44 special, RCBS 44-250-k

[Bazoo]

I am running an RCBS 44-250-k and it weighs 265 grains as opposed to the 250 that the manual suggests. I’m using 50/50 ww/pb alloy.

So if I use my bullet for the skeeter load of 7.5 unique, how close is that going to be to the 22,000 psi that the skeeter load is listed as? Will it be under 25,000 psi?

Does the Lyman 429421 usually weigh the suggested 245-250 grains that the manual says?

[AnthonyB]

I have shot a lot of those and that load with no problem, but have no idea on the pressure.
Tony

[Bazoo]

What weight does your mould drop at?

[Larry Gibson]

FYI; I've pressure tested the RCBS 44-250-K and the Lyman 429421 both cast of COWW + 2% tin at 254 and 252 gr over the 7.5 gr of Unique (Alliant) along with 3 other different 240 to 258 gr cast bullets in Starline cases using WLP primers. The average psi ran 18,600 with the RCBS bullet upwards of 24,700 psi with the Lee TL 240 bullet. It appeared the seating depth (not the OAL) was more critical that the bullet weight. The deeper the bullet was seated the higher the psi regardless of bullet weight.

[William Yanda]

FYI; I've pressure tested the RCBS 44-250-K and the Lyman 429421 both cast of COWW + 2% tin at 254 and 252 gr over the 7.5 gr of Unique (Alliant) along with 3 other different 240 to 258 gr cast bullets in Starline cases using WLP primers. The average psi ran 18,600 with the RCBS bullet upwards of 24,700 psi with the Lee TL 240 bullet. It appeared the seating depth (not the OAL) was more critical that the bullet weight. The deeper the bullet was seated the higher the psi regardless of bullet weight.

Larry
Did the higher pressure give higher velocity? Was the difference linear?
Regards
Bill

[Larry Gibson]

Larry
Did the higher pressure give higher velocity? Was the difference linear?
Regards
Bill

Bullet weight.....psi........velocity

240.......22,500......1079
240.......24,700......1070
255.......23,000......1051
258.......21,000......1022

The higher pressure did not give the highest velocity. However, all the velocities are close enough that a subsequent test might very well give a different velocity order. The velocities are well within the normal test to test variation range.

Pressure measurement results are a bit different. As previously mentioned the seating depth inside the case (again, not to be confused with the OAL of the cartridge) has a more significant affect on pressure than a small % difference of weight. Here we have a weight difference of just .07%. In this test with these 4 bullets the 240 gr Lee TL was the deepest seated and gave the highest pressure but not the highest velocity. That is quite consistent with similar tests in other cartridges. The heaviest bullet gave the lowest velocity and the lowest pressure as it was not seated as deep as the others.

Here is an example where we can see the seating depth variation. This was from another similar test in the 44 Magnum. The end results were similar to the test in the 44 SPL.....the seating depth was the variable factor in pressure, not the bullet weight 9given similar bullets with a small % of weight variation).

291097

[Bazoo]

Thank you Larry. I appreciate you taking the time to share your testing with me, and everyone.

[AlaskaMike]

I am running an RCBS 44-250-k and it weighs 265 grains as opposed to the 250 that the manual suggests. I’m using 50/50 ww/pb alloy.

So if I use my bullet for the skeeter load of 7.5 bullseye, how close is that going to be to the 22,000 psi that the skeeter load is listed as? Will it be under 25,000 psi?

Does the Lyman 429421 usually weigh the suggested 245-250 grains that the manual says?

I'm very surprised nobody has called this out yet. 7.5 grains of Bullseye with the RCBS 44-250-K would be extremely dangerous, and would go WAY beyond the 22 - 25k psi you reference.

You mention "Skeeter Load", so I'm sure that was just a typo and you actually meant 7.5 grains of Unique.

I just wanted to call this out explicitly so anyone not familiar with the Skeeter load didn't get confused. We gotta look out for each other!

Stay safe,
Mike

[Bazoo]

Yes it was a typo and I corrected it. Thank you. I’d hate for someone to inadvertently blow their gun up.

[ddixie884]

Good info. Thanx, Larry.........

[Bazoo]

Thank you again for sharing this Larry.

[TCLouis]

My 44 SPL is a Taurus 431 and I have never been able to figure where i is in the strength range.
Mags are available so I have no reason to hot rod it, but"full power" loads that the gun can survive long term are my goal.

[Bazoo]

I’d guess that the Taurus wouldn’t handle a large amount of +P loadings without loosening up. Those are nice looking guns though, and I’d buy one if I came across a decent example.