AznDragon533 Posted July 14, 2013 Share Posted July 14, 2013 Hello, I currently have a stag 3g with a 22lr conversion kit, along with an Burris MTAC scope. Ammo: Federal HP 36g 22lr When I shoot bench rest - 50 yards , I get about 2 inch of grouping When I shoot bench rest - 25 yards , I get about 2 inch of grouping When I shoot 7 yards....Point of impact go 4-5 inches low... how is this possible..and what are the possible solutions? Link to comment Share on other sites More sharing options...
jtielke Posted July 14, 2013 Share Posted July 14, 2013 Because of the scope offset from the center of the bore at close ranges you'll be shooting about 3" low. As you get closer to the distance you have your rifle zeroed at, the line and sight and bullet path converge. AR type rifles have a larger offset than most traditional rifles and you must take this into account when shooting at small close range target. Link to comment Share on other sites More sharing options...
Steve RA Posted July 14, 2013 Share Posted July 14, 2013 The above is correct, if you aren't satisfied with the group size, try several different brands of ammo. .22s usually favor one brand or model over others. Link to comment Share on other sites More sharing options...
P.E. Kelley Posted July 14, 2013 Share Posted July 14, 2013 The conversion kit still uses the 223/5.56 barrel. That is not the "optimal" twist nor bore diameter for super accuracy. 2" at 50 yards is just fine. Link to comment Share on other sites More sharing options...
jkrispies Posted July 14, 2013 Share Posted July 14, 2013 (edited) The conversion kit still uses the 223/5.56 barrel. That is not the "optimal" twist... +1 to all the above with the scope offset. Regarding the quote above, there could be a point here. You might try going with a heavier 40grain bullet to see if it makes a difference in group size. When the world returns to normal and I can pick and choose my ammo I may try this http://www.midwayusa.com/product/978147/winchester-m-22-ammunition-22-long-rifle-40-grain-black-plated-lead-round-nose-box-of-1000. I don't really know what would make it any better than other 40gr with the same velocity but the price isn't unreasonable so it wouldn't hurt to try. Having said that, I'd choose to stick with a copper jacketed bullet to stave off leading. As far as 2" at 50 yards goes, that isn't fantastic but it's good enough for close range practice, which is what I'd assume you bought the conversion kit for. I backordered one for the same reason... and continue to wait and wait and wait for it to come in stock... Edited July 14, 2013 by jkrispies Link to comment Share on other sites More sharing options...
gdboytyler Posted July 14, 2013 Share Posted July 14, 2013 (edited) Hello, I currently have a stag 3g with a 22lr conversion kit, along with an Burris MTAC scope. Ammo: Federal HP 36g 22lr When I shoot bench rest - 50 yards , I get about 2 inch of grouping When I shoot bench rest - 25 yards , I get about 2 inch of grouping When I shoot 7 yards....Point of impact go 4-5 inches low... how is this possible..and what are the possible solutions? Do you re-zero your scope when you switch to 22 LR? If you don't, that's the only reason I could think why your POI is so low at 7 yards; other than operator error. If your 25 yd and 50 yd groups are about the same, I'm going to guess that you are using the same size bullseye for both distances. Try shooting at a smaller bullseye at 25 yards. Your 25yd group should be at most 1/2 the size of your 50 yd group. I'm sure you've heard the famous line from "The Patriot", "Aim small, miss small". With a JP 22LR dedicated upper, I regularly get 1/4" 3-shot groups at 25 yards. Never tried it at 50 yards. I set the scope on the 22LR upper to match the POI at 25 yards of my 5.56 upper to practice the same holdover with my scope. Edited July 14, 2013 by gdboytyler Link to comment Share on other sites More sharing options...
Jaxshooter Posted July 14, 2013 Share Posted July 14, 2013 The JP and Nordic 22 uppers use a traditional 22lr barrel with 1/16 twist. You will never get that accuracy with your 5.56 barrel no matter what ammo you try. Both the JP and Nordic will shoot 1/4" groups all day at 50 yards. My Nordic will shoot Wolf Match ammo at 1/4" or less with no wind. Your groups are fine for practice as mentioned. To do any better you really need a dedicated 22lr upper with a 22 RF barrel. Link to comment Share on other sites More sharing options...
Dan Sierpina Posted July 14, 2013 Share Posted July 14, 2013 As Pat and Jaxshooter pointed out in different replies, the twist of your .5.56 barrel is much faster than the standard 16 inch twist of a .22 rimfire barrel, and the groove diameter is .224 for the centerfire cartridge and .222 for rimfire. The soft lead bullet is overspun and loose in the barrel. Conversion units will never give the accuracy of a proper sized barrel in a dedicated upper. Link to comment Share on other sites More sharing options...
Jesse Tischauser Posted July 21, 2013 Share Posted July 21, 2013 Not much to add that hasn't been said already other than it sounds like you have a sweet setup! Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now