Thread: Heckler & Koch SP5 (MP5A3)

Originally Posted by Joe Bob Briggs

How many high round count POF MP5s have you handled? And what failures did you see on the HK rifles? Most breakdowns of roller delay guns are due to extractor springs, magazines, and bolt gap.

About half a dozen POF's, all of which never gave any problems and are still going. Rifle problems are fractured receiver covers, fractured bolts, fractured rollers, fractured return spring arms (rimfire semi-autos), fractured pins, burred out trunnions, etc, as well as all the other problems you mentioned. A good number of H&K rifles were used by the venison recovery industry and were found wanting compared to other rifles, but, to be fair, these rifles were all firing many thousands of rounds. By comparison the FN FAL would go through several re-barrels without breakage over several hundred thousand rounds. With our Special Forces the H&K MP5's usually crapped out within a year. H&K offered NZ free military rifles some years ago provided we signed a long-term service contract. The offer was refused.

Originally Posted by gundoc

About half a dozen POF's, all of which never gave any problems and are still going. Rifle problems are fractured receiver covers, fractured bolts, fractured rollers, fractured return spring arms (rimfire semi-autos), fractured pins, burred out trunnions, etc, as well as all the other problems you mentioned. A good number of H&K rifles were used by the venison recovery industry and were found wanting compared to other rifles, but, to be fair, these rifles were all firing many thousands of rounds. By comparison the FN FAL would go through several re-barrels without breakage over several hundred thousand rounds. With our Special Forces the H&K MP5's usually crapped out within a year. H&K offered NZ free military rifles some years ago provided we signed a long-term service contract. The offer was refused.

I believe Battlefield Las Vegas attribute those problems to worn recoil springs.

The recoil spring is a completely different beast. By not changing it often enough, you will eventually destroy your receiver. The problem with the recoil spring is that it's right in front of your face but it rarely got changed up until recently. We now have a PC in the armory so the armorers can leave reminders to change springs out after three months. We've lost MP5 and G3/HK91 receivers because not changing the recoil springs. The receiver will start to bulge where the bolt carrier bottoms out at the stock. The weak recoil spring allows the bolt to come back with so much force that the rollers eventually to put reverse dimples/bulges on both side of the receiver. If not caught soon enough, the roller will eventually just start getting caught in those dimples and the bolt carrier will stay stuck to the rear. The other issue that occurs is the receiver will crack where the rear stock pins attach. Both issues are caused by the bolt carrier group slamming back so hard that the sheet metal eventually gives