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Posted: 12/7/2011 3:23:04 PM EDT
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Between QUALITY factory loads? I am asking about grains from 55 to 77.
Does a 55gr federal Game King fly much different then a 55gr Federal Match King? Or would a 55gr SMK fly much different then a 77gr SMK at say 100-200 yards? (Would you notice a difference while using iron sights?) Would a 55gr fly much different then a 64gr bullet that it would require that much adjustment? Is it the difference in inches high or low at 100 yards of barley enough to see unless you are shooting a precision rig with quality glass? I have sighted in with 55gr wolf and once I was consistent I've touched it up with my hunting ammo (64gr Winchester Power Points) and did notice a slightly tighter grouping but I am also using stock iron sights. At what distance will you see a noticeable deviation at between the 55gr and 77gr? ETA: If this is more appropriate in the Precision forum then please move 
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Quoted:
Between QUALITY factory loads? I am asking about grains from 55 to 77. Does a 55gr federal Game King fly much different then a 55gr Federal Match King? Or would a 55gr SMK fly much different then a 77gr SMK at say 100-200 yards? (Would you notice a difference while using iron sights?) Would a 55gr fly much different then a 64gr bullet that it would require that much adjustment? Is it the difference in inches high or low at 100 yards of barley enough to see unless you are shooting a precision rig with quality glass? I have sighted in with 55gr wolf and once I was consistent I've touched it up with my hunting ammo (64gr Winchester Power Points) and did notice a slightly tighter grouping but I am also using stock iron sights. At what distance will you see a noticeable deviation at between the 55gr and 77gr? ETA: If this is more appropriate in the Precision forum then please move It's not just a matter of bullet weight or powder charge of the ammunition. Different loads will come out of different barrels differently. You will notice POI changes between loads, but it's usually within 3-4 inches at 100 yards. If it's for self defense with iron sights, you won't notice the difference because you'll be much closer than 100 yards. If it's for target practice at or beyond 100 yards with a resonably accurate rifle with a barely decent scope, you will notice a difference. |
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Quoted:
Only one way to actually find out..............trigger time. There are WAY too many variables to ever guess, what your gun will do with different loads. 9080 Yeah I figure but a good guess would help out just as I have some hunting ammo and don't want to waste time I don't have at the range instead of in the field. |
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Yeah I figure but a good guess would help out just as I have some hunting ammo and don't want to waste time I don't have at the range instead of in the field.
Okay, here is the best "guess" I can give you. the 77 gr. will be 3'' low, 1.873'' left. If above 82 degrees F., adjust by a +factor of .0455 moa. As for the 55's, you might want to hold over (kentucky windage), 7 inches right, and 1/4'' low. That's a tricky one. As for the power points, dead center, but hold 16'' low, at 8:00. That is one you really have to be on your game with. As for FMJ stuff, not sure on that one. I might try extrapolating a formula between the rest of my scientific findings, and see if I might be able to come up with some type of an algrythem, that will yield a a result that I might be able to quantify into a usable data point that might give us a starting dope for that load. Not really sure though. I'll get back to you on that one. One last thing. These are all numbers using a 4000 decimeter zero, with a 40 kt. 1/2 value wind. I sure hope that this helps. It is the best guess that I could come up with. Please let us know how all of this works out. Good luck in the field. |
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Quoted:
Between QUALITY factory loads? I am asking about grains from 55 to 77. Does a 55gr federal Game King fly much different then a 55gr Federal Match King? Or would a 55gr SMK fly much different then a 77gr SMK at say 100-200 yards? (Would you notice a difference while using iron sights?) Would a 55gr fly much different then a 64gr bullet that it would require that much adjustment? Is it the difference in inches high or low at 100 yards of barley enough to see unless you are shooting a precision rig with quality glass? I have sighted in with 55gr wolf and once I was consistent I've touched it up with my hunting ammo (64gr Winchester Power Points) and did notice a slightly tighter grouping but I am also using stock iron sights. At what distance will you see a noticeable deviation at between the 55gr and 77gr? ETA: If this is more appropriate in the Precision forum then please move When I first started shooting Black Hills 77/75gr 14.5 M4 carbine I notice the POA/POI was very close to 62gr SS109 If I was shooting a scoped Rifle I might worry about the .5 difference |
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FOUND THIS IN ANOTHER PLACE. SAME QUESTION.
QUOTING:Part of an answer sort of on your topic question, copy/pasted from another time: I have done some experimenting using a Rock River Predator Pursuit and Leupold 1.5x5X Target scope off a bipod. All are 10 shot groups or averages of 10 shot groups. The windage did not change for any of the groups below. Same Windage zero for all weights/ammos. 200 Yard Info 0" impact: Federal GM .223 Match 69 grain Sierra OTM, stock #GM223M, (Groups in the 0.5-0.75 MOA range) 0" impact: Handload, 69 Sierra OTM, 25.3 and 25.5 Varget, CCI400 primers, mixed cases, intended to duplicate velocity of GM223M (Groups in the 1.0 MOA range) 0" impact: Black Hills 77 Match OTM .223 2650fps loading factory ammo. Groups at 1.0 MOA. Same exact point of impact as 69 grain loads factory and handloads. 1.5" low: Handload, 77 Sierra OTM, LC-08 Primed and crimped factory brass (not commercially available), 24.0 grains Varget, 2.25" COAL Groups at 1.0 MOA and very mild shooting. Fired cases just dribble out of the Rock River and go about 18"-24" to 1:30 on a clock. (roughly a 2550 fps loading and is too slow so impacts slighly low due to not enough muzzle jump at firing. Working on a faster loading.) 335 Yard Info 5.4" high impact: Hornady Superformance 5.56mm Match 75 grain OTM, stock #81264 (Groups from 1.8MOA through 2.5 MOA) 0" impact: Federal GM .223 Match 69 grain Sierra OTM, stock #GM223M, (Groups in the 0.5-0.75 MOA range) 0" or a hair down: Handload, 69 Sierra OTM, 25.5 Varget, CCI400 primers, mixed cases, intended to duplicate velocity of GM223M (Groups in the 1.0 MOA range) 0.7" low impact: Handload, 69 Sierra OTM, 25.3 Varget, CCI400 primers, mixed cases, intended to duplicate velocity of GM223M (Groups in the 0.75-1.4 MOA range) 2.4" low impact: Black Hills factory 77 grain OTM .223 Match loading (Groups in the 0.80-1.2 MOA range) 3.9" low impact: Handload, 77 Sierra OTM, 24.3 Varget, LC-08 USGI primed brass as above. (Groups from 0.72 to 0.96 MOA.)(extremely consistent verticle dispersion.)(Note impact of 0.5 MOA below BHA77OTM.) 5.7" low impact: Handload, 77 Sierra OTM, 24.0 Varget, LC-08 USGI primed brass as above. (Groups just over 1 MOA.) (Note impact of 1.0 MOA below BHA77OTM.) It would seem that the idea is useful. This rifle has been used at 200 yards for only one group of 55 grain .223 ammo, Federal FMJ, and that also landed at about the "0" but I need to check it more. The FMJ factory ammo is not so accurate as OTM loads. (Before any one yowls about the 24.0 Varget/77OTM loading, the Wylde chamber in the Rock River is neither a .223 nor a 5.56mm. The load is too mild if anything, pending further checking. On advice of the bullet maker's ballistic technicians, 24.3 grains Varget was tried with the results as above. That would seem the limit of Varget because while there were no case, primer, or ejection signs of pressure, the bolt velocity was increasing meaning the gas port pressure was moving up.) (The other item of note is the accuracy. The 1:8" twist's accuracy was fairly uniform. Note that these are 10 shot groups. The Hornady Superformance 5.56mm was terrible. Don't waste your money. It looked like shotgun pellet groups with no tendency to make a group center. My guess is that 55-69-77 grain ammo with "normal" full power recoil impulse puts the bullets at shorter ranges very close to the same point of impact using a heavy barrelled 20" rifle. There is a greater dispersion vertically from shorter and lighter barrels due to barrel jump and bore time. I would also note that the windage zeros were identical. All dispersion was verticle, if any.) |
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