THE NEW GUY 113 Posted August 28, 2015 Report Share Posted August 28, 2015 I recently purchased a new S & W MP 10 . It would not run ZQ1, or Federal Lake City FTF , no ejection problems . After cycling the charging handle about a million times , I decided it was time for a new test these are the results at 40 yards 2 Quote Link to post Share on other sites
Dad2142Dad 6,559 Posted August 28, 2015 Report Share Posted August 28, 2015 Nice holes Quote Link to post Share on other sites
THE NEW GUY 113 Posted August 28, 2015 Author Report Share Posted August 28, 2015 The middle between the 8 and 9 are were I was sighting it in after boresighting . This and the top of the red circle are Winchester 150 gr. power point . The bottom part is Federal 150 gr soft point . I was shooting at the numbers 9, 8 , 7 on the bottom part. the head and middle of the target is Pmc 308b ang Perfecta 308 , I thought it was going pretty well so I ran the last mag pretty fast . Now I am READY, I GO TO WALLY WORLD [yeh I know ] and see some new ammo Perfecta 150 gr soft point [they were out of Winchester ] . I go to the back of the farm put up a target about 100 yards and shoot about 5 rounds I am 8 inches high at 100 yards . I like to be 2 inches at 100 yards , so 6 inches that's 24 clicks . I go 22 clicks and shoot 55 rouns about 2 to 4 inches high . I change to 4 Pmags with ZQ1 and get ready to see if I have any FTF . I am not trying to be perfect just testing it out . I throw 100 rounds down range and have no trouble with feeding problems. YES !!!!!!!! I drive over to the target and all were about 6 inches low . WTF? 1 Quote Link to post Share on other sites
ChileRelleno 7,071 Posted August 28, 2015 Report Share Posted August 28, 2015 Is it dead yet? Quote Link to post Share on other sites
Dad2142Dad 6,559 Posted August 28, 2015 Report Share Posted August 28, 2015 (edited) Glad you got it cycling. Not sure what's up with the 8" drop, your optic still tight? Edited August 28, 2015 by Dad2142Dad 1 Quote Link to post Share on other sites
Hawk451 2,230 Posted August 28, 2015 Report Share Posted August 28, 2015 You missed the spleen, kidneys & epiglottis, I think... 1 Quote Link to post Share on other sites
THE NEW GUY 113 Posted August 28, 2015 Author Report Share Posted August 28, 2015 Is it dead yet? I think so I was wearing it out with good ammo Quote Link to post Share on other sites
THE NEW GUY 113 Posted August 28, 2015 Author Report Share Posted August 28, 2015 Glad you got it cycling. Not sure what's up with the 8" drop, your optic still tight? I don't know it was getting close to dark when I started shooting the ZQ1 . I was so disgusted that I walked off and left the other target screwed to the tree . I am going to check the base and scope tomorrow and make sure everything is tight . Then I will shoot some Hornady and sight it in , it's going in the lead sled . I was having so much trouble getting it to cycle with the ZQ1 that I bought about 150 rounds of various 308 ammo. I liked Winchester the best and the Pmc 308b next . 1 Quote Link to post Share on other sites
YOT 3,743 Posted August 28, 2015 Report Share Posted August 28, 2015 Well, as long as you're not concerned with accuracy, carry on. Quote Link to post Share on other sites
sccritterkiller 473 Posted August 28, 2015 Report Share Posted August 28, 2015 I have a few AR s that do the same thing. The ones chambered in 6.8 seem to have the greatest shift in POI. I can put 4 rd in the x with SSA 110 gr switch to Hornady 110 gr and it moves 3 inches to the left and up 2 inches. Good back to the SSA and I'm back in the X. I gave away the remaining boxes of Hornady I had left and bought 2 cases of SSA. Problem sovled. 1 Quote Link to post Share on other sites
G O B 3,516 Posted August 28, 2015 Report Share Posted August 28, 2015 Different ammo, different paramaters. The more the paramaters differ, the more the point of impact will differ. 1 Quote Link to post Share on other sites
Doug Hartley 526 Posted August 28, 2015 Report Share Posted August 28, 2015 My advice is to find out what your gun shoots the best and buy it by the case. That hole at the top of the red dot looks pretty tight, seems like it shot that stuff very well. Doug 2 Quote Link to post Share on other sites
HB of CJ 1,263 Posted August 28, 2015 Report Share Posted August 28, 2015 Best guess here is that something in the sighting system is very loose. Next possibility is the barrel flops around in the truncheon. Are you applying great down pressure on the barrel in the rest? The FTFs has me confused. What would cause that? Inspect the fired cases for gross head space concerns. Set up multiple targets and use a good spotting scope so you see the holes. Grab your rifle hard and try to literally twist/bend it around. See if there is any detectable movement. What does the Crown look like? Can you easily slug and measure the bore diameter? Use a 00 or 000 buck shot. Tap it into the bore, then push it through, then mike it. What does the bore rifling look like? The must be something major wrong with the build. Unsafe? Hope this helps. HB. Quote Link to post Share on other sites
Doug Hartley 526 Posted August 28, 2015 Report Share Posted August 28, 2015 Something similar happened to me this week. I got a new 6mm Creedmoor barrel installed on my JP LRP-07 (AR-10) and I could barely hit a 2'x2" target at 100 yards. Very disconcerting considering the gun should shoot around 1/2" at 100. Turns out the barrel was a 1-10 twist instead of a 1-8 that I had ordered. You have to have the correct twist for the shape and weight of projectile you are shooting. Too slow and the bullet will not stablize, too fast and the bullet may explode from over rotation. Below is link to the Berger Twist Rate Calculator that you can put in the parameters for your bullet and find out if you have the correct twist. http://www.bergerbullets.com/twist-rate-calculator/ Doug 3 Quote Link to post Share on other sites
YOT 3,743 Posted August 28, 2015 Report Share Posted August 28, 2015 Thanks for that link. 2 Quote Link to post Share on other sites
Doug Hartley 526 Posted August 28, 2015 Report Share Posted August 28, 2015 For those that have not seen over rotated bullets explode it's kind of interesting. I shot a 3 gun match with a friend that had loaded some light varmint bullets and he couldn't hit any far targets. We noticed little puffs of smoke when he was shooting. The bullets would reach a critical point and just vaporize. My 105 Bergers are supposed to be rotating around 250,000 rpm. The 1-10 barrel I got only rotated them at about 200,000 which was not fast enough to stabilize them. Doug 2 Quote Link to post Share on other sites
G O B 3,516 Posted August 29, 2015 Report Share Posted August 29, 2015 Quick and dirty way to find out what a new gun likes to eat Get 3 boxes of ammo. One with a light bullet and high velocity, one with a heavy bullet and slow velocity, and one with a mid range bullet and average velocity. Should dial you in to what it likes. 1 Quote Link to post Share on other sites
HB of CJ 1,263 Posted August 30, 2015 Report Share Posted August 30, 2015 One would think your new cool build would print pretty good using whatever ammo. Obviously that is not the situation. About the only thing not discussed and cussed would be to cast the chamber and lead. Then cast a short part of the bore.. Perhaps in one pour? Right now my feeble mind is keying in on the possibility of a bad barrel blank made into a bad barrel. Twist rate like already discussed better? Actual bore diameter? Can you provide pics of the fired brass? Right now I am swinging at air only. Sorry. HB Quote Link to post Share on other sites
Hawk451 2,230 Posted August 30, 2015 Report Share Posted August 30, 2015 (edited) What you might try for chamber/throat cast. Too shallow a leade might make big difference due to different ogive profiles of different loads. Edited August 30, 2015 by Hawk451 Quote Link to post Share on other sites
gunfun 3,931 Posted September 3, 2015 Report Share Posted September 3, 2015 For those that have not seen over rotated bullets explode it's kind of interesting. I shot a 3 gun match with a friend that had loaded some light varmint bullets and he couldn't hit any far targets. We noticed little puffs of smoke when he was shooting. The bullets would reach a critical point and just vaporize. My 105 Bergers are supposed to be rotating around 250,000 rpm. The 1-10 barrel I got only rotated them at about 200,000 which was not fast enough to stabilize them. Doug Not in person, but I read a few articles with super high speed photos. Interesting stuff for sure. Quote Link to post Share on other sites
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