“Stop the Hammering!”

[VLD Pilot]

Maybe it's the short throated chamber in mine that's causing the pressure excursion?

Yeah that's very possible

 

[BrentM]

Did you not ladder up to this charge and find out where max is before loading up that many?

As others said, it's hot. There are other powders that work better but 4831 is decent. I prefer 1000, retumbo, rl26. I would expect a 24-26 to run a 130 at 3000-3050. I run 140s in the 2950 range in a 24 and 3100 in a 28.

 

[Tex_Hunter]

Lawrence O'Donnell would not have been happy if he were at my house tonight. I just got done pulling 27 6.5-284 rounds with the kinetic hammer. Seems I had them loaded a bit hot. Had a moderately stiff bolt lift and looks like some pancakes and ejector marks. This was a 53.5 grain charge of H4831sc under a 130 Accubond. Does that seem hot to you guys in a 6.5 Norma? I was getting 3,082 FPS out of it (SD 10; ES 31). See pic of the cases. I'm kind of bummed out about it cause it was looking very promising. Any suggestions on a charge I might back off to?View attachment 193648

You didnt mention barrel length, but yes by almost any objective measure you are WAY over pressure here, regardless of what chamber/throat you are running. You are full 2grs over Max from Nosler's data (which in my experience is already pretty warm in any caliber I have used it for), and your velocity is approaching 200fps above their stated amount in a 26" barrel. If you were running a much longer barrel then maybe you would be fine if that was the only symptom, but combine that with primers that couldnt be any flatter if you smashed them with a hammer with multiple healthy looking craters in them, and everything is pointing to one really clear conclusion.

Is there a specific reason you felt the need to push this far over?

 

[338 dude]

What kind of velocities are you getting ?

I've been running 2980 with the targets pictured above and reloader 23

 

[Tex_Hunter]

Yeah, I was shocked to see the 51.5 Max charge. I had too, been operating off the older Nosler data. It's looking like a powder charge is in order if I want more speed. It was shooting 2,835 with a 51.4 grain charge and 2,940 with the 52.3 grain charge. Everything.020 off the lands. They both shot well but I wanted a little more steam behind it because I have just been accepted at a range in WV (was on the waiting list) and I can finally shoot out past 300 yards in a controlled environment!! Anyway, glad I keep and file my old targets so I got a fall back position. Thank you all for your commentary!

Follow on to my previous post. Velocity is going to be your best indicator of pressure in YOUR rifle. Depending on your barrel length, if you got 2940fps at 52.3grs then that is probably closs to the max in your gun as it most closely aligns with the max velocity in the Nosler book. What did your brass/primers look like at this load?

Stop chasing an arbitrary velocity threshold and look at other factors like SD/ES and overall group size. Those factors matter more at long range than another 50-100fps. Go read the "How Much Does it Matter" series on Precision Rifle Blog, incremental velocity has a negligible impact on hit percentage at ranges beyond 700yds (I remember is being something like <1% increase in hit probability for every 50fps increase in velocity), because vertical dispersion is not the major contributor to misses at long range. H4831SC is a very consistent and forgiving powder, find a safe load that shoots well and velocity will be what it is, learn your dope and move on.

 

[jasonco]

I'm thinking about this PTG tool for mine, It's an investment, but I'm not ready to give up on the barrel I have just yet?http://pacifictoolandgauge.com/throat-and-neck-reamers/5226-17-cal-uni-throater-kit.html

I also got in, a 8# of Ramshot LRT, mostly for my 28 Nosler & 300 RUM, but these burn rate powders also work in 6.5x284.

 

[VLD Pilot]

I've been running 2980 with the targets pictured above and reloader 23

I got a bunch of reloder 23. Been waiting on the 26 to come back in stock but it's hard to find. I've been running the 23 in my 22-250 Ackley improved.

 

[338 dude]

I got a bunch of reloder 23. Been waiting on the 26 to come back in stock but it's hard to find. I've been running the 23 in my 22-250 Ackley improved.

I guess I forgot about 26 in my earlier post I tried that also and I did not get any pressure signs until about 3100 ft./s but the accuracy was not there Also forgot to mention I have a 26 inch barrel

 

[YZ-80]

Very strange....as a buddy has his 65284 shooting bugholes at 2890fps...142lrab...54.3gr 4831sc with mag and he loads into the lands......liteweight rifle....no brake.....

Strange indeed. Every rifle is an individual. Ain't diversity grand!!

 

[YZ-80]

Follow on to my previous post. Velocity is going to be your best indicator of pressure in YOUR rifle. Depending on your barrel length, if you got 2940fps at 52.3grs then that is probably closs to the max in your gun as it most closely aligns with the max velocity in the Nosler book. What did your brass/primers look like at this load?

Stop chasing an arbitrary velocity threshold and look at other factors like SD/ES and overall group size. Those factors matter more at long range than another 50-100fps. Go read the "How Much Does it Matter" series on Precision Rifle Blog, incremental velocity has a negligible impact on hit percentage at ranges beyond 700yds (I remember is being something like <1% increase in hit probability for every 50fps increase in velocity), because vertical dispersion is not the major contributor to misses at long range. H4831SC is a very consistent and forgiving powder, find a safe load that shoots well and velocity will be what it is, learn your dope and move on.

Yes, sobering words. Don't recall any pressure signs at 52.3. I did forget to mention, however that there was a 20 degree temperature differential (warmer outside) then the last time I went to the range on 3/15. That may be pertinent as well. Much leaned from this discussion. Thank you.

 

[RAGGED EDGE]

Lawrence O'Donnell would not have been happy if he were at my house tonight. I just got done pulling 27 6.5-284 rounds with the kinetic hammer. Seems I had them loaded a bit hot. Had a moderately stiff bolt lift and looks like some pancakes and ejector marks. This was a 53.5 grain charge of H4831sc under a 130 Accubond. Does that seem hot to you guys in a 6.5 Norma? I was getting 3,082 FPS out of it (SD 10; ES 31). See pic of the cases. I'm kind of bummed out about it cause it was looking very promising. Any suggestions on a charge I might back off to?View attachment 193648

I buy once-fired brass of this caliber from a rifle manufacturer who tests it's rifles before shipment. They look every bit as bad as yours.

 

[YZ-80]

I buy once-fired brass of this caliber from a rifle manufacturer who tests it's rifles before shipment. They look every bit as bad as yours.

Yes but they are seasoned professionals. I shouldn't have tried this at home!

 

[30BR]

Yes but they are seasoned professionals. I shouldn't have tried this at home!

With PROOF loads!

 

[VLD Pilot]

I guess I forgot about 26 in my earlier post I tried that also and I did not get any pressure signs until about 3100 ft./s but the accuracy was not there Also forgot to mention I have a 26 inch barrel

Mine are all 28-30" barrels. I'll try some RL23 soon. I heard decent things about 26 but temp sensitivity was one thing I heard was iffy. 4831sc is about the best all around powder IMO for the 6.5-284 and 260s.