Load development problems



  • I have a 223 that is driving me insane. When i first bought it I worked up a good load for it with IMR 8208 and the 80 gr ELD’s. Gun consistently shot in the mid to high .3’s with single digit SD’s for a 20 shot string. I’ve even won a 600 yard Fclass match with it. It’s a Ruger Precision Rifle and had problems with primer cratering on mild loads so I sent the bolt off and had it bushed. Every since then it has shot like shit, It still shoots accurately but no matter what I do I can’t get the ES and SD in check. I haven’t changed lot numbers on any component powder, primers, bullets etc... I’ve even tried different powders, bullets and primer nothing works. For 3 rounds a typical SD will be in the high teens low 20’s. Barrel has just over 900 rounds on it so I can’t see that being an issue but it is a factory barrel so I could be wrong. Any ideas or suggestions?



  • If all that was changed was the bushed bolt... it sounds like they may have created an ignition problem. Does the firing pin move freely in there?

    Otherwise you could always try switching components. Try some varget or h4895.



  • @orkan
    Well you may not remember but I posted something a while back about this rifle, where I had shortened the firing pin and thought that was what caused the issue, so I sent it off and had it bushed which it needed anyway. I haven’t tried 4895, but I’ve tried varget, 8208, and power pro 2000 mr. Varget was actually the worst in terms of muzzle velocity consistency. I’ve tried the 80 eld’s and 70 gr RDF’s both of which I’ve had previously good results with it this rifle. For primers I’ve tried CCI 450, 400, BR-4, and federal. I’m at a complete loss. Firing pin moves freely and the fit is amazing, I haven’t checked the protrusion yet since getting it back so I’ll see what it’s at now. Anyway this could be barrel related?



  • So does it shoot like shit or does it shoot accurately? Bushing a firing pin shouldn’t degrade precision nor accuracy. Check your firing pin protrusion then review your reloading basics. When was the last time you annealed your Brass? When was the last time you calibrated your powder scale?



  • @rr2241tx it shoots like shit just like I said. It does shoot accurately and precisely at 100 yards, but the SD’s and ES have gone to hell regardless what I do which in turn means it will shoot like shit at range. I anneal after every firing and calibrate my scales every time I use them. I use a satorious Entris 64 and an auto trickler for my powder charges. I’m no self proclaimed expert but this isn’t my first rodeo either. I’ve been loading for close to 20 years and have been pretty successful at it. I usually try to avoid asking questions on forums due to smart ass responses unless it’s my last option. The original load of 23.9 grains of 8208 ran great for 500 rounds or so. The problem came about when I fixed the cratering primer issue which was due to a sloppy fitment of the firing pin. I’m not saying there isn’t an issue with the bushing job especially since this problem seems to have started after it was done, I’ll check the protrusion in the morning.



  • I'm wondering if colder weather has thrown your SD and ES off?



  • @norcal_in_az I could see that possibly for one load, but for everything regardless of charge weight, or components? I’ve never ran into anything like that before. Ever had anything like that happen to you due to cold weather?



  • @bull81 No I haven't. But I don't live where real cold weather exist.



  • @bull81 didn’t mean to be a smartass, sorry I offended you. I have had simple things cause problems before. A load cell developed a resistance problem once. It would calibrate fine with 20 & 50 gram calibration weights but wouldn’t weigh 25.9 grains for squat. Another time someone being helpful rearranged my box of annealed Brass and the box of freshly cleaned brass, amazing how similar two large Accro bins half full of shiny Brass look. It shouldn’t happen but even reliable gunsmiths sometimes don’t write down pin protrusion data beforehand and will return a target Rifle with pin protrusion “within spec” but quite different than it was when they received the Rifle for repair. Down here in the sunny south land it’s pretty common for scores to drop off during the winter because we aren’t wearing our summer shirts and our hands are cold. Might be worth the time to have a look at your throat and crown with a borescope that sends pictures to a computer screen.



  • @rr2241tx thanks for the clarification, it had been a long day yesterday. All to many times on forum you get smartass “know it all self proclaimed experts” that just spit out bullshit and that just pisses me off. Main reason I joined this forum is because that sort of thing is kept to a minimum, so I am sorry I jumped to conclusions. I am wondering myself if it’s not something with the throat area, figured if it was in the crown it would show up on target with poor accuracy. I’ll keep messing with it and will try some H4895 to see if any improvements can be made, I’m pretty doubtful at this point though. If I can’t get it squared away I’m gonna just have a good barrel spun up for it



  • Ok checked firing pin protrusion and it’s at .045 which is pretty close to where it was when I sent it off if memory serves me. Just ran an ocw with H4895 with the same results as everything else. Good accuracy with horrible ES and SD’s.



  • @bull81 said:

    it shoots like shit just like I said. It does shoot accurately and precisely at 100 yards, but the SD’s and ES have gone to hell regardless what I do

    This is a very confusing approach. It can't shoot like shit and also shoot accurately and precisely. Please talk specifics so I can help you here.

    What is your load details pre-bolt bushing? What were group sizes at 100yds? Did those groups drift POI at all? What was the ES/SD of that load at that time? How many rounds have you fired since that load workup and data collection? How many rounds lapsed since the last data collection to the time you sent the bolt off? Did you shoot it on paper before you sent it off to be bushed? If so, how did it shoot then? Did you chrono it at that time?

    If the bolt bushing is the cause of ES/SD, then the bushing is interfering with consistent ignition. < That's pretty much a certainty. However, if the ES/SD problem was there prior to sending it off... then it's not the bolt bushing's fault. Also, if the bushing is at fault, it could be at fault in a very subtle way. It doesn't take much to cause ignition issues.

    What about your priming process? Are you certain you're getting primers set correctly. BIG cause of ignition problems right there.

    If you think it's the barrel, drop in aftermarket barrels are plentiful for that rifle. Easy enough to find out.



  • @orkan
    The point of impact has not changed and the group size on paper has not changed. That’s what I meant by accurately and precisely. What has changed is the consistency of the muzzle velocity. The loaD for this rifle was 23.9 grains of 8208 and 80 grain eld’s. That load had a SD of 9. something for 20 rounds and a muzzle velocity of 2787. This was chronographed several times through out the first 500 or so. I can’t tell you exactly how many times or how many rounds between but it was always pretty much the same results. I was having primer cratering problems and had a firing pin protrusion of .060 or more so I filed it down. The primer cratering problem went away but accuracy went to hell and that load fell apart and opened up from the mid .3’s to a little over 1 moa. During this time I fired probably 50 or 60 rounds as I worked on the pin trying to straighten it up, all across the chronograph with pretty much the same results I’m getting now. Realizing I had created a new problem by fooling with the firing pin I sent it off and had it bushed and reworked by Gre-tan rifles. Once it was returned the accuracy returned to the mid to high .3’s but velocity consistency has continued to be an issue. I still have 100 rounds of the original load that shot so good before all of this and checked it as well. Velocity has dropped about 40 fps and the consistency is gone. I tried doing a complete new load work up which is what brought me to the thread. As for priming I use one of your CPS priming tools which by the way is flat out amazing.
    Like I said before I am not saying it’s not something to do with the bushing job but I don’t know what to check or where to start. I’ve taken it all apart and there doesn’t seem to be anything dragging or hanging up that I can see or feel.



  • @bull81 said:

    The point of impact has not changed and the group size on paper has not changed.

    @bull81 said:

    The primer cratering problem went away but accuracy went to hell and that load fell apart and opened up from the mid .3’s to a little over 1 moa.

    @bull81 said:

    I sent it off and had it bushed and reworked by Gre-tan rifles. Once it was returned the accuracy returned to the mid to high .3’s but velocity consistency has continued to be an issue.

    Everything you're saying points to ignition problems caused by something going on in that bolt. Have you tried switching primers? Have you torn the bolt down and polished/dry lubed all surfaces? You might also try to play with primer seating depth.

    Might be worth your while to get a new bolt entirely to try out.



  • @orkan
    I have tried several different primers with no luck. What would you suggest on primer seating depth? Currently I seat one until I feel solid contact with the bottom of the pocket then adjust the wheel another click or two deeper. I have no idea what to polish inside the bolt could you give me some direction as to what parts your referring too? Not sure about trying a new bolt, I see ruger has removed the 223 RPR from their website so it looks like they may be discontinuing it.



  • The procedure I recommend for seating depth is to measure the primer pocket depth, then measure the primer height across the anvil. Then seat the primer so that you get about .002 to .005 of crush on the anvil. So if the primer pocket measures .127, and the primer is .125 high, then the primer should be .004 to .007 below flush. This will give the prongs of the anvil a good firm hold on the bottom of the primer pocket. That's where I start. From there I will go deeper if necessary during testing of ignition.

    Regarding dry lube, I'd use a spray on graphite or teflon dry product which I'd use on the firing pin, spring, striker or any other moving part inside.

    RPR is certainly not what I'd call a quality firearm... and certainly isn't one I'd spend a bunch of time on.



  • @orkan thanks I’ll give all that I try. I know the RPR’s aren’t top notch but for the money the 223’s are a descent little gun that doesn’t cost a arm and a leg and the 223 is cheap to load and shoot. Up until this point it’s been a good shooter and I’ve enjoyed the hell out of it.



  • I would do what Orkan said. When it got bushed did he coat the face of the bolt and if so is there coating over spray in the hole for the firing pin.



  • Update

    Took the bolt apart and found a small spot on the back end of the firing pin that slides in the bushing that looked like it had some wear on it. I took some 600 grit sand paper and wet polished it out. Lubed everything up with a spray graphite as @orkan suggested and shot a OCW today. Landed right back on my original charge weight of 23.9 grains of 8208 and the velocity was 2785 for 3 rounds. 2 fps difference than the original load, I call that good. ES was 3 and SD was 1.5. All but one charge weight of the ocw test had single digit SD’s.
    Thanks everyone for the help, ideas, and advice.



  • Glad to hear you got it resolved.



  • I hope a lot of people have seen this thread, because it is first hand 100% direct evidence of how important it is to have proper ignition.

    I'll certainly be using this thread when people try to complain about our $600 priming tool. Improperly primed cases is probably the second most common cause of ES/SD problems. The most common being bullet seating pressure variance. However, as this thread proves, both ignition and seating issues can easily change positions as the cause of massive issues.



  • @orkan said:

    I hope a lot of people have seen this thread, because it is first hand 100% direct evidence of how important it is to have proper ignition.

    I'll certainly be using this thread when people try to complain about our $600 priming tool.

    Forgot to mention I also adjusted the CPS like you suggested, to give a .002 crush for the loads in the OCW test today.



  • @orkan
    Is it possible that something else was at work? Maybe a piece of brass shaving in the bolt keeping the firing pin from fully extending? It could have fallen out when the bolt was disassembled.

    Cant get my head around cleaning the BACK of the firing pin making a difference. I get the primer seating depth issue, but taking material off the back of a worn firing pin, don't get it.. I'd expect that if you take material off the back you shorten the pin.



  • Ignition is a complicated issue. Probably the most taken for granted and over-simplified aspect of this sport.

    It's very possible something else was at work. Yet without performing each step individually and testing after, you will never know what the actual cause was.



  • @martino1 said:

    @orkan
    Is it possible that something else was at work? Maybe a piece of brass shaving in the bolt keeping the firing pin from fully extending? It could have fallen out when the bolt was disassembled.

    Cant get my head around cleaning the BACK of the firing pin making a difference. I get the primer seating depth issue, but taking material off the back of a worn firing pin, don't get it.. I'd expect that if you take material off the back you shorten the pin.

    When the pin was bushed, he extended the small position of the pin. It’s about 1/2 to 5/8 inch long now. Inside the bolt is a long bushing that the small end of the pin rides in. There was a spot about half way down that small portion of the pin. I’m not sure what it was maybe a rough spot from the tooling or something like that.



  • said:

    There was a spot about half way down that small portion of the pin.

    ... and that was why I asked about the fitment of the firing pin early on. ;)

    It doesn't take much drag to really screw up the inertia in a firing mechanism. No doubt that spot you found was binding at high speeds during the pin fall, which would explain the inconsistent ignition. Good on you for checking and rechecking until you found it. Early on, you seemed pretty certain of fitment when I asked. ;)

    @martino1 I didn't understand this to be the "back" of the firing pin. I understood it to be as @bull81 has described, along the side on the cylindrical surface. If one of two parts made to slide past one another has a high spot, it will deflect under speed. Deflection = binding = inconsistent movement = inertia robbing.



  • @orkan said:

    said:
    Good on you for checking and rechecking until you found it. Early on, you seemed pretty certain of fitment when I asked. ;)

    Well I was pretty certain and had not noticed it at first. Also knew I could easily have missed something and wasn’t to proud to check again. I’m just glad you and everyone else that chimed in was able to help narrow it down. Really like that little rifle, and was about to loose my patience with it.



  • @orkan said:

    said:

    There was a spot about half way down that small portion of the pin.

    ... and that was why I asked about the fitment of the firing pin early on. ;)

    It doesn't take much drag to really screw up the inertia in a firing mechanism. No doubt that spot you found was binding at high speeds during the pin fall, which would explain the inconsistent ignition. Good on you for checking and rechecking until you found it. Early on, you seemed pretty certain of fitment when I asked. ;)

    @martino1 I didn't understand this to be the "back" of the firing pin. I understood it to be as @bull81 has described, along the side on the cylindrical surface. If one of two parts made to slide past one another has a high spot, it will deflect under speed. Deflection = binding = inconsistent movement = inertia robbing.

    Thanks Greg
    I understand.


 

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