9MM Carbine load, help please.

[daveuk]

I've got a 9MM Carbine in blowback. 14" barrel, 1 in 16 twist, slugs to .3565". So far with everyones help here i've got to 1.5" group at 25 yds but need better. Current recipe is a hard cast bullet from the lee 124 RN mould weighing in at 118.8 grns. This is loaded using fed 100 primers over 4.0grns of GM3 ( a european powder which is a tad slower than Bullseye). Next try i plan to load in increments of .1grn up to the Hodgdon listed max of 4.9 for Bullseye and use a bigger expander from a .38 die (idea pinched from here) is there anything else i can try along the way as you guys really seem to know your stuff or am i going in right direction!
Many thanks in advance for any help. PS i shoot in the UK so this will be my main target gun for 1500 and Bianchi thus the need for accuracy although i do admit that by choice i'd rather use a handgun.

[MT Gianni]

Does it group better with Jacketed? In other words, Is the gun capable of more or are the boolits the limiting factor?

[mag44uk]

Hi Dave,
Nice to another Brit here! I am guessing you have one of slim Bobs SGC AR`s.
One of my club members has one and it seems to shoot well with RG surplus.
He does say the only issue he has is the cases hitting him in the face! He solved it with electricians tape over the ejection port!
What worries me is the technical side of the mechanism with the sear. Would hate to break that!
Other than that I could get into one for the same reasons as you,open class 1500.
Have you though about getting spare mags? I am not keen on the 32 rounders. There are 20 rounders available. It looks to me like they have been thinned on a surface grinder to fit the mag well.
As soon as I saw them I looked to see what GB moulds are available and thought the 147 gn may be the way to go. I didnt know twist rate or bore size at the time though.
The lee 125gn 6 cav seems to get good reports too.
I can see another dabbling project coming on!
Regards,
Tony

[Three44s]

I don't know about a 9mm carbine, but do shoot a handgun in 9mm with lead .........

I would try a slower powder.

Unique perhaps .......... I currently am running SR 7625 because I have a part of a keg that's pretty old.

Three 44s

[daveuk]

Hi Dave,
Nice to another Brit here! I am guessing you have one of slim Bobs SGC AR`s.
One of my club members has one and it seems to shoot well with RG surplus.
He does say the only issue he has is the cases hitting him in the face! He solved it with electricians tape over the ejection port!
What worries me is the technical side of the mechanism with the sear. Would hate to break that!
Other than that I could get into one for the same reasons as you,open class 1500.
Have you though about getting spare mags? I am not keen on the 32 rounders. There are 20 rounders available. It looks to me like they have been thinned on a surface grinder to fit the mag well.
As soon as I saw them I looked to see what GB moulds are available and thought the 147 gn may be the way to go. I didnt know twist rate or bore size at the time though.
The lee 125gn 6 cav seems to get good reports too.
I can see another dabbling project coming on!
Regards,
Tony
The new mags aren't ground at all, it seems the last batch were over sized! I've done a couple of thousand rounds thru it now and no problems so far, the mechanism seems to be pretty solid. i've already tried a 147 (jacketed) and didn't get very good results, although in fairness i didn't try that hard. The best to date has been Sellor & Belliot 115grn factory though i'm getting close with the lead loads now.

[daveuk]

Does it group better with Jacketed? In other words, Is the gun capable of more or are the boolits the limiting factor?

It's best with Sellor & Belliot 115 FMJ, it can manage 2" at 50M if i could get the lead load to this i would be happy, for now. I'm hoping the method i've listed above will do it but any extra help certainly can't hurt.

[daveuk]

I don't know about a 9mm carbine, but do shoot a handgun in 9mm with lead .........

I would try a slower powder.

Unique perhaps .......... I currently am running SR 7625 because I have a part of a keg that's pretty old.

Three 44s

Ta, I've got some Unique I'll give it a go in my next loading session, it's all worth a try.

[mag44uk]

Just been having a think about this.The only 9mm I ever loaded for was a Steyr GB and I recall using alot of Bluedot.
I wonder whether your particular gun might handle semiwads. I am thinking of the Lee 140gn swc. If you look on a certain auction site some one in the UK has a few for sale.
If your bore is .3565 I am thinking .357 or .358.
I dont know where you are Dave but Peter Lawman is selling 9mm ammo for £16 a 100.
He also sells Vectan powders of which I am a big fan.
Just a few thoughts!
Tony

[KCSO]

I am using 4.2 of Bulls Eye and the same bullet in a M/A 16" barrel carbine and am shoooting under 2" at 50 yards with a 3x scope. With a red dot sight the grooups open up some and with irons I am running at just over 3". My bullets are cast from 1/2 and 1/2 ww and linotype. I don't know if a carbine like that will do much better.

[daveuk]

Just been having a think about this.The only 9mm I ever loaded for was a Steyr GB and I recall using alot of Bluedot.
I wonder whether your particular gun might handle semiwads. I am thinking of the Lee 140gn swc. If you look on a certain auction site some one in the UK has a few for sale.
If your bore is .3565 I am thinking .357 or .358.
I dont know where you are Dave but Peter Lawman is selling 9mm ammo for £16 a 100.
He also sells Vectan powders of which I am a big fan.
Just a few thoughts!
Tony

Good idea mate, I'll give the 140 SWC a go as i've already got the mould as i use it in my Taurus. Cheers, Dave.

[Moxy]

If you are wanting accuracy and that is your main concern , then you may be better of with a truncated cone design . The Air Force did a study and found that they are almost always more accurate . The air flow over the bullet and the lower center of gravity centered closer to the base of the bullet allows it to stabilize better . Hornady designed their truncated bullets this way as a result of the research . The other factor could be the faster burning powder (BE) as the bullet may actually be slowing down a small amount in a 14" barrel . One commenters suggestion of using Blue Dot should be much better . A load of 6.9 gr is very popular for people using it in 9mm .

[helg]

1. The closer is round diameter at neck to the chamber diameter, the better the center of the chambered round is aligned in the bore. You can measure chamber diameter by casting it with cerrosafe, or use a poor-man method, chambering a sized and flared brass and measuring the neck diameter of the extracted brass. There are couple of methods how to extend the neck diameter of a round to have a perfect fit into a brass. Flaring it a bit more and not crimping to "straight walls", which you are probably implying with the .38 expander is one of the methods. This is, probably, the most critical dimension for accuracy in a non-bottlenecked 9x19 round. Be careful, as undercrimped bullets may not seat tight enough.

2. At 25yds wind deflection is not yet a big concern. TCN bullet, which experiences more air resistance and therefore, is more deflected by wind, will give negligible difference in accuracy with RN design at this distance.

3. The longer is bullet bearing surface, the better is bullet concentricity in the bore. Lee 124 TCN has this length of about .3", while Lee 124 RN is around .23". The Lee TCN bullet should be more accurate at short distances.

4. Like in rifles, the best is when brass length is the same for the whole batch and is matches headspace. Unfortunately, unlike bottlenecked brass, which enlarges after each firing, and can be trimmed to the same length, straight-wall brass shortens after each firing. Accuracy of the 9mm brass, which was fired many times, suffers due to the shortage.

5. Again, the best alignment in round chambering is achieved when the whole round, not just the neck, perfectly fits in the chamber. With lead bullet, which is larger in diameter than jacketed, and fits tightly into slightly larger case neck, you can achieve better fit by not completely pushing brass into the sizing die. You still have to size it, otherwise the bullet will not hold tight enough in the shell, (remember, this may be dangerous). You may end up of finding three magic neck diameters: after sizer, after flaring and after crimping, which should give a tight seat on your bullet, and tight chambering.

6. Barrel harmonics, which are in the play with finding sweetest charge, are worth playing once your accuracy is 2MOA or better. 2MOA is 1/2" at 25yds. I do not think that the harmonics is a determining factor in your case.

And remember, safety first.