What should I try next?

[taylorce1]

I'm trying to load the 80 grain Speer Deep Curl in my 6X47 Rem Stevens 200 that I built. This bullet and pretty much any other bullet heaver than 70 grains gives me a bit of a fit. I've found the speed I want from the bullet and have been chasing seating depth trying to get better groups.

Posted in the picture are two three shot groups from the same rifle on the same day.

The 70 grain Nosler BT group is a little better than average than my normal three shot group out of it as it usually hovers under a .5" at 100. Day in and out it is a consistent .5 MOA rifle for three shots at 100 and 300 yards after three the groups open up as the lighter contour barrel heats up. One of these days I'll get around to a better than factory stock on the rifle.

The 80 grain DC load has been driving me nuts. I've the speed that I want and I'd be happy with a consistent .75-1" group but it just shoots all over the place. I'll have one load that shows promise but go back and shoot it another day and will be someplace different or just open up. However it shows just enough promise at times to keep me trying.

I'd hoped to use the Deep Curl bullet for an up coming deer hunt so I wouldn't have to be as picky about shot placement. However, looks like I'll be hunting again with my 70 grain NBT load. I haven't used it on white tail deer but, it has quite handily dispatched pronghorn out to 300+ yards.

 

[Sas874runner]

The ballistic tip should do just fine. It could be that the rifle just does not like the bullet or powder combo. I had the same problem with my 270 and 140 ab. Changed powder and the sucker shoots lights out. Day in and day out. I have no experiance with the deep curl so I couldnt tell you if there is something else you could be doing with the bullet

 

[Antelope_Sniper]

Taylor, when you adjust you powder charge, you are not looking for a specific velocity, you are seeking the best group size. Once you've completed this first step, then you adjust seating depth to further improve group size.

 

[taylorce1]

Taylor, when you adjust you powder charge, you are not looking for a specific velocity, you are seeking the best group size. Once you've completed this first step, then you adjust seating depth to further improve group size.

I get that and I load for group size. This powder charge gave me the best group size out of all the powder charges I worked with. The most consistent load is too long for the magazine at .015 off the lands, I have to seat the bullet around .050 to feed from the magazine. Getting it to feed reliably from the magazine and with an adequate group for hunting is my main goal. However this group which is .100 off the lands shot a .5" group last week for five shots and today it shot the 1.2" group for three today when I went to confirm the load. I've seated the bullets to .130 off the lands and it opens up even more.

This inconsistency is what is driving me crazy as it is a 40 mile round trip to the range, and I'm going about 3-4 times a week on average when weather is cooperating. I'm about to start reloading at the range so I don't have this issue anymore and can cut down on my mileage. My goal with this bullet was to get into the 2800 fps range to get the best balance of power and trajectory for hunting.

I'd think I could find an accurate load as I'm running an AVG speed of 2880 and a SD of 13 over all 8 shots.

 

[highcotton]

Sas874runner-- which powder were you running with the 140 AB and which powder did you switch to?

 

[Sas874runner]

7828 ssc was giving me hell! Switched to the tried and true h4831sc. 59 gr giving me a group of about .75" @100 yrds. 2 in one hole and then a flier. Overall group is .75" I have been slowly working the seating depth to find the node to get the flier in but ever group is the same size and I can count on it to 300 yrds with out thinking twice

 

[Sas874runner]

Looking at some of the info and you say that anything over 70 gr has a hard time finding consistant accuracy? What is your barrel twist. If its not fast enough you may be running into a stabilization issue.

 

[taylorce1]

1:12, but the 70 gr NBT is longer than the 80 gr DC.

 

[Sas874runner]

How do bearing surfaces compare

 

[taylorce1]

Flat base bullet protected point vs. boat tail ballistic tip, the speer has a larger bearing surface.

Measured the DC this morning .885" OAL, which gives me a stability factor of 1.32, not quite as good as the BT which gives me a stability factor of 1.55 once I figure in .160" for the plastic tip. If I go with the .910 OAL of the 70 grain BT then I have a marginal stability factor.