6.5CM Over pressure ??

[631Shooter]

Yesterday I tested out some H4350 to see what the rifle liked, my results kinda surprised me and I'm not sure i can explain why i got these speeds other then i have a tight chamber and short throat.

The rifle is a Savage Elite Precision, 26" barrel, 1:8 Twist. (Round count at the time of testing 200-+)

I was testing with S&B Brass, standard trimmed cases to 1.910, large rifle primers, used CCI 200.

The bullet: Nosler Custom Competition 140 grain.

Powder: H4350... (3 test rounds per charge) conserving heads.

Load #1 @ 40.6g Load #2 @ 40.8g Load#3 @ 41.0 Load#4 @ 41.2 Load#5 @ 41.4
Shot #1 2958 Shot #1 2976 Shot #1 2996 Shot #1 2999 Shot #1 3024
Shot #2 2959 Shot #2 2982 Shot #2 3000 Shot #2 2999 Shot #2 3019
Shot #3 2938 Shot #3 2980 Shot #3 2992 Shot #3 3013 Shot #3 3008
AVG 2951 AVG 2979 AVG 2996 AVG 3003 AVG 3017
ES: 21 ES: 6 ES: 8 ES: 14 ES 16
SD 11.8 SD 3.0 SD 4.0 SD 8.1 SD 8.1

Seating: To my lands i measures at 2.756, seated 2.726

Best group, 3/4'' at 100 yards with 41.0g load.


So the question i have is this normal, i feel I'm pushing them too fast.

 

[b6graham]

What chrono?

Thats SPICY speeds.

Maybe its the S&B brass?

 

[631Shooter]

What chrono?

Thats SPICY speeds.

Maybe its the S&B brass?

Magneto Speed V3 and yes my thoughts exactly... maybe the brass.

 

[Mike Casselton]

Some of that S&B brass is 25gr heavier than other S&B.
The brass is also very hard and does not indicate pressure signs very well.

The velocities you're getting (+ 200fps) clearly show you are waaaay over 62ksi.
Back it down at least two grains below your previous starting load and run your test again.

 

[Mike Casselton]

What chrono?

Thats SPICY speeds.

Maybe its the S&B brass?

Spicy.
Love it.

 

[631Shooter]

Some of that S&B brass is 25gr heavier than other S&B.
The brass is also very hard and does not indicate pressure signs very well.

The velocities you're getting (+ 200fps) clearly show you are waaaay over 62ksi.
Back it down at least two grains below your previous starting load and run your test again.

Yea that is what i was thinking too, last night i loaded 3 rounds of each charge starting at 38.8 to 40.2 and i'll see what i get.

 

[SonoranPrecision]

Magneto Speed V3 and yes my thoughts exactly... maybe the brass.

Your brass is playing a role, as is the seating depth. You’re a full .200” deeper than a lot of people. This eats up case capacity, which increases pressure.

 

[631Shooter]

Your brass is playing a role, as is the seating depth. You’re a full .200” deeper than a lot of people. This eats up case capacity, which increases pressure.

0.020, not 0.200... these bullets do like a little bit of a jump that much i know, and 20 tho should be raising me 300fps.

 

[Ozarkcop]

I had very similar results out of savage rifle as well. I was using the 143 eldx bullet I stopped at 41.7 bumping speeds around 2900 fps with no preassure signs. Best group was at the 40.5 mark though shooting right at 2700 fps but I am seating closer to the lands too

 

[631Shooter]

I had very similar results out of savage rifle as well. I was using the 143 eldx bullet I stopped at 41.7 bumping speeds around 2900 fps with no preassure signs. Best group was at the 40.5 mark though shooting right at 2700 fps

Interesting because using Nosler brass and 140 Nosler heads with Norma UPR @ 39.8 i was avg 2,675 and getting 3/8" at 200 yards.

 

[SonoranPrecision]

0.020, not 0.200... these bullets do like a little bit of a jump that much i know, and 20 tho should be raising me 300fps.

No, what I’m saying is most people running 140’s in 6.5cm, have at least a 2.810-2.850 oal, with many (myself included) out at 2.900-2.950. This puts your oal way shorter than most, and shorter than what most reloading data is tested at. Therefore, seeing higher pressure at lower charge weights would be expected.

 

[631Shooter]

No, what I’m saying is most people running 140’s in 6.5cm, have at least a 2.810-2.850 oal, with many (myself included) out at 2.900-2.950. This puts your oal way shorter than most, and shorter than what most reloading data is tested at. Therefore, seeing higher pressure at lower charge weights would be expected.

Yea totally get that,… what’s interesting is this bullet Max’s out at 2.756 do to it’s contour.

 

[John Glidewell]

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[Mike Casselton]

The Nosler 308, 168 gr are pretty stubby.

I had previously been loading them and the 168 Sierra at 2.7 and they were fine.
Decided to use up some space in the magazine and the Sierra was totally okay with that.
The Nosler, not happy at all. In fact, it started creating primer leakage, so I pulled them apart to recover the VarGet.

Now I have three more pounds of VarGet for my 6BR and I'll just shoot the 168 Sierra until I run out of them.
After that, I'll go back to loading the Nosler CC at 2.7.
Funny thing about it was the velocity of both loads was less than 20fps difference.

 

[Baron23]

Yesterday I tested out some H4350 to see what the rifle liked, my results kinda surprised me and I'm not sure i can explain why i got these speeds other then i have a tight chamber and short throat.

The rifle is a Savage Elite Precision, 26" barrel, 1:8 Twist. (Round count at the time of testing 200-+)

I was testing with S&B Brass, standard trimmed cases to 1.910, large rifle primers, used CCI 200.

The bullet: Nosler Custom Competition 140 grain.

Powder: H4350... (3 test rounds per charge) conserving heads.

Load #1 @ 40.6g Load #2 @ 40.8g Load#3 @ 41.0 Load#4 @ 41.2 Load#5 @ 41.4
Shot #1 2958 Shot #1 2976 Shot #1 2996 Shot #1 2999 Shot #1 3024
Shot #2 2959 Shot #2 2982 Shot #2 3000 Shot #2 2999 Shot #2 3019
Shot #3 2938 Shot #3 2980 Shot #3 2992 Shot #3 3013 Shot #3 3008
AVG 2951 AVG 2979 AVG 2996 AVG 3003 AVG 3017
ES: 21 ES: 6 ES: 8 ES: 14 ES 16
SD 11.8 SD 3.0 SD 4.0 SD 8.1 SD 8.1

Seating: To my lands i measures at 2.756, seated 2.726

Best group, 3/4'' at 100 yards with 41.0g load.


So the question i have is this normal, i feel I'm pushing them too fast.

Wow, that's pretty darn fast. I kind of have a fast barrel, IMO. Proof SS 6.5 manbun, 25", with 7.5 twist and almost every factory load runs faster through it than published on the box by about 100-125 fps.

With Hornady once fired brass, CCI BR-2, Berger 140 gr Hybrid Targets, and 42.1 grains of H4350 (which is well more than any of your loads), I'm getting 2870 fps.

At 40.9 (compared to your 40.8) I'm getting 2792 vs your 2979 and at 41.9 (compared to your 41.4) I'm getting 2855 vs your 3017.

I'm using a Labradar and my average mvs are derived from a pretty darm good sized set of shot data.

I have no clue as to why you are so fast except as mentioned above, the S&B brass perhaps.

Best of luck. empirical data trumps all of our internet BS so yeah...pay attention to the numbers YOU are getting right?

Cheers

 

[Steel head]

Very spicy.
Load it down to 2750-2850 and be happy.
That’s a realistic range for 260 and 6.5CM.

 

[631Shooter]

Wow, that's pretty darn fast. I kind of have a fast barrel, IMO. Proof SS 6.5 manbun, 25", with 7.5 twist and almost every factory load runs faster through it than published on the box by about 100-125 fps.

With Hornady once fired brass, CCI BR-2, Berger 140 gr Hybrid Targets, and 42.1 grains of H4350 (which is well more than any of your loads), I'm getting 2870 fps.

At 40.9 (compared to your 40.8) I'm getting 2792 vs your 2979 and at 41.9 (compared to your 41.4) I'm getting 2855 vs your 3017.

I'm using a Labradar and my average mvs are derived from a pretty darm good sized set of shot data.

I have no clue as to why you are so fast except as mentioned above, the S&B brass perhaps.

Best of luck. empirical data trumps all of our internet BS so yeah...pay attention to the numbers YOU are getting right?

Cheers

Thanks, I’m going to be dialing it down only because I feel I’m missing some accuracy.
I’ll post my results, hopefully I can get out to the range this weekend.

 

[Baron23]

Wow, that's pretty darn fast. I kind of have a fast barrel, IMO. Proof SS 6.5 manbun, 25", with 7.5 twist and almost every factory load runs faster through it than published on the box by about 100-125 fps.

With Hornady once fired brass, CCI BR-2, Berger 140 gr Hybrid Targets, and 42.1 grains of H4350 (which is well more than any of your loads), I'm getting 2870 fps.

At 40.9 (compared to your 40.8) I'm getting 2792 vs your 2979 and at 41.9 (compared to your 41.4) I'm getting 2855 vs your 3017.

I'm using a Labradar and my average mvs are derived from a pretty darm good sized set of shot data.

I have no clue as to why you are so fast except as mentioned above, the S&B brass perhaps.

Best of luck. empirical data trumps all of our internet BS so yeah...pay attention to the numbers YOU are getting right?

Cheers

Shit, I screwed up the mv I posted for 40.2. In any case you’re seem to be on your way. Cheers