Posted: 5/11/2013 3:13:31 PM EDT
|
OK. I am sure I will get all kinds of stupid answers (GD and all), but there is some good people here.
I have a POF-415 that has a 1:8 barrel twist and with a Trijicon Accupoint 1-4 x 30mm scope. I went to zero it for 200 yards with Hornady 75 grain BTHP Match. With that load and a 200 yd zero it should be hitting at 1.8 high at 100 yds with my set up (not really important, but I know people will ask). I proceeded to shoot and got several nice 5 round groups off a rest (.6 - .9 inches) with the Hornady 75 grain. So then I switched to Federal 55 grain (Walmart 100 round bulk packs) just to see what the difference would be since I use that for plinking. I proceeded to shoot a three round group and I was about two inches high which I expected, but it was four inches right ( the group was about 1.25"). So I shot another group with the same results. I then went back to the 75 grain Hornady and it was shooting dead center right with the other groups. I have talked to a few people, including folks at POF, and several say spin drift (but at 100 yds 4" seems extreme) and a few others say it could very well be the muzzle brake. FYI the POF muzzle brake has ports on the sides and one hole on the 10 o'clock position and three holes on the 2 o'clock position. Also I only had the two types of ammo on hand. When I can I am goin to go out with some 40, 55, 62 green tip, 68 hp, and 75 grain ammo from different manufacturers to see what happens. Also after I shoot one group each I will take off the brake and see if that helps. So what does arfcom think? Is it spin drift, the federal ammo, the muzzle brake, the barrel, aliens or what? Let me know! |
|
The easy way to check is go back to your normal load and see if it still hits in the same place.
Then you know it's the ammo. Otherwise I would start looking for any sign of optic shifting. I find a little reference spot so I can visually check if the scope has been shifting forward due to recoil. |
|
Quoted:
Quoted:
Quoted:
I've had horizontal differences in different loads in many different types of guns. It's normal. But 4" at just 100 yds? Normal, have seen worse. I have a Weatherby .257 mag. An older one. Say 1970's. that thing is an absolute tack driver. But only with Weatherby ammo. We bought some Hornady ammo for it because it was way cheaper. Those bullets on that gun are worthless beyond 30 yards. We had 1' groups or more at 100 yards. We would rarely hit paper That far. We would get decent groups at 50 yards then move back. Thought the gun had been shot all that it could shoot. Went and got some Weatherby brand and 6 shots later we had one jagged hole at 100 yards. Semi-long story short, some ammo just will not shoot out of a gun. Different bullet, powder, charge, bullet grain, all come into play. |
| 75gr PPU and 55gr PMC both grouped about 4" right of my 69gr hand loads this weekend at 200 yards, with PMC being about 1" higher than the PPU. Still managed a 90 1x with the PMC and 94 2x with the PPU at 200 yards standing once I dialed in for the difference in POI. |
|
Quoted:
The easy way to check is go back to your normal load and see if it still hits in the same place. Then you know it's the ammo. Otherwise I would start looking for any sign of optic shifting. I find a little reference spot so I can visually check if the scope has been shifting forward due to recoil. I did that and it was in the same spot as before. |