TMC Posted August 16, 2008 Share Posted August 16, 2008 Hey guys I need any input on why my rifle will not group. My JP 18" barrel with approx 10K through it would not group at 100 yards, the accuracy was about 2.5". I have 3 shooting buddies with the same barrel and their guns will shoot less than 1" at 100 with my ammo. I thought it was due to Winchester 55's but I have tried Nosler 69 BTHP's and Sierra Ballistic tip 55's with the same result. I had given up thinking it was the barrel so I bought a new Saber Defense 20" SS 1x8. The fist day out with all the above ammo got me the same results as the JP barrel. I chronoed the ammo and found the 55' were going 3250 and the 69's were going 2950. I loaded a new batch to get the 55's down to 3050 and the 69 down to 2800 but no better results. I have tried different scopes up to a Leupold Mark 4 6.5-20 and different people shooting but no luck. The rifle has an unknown brand mil-spec flat top receiver, Saber barrel, JP gas block, JP stainless LW bolt carrier & recoil system, JP Handguard, Olympic lower with JP trigger. I have found no cracks in the upper and nothing is loose that I can tell. Any ideas? Link to comment Share on other sites More sharing options...
Robbie Wheaton Jr Posted August 16, 2008 Share Posted August 16, 2008 Have you let someone else try shooting your rifle? Try shooting some factory ammunition. Are you using the same bolt and carrier? Have you checked the headspace on the rifle? It sounds like the bolt is causing the rifle to have excessive headspace which is ruining your groups. Another possible issue could be the brake. Are you using the same brake on the new barrel? Try shooting the rifle without the brake if it headspaces ok. Did you install the barrel? One other possible issue could be the barrel or the handguard/ free float tube has been installed incorrectly causing slight movement. PM me if you need more help. Link to comment Share on other sites More sharing options...
mpeltier Posted August 16, 2008 Share Posted August 16, 2008 I agree with Robbie, try it without anything on the muzzle. If it groups then try a different brand of muzzle break. Did you use the same one on both barrels? and what was (is) it? Link to comment Share on other sites More sharing options...
D.carden Posted August 16, 2008 Share Posted August 16, 2008 (edited) Have you let someone else try shooting your rifle? Try shooting some factory ammunition. Are you using the same bolt and carrier? Have you checked the headspace on the rifle? It sounds like the bolt is causing the rifle to have excessive headspace which is ruining your groups. Another possible issue could be the brake. Are you using the same brake on the new barrel? Try shooting the rifle without the brake if it headspaces ok. Did you install the barrel? One other possible issue could be the barrel or the handguard/ free float tube has been installed incorrectly causing slight movement. PM me if you need more help. I'm one of the "buddies" mentioned in the first post, and did shoot TMC's rifle. I could get a few shots to group and then a flyer or two also.......I'm also confused. When Todd (TMC) chroned the loads, there were huge spreads (am i right Todd ?).....could that be a head space issue ?????...........How does that get adjusted??? Dan Edited August 16, 2008 by D.carden Link to comment Share on other sites More sharing options...
Merlin Orr Posted August 16, 2008 Share Posted August 16, 2008 (edited) Woops.... Did not catch the new barrel my first read.. Edited August 16, 2008 by Merlin Orr Link to comment Share on other sites More sharing options...
JKSNIPER Posted August 16, 2008 Share Posted August 16, 2008 Are you canting the rifle? Possibly resting the barrel on something while shooting? Most weapons problems in quality weapons can be traced to the "nut behind the grip". Since you're already switching out components and achieved the same result I would think that its you and not the weapon. Have someone watch you and figure out whats going on. If noting from you then its probably time for that trip to a reputable gunsmith. JK Link to comment Share on other sites More sharing options...
Jaxshooter Posted August 16, 2008 Share Posted August 16, 2008 His post said his buddies also shot his gun with the same results. His ammo grouped like it should in thier guns so I would say that his gun has a problem. Link to comment Share on other sites More sharing options...
TMC Posted August 16, 2008 Author Share Posted August 16, 2008 Well I just got back from the range and to make a long story short it was the comp. After posting I went into the garage to look things over and noticed the last plate on the comp had some shiny marks on one side. Went to the range and shot the 69's with no comp. With a good wind coming over my left shoulder making it hard to hold steady it shot 1 1/4" group. I put on a differnt comp than yesterday and it shot the same 1" +/- with a slighty different point of impact. It shot the Sierra 55's, which are going 2350fps and then some, and got about the same 1" group. I'M SO HAPPY I guess I should have looked the gun over more closely before posting. I will check the headspace and see if that may be causing the extreme velocity spreads. Thanks guys! Link to comment Share on other sites More sharing options...
outerlimits Posted August 16, 2008 Share Posted August 16, 2008 todd-sounds familiar-my bullets hit my comp at the mem day 3 gun match...after it had unscrewed a bit. but, got a new upper out of the lesson. cool trade. Link to comment Share on other sites More sharing options...
bigsaxdog Posted August 17, 2008 Share Posted August 17, 2008 (edited) my sabre 20" 1 in 8" really likes hornady 75's and varget and LC brass and fed 205m primers. it also likes 77 sierras and noslers and bergers, but it likes hornadys better at longer ranges, i think cause' they're a bit shorter, and they are cheaper, and so am i....... winchester 55's pretty much suck, and any 55's won't shoot as good as the heavier(longer) ones in 1 in 8". just my saturday nite $.02...... Edited August 17, 2008 by bigsaxdog Link to comment Share on other sites More sharing options...
M ammo Posted August 17, 2008 Share Posted August 17, 2008 Things like this make you crazy..... check all of your. mounts and scope stuff. as well,, make sure they are, tight. .02 more cents, Link to comment Share on other sites More sharing options...
uscbigdawg Posted August 17, 2008 Share Posted August 17, 2008 Sorry for getting to this late. The comp was my only guess as all things otherwise were equal. Glad that worked out. Rich Link to comment Share on other sites More sharing options...
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