NEW 6.5mm Prototype: A Tale of Two Bullets

[jonny rotton]

i would be happy to assist you by doing some accuracy testing for you. you can send me a thousand loaded rounds and i will test them here in cold weather.
this sounds like a great project!!
thank you for this great forum.
jr

[BluntForceTrauma]

Ha! JR, I'll send you a thousand tips by loading them and shooting them in your general direction. The BC on this baby is gonna be so good I bet they'll make it there from Minnesota! Haha! I'll leave it to you to dig 'em outta the ground, though.

[stanc]

Aluminum tips now machined. Each weighs 3.6 grains. See attached photo below.

Pretty cool, John. But I have to say that I'm a bit disappointed you're developing another hunting bullet, instead of a state-of-the-art .mil projectile.

Yes, this is much, much worse than waiting for Christmas!

But not nearly as bad as waiting for someone to build a Grendel machine gun. Ho-ho-ho!

[ricsmall]

Cool stuff there! Sneaky and i were using RL7 in some weights and getting super velocities but I think that may have been in the 70-80 gr wt class. I'll look back this afternoon and see

Richard

[BluntForceTrauma]

So this post is my formal request for any ideas on where to start reloading this.

95 grains. Total length almost exactly 1.25". Copper body with pressure relief grooves on shank. Should be slightly less pressure than a Barnes 6.5mm 100 TTSX (1.156" length).

Want max velocity at safe pressures.

Let me bounce two ideas:

A) 31.5 (compressed) CFE 223?

B) 31.5 (compressed) IMR 8208 XBR?

Thoughts?

[cory]

So this post is my formal request for any ideas on where to start reloading this.

95 grains. Total length almost exactly 1.25". Copper body with pressure relief grooves on shank. Should be slightly less pressure than a Barnes 6.5mm 100 TTSX (1.156" length).

Want max velocity at safe pressures.

Let me bounce two ideas:

A) 31.5 (compressed) CFE 223?

B) 31.5 (compressed) IMR 8208 XBR?

Thoughts?

Everyone seems to find an accuracy node of 30gr of 8208 with the 100gr ttsx. I'd start at 28.5gr of 8208 and expect max load to be somewhere around 31grs.

[ricsmall]

Cool stuff there! Sneaky and i were using RL7 in some weights and getting super velocities but I think that may have been in the 70-80 gr wt class. I'll look back this afternoon and see

Richard

I want to correct myself. 27 grs RL7 gave 2850 fps with 95 gmx. 34.2 cfe gave 2919 with slight flattening and cratering of primer. 30 grs 8208 gave 2763 under a 98 gmx. All primers were cci400, which I was using to show pressure signs sooner, in theory. All these loads were tested in my gun and sneakys, so use caution and start lower, work up.

Richard

[BluntForceTrauma]

Thanks, Cory, that's sort of what I read, as well.

For example, Hodgdon has a 95 V-Max under 31.0C of 8208XBR from a 24" going 2,840 fps at 49,600 psi.

Barnes has a 100 TTSX under 28.7C of 8208XBR from a 24" going 2,793 fps, no pressure listed.

[BluntForceTrauma]

Richard, barrel length?

[ricsmall]

22" bartlein.

[am4966]

What about the load PA Allen uses for the 100gr ttsx, I believe he uses H335.

[PA_Allen]

What about the load PA Allen uses for the 100gr ttsx, I believe he uses H335.

I use 30 gr of 8208 now for any 100 gr class bullet. In my experience 30 gr of H335 gives practically identical results.
- PA

[cory]

Thanks, Cory, that's sort of what I read, as well.

For example, Hodgdon has a 95 V-Max under 31.0C of 8208XBR from a 24" going 2,840 fps at 49,600 psi.

Barnes has a 100 TTSX under 28.7C of 8208XBR from a 24" going 2,793 fps, no pressure listed.

Becareful using Vmax data. Copper and lead bullets build pressure differently.

[BluntForceTrauma]

Gotcha, Cory, we'll proceed per standard safety practices. I like to compare with the closest analogs I can find to at least get in the ballpark, before dialing down to the specifics.

Reading all the factory charts and as many individual reports as I can find seem to say H335 is great for best velocity with certain pills, but is accused of being quite temperature sensitive (TS). Even though it's advertised differently, XBR is also accused of secretly being TS, but I'm hoping it's less so. And, as PA notes, it performs neck-and-neck with H335.

Plus, if at all possible, I'd like to standardize on a common powder that works well for a lot of bullets in 65G, to make powder inventory more manageable for us all.

Plus, I read an online rumor (was it on PredatorMasters?) that XBR is the civvie version of the military powder used in the new M855A1, which just seems cool!

At any rate, am still waiting on the machining of the copper bodies!

[sneaky one]

Hey, project is lookin good. May be some versions of truth on the civvie idea of xbr- -- I'll get some local feedback eventually.

As far as a std. powder for the Grrr, ehhhhh- 4 may be better than a 1. CFE- 223, or H335, or xbr 8208- & or, RL 7- 10 ..;;

For the heavies- cfe. For the Lighter pills, I used RL 7.

RL 10 is next on the buy list. XBR 8208 seemed to be fine for the 120-123 class, also. Copper reduction from cfe- has its place tho.


If all I could find - like 3 years ago--- they all can work, speed changes are all I've seen. Accuracy has been fine with all.


Given a choice, by gunpoint, as an example+ == cfe 223,,, H 335 secondly.

One or both would cover all bullets.


Those tips look like a mirror copy of the W3 tips. Nice- we'll see how they load for lengths, the W 3's are an- oh no! If the ogive is good, on your pill- we can find a way,

or we can tweak as per needed- it's all good.

Cavity depths - we'll research that later. Wall thickness too, L 52 & I went thru this already- Gmx , is the one to mimic, as it's the rockstar in these monos.

Best in wt., best in all other uniformities in a copper pill. Get it to the range. I'll meet you there with my single stage press, and a tripod to mount it on. Scales, etc., to load onsite. Ladder tests on site, will freak out the local gang.

We'll get a few others on fones to figure this out while it happens. BFT, needs a new fone... Anyone have 1 to donate?

Ummm, I have found a spot locally to do longer indoor range shooting. Let's Go on this. Winter get's boring here, we need a few side projects to keep us warm.