Looking for suggestions to tighten groups

[quack1]

I have been working with 4198 powder in a 25-06 with the Lyman 257464 and have run into the problem of a flyer in every 3-5 shots( I occasionly cause a bad shot, but have been shooting long enough to know when it is my fault, and these flyers aren't from me). It doesn't matter if I shoot 3 shot groups or 10 shot groups, there will be a flier every 3 to 5 shots that opens a nice cluster of shots (3/4" to 1") to 2 1/2" to 3", and oddly enough, never any larger. The flyers are random, never the same number shot and can be any direction away from the group. I have shot at least 15 groups some 3, some 5 and some 10 shots and every 3-5 shots,one will be out of the group. The bullets are all the same batch of WW plus a little tin alloy and weighed to within .2 grains, the cases are segregated in groups within 3 grains and get necks annealed every 3 loadings. The bullets drop .2585 and the sizer I made just crimps the gas check on and lubes, without touching the driving bands. The lube is Felix and I lube 3 grooves. I tried lubing more and less grooves, but 3 works the best. I seat the bullets to snugly touch the lands, any more and the bullets stick when ejecting a loaded round. I did try seating deeper in .005 increments with no grouping change. I dont crimp, just smooth out the bell. Bullets are measured concentric within .005. Velocity is nice and steady 2050fps. I would like to keep velocity at least 2000 as I want to use the load to hunt with. I did try faster, with lousy accuracy and started to get leading between 2100 and 2200. I have a week or so that I can't shoot as the berms at the range where I shoot are being built up and was hoping somebody would have suggestions what might be causing the flyers. Although I don't suspect the scope and have checked the screws on the rings and bases, I am going to try a different scope when I can start shooting again.
I welcome any suggestions. Thanks.

[grouch]

If you've tried all the basics like bedding, I'd try another powder. My rifles have had some decided preferences. With your velocity requirements, I'd try H414, IMR 4320, 4831, and 4895 to start with. It may not help, but it's less expensive than new scopes and gunsmithing.
Grouch

[JCherry]

Many of the problems you have mentioned can be solved by simply checking that loose nut behind the butt plate.

Have Fun,

JCherry

[quack1]

Grouch- I forgot to say I have tried 4895 and 3031 and 748 with less success than 4198. I have some 4831 but thought it was too slow burning to reduce the minimum book loads (detonation). Plus, I don't think my alloy would take the 3000fps minimum book loads. The gun will shoot jacketed very well, and will keep the 257464 bullet within 1 1/2" with 2400 at velocities around 1400-1500.
JCherry- I thought the same thing, so had a buddy shoot a few groups-same thing, a flyer every 3-5 shots.

[44man]

Powder can do it. I had pressure and velocity excursions with 4198 in some calibers.
Try Varget and see what happens.

[Harter66]

I've had the issues you described w/my fast twist 30s , I have to get my cases w/in 1.5gn to get really nice groups beyond 1600fps .

[Char-Gar]

Step 1 is to weight and sort your bullets. Make certain there are no hidden voids or defects. Also be merciless inspecting your bullets and discard any that are not 100% perfect.

There could be a number of causes for your flyers, but I would start here. Rule out bad bullets before you go on.

[plainsman456]

I am beginning to like varget as well for cast.So far it has been doing a good job in my 8mm Mauser shooting a 220 grain boolit at 2235 fps with good groups at 100 yards.
Minute of deer groups so far.
I have been using 2500+ lube with a gas check.

[JeffinNZ]

Move closer to the target. :-)

[Gtek]

First I would push with tight dry patch after two rounds and see if that changes anything. It sounds like you found a recipe it likes, now tweek a little more. If it holds after two shot pushes start thinking lube change. Lube star or excess on muzzle face? Ain't it fun? Gtek

[quack1]

gtek-I'm getting what I think is a reasonable lube star-takes a couple of shots to appear, doesn't get any heavier with more shots. Bore shows about the same amount of powder fouling clear past 20-25 shots with no lead showing. Lube isn't something I have thought about changing as Felix has worked for me in other calibers with the same alloy and speeds. Maybe I should.
Chargar-I do weigh bullets- they are segregated in lots that are no more than .2 grains different, weighed on a laboratory balance where I worked.
Harter66- The cases I'm using are weighed into 3 grains difference lots-I'll tighten that up.
JeffinNZ- I forgot to say- I'm only shooting at 100yds. Typing this has just given me the thought-will the flyers show up at 50 or 75yds?. I have only been shooting at 100yds. I'll try a few groups closer.
I may have to try other powders as several have suggested, but the gun seems to be close to working with this load, and I'd like to try to eliminate the flyers, just to satisfy my curiosity.
This thread has given me some new ideas to try to tweak the load. Sometimes I get in a rut when developing a load, and need some fresh ideas to get me started thinking. I appreciate all the help and I'm open to more thoughts or methods.

[Larry Gibson]

hmmmm....25-06 with probably a 10" twist, faster burning 4198......"nice and steady 2050fps" (147,600 RPM) ......"there will be a flier every 3 to 5 shots that opens a nice cluster of shots (3/4" to 1") to 2 1/2" to 3",........"gun will shoot jacketed very well, and will keep the 257464 bullet within 1 1/2" with 2400 at velocities around 1400-1500"..........Hmmmmmm, now I wonder......nothing but the classic signs of it.........naw couldn't be......could it?

Larry Gibson

[quack1]

Larry- It is a 10" twist, forgot to add that in the OP. I had considered RPM's, but never read completely through all the threads as they always seem to turn into an arguement. I'll go back and read them the whole way through. Should be easy enough to try. I figure about 1900-1950 fps should get me at or just below 140000RPM. I also will try oven hardening some bullets (have been using AC WW plus a little tin) as I'm less than 8000RPM away from 140000. Who knows, harder might be enough to get rid of the flyers. I'll also try 4895 (slightly slower than 4198) at 1900-1950fps. I had tried it at over 2000 with poor accuracy.
I'm limited to powder selection as I'm developing this load for a buddy's gun (and to further my knowledge) and he wants to use powders that he has on hand without buying new ones, if possible.

[CJR]

Quack1,

Did you develop your current load using the "ladder incremental method"? If not, I'd give it a try to find your rifle's "sweet spot"; i.e. powder charge range where the VERTICAL POIs, in this charge range, are all very close on the target. Then pick the charge weight that puts you in the middle of that charge range and see if you keep getting fliers. Normally, this technique will keep your groups tight even though there may be pressure changes due to type powders, primers, neck tension, temperature changes, bullet weight spreads, barrel friction changes, etc.

Best regards,

CJR

[Mavrick]

Have you tried a filler?
I like to use dacron, about 2gr or so, then fluff it up so it holds the powder in place, but isn't packed.
If you don't like that, point the barrel up as you close the bolt, then ease it down on the bags.
Good luck, and have fun,
Gene

[Larry Gibson]

quack1

The uncalled flyers are the first indication that the load with the faster powder at that RPM rate is at it's RPM threshold with some shots (the flyers) exceeding the RPM threshold.

Since you are developing the load for a friend (nice guy that you are:-) ) and are stuck with the faster burning 4198 powder and the 10" twist let me suggest;

As maverick suggests use a dacron filler but I'd recommend a 3/4 gr amount of dacron. There is a good thread titled "Fillers" on another forum here at Cast Boolits. This will help with ignition consistency. If 4895 is available you might also retry that powder with the same dacron filler.

BTW; using a slow powder like 4831 at reduced density with the dacron filler or other fillers such as buffer and a cast bullet does not give any indications of "detonation" (actually SEE).

Start low where velocities will be in the 1600 fps range. Use a minimum of 7 shots in a test string, preferably 10 shots. Yes that is a lot of shots and componants but it gives the highest probably confidence that the chronograph data is and the group size are meaningful. Also if you call a shot out of the group a 10 shot groups still leaves a sufficient amount of 'good" shots to still give confidence in the group size. Using 3 and 5 shot test strings can give deceptive results many times, more often than many suspect..

Initially work up in 1 gr increments with the 7 - 10 shot groups. This will tell you quickly where accuracy and ignition consistency is best and where the RPM threshold is. Accuracy will go south; 1st with uncalled flyers and then with the whole group opening up. Sometimes this happens quickly and other times not.

Using this technique you will quickly find the best group with acceptable ES/SD. If a 7 - 10 shot test then an ES of 50 - 60 fps with and SD 25 - 40% of the ES is acceptable. Smaller is better but the % relationsip between the ES and SD needs to remain. An extremely sma SD with a large ES is not good.

Having found that "best" group then load up 10 shot test strings of that load an 1/2 gr on either side and test those. BTW; testing should be done at 100 yards minimum for group size. You should get a really good idea which load is best after that test. I would expect 1 1/2 to 2" 10 shot groups as max with 1 1/2" or less being my goal. A final test of a 10 shot string at 100 yards followed by another 10 shot test string at 200 yards will give absolute confirmation if you want to do that.

I would expect, given the accuracy capability of the rifle with J bullets, that such accuracy should be attainable in the 1850 - 1950 fps range. I also suggest using WW + 2% tin and them mixed 50/50 with lead as an alloy. You can WQ the bullets right out of the mould. With such and slower powders you could push the RPM threhsold upwards, possibly into the 2100 -2200+ fps range, especially with the Lyman 257464 Lovern, while maintaining 2 moa or less accuracy. It gets tricky doing that but is not beyond the capability of a knowledgeable reloader/cast bullet shooter. However, given the rifle is a friend and he wants to stick with what he has you may not be able to go there..........

Larry Gibson

[Bret4207]

Are you feeding from the magazine?

[quack1]

Bret- The gun is a Mauser and the extractor hasn't been ground to slide over the rim of a cartridge in the chamber. I have been removing the bolt and slipping the cartridge under the extractor and then replacing the bolt and chambering the cartridge to prevent any damage to the bullet from sliding up out of the magazine. That was one of the first things I thought of when the uncalled flyers started showing up.

[curator]

I had this problem with my .257 Roberts and eventually discovered the gas checks were coming off some of the bullets casuing the unexplained (until then) fliers.

[Bret4207]

Bret- The gun is a Mauser and the extractor hasn't been ground to slide over the rim of a cartridge in the chamber. I have been removing the bolt and slipping the cartridge under the extractor and then replacing the bolt and chambering the cartridge to prevent any damage to the bullet from sliding up out of the magazine. That was one of the first things I thought of when the uncalled flyers started showing up.

Okay, how about alignment? Are you checking for boolit runout on your loaded rounds? Have you checked for seating damage, ie- boolit "squish"?

[Shuz]

Try heat treating your boolits.

[sagamore-one]

Just thinking out loud here... could it be ignition variation caused by either a weak firing pin spring or possibly primer flash hole burrs or maybe even cases not all sized to headspace exactly the same? I have had the firing pin spring problem on a 700 Remington in 243.......... And I now routinely de-burr all cases used for group shooting..... And on my most accurate rifles I neck size only using Wilson hand dies. Again .. just thinking out loud. Feel free to ignore me.

[Bloodman14]

I used a .30 caliber socket wrench backed by a Lee spanner wrench with a Dillon extension; tightened my groups right up!:kidding:

[quack1]

To answer some questions:
Cases have had flash holes deburred, trimmed, weighed, etc., annealed every 3 loadings, are the same lot, sized in the same die and only fired in that gun.
Bullet runout is less than .005, bullets diameters measure the same before and after seating, no squashing. The M die is expanding the necks to give about .002 tension
checks are staying on. Interestingly, bullets from the first 25 cal mold I owned would lose a check now and then, got really wild flyers when the checks would fall off, found out by shooting into a stack of magazines and loking for the checks. Annealed the checks, still would lose a few. Broke my heart- it was a Bond mold and cast like a dream, sold it and got this one to replace it.

[Bret4207]

Boy, sounds like you've got most of the bases covered. I'd give the HT a try, maybe a slightly slower powder, even a primer change and look at the FP strike too as someone mentioned. I assume the barrel is copper free? IIRC you said you weren;t touching the boolit in sizing, so the only other direction to go is slightly smaller and that rarely works for me. Might be worth a try though if you can find a sizer that is a half thou smaller or so. You could also juice your alloy to gain a little girth.