Ammo selction -- a point of diminishing returns?

[CarlCyrus]

Have an MK9 that eats about anything I throw into it, and a PM9 that just doesn't like anything heavier than 115gr without throwing the old "slide-lock" problem.

Have started down the road of obtaining a new slide-lock for the PM9 and then slowly trimming the length of the nub on that piece back so it doesn't bump on 124gr bullets. So I buy expensive ammo, trim the nub, shoot the ammo, buy some more, trim the nub some more, etc.

Just how much better is a 124gr HP PD round over a 115gr HP PD round? Am I at the point of diminishing returns? I could spend a bundle of money on high-performance ammo to tweak this new gun, but maybe those 115gr HP PD rounds are "good enough."

Have always been a believer in the motto that "perfect is the enemy of good enough."

I know that some will say...well if you are defending your life, you want "perfect" and some will say...well a 9mm 115gr HP PD round is better than any .380 PD round, so be happy.

Don't want to start a fight here, but I'd like to know how the Kahr community here feels about this buy, tweak, shoot, buy, tweak, shoot cycle.

Carl

[jocko]

just file the nub down and then reinsert a loaded magazine with those 124 grain with the slide off and see if it hits. U should not have to test fire every time. If u can visually see it clears, then stop with the filing and retest at the range. Kahrs are not ammo sensitive. rthey willshoot anything up to 147 grain, certainlyt 124 gran for sure, as that is what kahr uses to test fire their guns.

This is not a pandemic thing Carl, so if you have a new slide stop coming in just wait on it and see if that solves your issue. I had to have 3 slide stops replaced in my Para Carry 9 before that issue went away. To me not worth making a big issue out of it IMO. It is very evident that they have some out of spec slide stop levers.

[jlottmc]

Let me see if I can frame this a little better. The trim is worth doing, and tuning, if for no other reason than you can then go to a store and not have to worry about what weight or profile your feeding it. There are times when that would be a concern, for example, you are in a strange town, and selection is limited kind of thing. Better to be able to sling it all than be out of luck because they only have some old surplus or something else that is not your brand. Just my 2.

[OldLincoln]

This is just my opinion here, but I fretted over the same issues and came to some conclusions. A 9mm is definitely better than a 380 but less than a 40 and above (see Hickock45 Knock-Down power? video).

When considering your mission is to stop an aggressor, not make him eventually bleed to death, you want a bullet that will bust him up deep inside which means penetrating through clothes and meat/bones.

The stuff I've read indicates a heavier bullet does that better than a light one, so I opted for 147gn and pushed it with +P ammo. Also the bigger the hole the more damage so I opted for Federal HST. I know it will never be a 45, but I try to make it like a 45 light. Others argue for lighter faster and that's fine. I did my homework and resolved to bet my life on my choice. Ultimately you have to do the same.

As for you 9mm not liking larger bullets, mine is a PM9 and didn't initially like HST. I found I needed to tamper with the mag lips & polish the feed ramp and it takes them just fine mow. The long story re mag lips is in this thread. I'll caution you to take it easy should you decide to take modification on, but even if not you can see what you have.

[CarlCyrus]

I'm going to check the mag lips tonight. If the rounds can wobble left to right, then when they wobble left, they can touch the slide-stop. This slide-lock problem may be a combination of two issues, rounds that can wobble left and right in the magazine and an out-of-spec slide-lock.

Carl

[jocko]

one can push that top round right or left, but some reason it seems to work out OK when in the gun. Kahr magazines work differently than most as the kahr mag top round is more exposed. That being said, THEY WORK, so if you feel that is the problem return the magazines for new ones. I can move left or right my PM9 mag top round but again it works perfect in the gun. Muy point is that one can maybe produce an issues that in reality is not an issue. Magazines can be bad, send um back, try a new slide stop lever first . Unless one is very skilled in doing mods. I would shy away from bending any mag lips etc, For sure then u lost all magazine replacement warranty.

[Bill K]

Hi,

I'm one of the other new PM9 Kahr owners with the same problem. Ideally I'd like to shoot the same Black Hills 124 +P that I've been doing for years with my Glock 26. On talking to Kahr about the problem I was having I was told not to shoot Black Hills. Tomorrow I hope to get out and shoot some of my RWS 124 grain standard pressure ball ammo. If this ammo gives me the same premature slide lock problem I'll be calling Kahr for further resolution. If it fires without issue then I'll buy some other 124 +P and see how the PM9 performs. I'll take it a step at a time and if I have to I'll switch ammo. I'd rather it be a slide lever release problem than an ammo sensitivity problem with my particular PM9.

BTW, I'm in no way upset. I've got other carry guns and just view this as another one of life's learning experiences. :19:

Bill K.

[Jeff00042]

Jocko's suggestion of gradually filing the nub on the slide stop worked well for me. Even when the nub slightly touched the 124 gr. bullets, the PM9 worked as it should. As to your original question about bullet weight, I prefer 115 gr. rounds. My favorite load is the relatively inexpensive, standard pressure Federal Classic 9bp round. Recoil is mild and they are also the most accurate in all of my pistols. Foremost, they are the most reliable hollowpoints I've found. This is #1 for me. I suspect bullet placement may be more significant than the differences between the various 9mm loads.

[Dietrich]

I`ve never had any problems with my PM9 regardless of bullet weight and type.For self defense I usually carry 124 gr,+P Gold Dots or Golden Sabers.I`ve also carried Winchester Ranger 147 gr.T-Series and Win.124 gr.Bonded JHP in +P.In all of my modest and totally unscientific testing these rounds all performed well and were consistent in expansion.But that can also be said about a lot of 115 gr. JHP ammo as well.I don`t want to get shot with any of it.I believe that most of the good brand name ammo for 9mm self defense will take the taste out of most anyone`s mouth with a well placed shot.If you have to shoot, then shoot until they stop moving or catch on fire.Regardless of caliber or bullet weight.

[CarlCyrus]

just file the nub down and then reinsert a loaded magazine with those 124 grain with the slide off and see if it hits. U should not have to test fire every time. If u can visually see it clears, then stop with the filing and retest at the range. Kahrs are not ammo sensitive. rthey willshoot anything up to 147 grain, certainlyt 124 gran for sure, as that is what kahr uses to test fire their guns.

This is not a pandemic thing Carl, so if you have a new slide stop coming in just wait on it and see if that solves your issue. I had to have 3 slide stops replaced in my Para Carry 9 before that issue went away. To me not worth making a big issue out of it IMO. It is very evident that they have some out of spec slide stop levers.

jocko,

I'm going to continue to file, buy, shoot, file, buy, shoot...until I have it right. I happen to have the mechanical background and the money to file the nub and keep buying expensive ammo until it is right. I can do this until the cows come home...but can the average "Joe Six Pack" do it?

The question I asked was, it is worth it? Is it better to declare victory on 115gr HP PD rounds and move on?

Carl

[Jeff00042]

Your question: "Just how much better is a 124gr HP PD round over a 115gr HP PD round? Am I at the point of diminishing returns? I could spend a bundle of money on high-performance ammo to tweak this new gun, but maybe those 115gr HP PD rounds are "good enough."

From my perspective, this is a personal preference/opinion issue. Your call.

[CJB]

Joe Six Pack would either send the gun back to Kahr, or have his local smithy apply tweakage.

Back in the day... when building or rebuilding a 1911 based gun, you'd get your "Kings Gun Works" extended slide stop, and extended safety, and have to fit EVERYTHING. It was made oversize all over - even pin diameter. Truth is, they were made horribly, but had enough extra meat so you could take your time and get things fitted ok. You'd even have to fit the "gap" between the slide stop's catch and the slide, width of the slot.. just everything. It was part of the way things were done, sort of like your parents walking to school five miles up hill each way.<grins>

Its ok to be overly exacting and very self demanding when you're dealing with something you feel very passionately about. Been there, still there... dont talk to me about Sportster top ends! Also gotta realize that Joe S. Pack doesn't always share the passion, and just wants it to work, and usually cant be bothered to even learn why its not working. He passes the problem to someone who gets paid to solve it.

[redjak]

The question I asked was, it is worth it? Is it better to declare victory on 115gr HP PD rounds and move on?

Carl

IMO, it is not worth it for civilian carry. According to http://www.goldenloki.com/ammo/gel/9mm/gel9.htm Corbon 115 gr +p penetrated 17.1 inches in ballistic gelatin, and all rounds expanded, when fired from a Kel-Tec P11. I think you will do as well with your PM9.

Now, if you tell me you are in law enforcement, and need to shoot through car doors, then I think you should stick to the heaviest grain +p 9mm bullets available.

Peace.

[Goffman]

If you take a look at the poll at the top of this thread, you'll see that you're in good company with the 115 grain round (about 26% of respondents).

http://kahrtalk.com/showthread.php?t=5444