9mm polygonal rifling - what boolit?

[ZX John]

Hi all! New to THR, thanks in advance for the help.

"SWMBO" recently got a H&K P30L, a darling little gun she's wanted for a long time { - is it even legal to call a gun "darling" on this continent anymore? Maybe down there; I'm pretty sure that up here in Canada it's good for at least 10 years...}. It has polygonal rifling and H&K don't recommend cast lead for it, but until jacketed bullets are as cheap as wheelweights, that's what it's getting fed.

So I spent ~$350 on 9mm reloading stuff, put together some reloads for it and off we went to the range. Bullets are Lee 90387, 120gr TC with the wide driving bands and single grease groove, sized .356 and lubed with beeswax-ish. Powder is 700X, the only fast powder I've got at the moment.

Results at the range were:

1) 3.8gr 700X - HOT!!! Definitely supersonic, and the P30L sprayed them all over the target, no grouping at all; but at least with all powder loadings, the TC's went straight through the target, no keyholing. The load was obviously 'WAY too hot, so I went lower;

2) 3.3gr 700X - still spraying but still cycling the action normally, although she was beginning to have problems with it;

3) 3.0gr 700X - still spraying, but beginning to sorta' look like a group. Most of them cycled with me, most of them stovepiped with her; and

4) 2.7gr 700X - NICE group; the P30L put them all in a small circle, but the slide had to be manually cycled every shot. And,

5) three different types of store-bought ammo; it grouped about as nicely as it did with the 2.7gr load, cycled normally and seems to like 115gr FMJ best.

I'm going to take a page from my .45 loading book, and go with a heavier bullet. Our .45's don't like light bullets; I have a SAECO 200gr SWC that is inaccurate and needs 3.6gr Trail Boss to cycle their actions, but they'll cycle just fine as low as 2.9gr with a 255gr Keith-form SWC, Lyman #452424.

So, what boolit and/or powder (and how much) would anybody recommend for a light 9mm lead-load? I've been thinking of Lyman #356637, a 147gr BBFP; does anybody have experience with this mould? One thing's for certain - I've spent too long trying to feed three hungry .45's with a two-cavity mould; it's 4 or 6 cavity for me!

Oh and; does anybody know a good, accurate .45 ACP load for that SAECO 200gr SWC? I'd love to use it instead of the 255gr, because I only get 28 bullets per pound of lead with the 255gr's...

 

[sexybeast]

I've shot 40k of lead through polygonal rifle barrels [glock], and I know a few that shoot lead through their HK's. There will be some that will come along telling you that you are going to blow up your gun if you do so. Perhaps you should ask them if they have "done" it or have "read" about it. There is a difference.
My loads cycle and are accurate and are also light. But I don't use 700x now and have never used it with 9mm so I'm not going to recommend any loads. I usually try to use 231/hp38. With 115gr my load is 4.0gr and with 125 it is 3.7gr and it cycles all of my 9's. I've only had 1lb of 700x and it was frustrating to use. Its very different than 231
I've just started using 147's and the load I use is 3.5gr of 231/hp38. Its turning out to be a tack driver and a soft "push" type of round rather than a snappy round.
I don't cast. I buy mine and I use either .356 or .357 bullets. Mic yours. Also slug your barrel. The bullet should be .001 larger than your bore. Too much pressure or too small of a bullet and gasses will go around the bullet and cause both terrible accuracy and leading of the barrel.
I did use 700x in 45acp and did not like how it meters. I did not keep records then so I have no data. Others on this site use it and I'm sure some one will come along and give you some of their data that "they use"