I have been struggling to find a load for a CZ 550 Varmint in .22-250 that will one hole. I have tried multiple different powders (IMR 4064, IMR4350, IMR4130, H380, Varget) and different bullets of different manufactures and different weights ranging from 50gr up to 60gr. The barrel is a 1-14 twist. I can't figure this thing out for the life of me. I can only manage to get at lowest about .4 and on average I would guess .75 - 1.0 groups. I have had another shooter who has more shooting ability in his pinky finger than I have in my entire body shoot. He was still only able to do slightly better.

The only thing I can think of is seating depth. I know the max depth in the books is 2.350. I have seated out to 2.375 with no real affect on groupings, so tonight after another range session with the same results I decided to just barley seat a bullet and see if I could chamber it and "seat" the bullet on the rifling, then back it down .005. Much to my surprise I was unable to do so. The bullet was molly coated and I did not see any rifling marks on it at all, and I did not feel any resistance when trying to chamber the round. I then measured the round and it was at 2.472 witch surprised the heck out of me.

My question is, do you think I could seat the bullet out to 2.4 without any negative pressure signs? If I do get signs of excess pressure, would you think it would be catastrophic? Also, what is the max you have heard a .22-250 being seated at?

Any input on how to increase accuracy would be appreciated.

I have a friend with a CZ 550 sporter in .22/250 that I load for . We seat the 52 gn Sierra Matchking to an overall length of 2.430 . Try about 40 gns of Win. 760 behind it .
Seating depth will vary from rifle make to make and varies greatly with the ogive design of the projectile . Seating depth would not have a catastrophic bearing on pressure unless you live right on the edge with your powder charges .
Have you had your rifle floated and bedded ? It made a big difference in the above rifle . Also a trigger job can turn the CZ set trigger into an absolute dream .
Nosler 50gn ballistic tips also shoot well in CZ's in my experience .Don't seem to have recorded the seating depth but I would bet that it was longer than the 2.472 which surprised you so much .

Thanks for the advice. Please have patience with me as I am a youngin when it comes to reloading (as you can already tell). That seating depth that I posted was with a Hornady 50gr A-Max.

I have tried 52gr match kings and I will give them a go with some 760 tomorrow.

I have not had the rifle bedded or floated. I have defiantly been thinking about doing both, but I figured I would see how well I could get it to shoot with just load development. I also was thinking I would get this done while I have it dura-coated in matte black. (I hate the bluing on hammer forged barrels).

What would a trigger job really offer me on with the set trigger? The trigger is already so light, just the presence of a finger will set it off.

Thanks a ton for the load data. I am defiantly going to give this a try.

Waffen ,
Hard to explain the trigger thing unless you've experienced a really great trigger before . CZ's I have tried including my own 527 were a bit inclined to creep before letting go . A bit of work from an experienced gunsmith can make them truly awesome .It's worth the 50 bucks or so that it will cost you .

Waffen, the 22-250 is very easy to load for. A charge of 36 to 38 grains of H380 behind a 52 grain sierra always works for me. One hole rifles do not grow on trees regardless of all these wonderful 1/4 inch groups you read about. I posted a couple links below and as you can see this is no store bought rifle. If you can tailor your loads to get you to 1/2 inch your doing good. Try seating your bullets out a little further and dont try to run full speed. My load goes 3550 fps and is .020 off the lands for an a.o.l. of 2.385"

http://img.villagephotos.com/p/2001-12/7063/Target22-250.JPG

http://img.villagephotos.com/p/2001-12/7063/Rem700Customleft2reduced.jpg

I certainly understand that off the shelf rifles are no one holers most of the time, but when shooting 5 shot groups this thing will usually put 4 REAL close together and then just throw one. It's happened more times that I would like to admit.

I cool the barrel with cool with alcohol between shots, so I know it's not barrel heat that causes this.

Nice rifle by the way. One day (I'm only 20) I would like to build one like it.

I did a lot of experiments with my 22-250. Mine is a cheap one as most of my rifles and I try to get the most out of it with reloading. After a year of frustration and an accuracy just sufficient for hunting I found my one hole load.
I give you the case length in millimeters, since I live in Europe and my gauges are metric.
Federal cases 48,5 mm. To my rifle federal cases are important, remington do absolutely not work, CCI large rifle primers, 37gr of H4859 and and 35 gr Impala bullet seated just to be in level with the second ring to the case mouth, crimping with a Lee factory crimp die, because neck tension is not sufficient with Impala bullets. This combination gives me 1250m/sec at the muzzle and shoots one hole groups. You have to wait about 10 minutes between shots, because barrel heating is a problem. Wear of rifling is heavy with Impala bullets at this velocity but fun is great. I tried a variety of other bullets but my groupings were like from an irrigator. With this load I am fine for roebuck and varmint. If you go for head shots, you may engage even bigger game but I would not recommend it.

Try Reloader 7 for accuracy.. 30 yrs ago it was very popular for accuracy, velocity and not using a lot of powder...

Now powders that fill the case more( causing you to use up a pound of it quicker) are the rage....

30 grains of RL 7 with a 50, 52, 53, 55 grain bullet has proven very accurate in any 22.250 I have worked with or asked to develop a load for....

I am not a fan of H4895 much.... however 32.5 grains of it behind a 55 grain bullet is a one hole shooter in 2 different 22.250s I have...

Cheers
seafire

I did a lot of load developing for my 22-250 not long ago. I used all of the powders mentioned above. My very best load was 32.6gr of Benchmark with a 55gr Sierra HPBT bullet and Federal 210M primers. Three shots into 1.4" at 100. Very close behind was 36.5gr of Varget with the same bullet. Bullets were seated .010 off the lands. YMMV
Don

Consider the 'very real possibility' that your rifle is a .500" gun and not a .200" gun. It is also quite possible that no matter what you load and how you do it that this gun still won't be a .200" gun. Thus far you have chased the load...what has been done to the rifle?

PS My 22-250 will let me load a 50 gr. Sierra BK to 2.500" no problems...fired up with H380 it shoots .500" on a good day...stills wastes prairie dogs out to 350 yds. all day long.

Thanks for all you're replies guys. This is some good advice.

I did pickup some Win 760 yesterday and I began loading some 50gr Hornady A-Maxes. I will see how that does on Thursday.

SKB:
Well, that is a possibility that I am not willing to accept. This guy will shoot, hopefully in stock form. If not, I will bed and free float and see what that does. It's just a matter of time before I get this thing to sub .5 groups consistantly.

I do see you're point about shoot .5 and still destroying prarrie dogs. I haven't taken this thing out into the field yet, but I can't wait until I do. I think I might try to turn spotlighting of varmint's into a long range event.

Well, I think I found my powder. The Winchester 760 put 5 rounds into a nickle-sized group @ 100 yards, and I have the "shoot and see" to prove it! I will get pics up ASAP.

I loaded 10 of each 39gr 40gr and 41gr.
50GR Molly Coated V-Max
Fed 210M Primers
Winchester Brass

Probaby 90 outside, with a light 10mph wind.

For some reason the 39gr and the 41gr were the best shooters, but the 41gr was a little tighter. I am going to seat these bullets out to 2.400 next time and see if it tightens up a little bit.

I am going to do the same now with different bullets and see what happens. A friend suggested that maby the longer 26' barrel would like a slower burning powder, looks like he was correct. I may try some IMR-4350 out too.

Either way, I have about 100 cases in the tumbler now, so it shouldn't be long until I get to find out.