30-06 velocity and bullet seating depth question

[mparsons911]

I've been developing a load for my 30-06 and I'm having a hard time getting the groups to tighten up (it's a given my talant is weak at best).
Load- 53.3 grains Hog4350, CCI BR2 primer, 190 gn Sierra BT Matchking, .002" jump, brass is trimmed and kneck turned.
Velocity- 2622 avg, High Low variations range from 2605-2641 (2641 being a cold barrel)
Barrel- 1.21 thick, 1:12, 24" long, (Not chambered real tight, I can get factory ammo in it).
Groups vary from .491" to 1.375" (indoors @ 100 yds)
Optics- Sightron SIII 8-32x56

Questions;
1. Is my Velocity (2622 fps, 190gn) ok or should I try to get it higher. No signs of over pressure yet.
2. What bullet jump do you expect will work out the best? I ran it out .005" .010" .015" and the groups got bigger so I keep it about .002" off the lands.
Any advise will be appreciated,
Thanks

 

[bheadboy]

a couple of points, 1st from a 24" bbl, the velocity seems high for the load you are using, 2nd it is hard to keep .002 jump as bullet vary slightly and they could be some jumping and some touching or in, 3rd the 1x12 twist may be a tad slow for the 190.

1- try 180gr smk look for 2600-2650fps
2- try jam of .010 with the 190 and back off on powder to get 2575+/-
3- you may have a fast bbl, (tight) thus the higher velocity thus back off pdr to bring velocity and stability under control

good luck
Bob

 

[frnkeore]

12 twist should be fine. I've run Horaday and Seirra 190's at 2100 fps in my A&M barreled 30/40 with as small as .31 groups with my (measured) 12 twist. I agree with jamming the bullet and backing off 1-2 gr then, try going back up.

Frank

 

[mparsons911]

Thanks guys lots of good stuff here,
I just read my notes and it looks like the barrel is 26" (I'm going to have to measure it again). I used a couple calculators and found the bullet stability factor to be 1.41 at sea level, so I'm thinking I can still chuck the 190's
1. I'll try jamming into the lands .010" and backing off the powder by 1-2 grains and then working back up.
2. Is there a fps I should be looking for with the 190 gn Seirra BTMK's
3. Once you push your bullets into the lands .010" and you have to eject the round for some reason can you reuse it and will it get stuck or move the seating depth in the cartridge?

 

[RonAKA]

Have you done a ladder test to find out what velocity your barrel likes the best? Some info here.

http://www.desertsharpshooters.com/manuals/incredload.pdf

 

[minnesota]

a couple of points, 1st from a 24" bbl, the velocity seems high for the load you are using, 2nd it is hard to keep .002 jump as bullet vary slightly and they could be some jumping and some touching or in, 3rd the 1x12 twist may be a tad slow for the 190.

1- try 180gr smk look for 2600-2650fps
2- try jam of .010 with the 190 and back off on powder to get 2575+/-
3- you may have a fast bbl, (tight) thus the higher velocity thus back off pdr to bring velocity and stability under control

good luck
Bob

53.6 grains H 4350 is listed as max for 180 and 55.3 IMR 4350 in manual and for 190's 53.1 grains IMR 4350. think your a bit to hot

call sierra at 1 800-223-8799 or email sierra@sierrabullets.com

 

[frnkeore]

I'm not trying to give dangerous advice here but, If you'll look at older reloading manuals, you'll find that 57 gr of 4350 was the max load with a 180 gr bullet. I've used that load and it doesn't loosen primers. It used to be a standard target load when the '06 was the gun to beat. Most modern '06 brass is good for 52,000 CUP and the 57 gr load is listed at 49,700 CPU by it's manufactor. I consider a safe max load to be one that will not loosen the primer pocket in 8-10 loadings. I have "safely" loosened many primer pockets, although I don't recomend it.

Frank

 

[dantiff2]

Try backing OFF the rifling .030". Seems to be the trend lately. I can say .002 off is not a good place to be for 99% of guns.

Dan