Signs of high pressure test?

[lysander]

Here's the description of the SOLGW BCG with all the details;
https://sonsoflibertygw.com/product-...arrier-groups/

I am sure they do a good job and all, but all that linked sight said, in a very long winded manner, was: "We make our stuff to print."

Literally, everything that site said they do is right on the drawings for the parts, saying, "You need to do this . . . "

[constructor]

(1) No.

The drawing 8448510, (19204), Bolt, Revision AD, dated 2011-04-21, says:

"8. EACH BOLT MUST WITHSTAND FIRING OF A HIGH PRESSURE TEST CARTRIDGE M197, OR SAAMI COMMERCIAL EQUIVALENT, WITHOUT EVIDENCE OF FAILURE. MAGNETIC PARTICLE INSPECT IN ACCORDANCE WITH ASTM E1444 USING A STANDARD 5 TURN MAGNETIZING COIL WITH A CURRENT OF 200 TO 300 AMPERES. CIRCULAR AND LONGITUDINAL CONTINUOUS MAGNETIZATION AND A WET FLUORESCENT SOLUTION SHALL BE USED."

(My emphasis.)

(2) SAAMI proof guidelines are higher than military.[/I][/U] According to SAAMI Z299.4 - Voluntary Industry Performance Standards for Pressure and Velocity of Centerfire Rifle Ammunition (available for free on SAAMI's website) give the proof range for .223 Remington as:

MINIMUM AVERAGE DEFINITIVE PROOF PRESSURE - 73,500 psi
MAXIMUM AVERAGE DEFINITIVE PROOF PRESSURE - 78,500 psi


M197 is not 78,000 psi, it's requirements are still the same 70,000 psi +/- 3,000 psi (average) they have been since at least 15 October 1964 (look it up, you should be able to find MIL-C-46936B on line). But, M97 is not what is used these days.

The current HPT cartridge for 5.56mm weapons is M197A1, covered under MIL-DTL-32530. The requirements for M197A1 are also below 78,000 psi; the average chamber pressure at 70 degrees F shall be 73,000 psi +/- 2,000 psi.

Yeah I see min73,500-max78,500 same as the old 8448509 and that is what Hornady said their proof loads should be, apx 78,000. I stopped machining bolts in 2017. There are several companies I would not buy bolts from just reading their description and since I have a history with and know I can trust Microbest that is what I would buy and sell if I needed bolts. There is no need for me to try to find a HP tested bolt like the OP only to find out the company made a mistake and sent one that was not HP tested. I don't care how it's done but if you put 73,500 psi on a bolt face you will see the results of it.
ETA- I would rather buy a bolt from the real manufacturer than a reseller who may sell a different brand every month but laser etches their name on all of them. It's odd I never see many companies advertising AO Precision, Microbest or LW Schneider bolts

[prepare]

I am sure they do a good job and all, but all that linked sight said, in a very long winded manner, was: "We make our stuff to print."

Literally, everything that site said they do is right on the drawings for the parts, saying, "You need to do this . . . "

Not only does SOLGW check all the boxes but they also tell you specifically what those boxes are instead of just saying mil spec.

Checking all those boxes and sticking to a proven formula and being transparent is what I like about them. And that combination is very rare in this industry.

[prepare]

Yeah I see min73,500-max78,500 same as the old 8448509 and that is what Hornady said their proof loads should be, apx 78,000. I stopped machining bolts in 2017. There are several companies I would not buy bolts from just reading their description and since I have a history with and know I can trust Microbest that is what I would buy and sell if I needed bolts. There is no need for me to try to find a HP tested bolt like the OP only to find out the company made a mistake and sent one that was not HP tested. I don't care how it's done but if you put 73,500 psi on a bolt face you will see the results of it.
ETA- I would rather buy a bolt from the real manufacturer than a reseller who may sell a different brand every month but laser etches their name on all of them. It's odd I never see many companies advertising AO Precision, Microbest or LW Schneider bolts

Consumers cannot buy directly from the manufacturer.

[constructor]

Consumers cannot buy directly from the manufacturer.

I sold direct, Maxim does, LWRC , pretty sure JP does, Y/M , Aero Precision, LMT, Sharps, I'm pretty sure those companies make their own bolts and sell them.

Resellers should tell you who made the bolts instead of sticking their own name on them like they made the bolts.

[Disciple]

Resellers should tell you who made the bolts instead of sticking their own name on them like they made the bolts.

What do you think of this? https://arftac.com/microbest-ar15-5-...roup-complete/

[prepare]

I sold direct, Maxim does, LWRC , pretty sure JP does, Y/M , Aero Precision, LMT, Sharps, I'm pretty sure those companies make their own bolts and sell them.

Resellers should tell you who made the bolts instead of sticking their own name on them like they made the bolts.

I meant direct from Microbest.

That being said, from what I understand just because a certain brand sells a Microbest BCG that doesn't mean it's the same specs as a TDP BCG.

[constructor]

I meant direct from Microbest.

That being said, from what I understand just because a certain brand sells a Microbest BCG that doesn't mean it's the same specs as a TDP BCG.

If you don't like Microbest don't buy them but if you buy Rubber city, spikes, toolcraft, PSA, Y/M or any nitride treated bolt and wont buy a Microbest you may want to dig a little deeper.

Microbest makes the same parts the same way for every customer, they don't change anything for anyone. They have part numbers, you send in a PO for the part number.
In 14 years I talked to the VP twice, he said they make apx 40,000 bolts a month and 30,000 carriers, they make all the small parts to build complete BCGs along with many other small parts of ARs. They make mil spec parts for many companies and you're right the are mainly concerned with filling big orders but I could send in a PO for 200 bolts or 144 BCGs and they will fill the order.

[prepare]

Microbest makes the same parts the same way for every customer, they don't change anything for anyone. They have part numbers, you send in a PO for the part number.

Interesting...

So as a manufacturer you can basically order 100% TDP BCG's from Microbest?

[constructor]

What do you think of this? https://arftac.com/microbest-ar15-5-...roup-complete/

I don't know anything about the reseller but if it's a microbest BCG it will be good to go.

I think any bolt from AO Precision, Microbest or LW Schneider will be good. I'm not sure who makes BCMs bolts but the tool path on the bolts looks like Microbest. I would also trust LMT.
If I feel like working I can make my own but if I'm buying it would be from one of those 5 companies.