Lyman 401638

[jim8115]

Does anyone know the length of the 175 grain Lyman #401638? I have some 180 Grain cast that I want to load in my XD40, but the closest data I can fine is for the 175 lyman 401638. The 180 cast are .621 long, and I dont want to use that data if there is a considerable difference in length, as I have to seat them deep to get them to chamber in the XD anyway

Thanks

[ku4hx]

Published cartridge overall lengths are just guides and should not be considered as an undeniable "gospel". You need to get your external neck diameter such that the neck area is not causing the cartridge to stick in the chamber (use a taper crimp die separate from the boolit seating die) and your max cartridge OAL should be such that the boolit doesn't stick on the rifling. Of course if the gun is magazine fed you need to consider fitting into the magazine was well.

Use your barrel's chamber as a guide. Once you've done the above, your loaded round needs to drop into the chamber with an audible "ker-plunk", and fall freely out when the barrel is inverted.

Of course there are always variations in chamber dimensions and you may need to use a smaller diameter boolit than is optimum. Conversely, you may be able to use a somewhat larger boolit than the loading manuals and conventional wisdom "dictate".

Be aware that deep seating boolits/bullets in a 40 S&W can cause pressure to spike far beyond what is safe. Always start with recommended starting loads and work up while watching for signs of excessive pressure.

[obssd1958]

My version of the 401638, is a 155gr HP. Just using calipers to measure the cavity in the mould - because I don't currently have any cast - it measures @ .570 in length.

...for what it's worth!

[jim8115]

lyman says oal 1.100 for that particular bullet
I guess I will just stick with the plated bullets for that gun. If the bullet is .050 longer than the one I have data for, and I have to seat it .015 deeper, thats .065 reduction in case volume. Probably not a safe thing in a 40.

[ku4hx]

lyman says oal 1.100 for that particular bullet
I guess I will just stick with the plated bullets for that gun. If the bullet is .050 longer than the one I have data for, and I have to seat it .015 deeper, thats .065 reduction in case volume. Probably not a safe thing in a 40.

For Lee's 175 grain TC boolit, my optimum OAL is 1.125" - 1.130". If I hold within that band and keep the neck diameter to .420" I get perfect functioning. My boolits are sized to .401". My factory Rem Golden Sabers are .420" neck diameter so that was where I started and finished.

Nothing wrong with plated boolits, but the 175 grain Lyman #401638 is very similar to my Lee boolits. You don't have to use 1.100" automatically. It's just a length they found to be optimum for them in their chamber. And IIRC, their chamber is a test barrel and not a production gun.

Lengthening a round within good-functioning limits is seldom risky; shortening a round (deep bullet seating) can be. Of course a round so long it jams the rifling can cause a pressure spike but I don't believe that's a concern here. But the choice is yours obviously.

Good luck; watch for excessive pressure signs.

[BulletFactory]

Mine was oval shaped.

There is somethin else going on here, you should not haveto set the bullet deeper in the case to get it to chamber in the XD.

[jim8115]

Mine was oval shaped.

There is somethin else going on here, you should not haveto set the bullet deeper in the case to get it to chamber in the XD.

I dont know what else it could be. Everything else i try chambers just fine. FYI, I got these from thebulletworks.net . Anything longer than 1.085, and they wont allow the slide to close. If i drop them in the barrel, i can tell the case is not hitting the rim, or whatever the correct terminology is.. In other words, the bullet itsself is hitting something.

[jim8115]

Also, the same bullets, set a 1.125 feed just fine from other .40s, sigma and hi-point carbine, just wont work in my XD40

[BulletFactory]

Are you sizing them? What is the diameter of the pulled bullets?

I have been through it with the XD.40, so I think I may be able to help you here.

[ku4hx]

Also, the same bullets, set a 1.125 feed just fine from other .40s, sigma and hi-point carbine, just wont work in my XD40

If these are the only boolits giving you problems and those problems are consistent with all loadings then I'm with BulletFactory ... suspect the boolits. Being out of round can definitely effect functioning. I doubt boolit length is the problem. Generally cast boolit abnormalities are in diameter, being out-of-round or some other similar problem.

You might try sizing them to check for being out-of-round and see if that solves your problem.

Looks like BulletFactory is your best bet at solving the problem.

[jim8115]

they measure .401, and appear not to be out-of-round. I really think it has something to do with the XD, as they work in 2 other guns. I could just seat them deep, but i am really concerned about pressure if I do that. I can just shoot plated out of it, but since I live in the area where thebulletworks is located, i can walk in and get a real deal on the truncated cast ones......

[BulletFactory]

Seat a "test bullet", no primer, way too long. Say 1.140, crimp it so the bell doesnt interfere with chambering, then set it in the magazine with the slide back, and release the slide stop lever to chamber the round under force. Eject the round, and look to see if the chamber has sheared the lead from the front of your sized boolit. If it has, the throat may not be cut properly in the gun. I had one like this.

You should be able to chamber a round that enters the throat by a couple hundredths.

[jim8115]

Seat a "test bullet", no primer, way too long. Say 1.140, crimp it so the bell doesnt interfere with chambering, then set it in the magazine with the slide back, and release the slide stop lever to chamber the round under force. Eject the round, and look to see if the chamber has sheared the lead from the front of your sized boolit. If it has, the throat may not be cut properly in the gun. I had one like this.

You should be able to chamber a round that enters the throat by a couple hundredths.

Well, i did try that , sort of. I tried to chamber one the batch I made at 1.125, and the dang thing stuck. I could not even pull the slide back.. Wasnt sure what to do, so I took it to the gun shop, they were able to force it open and get it out....so now, i am apprehensive about even trying .......

[BulletFactory]

Sounds like the thing is shearing the boolits as its chambered, it will jam it up. It takes some coordination, you put rearward pressure on the slide, as you tap the bullet rearward with a rod from the muzzle end.
Take the bullet seated at 1.140 or so, and put it in the barrel. Tap it in until it sits in the chamber like its supposed to, then you'll prolly have to tap it out from the muzzle end. You will be able to measure the throat diameter this way, and see if the throat is so tight, that it is swaging (sizing) the round.

You'll see the lead if its being sheared rearward by the lip that the case mouth headspaces from. In mine, after a dozen shots, it would build up a lead "ring" that was thick enough at that point to stop the gun from going into battery.

On my gun, I slugged the bore, sized the boolits to +001 they measured the same after they were pulled. Trouble is, the barrel was swaging the bullets down before they ever got to the rifling, making them too small. It had a throat, but it was a very very slight taper. It sounds like you very well might have the same thing going on here.

After you rule out ALL possibilities with the reloads that you can possibly think of, and its still leading, you may need to lap the throat of the barrel.

I chased my tail on this gun for a looong time before gear suggested that I lap the throat. As soon as I opened it up, the leading all but disappeared.