Need some input on this recipe

liscomb20 · July 28, 2014, 10:32 PM

Just got some xtreme 165 gr hp in and was seeing what you guys had for a min-max load with unique powder. What I have been finding is 6.2-7.3 compressed load then I went to alliant sight and that says 7.2 gr not looking for a hot load would like to be around 1000 fps. Just seeing what your guns like . By the way I'm shooting it through a glock 23 Gen 4 thanks

**Unclenick** · July 29, 2014, 09:19 AM

It's always good to assume nothing when providing the baseline information. If you make people look things up, they often won't take the time, so you end up getting fewer responses than you otherwise would.

Give your chambering (.40 S&W), your specific bullet brand and include its length as well as its weight. Say which primer you are using, give your case brand, and give your finished cartridge overall length (COL) along with the powder charge. Also give barrel length. In this case you have a 4" barrel which is the same length the SAAMI standard pressure barrel is this round. That matters because a different barrel length would give a different expected velocity.

Alliant's powder charge numbers are maximum recommended loads. You start 10% below their number and work up. For handguns, I prefer starting 15% low (Western Powder's recommendation) as different bullet lengths affect powder space more significantly in handgun ammunition than in rifle ammunition because of its smaller case volumes.

Pressures only match closely when the gun, case, primer, bullet, and seating depth all match up. It's not just affected by bullet weight, even though that is the largest factor (with some notable exceptions, like deep seated full wadcutters). Seating depth matching is important because it determines how far the bullet base is from the bottom of the case on the inside. That determines how much space the powder starts burning in, which affects peak pressure.

Seating Depth = case length + bullet length – COL

If you have more powder space than Alliant did, then you may have lower pressure. If your chamber lets the case expand more than theirs did (likely, because they use a SAAMI standard test barrel, which is made to minimum SAAMI chamber specs), you may get lower pressure. If your bullet is softer than theirs, or if you use a milder primer, again, you may get lower pressure. All those factors can mean your gun needs more powder to match their velocity result. However, given that it is in the nature of some powders to raise pressure rapidly beyond a certain charge level, and given that some chronograph setups are more accurate than others, it is generally best not to exceed the manufacturer's maximum number if you don't have a fair amount of reloading experience identifying pressure signs.

In this instance, Alliant is claiming 7.2 grains of Unique produces 1064 fps with the 165 grain Speer Gold Dot bullet seated to 1.12" COL using a CCI 500 primer from their 4" test barrel. QuickLOAD shows 6.7 grains of Unique would hit 1000 fps in their gun.

rg1 · July 29, 2014, 09:26 AM

Good info so far. Only testing I've done with 165 FMJ-FN bullets with Win cases and CCI 500 primers with an overall length of 1.125" showed 6.0 grains of Unique almost at 1000 fps. At 6.3 it was a few fps over 1000 and at 6.6 grains I was getting 1060-1070 fps. That's with my components and in my 40 SW G23. Note that my bullets were jacketed and not plated.

July 28, 2014, 10:32 PM	#1
liscomb20 Junior Member Join Date: July 6, 2012 Posts: 6	Need some input on this recipe Just got some xtreme 165 gr hp in and was seeing what you guys had for a min-max load with unique powder. What I have been finding is 6.2-7.3 compressed load then I went to alliant sight and that says 7.2 gr not looking for a hot load would like to be around 1000 fps. Just seeing what your guns like . By the way I'm shooting it through a glock 23 Gen 4 thanks

July 29, 2014, 09:19 AM	#2
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	It's always good to assume nothing when providing the baseline information. If you make people look things up, they often won't take the time, so you end up getting fewer responses than you otherwise would. Give your chambering (.40 S&W), your specific bullet brand and include its length as well as its weight. Say which primer you are using, give your case brand, and give your finished cartridge overall length (COL) along with the powder charge. Also give barrel length. In this case you have a 4" barrel which is the same length the SAAMI standard pressure barrel is this round. That matters because a different barrel length would give a different expected velocity. Alliant's powder charge numbers are maximum recommended loads. You start 10% below their number and work up. For handguns, I prefer starting 15% low (Western Powder's recommendation) as different bullet lengths affect powder space more significantly in handgun ammunition than in rifle ammunition because of its smaller case volumes. Pressures only match closely when the gun, case, primer, bullet, and seating depth all match up. It's not just affected by bullet weight, even though that is the largest factor (with some notable exceptions, like deep seated full wadcutters). Seating depth matching is important because it determines how far the bullet base is from the bottom of the case on the inside. That determines how much space the powder starts burning in, which affects peak pressure. Seating Depth = case length + bullet length – COL If you have more powder space than Alliant did, then you may have lower pressure. If your chamber lets the case expand more than theirs did (likely, because they use a SAAMI standard test barrel, which is made to minimum SAAMI chamber specs), you may get lower pressure. If your bullet is softer than theirs, or if you use a milder primer, again, you may get lower pressure. All those factors can mean your gun needs more powder to match their velocity result. However, given that it is in the nature of some powders to raise pressure rapidly beyond a certain charge level, and given that some chronograph setups are more accurate than others, it is generally best not to exceed the manufacturer's maximum number if you don't have a fair amount of reloading experience identifying pressure signs. In this instance, Alliant is claiming 7.2 grains of Unique produces 1064 fps with the 165 grain Speer Gold Dot bullet seated to 1.12" COL using a CCI 500 primer from their 4" test barrel. QuickLOAD shows 6.7 grains of Unique would hit 1000 fps in their gun. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

July 29, 2014, 09:26 AM	#3
rg1 Senior Member Join Date: November 6, 2001 Posts: 1,125	Good info so far. Only testing I've done with 165 FMJ-FN bullets with Win cases and CCI 500 primers with an overall length of 1.125" showed 6.0 grains of Unique almost at 1000 fps. At 6.3 it was a few fps over 1000 and at 6.6 grains I was getting 1060-1070 fps. That's with my components and in my 40 SW G23. Note that my bullets were jacketed and not plated.