HK Bore Axis question

[bzinbv]

I was doing a little surfing regarding HK's 416 when I came across a thread on another forum that had some serious HK bashing: (http://www.militaryphotos.net/forums/showthread.php?t=72167). Part of the rant has to do with how much higher the HK pistols' bore axis is compared to other designs, and how much harder it is to get back on target for a follow-up shot. I search around HKPRO to find out a little more about this issue, but I did not come across any hard data or measurements about bore axis.

Has anyone come up with any bore axis measurements comparing a USP/HK45 to a Glock or 1911? What I'm really after is to determine how much of an improvement the new HK45 is relative to the USP, and if the HK45c has the same improvements.

[cueist]

I don't see how the 416's bore axis could be higher then say a Colt M16, or M4 since HK designed the 416 Upper to be placed on current in service lowers.

If the 416's bore axis was higher then the mechanical componate interlockings would not be compatable, also the ammo would not be able to feed into the chamber since the barrel would sit higher on the lower.

[bzinbv]

I was interested in the comments refering to HK pistol bore axis. The thread is a long one and gets off the subject of 416's and becomes a debate about HK as a military supplier.

[cueist]

Ah, my bad I didn't bother to read all of the pages :)

The the HK45 does feature a lower bore axis, I don't knwo the measurements, but you should ask member GregBell who is running tests on his HK45.

[S5TIIOwner]

I thought bore axis was subjective? Isn't one of the measurements made off how and where you hold the grip?

[faris13]

to me bore axis is not a big deal. There are more important factors to me than bore axis such as the grip on the pistol, how the pistol points, trigger, trigger reset.

I have owned glocks, m&p's, Sigs, H&K's and walthers. I've realised that for me the difference in bore axis has a minimal impact in how I shoot.

[sfguard]

I think it is a bunch of crap written by people that want to hate people who only buy the best. I have several HKs, and only one Glock. That should say something about that theory. I don't have measurements to give you but the recoil system in the Hk is by far superior to that in most other pistols. IMHO I have no trouble shooting double taps due to it. But then again these are the same people still complaining about HK CS and we all know how wrong they are about that too.

[softmentor]

From a subjective point of view, I shoot the HK USP 45 better than other guns which may have a lower axis according to some technical mesurment. Most feel the recoil is less, and more manageable overall that other guns. For me, the proof is in th puddin' and I shoot well with the HK USP.
Not an issue for me.

[bzinbv]

I've just seen references to a higher bore axis, but never the amount. Sometimes these things take on a life of their own. It wouldn't surprise me to fine the difference might only be 0.050" yet folks will think all kinds off performance issues can be attributed to the difference. I'm not even sure if my HKs are higher than my Colt 1911s. The trigger alone on the 1911 will impact my target shooting, yet I carry the HK for a host of reasons, reliability being near the top of my list. I am curious to see the difference between the HK45c and the USPc. I know I will buy one when they come out, I actually called CDNN to get on a list when they do become available.

[Scooter]

Bore axis isn't subjective. If you are not holding the gun as high up as possible, you aren't doing it correctly.

Here's a picture I posted a while back comparing a USP vs. S&W M&P. The picture has not been scaled. It simply overlay my grip on both guns as high up as possible.

http://www.parkcitiestactical.com/album/00000169/bore_height.jpg

[carboncycles]

scooter, nice job on overlaying the 2 photos. i didnt realize there was that much of a difference.

[Scooter]

I don't have one with a P7 in there, but the P7 is even lower than the M&P.

FYI Glock is very slightly lower than the M&P which is slightly lower than the XD.

[Greg Bell]

Bore axis is the most overblown internet B.S. since Y2k. The P7M8 has the most amazing low bore axis ever. Whoop de do.


I am going to start a new internet gun nerd topic: Side weight/velocity ratio. Low bore axis actually creates more apparent recoil because they tend to have lower slide weight than guns with heavier slides. WOOHHH. Gotta get more bore axis!!
http://seoblog.intrapromote.com/more_cowbell.jpg
Anyway, if bore axis is your thing, buy a M13, everything else is crap. If SLIDE WEIGHT/VELOCITY Ratio is your thing, get a Desert Eagle.

[diesel1959]

I tend to like to have more of the mass of the weapon IN my hand rather than ABOVE my hand. Most of us aren't as worried about recoil as we are with the muzzle flip that recoil, acting through a longer moment arm can create.

[Greg Bell]

Yes, the USP's muzzle filp is incredible. The gun nearly flies:45: out of my hand!

Just kidding. I am just saying this whole bore-axis debate is so overblown it is comical.

[Mark71]

Yes, the USP's muzzle filp is incredible. The gun nearly flies:45: out of my hand!

Just kidding. I am just saying this whole bore-axis debate is so overblown it is comical.

Greg I agree with you 100%. Its just another thing that the armchair commandos love to talk about.

[rwb_1969]

I find grip angle to be more relevent for me than bore axis. In that regard the only pistol that bothers me is my Glock 19. Good gun but due to its grip angle it does not point as naturally for me as an HK or SIG.

I can say I have never honestly taken note of a gun's bore axis. Just my .02.

[Scooter]

Bore axis, slide weight, and slide velocity does make a significant difference depending on what you are doing. The typical person that just goes to the range, it won't really matter. For competition shooters, it will make a difference. While competitions aren't won on splits, a good balance gun like a M&P allows you to drive the gun faster and with less effort than a USP.

USP's are soft shooting because the recoil is translated into muzzle flip. Where as the P7 can be considered almost violent because the recoil is translated straight back. Give those guns to a new shooter, it will be easier for a new shooter to shoot at a faster split without much effort.

[sfguard]

Greg I agree with you 100%. Its just another thing that the armchair commandos love to talk about.

While they are talking about it I am out shooting. Also, I will compete with my HK up against them and their Glock anyday.

[diesel1959]

Yes, the USP's muzzle filp is incredible. The gun nearly flies:45: out of my hand!

Just kidding. I am just saying this whole bore-axis debate is so overblown it is comical.

I don't disagree with you there. I'm still in the "find what fits your hand and you can shoot well" camp. Then go out and shoot the hell out of it.

[Sarge819]

I love this board......lol.....Greg, I dont know about you, but if my HK45 flips outta my hand one more time......

[bzinbv]

Scooter: The image you posted was interesting. The difference looks to be 3/8" to ½" I would be curious to see the same image comparing the HK45 with a USP. I don't compete with pistol, but I do take my practice seriously. I'm always interested in finding the best solution for my particular needs. If HK has made an improvement with respect to bore axis, I think that will be a good thing. All other things being equal, i.e. grip angle, lower should be better. Still it is all speculation until the HK45c gets to the range in MY hand.

[Moonshiner]

Bore axis can make a difference when shooting fast, no doubt. Is it a big deal? Depends on the shooter. I like P7's and 1911's. The sight nice and low in my hand, the gun points more naturally for me, and my timed splits are faster. It could also be the trigger, but I believe bore axis as related to the shooters grip is a factor. One of the design criteria Larry Vickers laid out for the new HK45 was a lower bore to grip axis than the USP. Don't believe me? Some one ask him...

[MakeMineA10mm]

My $.02 is that there are MANY factors that effect the shootability/handling of a pistol. To be fair, the only time bore axis was ever noticable to me was when shooting several pistols of the same caliber in the same session, right after one another. Even then, it's hard to sort out what amount of difference in perceived recoil and muzzle flip was played by: slide weight, bore axis, grip width, grip angle and overal gun weight. The all interact.

Take a Glock 21, single-stack 1911, HK45, USP, Sig 220, and a Caspian 1911 out sometime. Load them with 2 rounds of the same ammo out of the same box. Lay them on a table in front of you. Pick them up and shoot the two rounds and move to the next pistol as fast as you can. You'll feel a difference in overall controlability. It won't all have to do with bore axis, or any other one factor. But you will feel a difference.

That said, during a session like this was the ONLY time I ever noticed a difference. Most of the time, whatever handgun I pick up, I just shoot and don't worry about these minor variables... (Of course, this is all considering guns of the same caliber... I Wildey in 45 Win Mag I WILL pay more attention to controlling recoil and muzzle flip! :) )

[AviatorDave]

Bore axis isn't subjective. If you are not holding the gun as high up as possible, you aren't doing it correctly.

Here's a picture I posted a while back comparing a USP vs. S&W M&P. The picture has not been scaled. It simply overlay my grip on both guns as high up as possible.

http://www.parkcitiestactical.com/album/00000169/bore_height.jpg

Forgetting for the moment that I would never make a gun buying decision based on the bore axis, if that was important to me, isn't the pertinant mearusement the distance from the bore centerline and a given point on the shooter's hand?

If it is, it seems like in the superimposed photos, you'd want to overlay the hands perfectly on top of each other to get a true comparison of the bore axis in relation to the shooter's hand. So if the hands were more closely superimposed, the bore axes of the two guns shown would be much closer together.

Or am I missing something?

[bzinbv]

AviatorDave: I think bore axis is just one small item in a host of variables that go into selecting/purchasing a hand gun. What I see in the photo is the web of the hand pushed as high up each gun as feels right, and then using that intersection as a datum point. Since both guns are level, it seem to be a good indication of relative difference

[AviatorDave]

AviatorDave: I think bore axis is just one small item in a host of variables that go into selecting/purchasing a hand gun. What I see in the photo is the web of the hand pushed as high up each gun as feels right, and then using that intersection as a datum point. Since both guns are level, it seem to be a good indication of relitive differnce

Ah, ok. I see what you're saying. The web of the hand in each of the superimposed pics is at the same level, even though the thumb and other knuckles in the background are not.

See there, I was missing something. But it makes perfect sense now.

I wonder if this would be any softer with a lower bore axis? Yeah, I know it's an old video, but I love it. http://www.youtube.com/watch?v=CQJSZs-euZU :)

Thanks.

[Greg Bell]

http://www3.telus.net/textures/images/brando_apoc.jpg


The bore axis...the bore axis.

[Greg Bell]

Here is Bruce Gray on the subject..

I've heard this high bore axis argument endlessly from all sorts of other shooting experts, none of whom could outshoot me I reckon. That's not meant to reflect some arrogant ego, as that's honestly not my way; the fact is, those who could outshoot me knew better anyway. There wasn't enough of a shortage of them, unfortunately for me.

It's just that, those of us who've figured out what actually matters in shooting an iron sighted gun competitively in IPSC (yes, Open guns live by different physics)realize that muzzle flip doesn't mean much. All things equal, it matters some, but all things aren't equal between pistol types, or even calibers / power factors.

If you do the math and examine the bore axis of a P226 in relation to the shooter's wrists, versus other pistols, it's not too high at all. That's the first thing to realize, but that's not the whole story by a long shot.
As a general rule, lower bore axis means more lateral displacement of the sights when they return from recoil.

The P-7 M13 has the lowest bore axis possible, but it is relatively difficult to shoot at the highest level of competitive performance at high split speeds due to torque and lateral sight displacement. I know something about this, having put a couple hundred thousand rounds through them in both stock and modified versions back in the day. I still managed to win everything but the Nationals with them at one time or another, because I worked hard at it and did what I could to attenuate the harsh recoil impulse that carried the sights off alignment. We made long slides with integral compensators to slow down slide speed and make the guns flip HIGHER so they'd be more predictable.

There are so many other factors such as weight distribution, lockup values (or no lockup values at all, as with the P-7...), slide mass, springing and bore to grip angle and grip shape / hand contact area to consider. Singling out bore axis height as a qualifying attribute of a competitive pistol makes no sense at all.

Ever look at the bore axis of a S&W N-frame revolver? Pretty tall, huh?
Ever see the videos of Jerry Mickulek setting new world speed shooting records with one? Moses on a pogostick, that boy can shoot them things.
Bore axis doesn't mean sh!t to him.

True, some guns with high bore axes aren't easy to shoot, such as the HK USP series for example. These have a very high line, but that's not the real reason why they "flip like Chinese gymnasts on speed" as I once wrote.
(Sorry to seem self-reverent here.)

No, these things flip and buck inconsistently because of the ingeniously sinister recoil buffer guide rod mechanism the HK engineers built into the fullsize design to prevent frame damage and parts breakages. ALL spring loaded recoil buffers make a given pistol flip higher and return the sights less consistently.

Take the damn thig out, and the USP is a much snappier, but far more shootable pistol. And so I ran without one in Limited, and did pretty dang well. In Production, I ran the stock setup to comply with the rules, and had to work hard to keep in the A-zones at anything faster than .22 splits.

I still did well with them, however, winning a couple Area matches and placing 7th at the World Championships with a USP9F. The key was to not overshoot the guns' ability to return the sights between shots.

That's when the lightbulb went on in my little brain. I realized that shooting fast splits was irrelevant to winning in Production; fast transitions between targets is the whole game.

I realized that flip didn't matter, as long as i was shooting a pace that produced A-hits at any given distance; having the sights come back and STOP as quickly as possible did matter, since it was the appearance of the sights on the target that prompted my subconscious to fire the next shot.

Thus, a lower bore axis really only helps the hosemonster get away with coarse technique. The guy who squirts .15's on everything can't deal with high flip, yet he can't consistently score A's at that pace no matter what.

[softmentor]

Bore axis isn't subjective. If you are not holding the gun as high up as possible, you aren't doing it correctly.

Here's a picture I posted a while back comparing a USP vs. S&W M&P. The picture has not been scaled. It simply overlay my grip on both guns as high up as possible.

http://www.parkcitiestactical.com/album/00000169/bore_height.jpg

Not quite sure what I'm seeing here. Are the bores in the 2 photo's aligned with each other? Where are the bore lines in this picture? It doesn't look to me as though they are lined up?
confuseledded.
Arthur

[bnsutton]

Great find Greg. Thanks for sharing that with us. I agree with what Mr. Gray and you have said on this over hyped matter.

[AviatorDave]

Not quite sure what I'm seeing here. Are the bores in the 2 photo's aligned with each other? Where are the bore lines in this picture? It doesn't look to me as though they are lined up?
confuseledded.
Arthur

I was confused at first too, but bzinbv 'splained it to me - the part of the pictures that is lined up in each of the superimposed pic is the web of the hand between the thumb and forefinger. That is a good point of reference because the exact locations of the knuckles will be different on each gun depending on the grip angle, grip diameter, etc.

So in the pics - the back of the thumbs are aligned, and the barrels are not, so it's showing the difference in the bore axis distances from the same part of the hand.

See it now?

[Scooter]

As I said before, bore axis, slide mass, and slide velocity all play a factor. Bruce Gray's reference of Jerry Miculek being able to shoot a revolver with a high bore axis extremely fast doesn't factor in how much non-moving mass there is on the barrel and the barrel hangs way out there. Shoot a USP Match and most of the muzzle flip will be gone.

As for my picture, there's no way I can place both hands in exactly the same spot. The USP does have a safety, which my thumb rides on, so that grip will always be higher than a gun without a safety lever. The only thing that you can be consistant about is gripping the gun at the highest point. The web between your thumb and index finger is also where the forces of the recoil will be directed on your hand. The lower you grip the gun, the more muzzle flip you have.

The bore axis of the USP in the picture is roughly below the top for sights on the M&P but above the top of the slide. The bore on the M&P is in the center of the slide. The P7 bore axis is just slightly above the guide rod on the USP.

[softmentor]

As I said before, bore axis, slide mass, and slide velocity all play a factor. Bruce Gray's reference of Jerry Miculek being able to shoot a revolver with a high bore axis extremely fast doesn't factor in how much non-moving mass there is on the barrel and the barrel hangs way out there. Shoot a USP Match and most of the muzzle flip will be gone.

As for my picture, there's no way I can place both hands in exactly the same spot. The USP does have a safety, which my thumb rides on, so that grip will always be higher than a gun without a safety lever. The only thing that you can be consistant about is gripping the gun at the highest point. The web between your thumb and index finger is also where the forces of the recoil will be directed on your hand. The lower you grip the gun, the more muzzle flip you have.

The bore axis of the USP in the picture is roughly below the top for sights on the M&P but above the top of the slide. The bore on the M&P is in the center of the slide. The P7 bore axis is just slightly above the guide rod on the USP.

got it now, thanks! that is quite a difference. I come back to my earlier thought. It seems that many people who are familiar with and shoot other guns, when they shoot an HK, they remark about the softer recoil, so, it would seen that there are trade offs. That would also seem to agree with Gray. Makes sense.