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Discussion Starter #1
MP5 have the same problems the higher calibers like the 308 have with the"bolt gap"?

Last year i was going to get a ptr91 308 but found out there's alot of wear on the rollers and "bolt gap" after so much use. do the mp5 have the same problems?
 

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All guns wear with usage, the HKs have a field adjustment unlike ARs and similar where you have to for the most part toss the barrel if a new bolt will not bring it in line.
You will find a good MP5 will, like all guns, have wear (in this case to the rollers, locking piece, bolt head and chamber/trunnion) you might have to change a $5 pair of rollers after spending the cost of a three bedroom house on ammo ;-).

Note Bolt gap is a measurement as as such it changes not wears.
 

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Discussion Starter #3
oh come on, but i see these guys shoot like 10,000 rounds with their full auto mp5's. I would think a semi auto would last forever. So whats a good bolt gap for a mp5? I was SO close to getting my first HK and it was a 308 but luckly someone stopped me and told me to ask the guy about the bolt gap and it was still in tolerance but just on the edge. So i figured it only had a few years left of life before i would need to do something about it. I read that bolt gap has more to do with the gun accuracy. with a smaller caliber bullet i wouldnt think the gun would be that far off shooting from 25 - 75 yards. So would bolt gap really be a factor? am i over reacting?
 

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oh come on, but i see these guys shoot like 10,000 rounds with their full auto mp5's. I would think a semi auto would last forever. So whats a good bolt gap for a mp5? I was SO close to getting my first HK and it was a 308 but luckly someone stopped me and told me to ask the guy about the bolt gap and it was still in tolerance but just on the edge. So i figured it only had a few years left of life before i would need to do something about it. I read that bolt gap has more to do with the gun accuracy. with a smaller caliber bullet i wouldnt think the gun would be that far off shooting from 25 - 75 yards. So would bolt gap really be a factor? am i over reacting?
Bolt gap has nothing to do with accuracy and everything to do with keeping the gun together. Small bolt gap will cause accelerated wear on the other parts of the gun including the bolt group and trunion.
 

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Discussion Starter #5
oh, i thought with more of a gap on the bolt the more the bolt would slam back into place making follow up shoots more inaccurate. I figured the more wear would happen as a bi-produce of that happening. So do that problem happen in mp5 too?
 

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Bottom line is if you shoot any rifle enough it will need adjustment or replacement of the rifle, in particle if the builder made mistakes in material and/or construction. Case in point several years ago I was looking for reasonable accurate scopes bolt action rifle and tried another Spring Field Armory M1A but had issues (have had 13 SA firearms and none could ever shoot 200 rounds with out failing due to soft materials, design / parts tolerance etc. even after trips back or to a smith), an Armslite AR10 (was during the era when they had rough chambers and the hammer failed, it is gone now also), a DSA medium heavy barreled FAL (worked great for a friend but extractor and spring had to be changed once, it is still around but did not get scoped yet) and an HK91 (had to clean it once after shooting a lot in cold weather .... its still around 30 years later). Of all the rifles the HK 91 shot the best, the DSA FAL is close but has not been scoped (late in the cycle) and the other two (plus several other M1As since ... all which failed) did not group as well and thus are long gone. For accurate scope rifle shooting, have moved back to bolt guns, where anything much over 3/8 inch MOA is broke (PSS and TRG42 being favorites along with friends DTs)

I have 30 thousand plus rounds through one SP89 (MP5K-PDW) on full and not even close to having to change a roller, figure at this rate it will be several hundred thousand rounds, before have to change to the next over sized rollers. Friends have tens of thousands of rounds through 308 HKs, which were shot hard to the point of melting the silver solder (not failure just little balls ... and was on semi ;-) with out changing rollers yet, once they do need to change rollers one can get over size rollers in several different increase sizes, then changed the locking piece and and lastly change the barrel or set it back if the rifling is still good and start the process over again. Some of the hammer forged barrels have had a very good life in the rifle calibers, so the story goes.

If a clone is built with the wrong bolt gap to start or another issue due to incorrect construction, then one can have issues, but that is true with any firearm system (reference my issues with SA and Armalite). Looks like you need to do a little more research on what bolt gap is, on going issues and corrective actions, before writing off a system or possible you just stopped by for the debate and increasing posting count ;-). For reading would get the Book Full Circle and do some searches here.

PTR Construction Issues
http://www.hkpro.com/forum/hk-clone...012-another-ptr-91f-diminishing-bolt-gap.html
http://www.hkpro.com/forum/hk-clone-talk/153650-new-ptr-91f-breaking-bolt-gap.html
http://www.hkpro.com/forum/hk-clone-talk/145901-newbie-ptr-91-problem.html

Century C93 Construction Issues
http://www.hkpro.com/forum/hk-clone-talk/155759-question-c93-bolt-gap.html
http://www.hkpro.com/forum/hk-clone-talk/149693-century-c93-bolt-gap-what-do.html
http://www.hkpro.com/forum/hk-clone...-back-ghillie-but-looks-good-before-hand.html


If you get a German HK94 or one of the high end "MP5" clones from some of the regulars you should be all set to go. The issues with bolt gap is more of an issue with the clone builder than a "design issue"
 

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Discussion Starter #7
i wasn't debating you, i was agreeing with you adding that i thought the accuracy was the main problem. I was wrong. I put off getting the rifle because i was affraid of someone lying when i questioned them online and selling me a bad one. I was over sea at the time and really wanted to order one before i got back. i found about this known issue while away. I caught a better deal on a dpms 308 so i figured why take the chance and brought that. I figured at the worst i would need to either fix the lower or upper receiver if there was a problem and would be cheaper.

and about post, type in "skittlekiller" on google and see what you get. That's all me from multiple forums. Forums is how i spend my time off so i post because i enjoy it, not for count...

thanks for some useful info though.
 

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Bolt gap can, in theory have an affect on accuracy in that an extremely large bolt-gap can cause the bolt to unlock before the bullet leaves the muzzle. That, in theory, could cause enough movement to throw off the point of aim before the bullet clears. While unlikely, it could happen.
 

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Bolt gap can, in theory have an affect on accuracy in that an extremely large bolt-gap can cause the bolt to unlock before the bullet leaves the muzzle. That, in theory, could cause enough movement to throw off the point of aim before the bullet clears. While unlikely, it could happen.
One would also ascertain that if the chamber pressures had not dropped to an acceptable level, accuracy wouldn't be what I was worried about. Especially not in .308. Ouch.
 

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i wasn't debating you, i was agreeing with you adding that i thought the accuracy was the main problem. I was wrong. I put off getting the rifle because i was affraid of someone lying when i questioned them online and selling me a bad one. I was over sea at the time and really wanted to order one before i got back. i found about this known issue while away. I caught a better deal on a dpms 308 so i figured why take the chance and brought that. I figured at the worst i would need to either fix the lower or upper receiver if there was a problem and would be cheaper.

and about post, type in "skittlekiller" on google and see what you get. That's all me from multiple forums. Forums is how i spend my time off so i post because i enjoy it, not for count...

thanks for some useful info though.
Is a good discussion, my primary point being the Bolt gap changing is a builders issues more than an "HK design" issue. Thus while some builders have issues (damage / cracking trunnions, turned down barrels etc), an actual German HK build or a good clone builder should not have issues. Sounds like if the DPMS works and the PTR91 was suspected, you made a good call. I just picked up a SAR8 (stamped built on German equipment) for $800 out the door, for my sear host gun (i.e. 922r compliant with the thumb hole stock and can ad a A3 folder with the sear installed, per my understanding ... beside not that many non US parts if don't have a semi pack ;-)

Some of the forums require a minim posting count (25 to 100+) to sell items and ever so often see some of the "new to the forum" guys stopping by and discussing topics... always glad to help get the post counts up on interesting topics (you might find one or two posts by JTinIN in Google) besides someone had to reply to my posts for the last 10 years here.

Take Care
 
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