Tuning my 9mm USPSA Ammo

[frankge]

I've been figeting with lots of different loadings for my Glock 34 and my kids M&P9 for USPSA matches, steel challenge, etc. I've got it down to two that seem to work well and would like some input to see if I can further tune them. BTW - a chrono is on the Xmas list this year. These are the results of trying quite a few types of powders and loadings

Load 1 - favorite so far

124g Zero/PreDelta FMJ
5.5g Unique
PMC SP
1.125 OAL
Lee FCD

notes: accurate, some recoil but more of a quick push, believe it or not with "flaming dirt" not smokey and very clean! I was thinking of stepping it down to 5.0g to further reduce recoil but question is will I make power factor and will the load then become dirty? I've found Unique loaded up to be clean.

Load 2

124g Zero/PreDelta FMJ
5.0 W231/HP38
PMC SP
1.125 OAL
Lee FCD

notes: another good load but definately snappier. Clean and accurate but I found the above load slightly more accurate. I do like this with a 115g FMJ best but then I need to load higher to make Power factor. Was thinking of dropping charge to 4.5g.

Thoughts?

 

[Marlin 45 carbine]

interesting post, sorry can't offer any tips as I use Power Pistol to load jacketed slugs in 9mm loading published data charge under Rem 124gr GS to refill cheap 'range/plinking' brass for me and nephews 9s.
does great - no need to go further IMO. we all have carbines along with pistols and the load really smokes in them.

 

[rfwobbly]

I'm using less powder at a longer OAL, so Load #2 sounds very hot to me. I'm using 4.3gr of 231 at 1.150" with 124gr RN and that works well. If your slide is having trouble going lower on the powder, go down on your slide spring about 4 lbs. An M&P is probably sprung fairly high for SD loads. You don't need that stiff spring in competition.

Try Wolff Springs. http://www.gunsprings.com/

 

[twofifty]

tuning

Tuning ammo suited to each HG is a great idea.

You'll really need that chronograph though, as without knowing your actual velocity there is no way of calculating PF or finding the sweet velocity/recoil range where you and your HG can optimally perform.

Making PF is a must:
Developing a round that makes PF is part of the game's rules. Since some days are colder than others and since range elevation ASL varies if you travel to matches, you will need to decide how much of a PF buffer you want.

124gr bullets don't all weigh 124gr:
The plated 9mm bullets I am now using weigh from 122gr to 124gr, so I've decided that my declared weight is going to be 122gr. But I developped my load by selecting 124gr bullets only. This yields a buffer should my ammo PF be verified by match officials.

Selecting a powder load:
I found that (a carefully weighted) 4.0 gr to 4.2 gr of 700-X gave average velocities that yielded a useful PF buffer AND also a recoil impulse that most quickly brought the HG back onto target for the second shot. This means that my splits are helped and accuracy is maintained. These loads also feed and eject very reliably.

Because of these benefits I chose to settle on 4.1grains of 700-X.
Since this is quickly and fairly consistently dispensed through a drum dispenser, any slight +/- load variation is of no practical import to this HG's recoil or accuracy or PF buffer or reliability. Works for me.

 

[1SOW]

frankge,
That chrono is really the only way you can 'tune' your load. I was pretty surprised at how far off my 'estimate' on speed was before I got my chrono.

You want an accurate light load that feeds and functions in your gun. Hot loads are generally accurate, cleaner and will function in any gun. A light load that works is faster and easier to shoot accurately. As rfwobbly said that may necessitate a recoil spring change.

As you said, 'tuning' your load makes it a lot easier to concentrate on the basics.

Load #2 is hot in my experience also. I don't know your gun, but at that oal, I'd load a few at 4.0 and 4.2 and chrono them. Win 231 is sooty for me at 130Pf/1050'/sec

 

[LiveLife]

I need to ... make Power factor. Was thinking of dropping charge to 4.5g.

frankge, if you are just trying to make minor power factor, you should make it with 4.5 gr W231/HP38 out of your G34 barrel. Many shooters make power factor with shorter G17 barrel with 4.3-4.5 gr at 1.125"-1.13" OAL.

Also, I find PMC primers burn less hotter than Winchester/Magtech/Wolf/Tula and therefore require 0.2-0.3 gr more powder. If you find yourself needing more powder to make power factor, might want to consider changing primers.

If you venture past punching holes in cardboard, you will find the heavier 147 gr bullet more suitable for steel challenge with softer recoil too.

+1 on the chrono.

 

[frankge]

thanx for the input, I did use power pistol but I hear its best at SD loadings as I tried with it. I'll try the lower loadings and definately get that chrono

 

[glockgod]

If you venture past punching holes in cardboard, you will find the heavier 147 gr bullet more suitable for steel challenge with softer recoil too.

My go to load for IDPA/USPSA
OAL-1.150
147gr bullet(I like Montana Gold)
4 grains Unique
Winchester primer
scrounged range brass

Chronos at 980 FPS out of a Glock 17,is accurate and does well on steel. No problem making power factor!!

 

[RhinoDefense]

147gr bullet
4gr WSF
1.125 OAL for FMJ/RN
1.100 OAL for JHP
133PF

 

[mboylan]

124 gr bullet 4.1 gr of VV N320. Very very clean and consistent. Only costs a fraction of a penny more per round. You need to go hotter with other powders to get the same level of accuracy.

 

[1SOW]

mboylan: +1

I use 4.0 but maybe my oal is less. 131/132PF

 

[rfwobbly]

mboylan: +2

As per Angus Hobdel

 

[chbrow10]

This has been said above, but you really need to chrono YOUR loads in YOUR gun, then couple that with grouping YOUR loads in YOUR gun with YOU doing the trigger pulling to effectively "tune" YOUR loads.