meatyrem
Well-Known Member
Where is this compared to h-870? I would think they'd be real close.
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Powder Bridging??? Fiftydriver
- Thread starter robbor
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Where is this compared to h-870? I would think they'd be real close.
htduckman
Active Member
Almost identical.
When I first started loading the WC872 I was advised I could use data for H870 as well as AA8700, both of which have been discontinued.
So far all good, no issues at all.
meatyrem
Well-Known Member
I'll Ty and do some checking but I would think that us-869 would be right ther next to wc-872 and h-870. I have one pound of h-870.
On that note if you didn't happen to know, the h-870 is made by thunderbird cartridge co. and is called t-870. Which I'm told is the exact same thing as h-870. Very cheap too: I think it was right around $88 for 8lbs.
On that note if you didn't happen to know, the h-870 is made by thunderbird cartridge co. and is called t-870. Which I'm told is the exact same thing as h-870. Very cheap too: I think it was right around $88 for 8lbs.
htduckman
Active Member
Check with Weidner's.
I got an email the other day and it said WC872 was $39.95 for 8 lbs.
Buy 6 and they'd pay the hazmat fee.
brianwinzor
Well-Known Member
I believe that I experienced an instance of powder bridging about 3 years ago when using my Custom .257 Weatherby, which had a Rem 700 Action, and Krieger 26 inch 1 in 7 twist barrel.
I had previously worked up to maximum pressure with the Wildcat 156 grain ULD using 69.0 grains of H870, and 70.0 grains of ADI AR 2218 (H50BMG in US), and subsequently fired over 300 shots using both powders and experienced no problems.
I decided to acquire some Vihtavouri 20N29, as on some reloading data it appeared to be slower than ADI 2218, and I was hoping to use a powder that would give me a better loading density, than the 82% at maximum pressure with this powder. My first shot with 70.0 grains produced a pierced primer, and naturally decided not to proceed further.
Next time on testing I fired a load of 67.0 grains of V20N29 and again got a pierced primer, and this confirmed my suspicions of powder bridging being the problem rather than a fast lot of 20N29. Unfortunately I was unable to do further testing as this rifle and others were then stolen.
Subsequently I have used V20N29, AR 2218, and H870 in my 300 RUM with the 240 grain Sierra without a hint of pressure spikes, and found that I reach maximum pressure with 97.0 grains H870, 100.0 grains of AR2218, and near maximum pressure with 101.0 grains of 20N29.
I decided to measure both AR2218 and V20N29 and found that ADI 2218 kernels measured about .080 inches in length and .060 inches in diameter, while VIHT 20N29 kernels measured .095 inches in length and .052 inches in width. The difference is not dramatic but it appears that it is significant.
Hope the above is of some help. Brian.
I had previously worked up to maximum pressure with the Wildcat 156 grain ULD using 69.0 grains of H870, and 70.0 grains of ADI AR 2218 (H50BMG in US), and subsequently fired over 300 shots using both powders and experienced no problems.
I decided to acquire some Vihtavouri 20N29, as on some reloading data it appeared to be slower than ADI 2218, and I was hoping to use a powder that would give me a better loading density, than the 82% at maximum pressure with this powder. My first shot with 70.0 grains produced a pierced primer, and naturally decided not to proceed further.
Next time on testing I fired a load of 67.0 grains of V20N29 and again got a pierced primer, and this confirmed my suspicions of powder bridging being the problem rather than a fast lot of 20N29. Unfortunately I was unable to do further testing as this rifle and others were then stolen.
Subsequently I have used V20N29, AR 2218, and H870 in my 300 RUM with the 240 grain Sierra without a hint of pressure spikes, and found that I reach maximum pressure with 97.0 grains H870, 100.0 grains of AR2218, and near maximum pressure with 101.0 grains of 20N29.
I decided to measure both AR2218 and V20N29 and found that ADI 2218 kernels measured about .080 inches in length and .060 inches in diameter, while VIHT 20N29 kernels measured .095 inches in length and .052 inches in width. The difference is not dramatic but it appears that it is significant.
Hope the above is of some help. Brian.
DennisPA
Well-Known Member
Ok I'm going to bring this thread back from the dead!
I'm wondering if I'm running into powder bridging. I have 7mmWSM that I use H4831SC in with great results and single digit ES muzzle velocities.
Now I built my wife a fast twist 220 swift to shoot the 90 grain Bergers. Since I had good luck with H4831SC and it was listed on the powders in the Berger reloading manual I thought I would give it a try. But I'm seeing huge swings in muzzle velocities. I tried 5 loads of 5 shots each and the best ES I got was 21fps and it was a terrible group. The two best sub MoA groups were ES of 52fps and 109fps. Could powder bridging cause such large swings in muzzle velocity?
Stats:
Chamber 220 Swift
30" 1:7 twist barrel new only 39 rounds
Remington fired brass
Neck turned, trimmed, chamfered flash holes
H4831SC powder loads from 35g to 38g
90 Berger VLD's
I'm wondering if I'm running into powder bridging. I have 7mmWSM that I use H4831SC in with great results and single digit ES muzzle velocities.
Now I built my wife a fast twist 220 swift to shoot the 90 grain Bergers. Since I had good luck with H4831SC and it was listed on the powders in the Berger reloading manual I thought I would give it a try. But I'm seeing huge swings in muzzle velocities. I tried 5 loads of 5 shots each and the best ES I got was 21fps and it was a terrible group. The two best sub MoA groups were ES of 52fps and 109fps. Could powder bridging cause such large swings in muzzle velocity?
Stats:
Chamber 220 Swift
30" 1:7 twist barrel new only 39 rounds
Remington fired brass
Neck turned, trimmed, chamfered flash holes
H4831SC powder loads from 35g to 38g
90 Berger VLD's
royinidaho
Well-Known Member
Powder bridging "could" be your problem but I doubt it.
Try a ball powder of close to the same burning rate as 4831 and see what happens.
The shoulder on the Swift isn't steep enough and the cartridge doesn't seem over bore enough for bridging especially with the short stick powder.
I get similar results as you describe with a light for caliber bullet and very slow powder in a 270 extreme mag.
If you are using a mag primer, try a lesser one and see what happens. If not switch the other way.
Give 4064 a go.
Try a ball powder of close to the same burning rate as 4831 and see what happens.
The shoulder on the Swift isn't steep enough and the cartridge doesn't seem over bore enough for bridging especially with the short stick powder.
I get similar results as you describe with a light for caliber bullet and very slow powder in a 270 extreme mag.
If you are using a mag primer, try a lesser one and see what happens. If not switch the other way.
Give 4064 a go.
DennisPA
Well-Known Member
Yes I was using GM215M's. I have some CCI BR2's that I had very good results when the swift was a slow twist. Thanks
