Group and reloading question?

[St_Gunner]

Remington Sendero in .270 Winchester
Weaver V16 scope

I loaded some SST's I got a few months ago 135gr. I'm a half grain below max with H1000 powder, 63.4 grains, shooting CCI mag primers, out of Remington cases(3 handloads on these cases and one factory). I turned the case necks after the second loading just to uniform them up. Seated the bullets to the cannalure, but didn't crimp them. All the primer flash holes are uniformed and centered, the brass all is within 1 grain of one another. Everything seems to be in order for some decent accuracy.

I got the range mowed today, so I shot 100yds first, got a one inch group out of 3 shots, 2 overlapping and one blowing it out, but I didn't feel I flinched at all. Fired 7 rds at 300yds at a steel plate, had a 1/2" dot to use as an aimpoint. I put in 2moa elevation and shot for the dot, knowing it should drop about 6" at that range. It was dead calm this evening. The first two shots hit 1.5" apart 7" low and 2" right of point of aim. Let the gun cool, fired the third, it hit 6" low and 1/4" right of POA. Next shot hit right on POA, so I think I jerked it. The next two shots I heard it hit, but couldn't find a mark on the fresh paint, the 7th shot flew into roughly the same area as the first two shots, actually made a 3" 3 shot group at that point. One on the POA which was probably me. I went to the steel to find my other two and found them touching the 6" low 1/4" right mark, those 3 shots where in right at 1"(strung horizontally which means I wasn't holding true) at 300yds.

Something is throwing off these loads, some of the brass is coming out dinged up on the bases, I actually find flakes of brass in the bolt face; but it only rubs one side of the base. Is it inconsistant pressure? Out of true lugs? At 100yds you can't make distinctions but at 300yds it really showed up. It looked like two totally different groups, cept my called flyer.

I'm going to pick up another box of remington corelokt factory and see if it holds to 3/4moa out to 300yds like it did at 100yds, since it is much milder loading than what I am shooting. Should pick up some H4831 on Monday that a friend is giving me to try, see if it makes a difference. But I have a feeling something else is wrong, makes me wonder with the group moving horizontally if it isn't the lugs and pressure difference, it just bounces a little harder because of a slight pressure rise.

Any ideas?

Steve
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[baldeagle713]

Try a different primer. Winchester large rifle or federal large rifle primer A little birdy told me to do that once and it did wonders. Also try weighing your bullets to with in 1 tenth of a grain that should help also. Good luck.

 

[H-BAR]

The Federal 215 primers might help burn that really slow powder but i would just change to a powder suited for this cartridge and the bullet you are shooting. I would try IMR4831 or Reloder 19. I would also NOT neck turn for a production gun. Sometimes it works but most of the time I find that the chambers on production guns are big and have a problem sealing the chamber when removing material from the necks. I would also check on the length. I would bet that you can push them out further than the cannelure to get closer to the rifling. Good luck!

 

[jcpython357]

Steve, When I had a 270, Model 70, Wincam, I used IMR4350, and 150BTs with Win. 120 primers, no longer in production, now there just called WLR primers, at any rate, tech fellow at Hodgdon says H4831 with 130gr. bullets is the way to go, Nosler has 55grs. H4831sc as the most accurate load for the 130BT, 59grs. the Max. I'd leave them necks alone, too. don't think you'll see the difference in a prod rifle, Jay

 

[Guest]

Have been shooting the 270 for many years. Just loaded some 140g sst with 4350 and 4831. Did well with both, groops under an inch in a factory tikka. The 4350 was just a bit tighter. After a few years of trying different powders I only use these two from IMR for any weight bullets in the 270. 9 times out of 10 it is the 4350 can. I also have had the best luck with federal primers.

 

[St_Gunner]

Thanks for suggestions.

Harv, I bought the H1000 to try in a Shilen barreled Mauser action .270 a few years ago. It took my 3/4moa 130gr speer groups and cut em to just under a 1/2moa. I've always used CCI mag primers of Federal match in the loads. I've tried both 135gr sierra match and the SST's in this rifle now and both seem to yield the same result.

Something is screwy, i'm going to try some fresh primers and powder this week and see what happens.

The neck turning was just enough to uniform the necks. The brass was cut back to just above min. The bullet can be seated out further, and will be next loading to see what happens.

Steve

 

[Guest]

I agree that something is screwy. I would try the factory loads to see what happens. Take the stock off and put it back on making sure everything is just right and tight. Make sure barrel is not touching the stock. Try some different brass, powder, primers, and bullets. Make only one change at a time and see if you can fix the problem. I havent tryed many different powders for a long time since the ones i use work well for my needs. My shooting distence is getting longer and i may need to make groops a little smaller so might try the H1000 sometime. good luck.