Boolit Diameter Versus Bore Size

[A J]

This my first post. I've been lurking on your forum and soaking up loads of information. You guys are great!

Now that I'm retired I've gotten back to casting. Shoot a lot of PPC and burn some serious ammo. Cast .45 acp and .40 S&W. Use only range scrap and tumble lube with LLA or JPW with a touch of toliet bowl ring. No leading problems.

My question: Is there a rule of thumb relating to bore size and bullet diameter? One of my .45's, a Springfield XD, refuses to shoot a group. Shot it off sand bags with four different boolit configurations and you couldn't cover the pattern with a dinner plate, while my 1911 was grouping six shots in 2 inches using the same loads. The XD slugs out at .447 and I've been sizing at .451. To me .004 seems kind of tight.

Comments?

[mtgrs737]

I don't have any comment on the XD but it does seem like a lot to swage down (.004") have you tried sizing to .450" then loading to see if it makes a difference?

Oh and Welcome to the forum, I'm kinda new here too! A great place filled to the brim with helpfull folks! Enjoy your stay!

[Buckshot]

.............Hi AJ, and welcome aboard! Your Springfield XD may be infected with bad ju-ju :-) I'm not a pistol guy. Handguns act even odder then rifles do sometimes in what they like or don't like. I bought a Tanfoglio Witness in 38 Super 8-9 years back and i twas easy to love as it shot most anything I put in it. I then bought a 45 ACP conversion for it and nothing I did worked.

I tried 230gr TC's, 230gr RN's, and a 230gr group buy called the BD, after it's designer. I started with heavy slugs as I figured they had lots of bearing surface, and if anything would show promise they would. My modus operandi is to figure the max OAL that will feed from the magazine and then check to see how they chambered. For rifles I like the slug to engrave the lands, or at least to touch. Plus it lessens the distance a boolit has to travel while unguided.

I was rewarded with minute of bad guy at 25 yards, but I wanted more then that. To back up I have a Ruger Vaquero in 45 Colt and one fo the first successes with it was when I used the little Lee 452-190 SWC. I had some on hand and had tried all the other 45 ACP capable slugs I had on hand so I loaded some of these up. They have a blunt nose and the shoulder could be set out of the casemouth close to 1/8" and they butted up against the rifling nicely.

I used from 5.1 grs to 5.9grs in 0.2gr jumps of W231 to shoot 10 round groups at 25 yards to begin testing with. Zounds! The very first group was half the size of the run of the mill I'd gotten before. In fact, except for 5.3grs each hotter load grouped tighter and tighter. I finished up with a couple 10 rounds groups of 2-2.5" with 7-8 shots clumped in a 50 cent piece sized hole. I jave no explaination as to why.

One other thing I do it to neck size the cases. They may look a bit odd. Kinda like a short fat rimless 38-40 :-). I figure if the boolit is centered in the lands, the expanded base would help center the back end. It seemed to me the extractor would want to push it over to one side. Another reason for seating the slug out is to take up some of the windgae in the chamber between the casemouth and the end of the chamber. As we all know, the 45 ACP tends toward being a bit too short.

As far as boolit sizing, per usual in a rifle you size to fit the throat if possible. My 45 ACP barrel is .4514" and I size to .453" which in some cases isn't sizing but just lubing an 'as cast' slug. So some boolit's I've tried have been from .452 something to actually sized at .453". Didn't seem to make much difference in my case.

So with all the above maybe you can glean something of use. And if not, that wouldn't surprise me as I just kind of flounder around and any success with a handgun is serendippity and I take it all with thanks.

One thing I just thought of too, but you've probably checked already. The first barrel I got with the conversion was no good. I think Tanfoglio buttons the barrels and the first looked like the button had stopped and started in 4-5 places in it's travel.

...............Buckshot

[9.3X62AL]

Is the Springfield XD a polygonal-form bore, or conventional land-and-groove? If it is a land-and-groove barrel, those measurements sound defective to me. How do jacketed bullets work in the pistol?

I did some slugging of the factory barrel in my Glock 21, and found its "flats" to run at .449" while its "peaks" were .453". Both .454" and .452" boolits have done well in this barrel (throat is .453").

[Taylor]

I also have a Springfield (not XD),had all kinds of issues with it.I re-sized down to .451,issues are gone shoots pretty good.Now the old War Colt I have likes the .452's. So either slug the bore (and know for sure)or play with different size boolits and see what it likes.

[randyrat]

Are you sure it slugged out at .447 i usually size my 45 acp cast at .452. I had a XD40 service model and sized them at .401,,, didn't lead but shot like hell until i found the right bullet/load....I think they are touchy on bullets/powder,,, You have to experiment with different loads.......... I also came to the conclusion they/ some are not cast friendly... Try some WSF that seemed to work the best with stuborn autos. I've had some loads with the "faurty cal" that looked like i threw a bowl of rice and then i tried WSF and life was good again. One more idea.....It took a while to break in my XD it needed a good amount before it started to shoot decent.

[A J]

Thanks guys for your input.

I took the XD over to Springfield (I live in Illinois) and they shot it from a Ransom Rest and it grouped 3 1/2 inches and if you threw out the flyer it would be two inches. They used Federal Hydra-Shok ammo. They said that they would refit the barrel anyhow.

Never tried jacketed ammo in this gun. What I've been shooting: LSWC 200gr TL, LRN 230gr TL (both Lee moulds), 200gr SWC and 230gr RN (both Ranier plated). When the gun comes back from Springfield I'll experiment with different loads until it shoots right with cast boolits. Springfield says the XD's like heavier loads.....let's see if it will learn to like cast.....don't have much use for a pistol that will only shoot jacketed.

[randyrat]

Yes! i forgot to tell you that. When ever i worked up a load with jacketed bullets the closer i got to max the better it(XD faurty) shot. Then i went to cast bullets and it was very picky on powder. XD40 -I also beleive they have shallow rifling so you need hard bullets.(9lbs WWs + .5lb tin+.5lb lino)aproximation. I not sure if someone already mentioned this,but i beleive its true. Mine tested at around 15 BHN...I found a good mix and then weigh it. Next batch cast a couple, weigh and add a little of this or that to match the weight, wait 2 weeks and test hardness.