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Currently I have an early '94 USP .40, I was curious if I should bother getting a polygonal barrel to complete my upgrades to it to bring it to the level of a "modern" USP. But after reading a few topics in the forums I'm seeing conflicting answers.

So back to the question, Should I bother upgrading my Land and Groove .40 USPf to a polygonal barrell? Keep in mind this gun is mainly for self defense, Something to have in the coffee table or in a desk drawer, Not so much target shooting.
 

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From what you are saying unless it has had so many rounds put through it that you can not pattern it I wouldn't bother. Spend that money on another!:43:
 

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Don't forget - the advantages to polyonal rifling over land and groove (whether it be cut or button type) are of longevity, not accuracy. They do seem to increase muzzle velocity a little as well, if you compare similar bullet loads and similar barrel lengths to other guns with land and groove rifling.

Evidence? Look down the barrel of any competition sharpshooter and you'll see lands and grooves, not polygonal rifling.

So... if you plan on starting to shoot thousands of rounds through it a year and want it to last forever, then go for the new barrel. If it's really just for self-defense and an occasional target practice, keep the one you've got and use the money towards a new USP. You can never have enough HKs. :)
 

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A polygonal barrel would last longer and be a little easier to cleam, but a quality land and groove one would also serve you for a very long time. Personally, I wouldn't bother.
 

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Discussion Starter #5
Well that seemed to be pretty unanimous, Personally I was thinking about picking up a P99 or a P2000SK. My hands are definitely on the small side and i'm beginning to dislike the grip of a full size USP. Maybe the HK45 will better suit that need.

I'll keep dreaming about that one.
 

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Let's see, polygonal: slightly higher velocity, so they say, I cannot measure any difference in the same ammo shot out of my HKs and other L&G barrels of the same length. Any velocity variation IMO is no more than you would see in any ammo's SD or ES or variation seen from one barrel to another. And if there is some velocity gain it is minimal and of no real world benefit.
Easier to clean. Not if you are using the right cleaning supplies. I find the polygonal bore no easier to clean than any other bore, and I shoot a lot of cast and X bullets.
Accuracy, can't see any difference here either. From all the HKs I have shot and all the L&G barrels I have shot, I'd say the accuracy limitation is behind the trigger, not in front of the action.
One little pitfall: You are not supposed to shoot cast. I know some do, but some drive 50 MPH over the speed limit. Just because some do does not make it a sound practice.

L&G barrels: Slower velocity, so they say. See above.
Not as easy to clean. See above.
Accuracy. See above.
And you can shoot all the cast bullets you want instead of the more expensive jacketed bullets (unless you want to buy in bulk 5,000 at a time) without fear of rapid leading which can lead to a KB if you don't stay on top of it at all times. HK and Glock say "no cast" for a reason.

Now, this is JMO and worth exactly what you are paying for it, but if I were King for a day all the barrels would be L&G and polygonal barrels would be a thing of the past. I am use to shooting hundreds of rounds of cast bullets (my bullet of choice in all handguns and rifles above .375 caliber) without having to worry about leading causing high pressures. With my luck I would get on a role shooting three or four hundred rounds of cast in a HK and KB the darned thing because I forgot to check the bore and clean every hundred rounds or so.
When a regular bore leads up, accuracy falls off and that's about it. When you are done you clean the darned thing. This I know from first hand experience and from years of shooting cast.
Now, this I do not know and can only go by what others have told me. Supposedly when leading starts in the polygonal bore it can build up quite rapidly and continue to do so until pressures are increased. If not caught in time... I know of no scientific proof of this, only what I have been told by those who have KBed pistols shooting cast in polygonal bored pistols, mainly in Glocks but some HKs also. Maybe true, maybe not; I'm not going to chance it.
 

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Currently I have an early '94 USP .40, I was curious if I should bother getting a polygonal barrel to complete my upgrades to it to bring it to the level of a "modern" USP. But after reading a few topics in the forums I'm seeing conflicting answers.

So back to the question, Should I bother upgrading my Land and Groove .40 USPf to a polygonal barrell? Keep in mind this gun is mainly for self defense, Something to have in the coffee table or in a desk drawer, Not so much target shooting.
I've got a '94 with land and groove rifling. There is nothing wrong with it. Keep your old rifled barrel and use it till it has been shot out.
 

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Let's see, polygonal: slightly higher velocity, so they say, I cannot measure any difference in the same ammo shot out of my HKs and other L&G barrels of the same length. Any velocity variation IMO is no more than you would see in any ammo's SD or ES or variation seen from one barrel to another. And if there is some velocity gain it is minimal and of no real world benefit.
Here is just one chart I could find quickly with actual velocity numbers using same ammo in various guns:

http://www.silencerresearch.com/swr_trident.htm

I know it's a suppressor test, but the USP9SD has 60-70fps increases over the other guns across all ammo brands, and in both suppressed and unsuppressed configurations.

Yes, it's only 60-70 fps, which is why I said "slight" velocity increase. But it is real, and measurable. Is it of any consequence? Probably not. But I've seen several charts like this, so I believe it is a correct statement.
 

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The part I like the most on the HK firearms is the barrel of them.
Very clean, smooth, shiny, hard to scracth rifling.
Perfectly cut and fitted outer surfaces.
Best.
 

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If I may chime in here about a few points... First, I agree with BigBore about the leading issue. If you're going to shoot the cheapest cast lead ammo through your pistol don't buy a polygonal barrel! A polygonal barrel is designed to give a longer service life and give a better seal on the bullet. That's pretty much it!
As far as the accuracy propaganda goes, I have two great examples of polygonal rifling not being accurate. The PSG1 and the P7 series!!! Both made by HK and both are damn tack drivers!!! I think that should end the conspiracy theories.
 

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I still say grab any two guns otherwise identical and shoot the same ammo through them and you can see the exact same velocity differences.
I've been loading for over 40 years and have loaded and tested a butt load of ammo through guns with identical barrel lengths and gotten spreads and velocity differences larger than that. I have multiple .45-70s, .44 mags, .357s, 9mms, .45s...the list goes on, that I have tested the same reloaded ammo through and velocities often vary as much as 150 fps out of guns with the same barrel length but of different manufacture and even among guns that are the as near being identical as you can get.
Case in point: I loaded some rounds for two SIG .380s, M230, for a friend of mine. Two identical guns with very close serial numbers. The velocity through them clocked a 35-40 fps difference. And that was well outside the ES and SD on those two guns (which I don't recall right now but do recall it was outside them). I gave up years ago trying to explain that one but I suspect a rougher bore on one but cannot feel it and didn't have a scope to scope it out.
In the sighted example there are two areas that cast doubt on the validity of the test. Look at the SD and you can see some rounds overlapped or came darned near it. If one could see the ES that would tell even a closer story.

And the real killer was difference in number of total rounds fired through the two barrels before testing. That alone would easily explain the velocity differences in that given example. One has over a thousand rounds through it, the other a hundred? Come on, that is apples and oranges and proves absolutely nothing about the differences in rifling.
Ask anyone who has ever lapped a barrel on a new gun and they will tell you that they usually get a velocity increase of that or greater. And a thousand rounds is a pretty good way to lap out a barrel.

Sorry, but that difference right there is enough to rule out that test as being significant for testing the difference between polygonal and L&G rifling.

As for the suppressor test. Very interesting but since all guns had different barrel lengths, as much as a half inch difference, while it does look like the HK and Glock gave higher velocities, even though the Glock had the next to shortest barrel, the SIG having the shortest and the 92 the longest, there are too many unknown variables.
Show me a test, same gun, two new barrels, same barrel length, same barrel maker using the same blank, one L&G and one polygonal, same ammo with a known low ES and SD, THEN the test MIGHT be valid.
Since those conditions will never be met this argument will go on for as many years in the future as it has in the past and nobody's mind will be changed.
 
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