+- 6.5 Grendel Forum (https://65grendel.com)
+-- Forum: 6.5 GRENDEL DISCUSSION FORUMS (https://65grendel.com/forumdisplay.php?fid=3)
+--- Forum: 6.5 Grendel ARs and Other Semi-Autos (https://65grendel.com/forumdisplay.php?fid=8)
+--- Thread: 65G HLB Project (/showthread.php?tid=9416)
65G HLB Project - Variable - 05-29-2015
BluntForceTrauma Wrote:And this may well prove the case. LR brought up a similar issue, asking if any gains are worth the effort. It's probably hard to get a consensus on what is "significant," but I'd like to hear input.
If we start with a base velocity of 2500 fps and increase it by 1%, we've added 25 fps.
By 5%, we add 125 fps. Adding 10% gives us 250 fps. You get the picture.
So is 100 fps "significant"? Is 250 fps "worth it"? What say the Horde?
FWIW--- It's worth it to me. I hate leaving anything on the table. If it can be had with out proportionately detracting from somewhere else? Sure, I definitely want it! Paper targets might not notice, but increased expansion/fragmentation threshold and energy on target is almost always a good thing to me.
I share your curiousity about this, and while I don't have any helpful data to contribute, I'm all ears on this thread. I also find it hard to believe this hasn't already been definitively hashed out and quantitatively studied somewhere. I just don't know where.
65G HLB Project - stanc - 05-29-2015
Variable Wrote:FWIW--- It's worth it to me. I hate leaving anything on the table.Isn't that what the 6.8 guys have done? From the OP:
I share your curiousity about this, and while I don't have any helpful data to contribute, I'm all ears on this thread. I also find it hard to believe this hasn't already been definitively hashed out and quantitatively studied somewhere. I just don't know where.
BluntForceTrauma Wrote:I want to specify and test a 6.5 Grendel barrel to see if there's any way to increase velocities while keeping pressures within SAAMI 6.5 Grendel guidelines.Perhaps John should spend some time on 68forums and see what type rifling they're using?
The 6.8 SPC II camp, for example, claims that this can be done in their cartridge with similar case capacity to the 6.5 Grendel...
The 6.5 Grendel was founded on innovation and I want to see if there's room for more.
I wouldn't expect 6.5 Grendel to benefit as much as 6.8 SPC is claimed to have, due to a significant difference in max pressures. But, there's only one way to find out how much effect rifling can have on 6.5 Grendel muzzle velocity: That's to buy a barrel with the desired rifling and start testing.
65G HLB Project - stanc - 05-29-2015
P.S. I forgot one thing. IIRC, the main reason for increased MV with 6.8 handloads is the different chamber dimensions with SPC II vs the original SPC chamber.
Since the Grendel chamber design was optimized at the beginning, there is no room for improvement in that aspect, so gains from rifling alone may not be much.
65G HLB Project - BluntForceTrauma - 05-30-2015
stanc Wrote:Since the Grendel chamber design was optimized at the beginning, there is no room for improvement in that aspect, so gains from rifling alone may not be much.
My thinking, as well. Bill Alexander really thought through the SAAMI compound chamber. If there was something "wrong" with the compound throat, velocity-wise, the .264LBC would have "fixed" it. It hasn't. Velocities are comparable.
And, yes, "micro" lands (aside from just plain hitting the pressures hard) is basically what the 6.8 guys have done, and I know all about their program. Here I think we can explore it without all the ego, defensiveness, and name-calling, to see if there's actually something to it or if they just upped the pressure and all the rest is marketing hype. I like Chris Lucci and have the same grudging respect for Beene that I'd give a rattlesnake; they're bright guys. But the jury is still out, in my mind, whether they're on to something or are fooling themselves.
By the way, the 6.5 and 6.8 camps should have a rivalry like the annual Army-Navy football game. Go at it hard, but in the end we're on the same side. I'm noticing on other forums that some guys, however, seem to make it waayyy too personal.
These things I know so far: First, high BC is one of the best ways to get "free" velocity. And we've got a lock on that, hallelujah-praise-Jeezus-can-I-get-an-amen?
Second, the 65G camp needs to keep exploring the uncharted territory of lighter weight, but very sleek and pointy and BC optimized form factor bullets to round out our capabilities.
65G HLB Project - stanc - 05-30-2015
BluntForceTrauma Wrote:These things I know so far: First, high BC is one of the best ways to get "free" velocity. And we've got a lock on that, hallelujah-praise-Jeezus-can-I-get-an-amen?Amen, brother John!
Quote:Second, the 65G camp needs to keep exploring the uncharted territory of lighter weight, but very sleek and pointy and BC optimized form factor bullets to round out our capabilities.I'll second that emotion.
65G HLB Project - BluntForceTrauma - 05-30-2015
I know that "Sneaky" here, the West Coast Gang — yo! represent! — and others, have been working hard on the lighter weights. If anybody is independently wealthy, GS Custom always has some beautiful pills.
65G HLB Project - sneaky one - 05-30-2015
Eagle calling Raven, talk to me Jonny. That design you sent me today is about -- what I had planned to send to hornady last year. You have my alterations. It took a while to get you convinced on lighter pills, now we stand side by side on this. I have one more concept to add- it will cost you a burger , tho.. It will shock the mind. It's Lutz Mueller class stuff.
I'm with you , and others on the ongoing idea-projects on lighter pills. I hoped to create a stir when I started tweaking factory pills for the Grrr 6 years ago.
We have lobbed a many ideas back forth, between a MANY forum members.
I have made a TON of pills for trials, accuracy testing , gel tests, pressure tests, on game shots, autopsy results,,, etc.
Through all of this, a few things became apparent, lighter Gmx bullets in the Grrr, are awesome inside of 300 yds. The speeds are up- impact, then the next few inches, say into a chest cavity-is devastating, same as or better than a 120gr std. pill. No wt. loss, almost always a pass through. Deer are my targeted mid sized game.
Next, past 300 yd for mid size game.,, the 103-108 gmx really shined . RS took a couple deer last year at longer ranges. He texted me, Dan, I never saw meat hanging out of the entrance, & exit holes before. Not even from his magnum rifles.
A barrel will be made to some crazy dimensions- maybe a BHW unit with 1/3 less rifling- it's a wow! to see that rifling as it stands now! Tools of the trade=Tools, has a BHW Grr bbl.
I have a BHW 5.56 tube. There is a speed gain from that rifling alone.
Also, .2635 diam pills are a diff option . More great ideas will pour in here I hope.
I'm still in suit and tie , after MIL'S funeral today. Its after midnite- more good converse tomorrow. Nite gang.