IN need of help 45 acp - Page 2

floydster · June 22, 2011, 09:48 AM

I have never had good luck with Titegroup and cast bullets in my 45"s, and I have tried a lot of different loads--however with plated and FMJ I had reasonable success.

**Unclenick** · June 22, 2011, 09:50 AM

CAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assume any liability for any damage or injury resulting from use of this information.

If you're getting 785 fps from a load that should produce around 890 fps (extrapolating from Hodgdon's load data) from a 5" barrel, then pressure is low. Loose chamber or maybe just gas escaping around the case because the start pressure is low (about 13,000 psi to get that velocity with that much powder). Or maybe your bullets just have a super good lube, so neither the case grip nor the bore friction are normal.

I'm going to guess the low pressure is slow getting the slide to start back into counterbattery, so the gun unlocks more slowly and the barrel line stays low longer. That's great for perceived recoil, but will lower POI. I suggest you creep the load up, rather than down, as you are already getting low pressure load behavior. Keep going until you get to the 855 fps published velocity from Hodgdon. Your pressure should then be slightly lower but still much closer to Hodgdon's (because you are using a greater quantity of powder and making more total gas volume, so a larger portion of the bullet acceleration is later in the tube).

That should happen in your gun somewhere around 5.4 to 5.6 grains. I would work up to it in 0.1 grain steps, though, as you could pass a threshold where the case seal improves, then get a velocity and pressure jump.

Note that all the above assumes your chronograph is accurate.

Edit:

I just noticed that Hodgdon's data uses a 1.200" COL. That may account for the lower charge.

Lost Sheep · June 22, 2011, 10:33 PM

Jim, in post #4 seemed to me to have asked the right first question. At what distance are you zeroed? Not factory load, the load that is giving you the question.

Lost Sheep

**Unclenick** · June 23, 2011, 07:56 AM

I don't believe he has a zero for them. In post three he says factory ammo is fine (no drop), and this is so in both his full-size and Commander size 1911's. They may be fixed sight guns. I don't know.

I think his bullets are just scooting down the tube so easily the powder can't build enough pressure to perform. My solution would be to switch to 5 grains of Bullseye, which I know works well in various low pressure loads. Maybe he could borrow a few teaspoons from someone using it to see what happens?

June 22, 2011, 09:50 AM	#27
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,060	CAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assume any liability for any damage or injury resulting from use of this information. If you're getting 785 fps from a load that should produce around 890 fps (extrapolating from Hodgdon's load data) from a 5" barrel, then pressure is low. Loose chamber or maybe just gas escaping around the case because the start pressure is low (about 13,000 psi to get that velocity with that much powder). Or maybe your bullets just have a super good lube, so neither the case grip nor the bore friction are normal. I'm going to guess the low pressure is slow getting the slide to start back into counterbattery, so the gun unlocks more slowly and the barrel line stays low longer. That's great for perceived recoil, but will lower POI. I suggest you creep the load up, rather than down, as you are already getting low pressure load behavior. Keep going until you get to the 855 fps published velocity from Hodgdon. Your pressure should then be slightly lower but still much closer to Hodgdon's (because you are using a greater quantity of powder and making more total gas volume, so a larger portion of the bullet acceleration is later in the tube). That should happen in your gun somewhere around 5.4 to 5.6 grains. I would work up to it in 0.1 grain steps, though, as you could pass a threshold where the case seal improves, then get a velocity and pressure jump. Note that all the above assumes your chronograph is accurate. Edit: I just noticed that Hodgdon's data uses a 1.200" COL. That may account for the lower charge. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

June 22, 2011, 10:33 PM	#28
Lost Sheep Senior Member Join Date: January 24, 2009 Location: Anchorage Alaska Posts: 3,341	What zero? Jim, in post #4 seemed to me to have asked the right first question. At what distance are you zeroed? Not factory load, the load that is giving you the question. Lost Sheep

June 23, 2011, 07:56 AM	#29
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,060	I don't believe he has a zero for them. In post three he says factory ammo is fine (no drop), and this is so in both his full-size and Commander size 1911's. They may be fixed sight guns. I don't know. I think his bullets are just scooting down the tube so easily the powder can't build enough pressure to perform. My solution would be to switch to 5 grains of Bullseye, which I know works well in various low pressure loads. Maybe he could borrow a few teaspoons from someone using it to see what happens? __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

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June 22, 2011, 09:48 AM	#26
floydster Senior Member Join Date: May 26, 2008 Posts: 472	I have never had good luck with Titegroup and cast bullets in my 45"s, and I have tried a lot of different loads--however with plated and FMJ I had reasonable success.