65 Receiver Set with Polymer mags from PF (HOPEFULLY)

[cory]

Well at least we think the 68 receiver might work with a modified mag.
I hate to rain on anybody's parade, but unless they secretly designed the 68 to really be a 65 and then modified it to take 6.8, it can't be stated with any certainty that it will in fact accept 6.5.

Why would it not? The 68 receiver is merely an enlarged AR15 with all the same interchangeable parts, correct?

[stanc]

No membership. they threw me out years ago when I asked what happened to one of the moderators that had disappeared.

Post it on arfcom? Word would probably make its way back to 68forums.

[stanc]

Why would it not? The 68 receiver is merely an enlarged AR15 with all the same interchangeable parts, correct?

Because nothing is certain until it's actually tried and proven to work.

[cory]

Because nothing is certain until it's actually tried and proven to work.

The design world does not work this way Stanc. It's not longer 1875. The sciences are a little more mature.

Is there inherent risk involved in anything that hasn't been specifically tested, yes. That doesn't mean we can't make educated assumptions and move forward through analysis. If we were to test every single change as we go, then no R&D program would ever be affordable.

[bwaites]

The design world does not work this way Stanc. It's not longer 1875. The sciences are a little more mature.

Is there inherent risk involved in anything that hasn't been specifically tested, yes. That doesn't mean we can't make educated assumptions and move forward through analysis. If we were to test every single change as we go, then no R&D program would ever be affordable.

But this assumption is still based on getting a modded mag, which is hundreds of thousands of dollars in expense. So it's a no go unless a big boy jumps in, and then the market remains very limited without a government level buy to help cover costs.

[PrecisionFirearms]

Bwaites:

Please load that 68 Mag with 6.8 SPC and check the same measurements. If you don't have 6.8 Ammo, I will buy that mag so I can test it.

Mark Hostetter

[bwaites]

Bwaites:

Please load that 68 Mag with 6.8 SPC and check the same measurements. If you don't have 6.8 Ammo, I will buy that mag so I can test it.

Mark Hostetter

Mark, it's yours for the asking! You've helped me so many times it's only a small token of my appreciation! Tell me where to send it!

[cory]

But this assumption is still based on getting a modded mag, which is hundreds of thousands of dollars in expense. So it's a no go unless a big boy jumps in, and then the market remains very limited without a government level buy to help cover costs.

I think you're assuming just any company designs and builds the mag. I find it hard to believe that it'd cost Magpul (a company that specializes in polymer mags and accessories and releases newer gen pmags on almost a regular basis) anywhere near that much to develop a prototype and produce it on one of their current pmag lines.

[cory]

Mark, it's yours for the asking! You've helped me so many times it's only a small token of my appreciation! Tell me where to send it!

Wait, but you promised it to me. HAHA

Looking forward to seeing the comparison with 6.8 ammo, Mark!!!

[bwaites]

Wait, but you promised it to me. HAHA

Looking forward to seeing the comparison with 6.8 ammo, Mark!!!

You didn't say you wanted it!

[stanc]

I think you're assuming just any company designs and builds the mag. I find it hard to believe that it'd cost Magpul (a company that specializes in polymer mags and accessories and releases newer gen pmags on almost a regular basis) anywhere near that much to develop a prototype and produce it on one of their current pmag lines.

I think Bill was indulging in a bit of hyperbole with that "hundreds of thousands of dollars" comment. However, it would still require expenditure of no small amount of money to produce a magazine for which there seems to be negligible customer interest.

MagPul is in business to turn a profit. With "small-dollar" items like magazines, that requires high sales volume. I don't see that happening in the relatively low-volume Grendel market. Or perhaps you have an idea how to show MagPul they could be sure of getting a good return on their investment?

The only idea I can think of -- in the absence of adoption by some military, somewhere -- is if Mark were to produce and sell quantities of billet-machined Grendel magazines for the LWRC Six8 receiver set, as per http://www.65grendel.com/forum/showthrea...post101494 That would demonstrate a market demand, but how many Horde members would pay that much for mags, in addition to a receiver set that costs 2-3 times as much as a standard receiver?

[LRRPF52]

I inspected an injection molding company in Colorado one day, and was given a tour of the facility, how the molds are made, costs, etc. One plate cost them tens of thousands of dollars if it was made in the US. Molds require at least 2 plates, with specialization as to how the polymer flows into the cavity, and how the push rods are placed when the plates separate.

Just the design of the plates takes a lot of highly skilled man hours, even with the assistance of computer drafting and modeling. The plates have to be polished to a mirror-like finish, and maintained periodically because of fouling from the mold process. If you outsource to China, you can have the plates made for ~$10-$14k each, then do finish work on them Stateside.

There is a lot of RDT&E that goes into injection molded products. I had a Gen I MIAD grip from Magpul, which had a major design flaw in it with a conical grip screw. They had to eat those costs and develop a Gen II MIAD. A first run of mold plates for a new mag will most likely turn out to be a beta test, but Magpul has accumulated a lot of knowledge on thermal shifting and its effects on dimensional tolerances. Even still, their Gen 3 7.62 PMAG has proven to have a lot of problems in AR10's, not locking the bolt to the rear because of a small dimensional change in the rear of the follower.

Their RDT&E on the quad stack magazine proved what we already knew: casket mags have a very bad track record for reliability. Surefire decided to take theirs to market, and Magpul shelved it due to reliability.

Magpul also did a lot of RDT&E on a translucent PMAG in 2007, but refused to produce it because the polymer wasn't as strong as the solid color mags.

Like I said, I think Lancer is the way to move forward with a hybrid metal/polymer 6.5 Grendel magazine if 30rd capacity is what we want.

[PrecisionFirearms]

Send to my shop address/

74 Dupont Rd
Ste A
Martinsburg WV 25404

[bwaites]

Send to my shop address/

74 Dupont Rd
Ste A
Martinsburg WV 25404

Will do!

[bwaites]

I think Bill was indulging in a bit of hyperbole with that "hundreds of thousands of dollars" comment. However, it would still require expenditure of no small amount of money to produce a magazine for which there seems to be negligible customer interest.

MagPul is in business to turn a profit. With "small-dollar" items like magazines, that requires high sales volume. I don't see that happening in the relatively low-volume Grendel market. Or perhaps you have an idea how to show MagPul they could be sure of getting a good return on their investment?

The only idea I can think of -- in the absence of adoption by some military, somewhere -- is if Mark were to produce and sell quantities of billet-machined Grendel magazines for the LWRC Six8 receiver set, as per http://www.65grendel.com/forum/showthrea...post101494 That would demonstrate a market demand, but how many Horde members would pay that much for mags, in addition to a receiver set that costs 2-3 times as much as a standard receiver?

Not much I wasn't. I have a pretty good idea of what the molds cost, then figuring R&D hours for the molds and then the cost of ammo to test, then knowing about the AR10 issues, I know I'm pretty close.

[cory]

$10k R&D molds??? Y'all should look into 3D printers. For under $1k you can have a printer and a few prototypes, not counting labor and assuming you already have cad software.

[stanc]

$10k R&D molds??? Y'all should look into 3D printers. For under $1k you can have a printer and a few prototypes, not counting labor and assuming you already have cad software.

Why depend upon anyone else? Go buy a 3D printer, make your own 30-rd mags, assemble a 6.5 Grendel rifle on an LWRC Six8 receiver set, and let us know how it works out.

If you show it's worth doing, I'll write an article for the gun rags, and maybe enough shooter interest will develop to entice MagPul to add a "Six5" Pmag to their product line.

[Lonehill]

I have 3 AA 25 rd mags and 4 10 rounds mags, I don't even know if any of them work as I have never used them. I exclusively us the 10 rd pmag loaded with up to 5 rounds as it is softer on the brass

Careful now....I've had my butt reamed on here once before for merely mentioning it's too bad it isn't possible to manufacture a Grendel specific Pmag!

[NugginFutz]

I don't know if I would've characterized the exchange as a butt reaming. The respondent was encouraging you to research the question from the existing archive. Could he have been less blunt? Yes. Was he chewing you a new one? Not in my opinion.

http://www.65grendel.com/forum/showthrea...#post95130

That exchange was also in the context of the existing AR 15 platform. This particular thread, while similar, revolves around the six8 receiver set.

Relax and enjoy the show, I'd say.

[cory]

Mark what was the outcome on the 68 mag?