The Chart for ar 10?

[mos2111]

Am I imagining this or is there a "chart" for the AR 10 like Rob did for the AR 15? I used search to no avail?

[Alric]

The chart was built around the premise of comparing different AR brands to the actual military spec, to my knowledge. There isn't really a military spec for an AR-10 that I'm aware of. The focus of an AR-10 chart would have to be different somehow.

[AnchorStation]

Knights (US)

LMT (UK)

That was easy lol

[caporider]

Knights (US)

LMT (UK)

That was easy lol

I'd guess you have to add Armalite (Canada)...

[AnchorStation]

Wasnt aware of that.

[Dano5326]

Due to the larger caliber & format of the 7.62 weapons, they will not see the severe firing schedules of the 5.56. The larger sizes of individual components probably helps in regard to less reported parts failures.

My own opinion is the chart means less if you have a working familiarity with weapons, alloys, and coatings. There are better options now.

For example, why HPT? To ensure some troop doesn't get handed a POS weapon that will fail immediately upon use. Many professionals will put 500 rds through before carrying for duty... so.. A good alloy steel, heat treated, shot peened, and MP'd will have a longer life than one that was overstressed with HPT.

[rsilvers]

HTP is something that is done on most guns but it is called proof firing.

A visual and headspace inspection is generally done afterward, but not mag particle testing.

The mag particle test is really money that would be better spent on other inspection procedures, and it is only mil-spec for an M4/M16 - not a G36, Sig 550, M14, etc.

What is very useful is gauging everything. You can, for example, have go/nogo gauges that you stick in every pin hole on the lower and the firing pin hole, etc. And go/nogo gauges that you drop the bolt and carrier through.

Companies that do that will actually find bad parts and prevent them from shipping. Companies that mag-particle test will not find bad parts, because, I am told, that no parts ever fail that. So since reality is there is an inspection budget, that is a poor way to spend your time on inspection.

I would more like to see an AR company say "We gauge 23 spots on every AR before shipping" than "We check our bolts with mag particles even though the process has never rejected a part." It was just something someone put in the spec at the time, and Colt has to do it due to contractual requirements.

[Alaskapopo]

HTP is something that is done on most guns but it is called proof firing.

A visual and headspace inspection is generally done afterward, but not mag particle testing.

The mag particle test is really money that would be better spent on other inspection procedures, and it is only mil-spec for an M4/M16 - not a G36, Sig 550, M14, etc.

What is very useful is gauging everything. You can, for example, have go/nogo gauges that you stick in every pin hole on the lower and the firing pin hole, etc. And go/nogo gauges that you drop the bolt and carrier through.

Companies that do that will actually find bad parts and prevent them from shipping. Companies that mag-particle test will not find bad parts, because, I am told, that no parts ever fail that. So since reality is there is an inspection budget, that is a poor way to spend your time on inspection.

I would more like to see an AR company say "We gauge 23 spots on every AR before shipping" than "We check our bolts with mag particles even though the process has never rejected a part." It was just something someone put in the spec at the time, and Colt has to do it due to contractual requirements.

Actually from what I was told during my last Colt Armorers trianing they reject 20% of their bolts and barrels after the magoparticle test.
Pat

[rob_s]

I'm not sure where this idea that no parts are ever rejected in the MPI process came from.

On the subject of the AR10 Chart, it's not likely to happen due for the most part to the lack of a military specification for AR10s. I suppose we could apply the M4 spec or the M16 spec to the AR10 but I imagine almost all would come up severely lacking if measured with that yardstick, and it may not be applicable.

[rob_s]

For example, why HPT? To ensure some troop doesn't get handed a POS weapon that will fail immediately upon use. Many professionals will put 500 rds through before carrying for duty... so.. A good alloy steel, heat treated, shot peened, and MP'd will have a longer life than one that was overstressed with HPT.

I have heard HPT compared to driving a car into a wall to test the bumper. I'm not sure I buy that comparison, or the idea that it necessarily shortens the life of the part. To know for sure one would have to take 100 bolts non-HPT and 100 that have been and run them all to failure. Not sure that's likely to happen anytime soon.