Bad lot of powder

[Gil P.]

I think I may have a bad lot of H4350.

I'm loading 40.1 gr of it in my (trued Rem 700 with PTG bolt) 6.5x47 Lapua with a rock creek barrel, cci 450s, Berger 140 Hybrids, and Lapua brass.

This rifle has been giving me problems since I got it, I also think something is wrong with the barrel.

From 60 degrees to 104 degrees ambient temp, my velocity went from 2815 to 2970. All shooting is done from the shade. The rifle can't seem to group well.

I've tried 123 scenars, and Berger 130 hybrids with varget and got pretty good results. The problem was sometimes the rifle would group really well with those loads and sometimes it would scatter groups over 1 inch at 100 yards.

I tried shooting with and without a brake and the rifle still exhibits the same behavior.

I noticed that the barrel copper fouls a lot more than the Bartlein that was on the rifle before.

I've tried different primers and that didn't help either.

What should I do about the powder? A 44 degree temperature change shouldn't cause a 155 fps change in velocity should it?
The same gunsmith barreled this rifle with a Bartlein barrel chambered in 308, and I was able to get quarter inch 5 shot groups at 100 yards with it.

 

[X-Caveman]

I've had & heard of H4350 lots being faster or slower than normal, but I simply can't imagine than much of a velocity swing. Something else must be awry. 2,970 with a 140 is incredibly unlikely with 40.1gr H4350, even if your barrel is super long. What chrono were you using? Did it show pressure on the hot day?

I use & sell Rock Creeks. They are a premium hand lapped barrel that shouldn't make much copper if properly chambered & broken in. Anything is possible, however, and you may have a barrel issue. Russell @ RC is a stand up guy. You should call him and discuss it with him. Your expectation of 1/4 MOA 5 shot groups is well within reason with a good shooting platform and a well tuned load.

How much firing pin fall do you have? A 450 is pretty hard, and you are trying to ignite 40+ grains of powder thru a small flash hole. I'm thinking maybe marginal ignition would show in the 6.5x47 and not in the .308 win...

 

[Rob01]

That’s pretty fast for that set up but the swing in temp is crazy. I have shot H4350 from single digits to over 100 and never got over a 20fps difference. How long of a barrel?

What chrono?

 

[PopCharlie]

I have a 6.5x47L on a trued Remington action with a Criterion barrel. I shoot 140 gr Berger VLD bullets. I use 36 gr of IMR 4451 and CCI 450 primers. It's picky about seating depth and neck tension. The 140gr vld bullets like to be .002 off and necks sized to .2635. 130 gr. VLD and hybrids behave the same. These are 1/4 MOA loads.
My 120 gr Berger BTHP bullets shoot best with 39 gr. H4350 seated .005 off with necks sized to .2625.
I was getting sketchy accuracy with 130 and 140 gr. bullets until I switched to IMR 4451. Give it a try.

PopCharlie

 

[ShootDots]

The 2815 with 40.1grs is right on the money for most lots of H4350. In my experience, it would be very doubtful that you reached 2970 under any circumstance(s) with H4350 and any 140 class projectile. I think you have an error from the chronograph you are using. I have used a Shooting Chrony, P.A.C.T. Professional, CED M2 and currently a LabRadar. In each of these chronographs, I have, from time to time, come across some "less than believable" velocity readings. In my estimation, even if you used 40.1grs of VV N550, you would not be able to push the 140 Hybrid to 2970.. My guess is chrono error. Now, whether you have a "problematic" barrel as far as accuracy goes, that is another story that would be nigh on to impossible to diagnose over the computer..

 

[Gil P.]

The 2815 with 40.1grs is right on the money for most lots of H4350. In my experience, it would be very doubtful that you reached 2970 under any circumstance(s) with H4350 and any 140 class projectile. I think you have an error from the chronograph you are using. I have used a Shooting Chrony, P.A.C.T. Professional, CED M2 and currently a LabRadar. In each of these chronographs, I have, from time to time, come across some "less than believable" velocity readings. In my estimation, even if you used 40.1grs of VV N550, you would not be able to push the 140 Hybrid to 2970.. My guess is chrono error. Now, whether you have a "problematic" barrel as far as accuracy goes, that is another story that would be nigh on to impossible to diagnose over the computer..

I've recorded odd jumps in velocity with my magneto speed sporter and it's always been right on when I shoot at distance using an AB calculator. It's jumped up to 2873 before and the magneto speed was correct.

It's jumped up to 2900 before as well. I kept all the velocities logged in a notebook.

At first I thought it was my Lyman digital scale. I upgraded to an FX120i and verified on a beam scale and the same thing is happening.

 

[Gil P.]

That’s pretty fast for that set up but the swing in temp is crazy. I have shot H4350 from single digits to over 100 and never got over a 20fps difference. How long of a barrel?

What chrono?

Magneto speed sporter, 26 inch barrel.

The barrel is very fast. I really think it's the powder. I got some nice catering for the 2 rounds I fired. 2968 and 2970.

I thought maybe it was that lot of brass so I tried another lot and got 2917.

 

[Ranger188]

Can you buy a 1lb of H4350 to test your theory? Or borrow some from a friend.
Buy some different powder, RL16 or such. If it still does it, then you have a different problem.
How rounds down this barrel?

 

[gunsandgunsmithing]

With the lot to lot variations of newer 4350 powder, is it possible that it might just be too hot in your bbl, in this heat? I've seen groups blow up big like that this time of year when loaded at the top for a given gun/bbl. You can't tune that out any other way than dropping the powder charge, IME. You might try backing off a bit and see if it improves.

 

[Gil P.]

I will do that this weekend. About 800 rounds. I think I've exhausted every other avenue.

 

[Gil P.]

With the lot to lot variations of newer 4350 powder, is it possible that it might just be too hot in your bbl, in this heat? I've seen groups blow up big like that this time of year when loaded at the top for a given gun/bbl. You can't tune that out any other way than dropping the powder charge, IME. You might try backing off a bit and see if it improves.

The problems is that there has been a consistent and large increase in velocity once I settled on 40.1 gr last winter.

 

[BartsBullets]

The problems is that there has been a consistent and large increase in velocity once I settled on 40.1 gr last winter.

If you wait and shoot it this coming winter, I think your load will come back to you.

 

[whatsupdoc]

What is the lot number?

 

[Ned Ludd]

Have you contacted Hodgdon and the barrel manufacturer? I'd start there.

 

[Alex Wheeler]

I have a lot of powder now that I have been fighting. 20 degrees will take it totally out of tune. Its been impossible for me to keep up with. Even the "extreme powders" still change velocities and different lots act a little different. I would definitely try a different lot or powder all together before you blame the barrel. Varget and H4895 are also good options for the 47.

 

[X-Caveman]

I have a lot of powder now that I have been fighting. 20 degrees will take it totally out of tune. Its been impossible for me to keep up with. Even the "extreme powders" still change velocities and different lots act a little different. I would definitely try a different lot or powder all together before you blame the barrel. Varget and H4895 are also good options for the 47.

Throw RE-15 & RE-16 on the "worth a try" list, too!

 

[Nick Caprinolo]

You can't condemn the powder and then say you suspect you have a bad barrel. Everyone knows that one batch of powder is not going to be the same as another. That's why we try to buy frequently used powders in larger volumes.

I have two rifles that absolutely want H4350. I have had them for many years. When it is necessary to buy new powder, I then have to fine tune the load to match any inconsistency between the batches. Nothing out of the norm, it's just something we must do from time to time.

If you have a bad barrel, no powder will correct it.

 

[expiper]

the rifle has been giving you problems since you got it,,,,you also think there is something wrong with the bbl.,,,,and you may have a bad lot of powder,,,,step back and look at what your doing,,is there somone who shoots there in your area (that is a competent/competetive shooter) that can help you with your loads ,,,,you dont just pic a powder charge and shoot your way into the hall of fame,,,,it could be many things that keyboard shooters will pontificate over for years on end that somone could spot in an instant,,,how are you cleanige the bbl,,,etc,,,if a load increases 155 fps it was wrong to start,,,,clean the bbl and find the correct seating depth and watch the wind not the chronograph ,,,,if you dont have faith in your equipment ,,get rid of it,,,you have to be thinking about one thing when your looking at the target ,,what is the wind doing,,,Roger

 

[Alex Wheeler]

Id also check neck clearance. Too tight here causes all kinds of accuracy, ES, and velocity related issues.

 

[Gil P.]

the rifle has been giving you problems since you got it,,,,you also think there is something wrong with the bbl.,,,,and you may have a bad lot of powder,,,,step back and look at what your doing,,is there somone who shoots there in your area (that is a competent/competetive shooter) that can help you with your loads ,,,,you dont just pic a powder charge and shoot your way into the hall of fame,,,,it could be many things that keyboard shooters will pontificate over for years on end that somone could spot in an instant,,,how are you cleanige the bbl,,,etc,,,if a load increases 155 fps it was wrong to start,,,,clean the bbl and find the correct seating depth and watch the wind not the chronograph ,,,,if you dont have faith in your equipment ,,get rid of it,,,you have to be thinking about one thing when your looking at the target ,,what is the wind doing,,,Roger

I get what your saying Roger,
but I don't have friends, I compete in club matches and have competed in PRS matches up until a couple years ago when my daughter was born, I know I'm new to this site, but I consider myself a competent shooter.

I've been reloading for about 10 years, but I don't turn necks, measure runout, measure neck thickness, or weight sort anything besides powder. It hasn't been a problem up until now, and I've exhausted everyththing I think could be wrong except for 1) the powder, 2) the barrel, or 3) the gunsmith really messed something up.

40.1 gr wasn't a charge I saw in the internet and started loading I did a ladder test and then I adjusted the seating depth until it shot good. And I kept adjusting the seating depth because the rifle was acting funny, I adjusted the charge weight several times until I went back to 40.1 gr and every time I shot I observed the difference in velocity so I can at least find an fps/degree change I could use. The sensitivity was bad and that's why I think something is up with the powder.

I am getting a new jug of powder this weekend to test my hypothesis about the powder. Im posting on this forum to try to learn some new things as well as for general information about powders.