65 Receiver Set with Polymer mags from PF (HOPEFULLY)

[PrecisionFirearms]

This sound like a no go at this time for the 68 mags.

[cory]

Single stack mag will require a redesign to the barrel extension due to feed ramps.

True, for some reason that didn't occur to me.

[cory]

This sound like a no go at this time for the 68 mags.

Bwaites was kind enough to order a mag for testing. We're currently waiting to hear back from him once he gets it.

[cory]

I was thinking about the single stack mag some more. My suggestion for it came from a concern that if the magazine was the nominal width for stacking the Grendel case, the bolt lugs may be to short to catch and chamber a round from the magazine.

I think converging the top of the magazine may still be a solution, just not to a single stack. We could converge it to roughly the width of a standard M4 mag.

[stanc]

I think converging the top of the magazine may still be a solution, just not to a single stack. We could converge it to roughly the width of a standard M4 mag.

That would likely still prevent proper alignment of the cartridges with the feed ramps.

The companies that make polymer magazines have intelligent, creative design staff. If a Grendel polymer magazine that fits the standard AR15 mag well was feasible, it would've been made by now.

The unavoidable fact is that such a polymer mag is simply not doable, and none of the proposed mickey mouse "solutions" are viable.

Want a Grendel Pmag? MagPul and LWRC have shown what is necessary.

[bwaites]

So the Six8 mag arrived.

Loaded with new Lapua brass and Amax's loaded to 2.26". Mag capacity is 28. It was easy to load, comparable to PMags and 5.56. No apparent drag or increasing difficulty beyond spring compression.


Very Pretty:

[cory]

Huh, I didn't think it'd work. Happy to be wrong! It looks like they stack perfectly. Does it rattle when you shake it with 25+ rounds?

What's the max length on those?

[stanc]

So the Six8 mag arrived.

Loaded with new Lapua brass and Amax's loaded to 2.26". Mag capacity is 28. It was easy to load, comparable to PMags and 5.56. No apparent drag or increasing difficulty beyond spring compression.

Good show, Bill!

Very interesting, and extremely surprising, considering the magazine was designed for a smaller diameter cartridge. Also seems to contradict what Harrison reported.

I guess the next step is to find out if the loaded mag fits correctly in the mag well, and the rounds feed reliably. Too bad that will cost a lot more $$$.

[NugginFutz]

Looks quite promising.

Now comes the $64 question. You got them in there, now how well do they come out?

How would one go about determining how well they feed without the appropriate receiver assembly? What does the feed angle look like? And whatever happened to Baby Jane?

[stanc]

Huh, I didn't think it'd work. Happy to be wrong! It looks like they stack perfectly.

They do indeed. Looks just like 6.5 G rounds in a metal mag.





Most puzzling, what with the difference in case diameters. :confused:

[stanc]

So the Six8 mag arrived.

Loaded with new Lapua brass and Amax's loaded to 2.26". Mag capacity is 28. It was easy to load, comparable to PMags and 5.56. No apparent drag or increasing difficulty beyond spring compression.

Bill, to see if there's swelling that would cause a tight fit in the mag well, can you precisely measure width of the upper part of the magazine, both unloaded and with 28 rounds?

[bwaites]

Measurements taken at the first rib from the top did not change at 1.0325 inches, before and after loading with 10, 20, and 28 rounds.



Taken at the rib between the second and third waffles, which is about midway, started at 1.0815 empty, increased to 1.0860 with 10 rounds, 1.0890 with 20 rounds, and 1.0990 with 28 rounds.

Unloading revealed that there is drag on the first 12-15 rounds, then they move freely. The mag ribs would have to be significantly moved to make it work.

This is a no go.

Anyone need a Six8 mag?


Sorry this took so long, I planned on posting pictures, but Imageshack crashed and I was hoping it would come back!

[bwaites]

Bill, to see if there's swelling that would cause a tight fit in the mag well, can you precisely measure width of the upper part of the magazine, both unloaded and with 28 rounds?

The stack room is fine, and would work, the internal ribs have to be repositioned.

[bwaites]

Huh, I didn't think it'd work. Happy to be wrong! It looks like they stack perfectly. Does it rattle when you shake it with 25+ rounds?

What's the max length on those?

You could get 2.30, and maybe a tad more, I think.

[bwaites]

[cory]

Well at least we know the 68 receiver would work with a modified mag.

[Paul45LC]

Well at least we know the 68 receiver would work with a modified mag.

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.

[stanc]

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.

Concur.

[stanc]

Measurements taken at the first rib from the top did not change at 1.0325 inches, before and after loading with 10, 20, and 28 rounds.

Taken at the rib between the second and third waffles, which is about midway, started at 1.0815 empty, increased to 1.0860 with 10 rounds, 1.0890 with 20 rounds, and 1.0990 with 28 rounds.

Unloading revealed that there is drag on the first 12-15 rounds, then they move freely. The mag ribs would have to be significantly moved to make it work.

This is a no go.

Good info. I hereby award you six attaboys!

Anyone need a Six8 mag?

Try posting it for sale on 68forums?

[bwaites]

Good info. I hereby award you six attaboys!

Try posting it for sale on 68forums?

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