Slugged .40 storm bbl

[popper]

Cleaned the storm this morning, lots of leading the length of the bbl after 100 rnds of .401 165s, with harder alloy, upper end load of 231. Accuracy wasn't great but was with plated. Slugged the muzzle after I cleaned. 0.389! I guess I'll stick to plated in this gun.

[runfiverun]

389??
i'd send it right back with a question about what they use to measure thier bbls with.
i think i can eyeball .010

[popper]

I'll probably drop them a note. I noticed the chamber is a bit tighter than the XD. Lead in the groove just sheared off into the lube groove. I guess I shouldn't be lazy and slug the chamber end also. Really like the feel of this one and the sights are good for my eyes. Got it for my wife to shoot, rotating bbl for lower recoil (I can hardly tell the difference), but that won't happen till she learns not to point it at anyone.
Looked at the slug under 20x, interesting. Alloy is ~COWW. excess lead piled up in a ridge, eventually broke off and was left in the lube groove. BIG chunks from the groove and rope like strands from the bore. Groove displaced lead is 1/2 the width of the lube groove before it breaks off. The fracture is a nice break, like steel, not like a softer alloy that has a break edge like cookie dough that is too dry, frilly. Anyway, no wonder the accuracy stunk, shows what happens when the CB is too big and alloy is hard. Sorry I don't have a good closeup camera, picture is interesting.

[williamwaco]

I will bet a Big Mac against a peanut you measured from the top of one land to the top of the opposite instead of the bottom of one groove to the bottom of the opposite.



Note that on the slug, the lands and grooves are reversed. The high points on the slug correspond to the grooves in the bore.





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[40Super]

Ya, I would really be surprized if it is actually that small.90% of Berettas are too big, mine are .4035-.404.
They would like to have that barrel back(reguardless of warantee period) if it is.

[popper]

From CS -
The correct bore diameter is 0.390 so your firearm is within specifications.

[popper]

Can't get a pic but this is a dwg. Sure will mess up accuracy as the sheared part spins off at the muzzle.

[runfiverun]

bore at 390 is one thing, what's the groove depth?
399 would be fine.

[popper]

Not being cagey, but hard to tell. Measure with HF digital cal, 308 Amax = .307. CBs measure .401. Slugged CB =.401/.389. However, slugging a well oiled slug and bbl; the CB still got shaved excessively. Only slugged the muzzle end so far. My concern is 1) lousy accuracy 2) all the lead in the lube groove, as shown above. It's kind of a lumpy 'rope' of lead that is partially attached, ~ .010" dia. between chunks of lead pushed from the rifling. My assumption is that CB going the other way will get the same 'rope' of lead. XDm & same CB shoots OK. XD is good with 50/50 #2 pure, just OK with 1% tin/pure. This alloy is just 2 1/2 % SB/pure, tad of As & S, same I'm using in 30-30 & 308. Groups with rifle & pistol look the same, tight core but a lot of fliers (> 100 rnds shot, 10% fliers, total spread ~ 4"), but no leading in rifle. I think I see why. Think I'll have to size smaller for this alloy. Anyway, this one does good with plated so that's what I loaded couple 100 for now.

[runfiverun]

the lube groove is there for displaced metal just like the cuts on barnes bullets.
i see you are displacing A lot of lead though.
smaller would equal less displaced metal.
some kind of throat would also help,many of the new guns are coming with an abrupt edge where the rifling just starts at the end of the chamber.
the boolit has no chance to do anything but get the rifling impressed into it.

[40Super]

I'd agree that it must be pretty sharp in the steps. Once a chunk of lead tears off, the next boolit smears it. I spun some unitized wheel(for SS polishing)cuttoffs in my chamber and throat area to smoothen most of my new barrels out. Can't spin'em fast or too much, but works good. I have a ream made also that I can put a small chamfer there.
I wouldn't go smaller boolits or harder for your alloy. I run 12ish bhn in my 40's, even in 9 quite a bit, doesn't lead any.

[popper]

40super - I understand what you are saying, but haven't tried it . On reflection, I do think I will keep this one shooting plated and as a low count HD pistol. It's the 1 with the rotating bbl. Ergonomics are great but I think the bbl quality isn't what I expect. ~ 500 rnds and the rear bbl bushing is showing signs of wear as is the frame bbl support bushing. Frame rear slide flanges are showing wear also. Tried lubriplate and oil, neither appears to solve the problem. This is the model that passed all the military tests but wasn't accepted. My SIL is looking for a SA shotgun, I was reading about the 391 Beretta and get hints that the 391 has reduced quality from the 390. So I'll use my XD for my range gun - no signs of wear after thousands of rounds.

[40Super]

Agreed < I do see where your coming from. I have 4 Berettas(and can't hardly give them away, nobody wants them around me), plus I have 3 XDm's(9,40,&45). I will never get rid of the XDm's, unless to get another one. Once I put in a Powder River Precision trigger kit(I really like lighter triggers), they are sweet shooting autos. Haven't had a hic-up with any of them yet.

I have to keep seperate loads, with oversize boolits, because of those loose Berettas, it rather annoys me to have to shoot jacketed just for them.

[popper]

Powder River Precision trigger Does it have a better trigger position than the XD? I get a blister on my trigger finger, next to the nail, after shooting 200 rnds. Unfortunately my finger is crooked. The Beretta doesn't give me one.

[popper]

40super I've been playing with alloy and I did learn a lot in my frustration. I found lad/tin tends to peel off the surface and roll up a thin layer, like that kid's fruit roll. Add Sb and it cuts (shears) like you get when seating, a slice of metal. This alloy seems to move until it's shear strength is exceeded and then it breaks off. There are lots of names for cast strength, I'm looking for 'durability' in the bore and when it hits something. When it does break, it is a clean break. When I hit it hard with a hammer, the results are like the drawing, no 'fraying', just movement. My thought is when it hits it won't fragment, but break into large chunks. More testing to validate my theory.

[40Super]

Your looking for an alloy that would be good for hp's. One member here I believe did a bunch of hp mushrooming tests with some alloys and his best "squishing" without fragmenting was 97%- 1.5%-1.5%. I believe the tin and antimony need to be equal for them to form their "ideal" strength. Maybe a little copper added in the alloy wouls add some stregth, but above 1.5% will want to not mix in and seperate.

As for the XD trigger, the PRP kit takes the pull down to 3.5lbs, shortens the take-up, and eliminates the over travel. Reset is also shortened and has a distinct click.

[popper]

Weighed the 'lost' lead today, 0.9 gr. Not much for a 165 gr CB but enough to cause a problem when it gets slung off the CB. I may need to add 1/4% tin and see what happens.

[runfiverun]

popper:
the copper idea isn't a bad one, it adds some schloober,and some slippery to the alloy wthout adding brittleness.