6.5 Creed with 120 grain pills and H4350

thatmikeguy said:
This rifle wears a muzzle brake from the previous owner. I have also wondered if muzzle brakes can negatively affect barrel harmonics. Or maybe I'm just impatient and need to keep trying.
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Anything touching the barrel will affect barrel harmonics. Whether it’s a positive or negative effect is up to the end user to determine.
 
thatmikeguy said:
Sierra Lists max at 45.6 grain of H4350. I started 2 grains below and worked up in .5 increments. It shot best at 45 grains. 45.5 seemed like over pressure. The bolt felt sticky. Hornadys max for the ELDM is 43.9 of h4350. Thos one shot best at 43 grain. Both best 3 round groups were .960 when measured with a digital caliper. Id like to get it smaller yet. Typically my loads go from moa to sub moa with a charge weight change or a powder change.
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Both my 6.5 CM's prefer RL17 Powder with CCI BR sparkers over H4350 - RJ
 
I noticed something interesting about my targets.
With the SMK, 44.5 grains produced a horizontal dispersion of 1". Then at 45 grains it produced a vertical dispersion of .960".
Maybe there will be a happy medium there around 44.7 or 44.8.
 
If H4350 is giving great velocity, the pressures are high. Try backing off in 0.4gr steps until groups tighten up
 
thatmikeguy said:
Okay. So H4350 isnt typically a top speed powder? Sierra data shows 3000fps with 45.6 grains. But....that charge gave stick bolt syndrome.
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Code: 
Cartridge          :[B] 6.5 Creedmoor [/B]Hornady
Bullet             : .264, 120, Sierra HPBT MatchK 1725
Useable Case Capaci: 48.092 grain H2O = 3.123 cm³
Cartridge O.A.L. L6: 2.700 inch = 68.58 mm
Barrel Length      : [B]22.0 inch[/B] = 558.8 mm

Predicted Data for Indicated Charges of the Following Powders.
Matching Maximum Pressure: 62000 psi, or 427 MPa
or a maximum loading ratio or filling of 104 %
These calculations refer to your specified settings in QuickLOAD 'Cartridge Dimensions' window.
C A U T I O N : any load listed can result in a powder charge that falls below minimum suggested
loads or exceeds maximum suggested loads as presented in current handloading manuals. Understand
that all of the listed powders can be unsuitable for the given combination of cartridge, bullet
and gun. Actual load order can vary, depending upon lot-to-lot powder and component variations.
USE ONLY FOR COMPARISON !

108 loads produced a Loading Ratio below user-defined minimum of 80%. These powders have been skipped.
Powder type          Filling/Loading Ratio  Charge    Charge   Vel. Prop.Burnt P max  P muzz  B_Time
                                      %     Grains    Gramm   fps     %       psi     psi    ms
---------------------------------  -----------------------------------------------------------------
Alliant Reloder-17                  95.1     44.2     2.87    3006   100.0    62000   10969   1.034  ! Near Maximum !
Alliant Reloder-16                 101.6     43.8     2.84    2972   100.0    62000   10837   1.045  ! Near Maximum !
Ramshot Hunter                      99.8     45.7     2.96    2954    98.7    62000   11136   1.045  ! Near Maximum !
Winchester 760                      94.1     44.1     2.86    2943    98.0    62000   11104   1.049  ! Near Maximum !
Hodgdon H414                        94.1     44.1     2.86    2943    98.0    62000   11104   1.049  ! Near Maximum !
Alliant Reloder-19                 104.0     46.1     2.99    2937    96.3    61314   11262   1.045  ! Near Maximum !
IMR 4831                           103.9     44.1     2.86    2918    99.7    62000   10530   1.060  ! Near Maximum !
Hodgdon Hybrid 100V                101.9     43.7     2.83    2908   100.0    62000    9941   1.051  ! Near Maximum !
[COLOR=#ff0000]Hodgdon H4350                      101.5     44.0     2.85    2883    97.4    62000   10462   1.054  ! Near Maximum ![/COLOR]
 
H4350 and 120gr should work best in the low 2700 fps range in a 22.4" Tikka. The 140gr bullets can be pushed to the same speeds, and pressures still within SAAMI specs. That truly is the sweet spot for the Creedmoor, and why they're twisted 1:8
 
todbartell said:
H4350 and 120gr should work best in the low 2700 fps range in a 22.4" Tikka. The 140gr bullets can be pushed to the same speeds, and pressures still within SAAMI specs. That truly is the sweet spot for the Creedmoor, and why they're twisted 1:8
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Thanks for your input. I may load a couple more charge weights on the low end yet. I never expected that the sweet spot would be that slow. I usually find the sweet spot near max.
 
Very nice. Makes sense for 140s. I thought 120s would be substantially quicker. I tried some Nosler BT 140s and got just over 1 inch for 3 rounds. 2729 2734 2749 fps were my results. Not much sub moa for this rifle yet.
 
3 round groups are essentially useless, but if a 3 round group is hovering around 1 MOA, a 5 or 10 round group isn’t going to get any smaller.
What’s you’re intended purpose for this gun? What are you hoping to get out of these crappy bullets?
 
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