AR Thread

[redbang]

I have been using and assembling AR rifles and more specifically parts for 13 years now (Is that unlucky?) As yet I have had no issues with DPMS. In fact I used DPMS barrels exclusively because they shot so well. Sometimes DPMS parts are not as pretty as others but I have never had a bolt fail and I have seen a few bolts fail especially recently.

Which breed has been busting bolts ?

[Beavis]

Well done

[Danny]

.

[Bill999]

only one Iv seen has been NEA,

[Towely]

I had an Nea break one as well.

[Rushy]

I had an Nea break one as well.

What was the cause? After how much use?

[scaggly]

What was the cause? After how much use?

Digit might be able to chime in here, but as far as I know it was only the very early 1st gen NEA's that had any issues with this. I know personally of one NEA bolt that spat a bolt lug, but that was at a reasonably high round count, and losing lugs is a hazard with AR bolts from a variety of manufacturers from what I've read online. The great thing is that unlike all the other brands in NZ, NEA has local support so replacement bolts came out overnight under warranty.

I've got a gen2 NEA and I must have put at least 5,000 rounds through it without any issues at all, and from what I've heard this isn't a problem on their newer rifles.

[Rushy]

Thanks Scaggly.

[Beavis]

A friend had a bolt lug fail on a Gen 1 NEA after 500 odd rounds maybe, all suppressed. Was replaced quickly. I typically prefer to buy brands that individually high pressure then MPI test their bolts, for that reason. It takes a long time for a brand to shake a bad reputation in the AR world.

[redbang]

The NEA's have MPI and HPT in their specs now

[gimp]

The NEA's have MPI and HPT in their specs now

They always claimed "HP and MPI tested" but it was disingenuous as it was only batch testing ie 1 from a batch of however many, which not as good of a QC test as individually testing each bolt (but cheaper!)

[scaggly]

They always claimed "HP and MPI tested" but it was disingenuous as it was only batch testing ie 1 from a batch of however many, which not as good of a QC test as individually testing each bolt (but cheaper!)

I was under the impression that the HPT process was basically subjecting the bolt to a proof test, which also has the effect of potentially shortening the overall life of the bolt by quite a margin. I read that the US army found that bolts (even HPT/MPI tested) will begin to crack at 5,000 rounds, and will generally break at 10,000 rounds.

If bolts tend to let go at the same time, I'm not sure if the benefits of HPT stack up, but interested in others views.

[gimp]

I was under the impression that the HPT process was basically subjecting the bolt to a proof test, which also has the effect of potentially shortening the overall life of the bolt by quite a margin. I read that the US army found that bolts (even HPT/MPI tested) will begin to crack at 5,000 rounds, and will generally break at 10,000 rounds.

If bolts tend to let go at the same time, I'm not sure if the benefits of HPT stack up, but interested in others views.

It picks up the bolts with faults that will fail early, well before end of service life. As I understand it. Failing at a predictable interval after many thousand rounds is ok (wearing out), failing at random with low round counts because of metal/machining flaws isn't

[steven]

I was under the impression that the HPT process was basically subjecting the bolt to a proof test, which also has the effect of potentially shortening the overall life of the bolt by quite a margin. I read that the US army found that bolts (even HPT/MPI tested) will begin to crack at 5,000 rounds, and will generally break at 10,000 rounds.

If bolts tend to let go at the same time, I'm not sure if the benefits of HPT stack up, but interested in others views.

All colt bolts as far as I know are tested and marked MPI. Many others do not or batch test only.

Personally when I have a new boiler (or any pressure vessel) a 1.5x or 2x overload test is the normal for insurance / QA purposes and gives some assurance that there is no serious but hidden unique defect. So no it doesnt or should not shorten the life for a component as a one off when new.

Army, well apparently they replace the bolt at 7500rounds or so as they do a lot of auto fire which really stresses the bolt. Again from what I can read 20,000 rounds or 2 or 3 barrels in a "retail" environment ie you and I is quite typical. Bolts are however really cheap and getting a matched bolt and barrel seems to be the best option for accuracy and long life.

[EK9132]

Anyone running the Oceania defense samson suppressor and samson rail combo? Having a few issues with massive poi shift 12inch low 5inch left, 6moa after install and only just stopped it contacting due to barrel whip after a big missio with the file taking some meat out from inside the fore end. Any ideas?

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