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Boberg XR9-S vs Kahr PM9 cronagraph results.

Discussion in 'Handguns: Autoloaders' started by LightningMan, Sep 30, 2012.

  1. LightningMan

    LightningMan Well-Known Member

    UPDATE: Hello, Decided to post this seperate anyway rather than leave it attached to the Boberg XR9-S post. I went to the range today with my Boberg XR9-S & my Kahr PM9 as these pistols are very similar in size. The perpose was to do some tests with my cronograph. These will not be actual dimentions but they are what I get with my calipers.
    Kahr; width, .893" (without slide lever-lock) width .980" (with lever).
    Boberg; width, .960". (lever is within the frame width)
    Kahr; height, 4.200" (includes sights).
    Boberg; height, 4.240" (includes sights).
    Kahr; lenght, 5.530".
    Boberg; lenght, 5.110".
    Kahr; barrel lenght, 2.800".
    Boberg; barrel lenght, 3.187".
    Now to my test results, I used Win. brass, & primers. Powder was Win. 231 using 4.3 grs. Bullet was 115 gr. Rainier plated RN. OAL 1.130"
    (Note: I had to shoot the XR9-S loading rounds 1 at a time, as I have had plated bullets come apart, this was to avoid that problem.)
    Kahr PM9
    1). 909 fps.
    2). 886 fps.
    3). 916 fps.
    4). 903 fps.
    5). 887 fps.
    6). 902 fps.
    7). 914 fps.
    8). 927 fps.
    9). 869 fps.
    10). 903 fps.
    Average; 901.6 fps.
    Boberg XR9-S
    1). 944 fps.
    2). 968 fps.
    3). 954 fps.
    4). 971 fps.
    5). 995 fps.
    6). 918 fps.
    7). 969 fps.
    8). 919 fps.
    9). 965 fps.
    10). 935 fps.
    Average; 953.8 fps.
    Difference of 52.2 fps.
    Note; I did check the average throwing out the high/low readings but it didn't make much difference. (902.5 fps. for the PM9 & 953.1 for XR9-S)
    These were my results, yours may vary. LM
    Last edited: Oct 1, 2012
  2. Girodin

    Girodin Well-Known Member

    Interesting, pretty negligible difference, not surprising for the very small barrel length difference. I would be interested to see numbers for the CM9 as well as one would expect the polygonal rifling of the PM9 to offer slightly higher velocities. I'd imagine there is still very little difference.
  3. JellyJar

    JellyJar Well-Known Member

    According to my calculations it was just an aprox 5.8% improvement.

    Have you tried any factory ammo?
  4. DAdams

    DAdams Well-Known Member

    You going to try a Plus P comparison?

    I put the first 72 rounds through my Boberg. The only issue I had was my inability to just slingshot the first round in.

    I actually ran the same ammo through my PM9, 24 rounds.

    All ran without issue. I liked the feel of the Fiochi 123 grain over the Winchester, Remington, and American Eagle.
  5. wow6599

    wow6599 Well-Known Member

    What was your OAL? The charge seems fine, but the velocities seems a little slow.
  6. oneounceload

    oneounceload member

    Compared to what? Published velocities from a 4" test barrel? I expected the differences to be greater - at least according to Boberg's site, there is to be an expected 25% increase n muzzle energy, so corresponding velocities should be greater

    They also list the barrel as 3.35"
  7. wow6599

    wow6599 Well-Known Member

    My mind was just wondering.....

    I don't know.... I went back and looked at some old loads.....and then on to loaddata.com. I guess that a 902 fps average with 115 grain bullet over 4.3 grs. of 231 from a PM9 might be on the money. I was just thinking it would be closer to 1000 fps.

    I found one load from a 4" barrel using 4.9 grs. of 231 and 115 gr. bullets (XTP) and getting 1253 fps.
  8. k_dawg

    k_dawg Well-Known Member

    Well, do not forget that the 'Marketing hype' also includes Mr Boberg comparing regular ammo in the 'other' gun, and +P in his.

    I find that misleading, especially it is conflating two seperate issues: barrel length versus cartridge differences.

    Since it appears you were firing the same ammo in both, that explains ~10-15% of the 'non difference'.
  9. StrikeFire83

    StrikeFire83 Well-Known Member

    Honestly, I hate to admit this because I've been following it since 2008, but the Boberg XR9 is all sizzle and no steak.
  10. LightningMan

    LightningMan Well-Known Member

    wow6599Quote; What was your OAL? The charge seems fine, but the velocities seems a little slow.
    It was 1.130" Yes it may seem a bit slow, but I was being cautious as I hadn't used Win 231 untill lately, and these were what I thought would be a good start point. I have sence bumped up the charge to 4.5 gr. FYI, If I do some more tests I will post them, but it may be a few weeks as I won't make it to the range till then. LM
  11. Billy Shears

    Billy Shears Well-Known Member

    This is not really a fair statement. The XR9 was originally intended to be offered with a longer barrel -- over four inches. It ended up being offered with much shorter barrel -- not much longer than that on most subcompact handguns -- after people right here on this website started clamoring for the shorter barreled version that is being offered now. So, Mr. Boberg took a poll, and this is what the majority of potential customers said they wanted. This resulted in a gun that's not all that much smaller than a conventional compact 9mm of conventional design, while also negating the principle advantage of the gun, and it's main selling point: the ability to have the barrel length (and thus the velocity) of a full size handgun, packaged in the overall dimensions of a compact handgun.

    Of course the XR9-S doesn't have velocity figures all that much higher than other compact 9s -- it doesn't have a barrel all that much longer than other compact 9s. What did you expect? When Boberg introduces the XR9-L with the 4+ inch barrel (which his website says might be as early as January of next year), then you will see notably higher velocities, because then, finally, you will have the barrel length of a full size gun, in the overall size of a compact 9. That's what I've wanted all along. It's why I didn't bother with the XR9-S. I want the XR9-L.
  12. StrikeFire83

    StrikeFire83 Well-Known Member

    ^I really wanted to like this gun. I like Arnie and wish him the best. But it just seems to be a solution to a problem that doesn't exist. Add to that the expense and the reliability issues that this weapon has experienced, and I'm just not interested. Apparently he's selling them as fast as he can make them, and that's all that matters.
  13. Billy Shears

    Billy Shears Well-Known Member

    I've heard those same words "solution to a problem that doesn't exist" used to describe traditional DA autos, DA only autos, piston AR's, etc. -- the list is endless. Just because some people are happy with existing tools doesn't mean there isn't room for improvement.

    Name a brand new gun without them. All new designs have bugs to be worked out. If the AR-15, with enormously greater amounts of development, and huge government contracts, for example still had major shortcomings before it settled down to be a reliable design, why do you somehow expect it to be any different from a small company just starting up and introducing its first product?

    In a world where firearms designers have been mostly copying John Browning for the last hundred years, I don't think it's a good thing to discourage someone who comes along with something truly different and innovative. I for one think it's nice to see an American firearms company start up and offer something other than yet another iteration of the M1911 or the AR-15 (even though I own and love both designs).
  14. Jim Watson

    Jim Watson Well-Known Member

    I am with Billy.
    I am fascinated with the design and await the introduction of the -L.
    Even the -S is marginal for pocket carry and if I am going to wear a holster, I want to get something for my trouble.

    I don't understand why the OP did his chronographing with a reload he knew for sure would not work in the gun. I'd have squandered some factory loads, preferably a good hollowpoint carry load.
  15. LightningMan

    LightningMan Well-Known Member

    JimWatson Quote; I don't understand why the OP did his chronographing with a reload he knew for sure would not work in the gun. I'd have squandered some factory loads, preferably a good hollowpoint carry load. Jim, I had originally planned to use some factory ammo, but the day I had arrived at the range to do the tests, was being used for a match that day, so I blew it off. So when I went to the range the day I did the test, was a spur of the moment, because I forgot I still had the crony in the trunk. By then the only ammo I had that would be do-able was those reloads. I really want to try some factory ammo tests, as I have some Speer GoldDots 124 gr. +P ammo I want to try. As I said next time I get the chance. LM
  16. Billy Shears

    Billy Shears Well-Known Member

    My sentiments exactly. I'm not a fan of pocket carry, and don't practice it. I find it easier and more comfortable to wear a concealable holster, not to mention finding it easier and faster to deploy the weapon. I was not pleased when a majority demanded the shorter length S version; it seemed to me, as I said, like giving up the weapon's major advantage for not all that much reduction in size. Every gun is a balance of characteristics, but the ultra-snub-nosed XR9-S got the balance just a bit wrong for my taste.

    It's driven by the hugely increased market for concealed carry that's sprung up in the last couple of decades as shall-issue laws have become more widespread, but I think a great many shooters are a little bit too enamored of having the absolutely smallest and lightest guns they can lay their hands on, while still firing potent calibers. The result has been weapons that are beasts to shoot, and often seem to have reliability issues -- it's just not as easy to make an ultra small, compact, yet powerful gun work as reliably. Too small slides don't have the inertia to resist overly abrupt openings, and even the double captive recoil springs don't always rectify the problem. Ultra small, ultra light revolvers, firing full power cartridges aren't immune from reliability problems either: featherweight revolvers firing such cartridges can have recoil so sharp and snappy that bullets pulling out of the cases can become a problem, and creep forward enough to jam the cylinder and keep it from rotating. Interestingly, one of the reliability problems that is plaguing the XR9 is similar bullet pull-out, since the cartridges get yanked backward out of the magazine instead of being pushed up a feed ramp. Again, the ultra-compact slide ends up having less mass, and therefore less inertia to resist an overly abrupt opening, with the result that bullets that don't have enough crimp get yanked right out of the case. The XR9-L, with the longer barrel and slide, should see this problem greatly reduced.

    I've seen the computer renderings on Boberg's site for the XR9-L, which will have a 4.4 inch barrel, and longer slide (and may be offered in versions both with and without a rail), and for which he also plans to offer an extended magazine (with a boot around the base of the magazine to extend the grip). This, to me, would get the balance just about exactly right for a concealed carry weapon: a pistol with similar overall dimensions to a Walther PP, but capable of firing 9mm +P rounds, with a single column magazine holding 8 rounds, and a barrel length basically the same as a full-size Glock 17, and which one could carry with the shorter magazine, without the grip extension, when more concealability is called for.
    Last edited: Oct 1, 2012
  17. StrikeFire83

    StrikeFire83 Well-Known Member

    Honestly, I don't see improvement. I see difference. Different doesn't mean better. I see this gun as the Wankel rotary engine of the gun world: Something that is more complicated than what came before which offers few benefits at significant additional cost and complexity.

    I don't expect anything to be different, I just don't want to pay over $1,000 to be a beta tester. If you do, more power to ya. Free market and all that jazz.

    I'm not discouraging anything. Look at my posts. I'm really rooting for Arnie and hope his idea and company succeed. But I'm not a fanboy or a true believer. The Boberg XR9-S costs almost as much as two and a half Kahr CM9's and, frankly, can't do ANYTHING better than the Kahr. The only reasons to buy a Boberg right now: 1) It's interesting. 2) It's exclusive. I'm not telling anybody how to spend their money...I'm not a Democrat. I've purchased things for those reasons myself. But until/unless Arnie can address the reliability/cost/benefit issues with his design, these guns will remain nothing more than a mail order curiosity.
  18. Billy Shears

    Billy Shears Well-Known Member

    Actually, the Wankel is a lot simpler than a piston engine, with far fewer moving parts (no valves or complex valve trains; no connecting rods or crankshaft, etc.; plus the elimination of reciprocating mass means less vibration [with attendant wear and tear], smoother flow of power, and a much higher power-to-weight ratio -- the reason they haven't caught on is the design has an inherently less efficient shape for the combustion chamber, which results in more unburned fuel, leading to less than ideal fuel economy, and makes it harder to make Wankel engines comply with emissions regulations.). And a lot of the additional cost of the Boberg is simply a matter of its being new and low volume in production, not to any inherent complexity of the design. If Boberg can establish his company well enough to greatly increase production, economy of scale will kick in, and per-unit cost will go down.

    Somebody's got to do it, if he's to establish a toehold in the marketplace. But in point of fact, I didn't, when the initial pistol became the shorty version. I'm holding out for the original concept with the longer barrel.

    You'll have to excuse me, but it doesn't sound at all that way when you dismiss the gun as "all sizzle and no steak."

    It can if he can get it to run reliably. The last Kahr I bought could not be made to run right after two trips back to the factory, and the local gun shop where I live has stopped carrying them, they've had so many complaints from owners with the same problems.

    I sort of agree about the XR9-S. I disagree about the XR9-L, for reasons I explained in my last post.

    Give him the time to do it before dismissing his product as a non-starter. With a brand new design, do radically different from other pistols, it was inevitable that there would be bugs. From all I've heard, he's bending over backward to offer good customer service and address any issues with pistols he's already sold. That bodes well, and should help him zero in on whatever bugs remain in the design, and eliminate them in subsequent production.
    Last edited: Oct 2, 2012
  19. StrikeFire83

    StrikeFire83 Well-Known Member

    Well, I hope you're right. I hope his business grows and flourishes and that he eventually releases the XR9-L and that you buy one and enjoy it. Another American gun company making firearms right here in the USA is a good thing.

    However, I can't agree with you about Kahr. My PM9 was excellent. 3K rounds with only 1 malfunction within the "break in" period.
  20. OcelotZ3

    OcelotZ3 Well-Known Member

    I wanted the longer version but got on the list for the shorter version.

    I'm very glad I did.

    The gun is very different, very nice to shoot, interesting, and small. It's more than I thought it would be, and it was <$1000 (contrary to what was said in a previous posting).

    I'll be buying the full size version when it becomes available.

    Friends who have shot it say the same thing. Not a bad thing to say so far.

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