9mm Reloading Accuracy Secrets

[schmeky]

I shoot hard cast bullets, almost exclusively. I have had a hard time finding a consistently accurate 9mm load at a casual plinking/target velocity. I prefer the 145/147 grain cast projectiles. Using a rest at 25 yards, I can get 5-7 rounds in a tight group (1.25-1.50"), but the remaining rounds will be 2-3" from the main cluster.

I recently read that using mixed brass headstamps will typically result in mixed accuracy; I use mixed brass. I have sorted my 9mm headstamps. I have yet to work up some loads using standardized headstamps.

Has anyone else done this with the 9 and was it worthwhile?

 

[Deavis]

I tested a couple of those theories and at ranges (less than 25 yards) most people use their handgun at there is no difference in accuracy between

New brass and OF brass
OF brass by headstamp
Trimmed and untrimmed
Primer brands

If there is, I couldn't find it.

 

[Floppy_D]

Was it a ransom rest or were you resting your hands on something? Does it group better with factory ammo from this rest?

 

[rcmodel]

It seems to me you need a baseline to rule out the 147 grain cast bullets causing flyers.

I'd suggest you try a box of 124 grain Hornady XTP's.

Whatever your gun & rest will do with them is probably all it will do with anything.

rc

 

[Oyeboten]

I am not in the front of the class on all this, but...just to muse -


Forcing Cone - or it's equivalent in an Autoloader...it's rate of taper...or, the area where the Chamber ends and the Rifling begins, anyway


Bullet Diameter in relation to Barrel's Groove diameter...vis-a-vis the Bullet Alloy...or type


Powder-type, for Barrel length...behavior of Powder in that length Barrel for that Bullet kind and Weight...


I doubt that any subtle differences in Cartridge Cases would be as meaningful as these other considerations for Pistol Ammunition/Accuracy.

 

[bluetopper]

Try 3.8gr of Green Dot.

3.5gr American Select.

I've been experimenting for 25 yard 9mm accuracy for 2 years with cast bullets in my 9mm 1911.

9mm accuracy is not necessarily a secret but it is harder to obtain.
JUST the right combination has to be found. I myself don't pay much attention to headstamps.

 

[Walkalong]

N320 & N330, or it is a bullet/barrel problem.

 

[Macca38]

+1 oyeboten's advice

I doubt mixed brass is likely to be the source of the problem, or the only cause.

I'm doing a load work up now for 9mm hard cast in every conceivable load I can get my hands on and when I've finished loading and testing I can let u know the results if you like. From loading other cartridges I have found that loading something very heavy isnt always the best bet....from what Ive read 124/5 grain seem to be what people are reporting as most accurate for 9mm most of the time. I have a dozen loads for the 147 to test in hard cast though.

I've loaded various rounds and been very careful with brass, weighing projectiles etc in the past and often found it makes no real difference. In fact I had one episode with .357 magnum where it shot badly when all neatly separated etc and then shot well when i just mixed everything up...no idea why...just stupid luck i guess.

One other thing I have noticed over the years is that some powders just don't meter as well as others or meter differently in different presses. I have had powders do things like throw a .2 grain difference every 5th round or similar weird stuff, where others are spot on every time.

What I would do if I got stuck was manually load 20 rounds of each test load by hand (which is what Ive just done) to ensure primer is seated just right, powder is exactly the same. if that fails then i look at the projectiles, and cases.

obviously looking at cases and projectiles is more painful, you would weigh them, size them with calipers etc...

let me know if you want my data when Im done testing.

 

[Cajun CB]

Test in a different gun also.

 

[Marlin 45 carbine]

I load cast 124gr in my pistol for 'practice' and plinking loads.
I've tryed Power Pistol, Bullseye and Red Dot with the RD being the best - better groups than either and cleaner too, this is mixed brass but I segregate out the Rem, Fed and Speer which seem to me to be the better brass and load them with jacketed for serious shooting with PP.
my practice round are all just moderate loads, I haven't compared the mixed brass vs. any other for accuracy.
wish I had more time to shoot and could find primers to load w/o getting skinned.

 

[fecmech]

My experience with the 9 shows that size matters (bullet dia. at least .001" over groove dia.) and powder choice is a big deal. Some 9's run really large on groove as did my Browning HP had a groove of .3575, I had to use .358 in it. The most accurate powder I've used with cast was Hogdon Long shot in both the 120 and 147 bullets followed by Blue Dot and WSF. Plain base slugs operating in the 30K+PSI range that is the world of the 9MM need as gentle of a start as you can give them IMO.

 

[ohwell]

For me the biggest factor in accuracy for 9mm was COL make sure your close to the lans I shoot Hornady 124 XTP's in a Browning BDM , Hornady recommends a COL of 1.060
My most accurate loads have a COL of 1.10