6.5 Grendel as cast bullet shooter?

RicinYakima

High Steppes of Eastern Washington
LGS has a Ruger American in 6.5 Grendel. Price is OK. Now, I load for my son's 6.5 Grendel AR15 so I have all the stuff, but could it be a cast bullet shooter? MY main fear is it will turn out to be like the 6.5 Swede that I spend two years of my life working on that was only so so at the end of that time, so I sold it.
 

RBHarter

West Central AR
Against all practical thought the 264 WM is a dandy with cast .
A paper patch 258-120 NOE over 12 gr of Unique is ......well it's pretty darned good . 3 for 3 on a 22" gong at 400 yd . No clue about what it's doing for speed .
It possesses all of the best things for cast , enough case to misplace a VW Bug , a 1.25 dia neck length , short throat , long leade , whippy pencil barrel .....(sarcasm) .

New barrel , small case , happy with heavies and super slow (for cartridge) powders the only thing that has to work out is the neck and where that front band hits . If you still have a .266 mould or 2 and sizers it really shouldn't be too bad to get a full power jacketed load with a 140 cast .
 

Spindrift

Well-Known Member
I have no experience with the grendel, but I want one quite badly :)
But I do have 3 6,5x55 barrels that I shoot regularily with cast bullets, and they are not particularily difficult to work with. I have an impression the bad reputation of the 6,5 as a cast bullet shooter stems from the peculiarities of the swedish mauser, rather than the cartridge itself.

NOE 266-126 is designed with the Grendel in mind. It is perhaps the most accurate bullet in all my x55 barrels.

I suspect the Grendel would be a good cast bullet shooter. Maybe not the best choice if you’re chasing HV.
 

CWLONGSHOT

Well-Known Member
I like the lil Grendel allot. Haven’t tried cast in it. When I ran across that 268 Lyman lold that was my thought. But its 150 ish bullet was/is large in stature and diameter.
But its a dandy of an accurate caliber. My lil brother went with me to the range back before deer season started. He isnt a great shooter and nearly never practices. I let him shoot the lil Howa Grendel and he shot THE best group he ever had, two bullets touching and one 1/2-5/8” out. @ 200. He was smiling ear to ear after gazing thru that spotting scope. I asked him if he wanted the target for his “fridge”. ;)

CW
 

fiver

Well-Known Member
he would be Larry Gibson's original arch nemesis or more better described as his Anti Christ. [complex beaker]

hey,,, there has to be a song in there somewhere.
there was quite the cast of characters in there that opposed him but starmetal made episode one. Dr-B made a cameo in there somewhere 45-2.1 made a running bid for a few episodes then there was the syndicate, and the 3 amigo's and I believe the most recent was the Waco kid.
the reigning super hero vanquished them all and goes forth with his shining beacon of bullshit to befuddle and dazzle the rest of the world setting back clocks 30 years with his jazz hands and super utter stupidity.
meanwhile [in the stupid cave] he is stealing their ideas and is figuring out the code to breaking his own super force field of RPM theory which was supplied to him by some books he accidentally read 40 years ago.
 

Ian

Notorious member
I think credit for the RPMTHbbbbhhttt thingy should be given to Tom Gray, way back in a Fouling Shot article from issue #116, page 8. However, unlike SUMbody, Gray offered a concise identification and explanation of the mechanism causing what he calls "twist limited" systems.
 

RicinYakima

High Steppes of Eastern Washington
That is OK. I don't get wound up in the theoretical stuff much. I'm mostly a history and practical application guy (for the game I am playing at the moment). I'm still trying to get my head around the "dynamic fit" concept.
 

Ian

Notorious member
I'm still trying to get my head around the "dynamic fit" concept.

Get your head around the practical application of that concept and lots of things become easier, such as taking on a completely new caliber/cartridge as a cast bullet shooter. Static fit (bore/groove, in essentially only two dimensions) is a line (algebraic function), dynamic fit is the area under the curve (derivative).
 

RicinYakima

High Steppes of Eastern Washington
So we are speaking of malleability of the bullet? As in the static bullet has pressure applied to the base and becomes plastic. Beginning at the rear and spreading forward as the pressure rises? Then as the bullet begins to move forward from the case neck, through the throat and leade, and into the bore. Which is why bore rider design bullets sometimes get land marks on the nose even though they began smaller than bore size? Am I following on the right track here?
 

Brad

Benevolent Overlord and site owner
Staff member
Yep.
What happens when the Big Bang hits the base of the bullet? How does for change as bullet moves from case into the throat and bore?
Does it stay straight? Can it self center at all? How do alloy, design, and pressure curve all play off each other?
How does alloy composition alter dynamic fit?
 

Ian

Notorious member
Yes. What I do is sort of a mental 3D stress analysis on the bullet as it moves through the first half-inch of barrel. Where are the forces? Where is the path of least resistance of the alloy, the gas pressure, and how do these things change as each portion of the bullet shape in question interacts with each part of the case neck, throat, and barrel? I make an impression of the chamber neck and throat, transfer those dimensions to a scale drawing, do the same with the bullet, and observe the points of contact from case neck to full engravement (yeah I made that up) of the gas check. I play that movie in my head over and over and over and sometimes even drive a series of bullets into the throat to different depths and back out again with a brass rod to see how they actually fit and how the metal is displacing. Sometimes I trap bullets for examination, particularly when diagnosing a problem.

Then I figure out what I think the problem areas are and go shooting to see if they are or not. If so, I fix and repeat. If the fix works, I learned something and tackle the next obstacle. If not, I may have fixed the wrong problem or misunderstood what was really going on. Always trying to get better.

What won't get you anywhere is shoving a hard, two-diameter cylinder through a funnel and assuming that a) the nose will magically stay centered between the tiny bearing surfaces of the land tops and b) that the cylindrical body followed that nose straight into the bore along the bore's center line.....when it had .010" of slop around the case neck to go sideways and no feature on the bullet itself to interact with the cone in a way which would direct the body straight forward as it moved.

Locking 90% of a tapered bullet into a perfectly matched tapered throat and using a very hard alloy (God, why?) seems to be the competitor's answer to the alignment problem, but it solves the alignment problem at the cost of extremely high shot start initiation pressure, causing a lot of unnecessary stress and probable distortion to the bullet before it even begins to move.

There are several other, better ways to go about this with conventional rifles that give very good results if done correctly. The more successful ones minimize tolerance and support the bullet in the places it needs to be supported as it moves and yet gives it freedom to self-correct without getting damaged. Doing that involves the three things I've preached and preached about for years: FIT. ALLOY. POWDER. These are some of the tools needed to achieve dynamic fit. There's a helluva lot more to this than Titegroup and Linotype alloy, so explore a little.
 

fiver

Well-Known Member
start with finding the center of the barrel with the center of your bullet.
that is step ONE period no way around it,,, spend your time there.

then move on to design.
once you design on paper [your throat shape] the bullet draws itself, and you basically have to account for movement of the lead as it contacts the steel.
that's where gas check shank, lube wall angles, lube volume, and land volume displacement becomes important.
you don't have to get anal about 1-2*s, most of them are laid out for you on the saami sight, so you can use them to get fairly close and shape the nose tip for strength instead of looks.

there's little cheats you pick up along the way.
but you have to do 3-4 designs [and wring them out] before you start to develop a 'style'.
 

Bruce Drake

Active Member
If you can find the molds, as I believe both are discontinued by Lyman now, but I use the 266305 103gr and 266455 127gr bullets in my 6.5 Grendel AR. Both gave me good enough accuracy to warrant more load refinement when I can get back around to them in the spring. Both are also gas check designs and worth looking for at gunshows or Ebay.
 

Bret4207

At the casting bench in the sky. RIP Bret.
At last! Some good discussion of something beyond, "I got super duper HARDCAST and lube made from the tears of pure virgins under a blue moon!" Posts 14-18 pretty much lay it all out. Well done!

Post 11- The Syndicate, that sounds about right for the time I left. Some of that reminded me of Lord of the Rings where the weasaley little dude had influenced the mind of the feeble old King. There just wasn't any Grandolf type to kick his butt down the stairs...