a pistol she's done thus far.

The only functional difference in the gun is the recoil spring. So I put a stop to our day of shooting and decided to throw her recoil spring in my USP.

This is me shooting at 20 feet with my normal USP .45 set up. This is after about 20 rounds.

http://archangeltech.dnsdojo.com/pictures/range/03222008/640x480/hk45goodspring.jpg

This is me shooting 10 rounds after swapping out the recoil spring.

http://archangeltech.dnsdojo.com/pictures/range/03222008/640x480/hk45badspring.jpg

Holee crap. Needless to say, I'm going to be ordering a new recoil spring as soon as I get some extra scratch. If you've got any recommendations as to where to get a new spring, lemme know. Otherwise I'll just order it from HK I guess.

[Sobriquet]

http://www.gunsprings.com/SemiAuto/HecklerKoch.html#USP

Wolff Springs seem to be highly recommended on this forum. I have no personal experience with them.

[bspring]

I have ordered many springs from them and have been very satisfied. For the USP .45 I would recommend the 16lbs spring, its only 2lbs heavier than stock. But it does provide better feeding and barrel lock up.

Bill

[Germanic]

I'm at a loss as to how the recoil spring would affect accuracy. I can certainly understand how a weak spring might cause reliability issues but as far as throwing off the accuracy. I just don't get it. Most target pistols I've shot have pretty light springs.

[Sobriquet]

I'm just guessing here, but perhaps the spring is so weak the slide is going back and the gun starting to flip before the bullet leaves the muzzle? That would be the only thing that makes sense to me.

[Scooter]

At 20 feet, that's operator error. Even with an incredibly poor lock up, there's not enough slop in the gun to produce a group that bad. I'd bet if you shoot the gun off a rest, it will be a really tight group.

There's no way the gun starts to flip before the bullet leaves the barrel. Even if you took out the recoil spring, the bullet would have left the barrel before the slide unlocks.

[harrydog]

I'm just guessing here, but perhaps the spring is so weak the slide is going back and the gun starting to flip before the bullet leaves the muzzle? That would be the only thing that makes sense to me.

I think that's impossible.

[5wire]

III. For every action there is an equal and opposite reaction. — Sir Isaac Newton

There is no time delay involved.

[edit15]

I've always heard that unless the manufacturer specifies otherwise, it is a good idea to replace your recoil spring after 5,000 rounds. If the spring gets too weak, it can cause excessive wear and tear on the slide and frame. Springs are a lot cheaper than slides or frames.
If I've heard correctly, Sig Sauer recoil springs need to be replaced at 3,000 rounds, for example.

[praecorloth]

I'm willing to believe that some of that second pic is operator error. Like I was expecting it to be inaccurate so in the back of my head I just wasn't trying as hard. But I think the theory is sound mainly because the wife did significantly better using my USP with the good recoil spring despite the fact that it didn't have the extra grip pad that makes is more comfortable for her. And she wasn't expecting to do any better with my USP so I wouldn't guess it's like she tried a little harder or anything.

But at the very least I figure this is good enough incentive to spend the $8 to buy a new spring. The wife was pretty against it when we originally got her USP. She said my USP's slide was too hard to pull back.

[Scooter]

If you are at the range firing single round at a time every 2 seconds (typical range rules), the recoil spring really doesn't matter. The recoil spring does affect the percieved recoil of the gun, BUT this occurs AFTER the bullet has left the barrel. The recoil really doesn't play a part in the accuracy of the gun. All it does is play with your mind if you are weak of mind.

If you are shooting at a faster pace and using standard loads, guns typically handle better with lighter springs. The USP's are oversprung for standard loads because they have to accomodate heavier loads too. If you never shoot +P, going to a lighter spring will typically make the gun shoot flatter but the recoil will be directed straight into your hand more, making it feel snappy. Flat and snappy is much easier to shoot fast than flippy and soft.

I never like the Hogue Handalls. While it makes the gun feel comfortable in your hands, you lose a lot of the feedback from the gun. Plus it is more slippery than putting grip tape on the gun.