Followed load data 9mm 145gr wonky results

D

Dundgren

New member
Hi,

I've seen a few sources stating 4.4 grains of VVn340 max behind a 145gr LRN. I have LOS 145gr Plated RN bullets. I loaded a few of these with 4.4 grains of VVN340 at 29mm COL as suggested and shot them today. (I had done a ladder-load before this with inaccurate results.) I shot them out of a glock 17 and a Colt 1911. Both got bad results and the 1911 had one land basically sideways. I chronoed a few as well:

Glock 17

286 (938)
310 (1017)
297 (974)
311 (1020)

1911

309 (1013)
312 (1023)
313 (1026)
311 (1020)
308 (1010)

These are supposed to go at 1060 fps and at 4.3gr of N340 at 1040 fps according to VV.

I measured my loads at almost exactly 29mm and when tightening die for crimping using only intermediate fingerstrength. I have tried with very slight crimp as well with same results.

Any ideas? I'd love some help.
 
I couldn't get LOS's website to work.
I checked Rainier and they specifically say to use a separate crimp die. Not using it could lead to accuracy problems.

Worth a try. I use Lee crimp die.
 
Yep sounds like you should remove crimp entirely and see how that goes firing one at a time in magazine, if you do that and get the same chrono results then your crimp wasn’t one to start with. Crimp on straight wall does have an affect on final velocity by delaying movement until the burn is building more pressure and will help fully burn the powder before bullet leaves the barrel which is the goal.
 
Could you measure the diameter of the bullets and slug your barrel? If the bullets are undersize for the bbl then erratic velocities and keyholing can result. The reason I ask is the 1911's velocities seem much more consistent...
 
"...with inaccurate results..." The ladder test doesn't test the accuracy of a particular load. It only tells you the POI in relation to other loads.
"...seen a few sources..." There's only one that matters and that's .vihtavuori.com(add the W's.). Max for a cast or plated 145 is 4.3 of 340. 4.4 is close enough. That'd be the differences in manuals. Your velocities will be slightly different anyway. However, you do not, ever, start with the max load.
Their test barrel was a 1 in 10 twist, 4" barrel. Glock uses 1 in 9.84". Close but not the same. A Colt 1911 uses 1 in 16. Really slow.
"...had one land basically sideways..." Key holing is caused by undersized bullets, an oversized barrel and sometimes low velocity. LOS 145gr Plated RN's are .356". The Colt's slow twist might be the cause due to low velocity.
Only ever loaded 9mm with cast 121 TC's to 1.169" OAL. Used in my Inglis BHP, I've never had any feeding issues. The 1.142" Vihtavuori says seems short.
 
Different barrels produce different velocities, and different lot numbers of powder will produce different velocities. Different case capacities will change velocity. We can't expect our results to be exactly like published results.
 
I don't shoot 9mm lead but do shoot a lot of 147gr platted bullets in 9mm . It seems hard for me to find much data pushing a 147gr bullet faster then 950fps and thought the rule of thumb was caution pushing anything that heavy in 9mm over 950fps .

As far as the results you got . That looks about right "if" you shoot and or hold the two firearms differently . The heavier 1911 is clearly more consistent . I'd try the test again and this time make sure you keep a tight firm grip with locked out elbows on the G17 every shot . Now that has to do with the velocity differences .

Then there's the size difference from bullet to barrel as others have mentioned as well as inconsistent size from bullet to bullet that could cause problems .
 
Metal god said:
I don't shoot 9mm lead but do shoot a lot of 147gr platted bullets in 9mm . It seems hard for me to find much data pushing a 147gr bullet faster then 950fps and thought the rule of thumb was caution pushing anything that heavy in 9mm over 950fps .

As far as the results you got . That looks about right "if" you shoot and or hold the two firearms differently . The heavier 1911 is clearly more consistent . I'd try the test again and this time make sure you keep a tight firm grip with locked out elbows on the G17 every shot . Now that has to do with the velocity differences .

Then there's the size difference from bullet to barrel as others have mentioned as well as inconsistent size from bullet to bullet that could cause problems .
Click to expand...

That's a myth. As with any bullet weight, select the right gunpowder for the job.
 
Between a Glock 17 and a 1911 9mm I would expect the 1911 to be more accurate. My 1911 has a much tighter chamber and closer lands than my Glock 19. Ammo I had optimized for my G19 would not chamber in my 1911 Colt Govt. Anything optimized for my 1911 worked well in the G19 but I had tighter groups with the 1911. The Glock was a slop machine that was fairly accurate.
 
That's a myth
Click to expand...

Not sure what you mean for sure . I understand the point but starting that out with it's a myth ? Hmm , not sure it's a myth . Sure there are a few powders that will push a 147gr bullet 1000fps+ . All of those will be at max published loads so saying it's a myth to use Caution once you start passing 950fps with heavy 9mm bullets is not how I'd say that . I did not say you can't or shouldn't , just be paying very close attention to what you're doing with those combinations of components .
 
Ladder loads as far as I know are 200 yards and used for rifles.

I would guess they are impossible with a pistol.
 
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