I have been a victim of "the torque theory".
It was by my own doing.
My first build was an 18" BA SPR equipped upper.
Shot what were for me great groups right outta the gate.
Later decided I needed a brake.
Worked fine until one day I decided to take it off. (Don't remember why)
When I reinstalled it, my groups opened up by 4x!
Removed the brake, (It was on there TIGHT), inspected, and reinstalled it ... hand tight with blue loctite.
Groups shrunk back down to original size.
Torque theory?
It's real IMHO.
PS .... Now the only muzzle devices I use are thread protectors on long barrels, and linear comps on short ones. (All hand tight w/ blue loctite.)
Funny thing. I have an Odin brake that does not require timing (outer sleeve you adjust) and it is torqued down as much as I dare. It rotates (the outer sleeve). I have a Gamma VG65 on another that is hand tight plus maybe 6* for clocking on a crush washer with a cressent wrench and holding the barrel by hand and has not budged. Neither have any locking compound on them.
09-17-2018, 12:49 PM (This post was last modified: 09-17-2018, 06:53 PM by A5BLASTER.)
This is why I like the accuwasher system so much, you find the one that lets you time the muzzle device at handtight then back it off and put on some red locktite and it won't ever move unless you want it to, plus no torque is introduced to the barrel at the muzzle end.
A5BLASTER Wrote:This is why I like the accuwasher system so much, you find the one that lets you time the muzzle device at hindsight then back it off and put on some red locktite and it won't ever move unless you want it to, plus no torque is introduced to the barrel at the muzzle end.
Me too. Accuwashers are great.
NRA Basic, Pistol, Rifle, Shotgun, RSO
CCW, CQM, DM, Long Range Rifle Instructor
6.5 Grendel Reloading Handbooks & chamber brushes can be found here:
4.80mm, 4.75mm, 4.72mm, 4.72mm. Those were the very unscientific measurements of the inside of the bore to thread top height at the 12, 3, 6, and 9 o'clock positions of my barrel. So assuming user error (totally safe assumption) I would say the threads are concentric. I am taking the rifle, a handful of brakes, a ton of tools, and some ammo out tomorrow, and will post results of the various boring but important testing that occurs. At least I will be generating spent brass.
10-03-2018, 08:08 PM (This post was last modified: 10-03-2018, 08:17 PM by tucansam.)
Too much wind yesterday for accuracy testing. Today it was dead calm. Almost 1PM and still dead calm. Kinda creepy.
Rifle:
[ATTACH=CONFIG]12818[/ATTACH]
The $50 vise holder that attaches to my hitch from amazon works, even though the cutouts don't let me bolt it down, this thing was a Godsend out there considering I shoot 30 minutes from my house and tools:
[ATTACH=CONFIG]12819[/ATTACH]
[ATTACH=CONFIG]12820[/ATTACH]
Was shooting the < $140/case bulk Hornady American Gunner from Sportsmans. 100y, orange dots are 1" approx, prone off bags.
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Naked gun, no brake, threads only, control group, shot group #1:
[ATTACH=CONFIG]12821[/ATTACH]
Spun on the shorter/newer version of the YHM 30 cal brake, timed it more accurately I think, needed minimal torque to time perfectly (didn't use my torque wrench, but much less torque than the original brake had on it for sure). Group opened up and flattened out, that's curious, shot group #2:
[ATTACH=CONFIG]12822[/ATTACH]
Added the heavy SS Phantom 30cal can, shot group #3:
[ATTACH=CONFIG]12823[/ATTACH]
Came up a mil and left 0.5, shot group #4:
[ATTACH=CONFIG]12824[/ATTACH]
Came down 0.5 mil, shot group #5:
[ATTACH=CONFIG]12825[/ATTACH]
Brake wasn't timed 100%, I wanted to put a touch more toque on and it and see what happened. I used the shims YHM provides and spent a few minutes getting it just perfect, this group is with it timed 100% perfect and probably a bit less toque, actually, than shot group #2 above. Shot group #6. First shot was fired at the top right dot on the target, and was off paper, high. Aimed at a different dot and fired four shots:
[ATTACH=CONFIG]12826[/ATTACH]
One mil down, 0.5 mil right, shot group #7, brake only:
10-03-2018, 08:17 PM (This post was last modified: 10-03-2018, 08:27 PM by tucansam.)
0.5 mil down, shot group #8:
[ATTACH=CONFIG]12828[/ATTACH]
Attached the 30 cal Phantom can, shot group #9, five shots in there:
[ATTACH=CONFIG]12829[/ATTACH]
Final zero check, can attached to brake, last group of the day, #10:
[ATTACH=CONFIG]12830[/ATTACH]
So the damn barrel shoots after all.
[ATTACH=CONFIG]12831[/ATTACH]
Sorry for all the out of sequence shooting, I marked them better above.
Interestingly, I ended the day with almost the exact same dope as I had on the gun when I ended my last session, with the threads only (windage was the same, elevation was adjusted by 0.1 mil).
The old brake is this style:
[ATTACH=CONFIG]12832[/ATTACH]
The new brake is this style:
[ATTACH=CONFIG]12833[/ATTACH]
The old brake and/or old brake & suppressor combo resulted in minute-of-volkswagon accuracy, and I have the exact same (old style) brake on my 308 bolt gun, and it shoots 0.5 minute. I inspected the brake as closely as I could, and don't see anything obviously wrong with it. No obstructions in the bullet channel, etc. I may contact YHM and see if they want me to send it in. At this point the rifle is shooting "good enough" for my deer hunt in Nov, so I won't touch it. Once I have some time I'll work up some hand loads.
I remain clueless as to whether it was the brake, or the torque.
Anyone know if the 123gr Hornady American Gunner (BTHP) is suitable for deer? I have some Black and other ammo that is probably more appropriate, but would need to test and re-zero. Wondering if this bulk stuff would do the job out to 400y or so.
Thanks again to all for the suggestions and replies.
The dirt in front of the muzzle was cool at the end:
I have been told that you won't get your best groups when prone, without some additional space between the Earth and your muzzle. That is an awesome pic of the dirt after your session, which is what ignited this particular synapse to recall the discussion. He told me that it'd be better off a pica-nick table than off the ground... He seems to know his stuff. I was unhappy with my 3/4-1" groups, and sure enough, elevating helped me shrink my groups. Nothing fancy like his shooting but I can bet on 1/2-3/4" groups from the platform, 3/4-1" groups prone from the ground.
Nothing kills the incentive of men faster than a healthy sense of entitlement. Nothing kills entitlement faster than a healthy sense of achievement.
That's interesting. I hadn't heard that before, however I suppose the science might make sense, if you account for pressure waves reflecting off the earth. Then again, one would think the bullet might be travelling fast enough to outrun said pressure waves before they exerted an influence on the path of flight.
I generally shoot out of the bed of my truck, nice and comfy on a yoga mat covered with an old gortex sleeping bed liner. My old bones don't like to stay prone for long periods of time anymore without some creature comforts. But I had the vise mount thing attached to my trailer hitch, so I couldn't put down the tailgate to shoot. Hence, I shot off the ground. But I will get the rifle up off the ground next time.
I have a few boxes of the Hornady left, Black, AMAX, and SST. Now that I think the rifle may shoot, I'm going to retest everything I have and see where I'm at.
tucansam Wrote:That's interesting. I hadn't heard that before, however I suppose the science might make sense, if you account for pressure waves reflecting off the earth. Then again, one would think the bullet might be travelling fast enough to outrun said pressure waves before they exerted an influence on the path of flight.
I generally shoot out of the bed of my truck, nice and comfy on a yoga mat covered with an old gortex sleeping bed liner. My old bones don't like to stay prone for long periods of time anymore without some creature comforts. But I had the vise mount thing attached to my trailer hitch, so I couldn't put down the tailgate to shoot. Hence, I shot off the ground. But I will get the rifle up off the ground next time.
I have a few boxes of the Hornady left, Black, AMAX, and SST. Now that I think the rifle may shoot, I'm going to retest everything I have and see where I'm at.
Best method to test what the rifle can do is off a bench with the gun bag front and back with some nice thick sandbags that it can settle down into.
Shots are marked "1, 2, 3" etc. First four are 123gr Hornady Black, last is 123gr BTHP American Gunner. I came up a total of 0.3 mils between targets one and four. Adjusting for that, I can safely say that, in my gun, at 100y, Black and American Gunner share the same point of impact. Of course BCs will determine any similarities or differences at range, but for now, it looks like I can use the cheap stuff to practice, and the good stuff to hunt, without having to do a whole lot of math or worrying about correct dope on the scope. Velocities are listed. Shot #1, Group #1, was cold bore.
Next week I will take both ammunitions to 600y and see how they do.
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[ATTACH=CONFIG]12878[/ATTACH]
Shot group 1, 2256, 2261, 2237, 2275, 2244
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[ATTACH=CONFIG]12879[/ATTACH]
Shot group 2, 2252, 2225, 2196, 2225, 2225
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[ATTACH=CONFIG]12880[/ATTACH]
Shot group 3, no velocity data
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[ATTACH=CONFIG]12881[/ATTACH]
Shot group 4, 2240, 2290, 2279, 2314, 2279
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[ATTACH=CONFIG]12882[/ATTACH]
Shot group 5, American Gunner, 2248, 2256, 2233, 2218, 2240
360y, quartering shot, 123gr Horn Black, impact just behind left armpit, exit out right bowel. Exit hole was 3x larger than entry. Heart and lungs were hamburger, no meat damage and minimal fecal contamination, and the beast walked about six yards before he fell.
I went to the range and shot to 558y with this ammo, and the results past 250y were *way* different than predicted. I entered corrected dope into Strelok and shot the corrected dope at this deer, and it was a win. Either Hornady's BC is quite optimistic, or my chrony is crap (likely). Or both. I am buying a Magnetospeed and will get more numbers.
Rifle still groups between 1-1.75", sometimes more if I am being careless. I'll be handloading soon enough.
360y, quartering shot, 123gr Horn Black, impact just behind left armpit, exit out right bowel. Exit hole was 3x larger than entry. Heart and lungs were hamburger, no meat damage and minimal fecal contamination, and the beast walked about six yards before he fell.
I went to the range and shot to 558y with this ammo, and the results past 250y were *way* different than predicted. I entered corrected dope into Strelok and shot the corrected dope at this deer, and it was a win. Either Hornady's BC is quite optimistic, or my chrony is crap (likely). Or both. I am buying a Magnetospeed and will get more numbers.
Rifle still groups between 1-1.75", sometimes more if I am being careless. I'll be handloading soon enough.
What version of sterlok?
If it was the free version that is the reason your dopes were off.
The free sterlok version did the same thing too me upgraded too the pro version and dopes line up perfectly with my chrongraphed velocity's and the stated hornady bc.
360y, quartering shot, 123gr Horn Black, impact just behind left armpit, exit out right bowel. Exit hole was 3x larger than entry. Heart and lungs were hamburger, no meat damage and minimal fecal contamination, and the beast walked about six yards before he fell.
I went to the range and shot to 558y with this ammo, and the results past 250y were *way* different than predicted. I entered corrected dope into Strelok and shot the corrected dope at this deer, and it was a win. Either Hornady's BC is quite optimistic, or my chrony is crap (likely). Or both. I am buying a Magnetospeed and will get more numbers.
Rifle still groups between 1-1.75", sometimes more if I am being careless. I'll be handloading soon enough.
What BC were you using for the 123gr ELD-M? Hornady has graduated BC values for the ELD-M listed on their site based on Mach values shot over their doppler radar.
NRA Basic, Pistol, Rifle, Shotgun, RSO
CCW, CQM, DM, Long Range Rifle Instructor
6.5 Grendel Reloading Handbooks & chamber brushes can be found here:
