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Discussion Starter #1
ive heard p7's dont like 147gr. i would like to know why this is. i have 220rds of speer gold dot +p, but if these wont work well... id need to go with something else, for both testing out the ammo in gun, and Self Defence purposes. I found a farily good deal on 500rds of Federal 9BPLE 115gr +P+. any of you guys have experience with this stuff? ive never shot +P+, but i heard its fun as hell, and very accurate. i would like to double check, and tripple check, if this stuff will work well in a p7m8, and if the gun will actually be able to take a couple hundred rounds in a row. or am i risking such a old beautiful expensive gun shooting that kind of ammo with? i have not yet shot my p7, that is this comming sunday to a desert trip with some buddies.
 

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Skip that thread, read this earlier post on the subj.
G3Kurz

This is not an uncommon stoppage with 147 grain ammo in the P7M8 or P7 PSP. These stoppages are called "nosing up" and are in fact failures to feed. They are caused by "over function", too much recoil impulse to the slide. Let me guess. These stoppages occur on the last or 2nd last round? If so what is happening is that the heavy 147 grain bullet is imparting excessive recoil energy to the slide (the P7 was designed for 124 grain NATO ammo). When it does so it increases the slide velocity rearward. This causes the slide to strike the frame at its most rearward position harder than normal. When it does the top round slides slightly forward in the magazine (due to less upward pressure on the round under the feed lips towards the end of the magazine). When the slides comes forward again at higher than normal speeds and strikes that partially fed round the round “jumps” out of the magazine rather than being pushed forward by the slide under controlled feed as designed. It then often ends up sticking up and out of the ejection port or impacts on the top of the chamber when the slide comes to rest out of battery. This problem is increased when the piston is worn and there is thus less braking effect in the gas retardation system. It is also made worse by weak magazine springs. Likely the reason others here do not report the problems with 147 grain ammo is related to the state of their mag springs and piston, the specific ammo characteristics (not all 147’s are the same) or they shoot P7M13’s where this problem is less likely to occur.

So how do you fix this? Don't shoot 147 grain ammo. 115-124 is best and +P or +P+ is okay (US +P+ is @ NATO spec). It is the excessive bullet weight that causes the issue. This is why the .40 S&W P7M10 has such a massive slide, to slow down the slide velocity. Or try replacing your magazine springs and/or piston. HK makes a little go/no go gauge for the piston. Send it in and have HK check it out. This does not happen in the P7M13 because the magazine springs are stronger and the feed lips are longer. Newer P7M8 magazines (after @ 1990) have longer feed lips like those of the P7M13 to help reduce this. They are marked with a date code but I do not recall what that was. If you keep you P7M8 magazines fully loaded I would replace them every 5 years or less and leave the magazine down loaded by one round (7 versus 8) regardless of the ammunition used. That will extend the life of the springs considerably and thus insure the best reliability. Cheap life insurance.

Always remember to clean the gas cylinder with the brass bristle brush AND the metal tool provided after each firing. If you don’t have the tool, contact HK to get one. NEVER clean the piston with metal brushes (nylon brush and solvent only). Also never shoot lead bullets in a P7. Small particles of lead get shaved off and melted and build up in the back of the gas cylinder. In time that accumulation may cause the piston to stick to the lead build up in the cylinder and impair the free movement of the slide.

Good luck.

G3Kurz
 

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Discussion Starter #4
i read that +P was around 36000, nato was 38000, and +P+ was 40-42000, in several different post while googling
 

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Discussion Starter #5
also i would like to know, if its okay to use wolf ammo in my p7m8, i had some given to me, if its okay to use id like to get rid of them lol
 

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Thanks for posting that G3Kurz. I like the part about cleaning after every time you shoot. I grew up doing that. Just seems wrong to not clean my firearm after I shoot it.
 

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Thank you for the post G3Kurz.
I referred to your posts in the past when deciding what ammo to use in my P7.
I appreciate the knowledge transfer and your time.
 

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Here is another slight variation on the subj also from an earlier post.

G3Kurz

The 147 grain 9mm rounds, due to their increased projectile weight, increase the slide velocities of the P7 beyond what the weapon was designed - for 115-124 grain NATO ammo. The first 147’s were developed for suppressed use by the Navy in sub guns and conventional recoil-operated handguns. What occurs in the gas-retarded P7 platform when firing 147 grain ammo is that the P7 slide moves rearward faster than normal when firing these heavy bullets and impacts harder on the frame at full travel. On the last round or two in the mag, those rounds are under less spring tension in the magazine then under full 8-round load, they can then slide (be bumped in fact) slightly forward out from underneath the feed lips BEFORE the slide comes forward for what is normally controlled feed (gradual push). When the slide, now also coming forward faster than usual, strikes the base of the mispositioned round it can "jump" out from under the feed lips and usually ends up sticking out of the ejection port at 12 o'clock bullet tip up - a la "nosing up", a term coined by the German techs when this problem first became apparent on P7M8's with the New Jersey State Police in the late 1980’s.

Nosing ups are not uncommon when heavy ammo is used, pistons are worn, mag springs are weak, or a slight combination of all of the above. They are less common in the P7M13 because the feed lips are slightly longer on M13 mags. Later P7M8 magazines (no I no longer have the date code - sorry) had the length of the feed lips increased to that of the M13 mags as an additional safety margin. If you stay away from 147's and don't overclean your piston as described above you should never see a nosing up stoppage regardless of which style M8 magazine you may have/use. If you do, you'll now know what to look for. If you shoot 147’s in your M8 and have not seen this you’re lucky.

As a safety margin I down load my mags by one round and replace my concealed carry magazine springs every 5 years – good insurance. In over 100K rounds fired I have only seen a single stoppage in a P7M8 that was not ammo related.

Incidentally P7/PSP magazine were never made with the longer feed lips to my knowledge.

G3Kurz
 
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