Elsewhere on this forum I read a recommendation for Atomic Ammunition .38 Spl +P LSWCHP, so I ordered a couple boxes to try it out in my 640-0. They just arrived today.

I found that they will not seat in the chambers of my cylinder without a lot of force. The last 1/16th of an inch requires a lot of firm pressure applied to the heel of each case, one at a time, to press them all the way home, and then ejecting them requires an even more ridiculous amount of pressure to break all six rounds free at once. I'm disappointed, as there's no way I can run these in my preferred CCW piece.

Looking at the shape of the bullet, I'd say that it's due to their being extremely square-shaped (when looked at from the side).



My round nose FMJ and truncated cone JHP defensive rounds both slide right into the chambers (despite longer overall length), but those bullets taper to the tip, so I suspect that the throats in my 640 start tapering where the squared-off tips of the Atomic rounds encounter the throats.

Of course, these will seat just fine in a .357 Magnum cylinder, but I don't have a J-frame .357, so I'll have to run them through one of my other revolvers and see how they perform.

Just another reason why people need to stick with brand name factory loaded ammo for SD guns. Why gamble with your life by using unknown and unproven ammo?

Seems like - "eons ago" that when you bought a box of factory ammo it dropped right in, and functioned with 100% reliability...back when Remington, Winchester, and S&W had a corner on the domestic market.
Nowadays when you purchase factory ammo from one of the many "newcomers" you just don't know what you'll end up with. Even hand loaded shells (at least the ones I make up) fit and function and one would expect any company building ammo and faced with all the liabilities that comes with it would be absolutely fanatical about ensuring quality control - fit and function.
One has to wonder...just WHY a "factory" round can be so far out of spec as to not seat in a revolver chamber - especially a revolver chamber from a known, reputable gun maker like S&W.

I'm sure that they will eject with out problems after you fire them.

Right; I'm sharing my experience so that others may benefit from it.

I assume the chambers are all clean?

Good thought, but yes they are clean. I'm not the only one who has seen this problem, apparently, as further searching on this forum reveals.

Sent from my SGH-T989 using Tapatalk

Just had to ask. I've found carbon and even lead build up in what I would have sworn up and down were clean chambers. But that's what I got for being cheap and cleaning with CLP for everything all the time.

Those of us who choose to reload know to use use calipers and case gauges to ensure these things don't happen (as well as test-fit our rounds to our particular revolvers). The shape of the projectile isn't the problem. The case mouth is binding in the cylinder. If your chambers are clean, it is pretty obvious that this particular ammo manufacturer failed to apply enough crimp to the case mouth. Have you contacted Atomic?

IMO, if a person does not feel comfortable with their own ammo, Remington SJHP have been a proven performer for a long time.

Much cheaper than the so-called "boutique" ammo, too.

I disagree. I handloaded the equivalent of Atomic's LHP round not long ago using Speer HBWC's and encountered the same issue. The problem (in my case anyway) is that the bullet is full caliber sized right out to the very end-- there is no ogive. The chambers are cut with the extreme forward end being smaller than full-caliber-- in fact, on my Chief Specials, the forward end of the chambers have a smaller ID than the barrel forcing cone. Try inserting the LHP into the forward end of the chambers- you'll probably find that they won't go.
My take is that Atomic needs to seat the bullets a bit deeper to allow them to chamber in all 38 specials.

i have noticed the same with some ammo I have reloaded, that you have to 'snap' them into the charge hole the last 1/16". I ran the offending cartridges back through the resizer die just a slight amount and it cleared up the problem. (I figure it was a makeshift taper crimp die). I would really like to know what dimension it is on a reloaded cartridge that causes this 'snap in' problem and how to avoid it first time around without tinkering with finished cartridges.

I think the ammo is ok, just not set up for your revolver.

As mentioned some cylinders past the smooth part that support the case, start to taper down a little in the last part of the cylinder that is not usually "Machined" down to a smooth surface.
Any full size diameter bullet will tend to come into contact, some where as it is chambered. This happens with my J frame, also.
On some bullet styles I need a OAL less than what the reloading data calls out for.

Thanks for the heads up.

I think .38 spcl ammo designed for short barreled revolvers should work in my short barreled .38 spcl revolver. Atomic markets it specifically for the application I bought it for.

I imagine they would, at that. However, the next reload would still be a problem. Not something I'd want to deal with if I were ever reloading in a stressful situation.

You are correct and after further research it is quite evident that you're not the only one.

I agree. If the Atomic LHP ammo has chambering issues, their QC should get on it and correct it. Esp since it is "self-defense ammo" ( not "range ammo"). To be fair though, this is a fairly new product and sometimes it takes a little while for problems to be identified and corrected.

I bought some of these a while back, but haven't used any yet.

This morning, after reading this thread, I tried loading them into my M60.

They drop right in with no pushing. And fall back out without using the extractor.

I think you got a bad batch somehow.

Or perhaps your gun has undersized cylinder bores???

Also tried it in my M642 and it fit perfectly there also.

The owner of Atomic is a member and has posted in the past. Perhaps he has some insight?

Well, I do have other 38s, but I haven't tried it in them yet. I guess I'll have to do that. I'm planning on contacting Atomic about it, too, but haven't done so yet.

This looks like someone trying to reinvent the wheel. I don't think it's logical to re-imagine what the ideal projectile should be. I am not a reloader (although I have aspirations of joining your number in the future) but this projectile looks like it would have a poor ballistic coefficient. Maybe it's just me, but I trust the current major/mainstream manufacturers' interpretation of what a bullet is supposed to look like (no offense to Atomic Ammo!).

I've encountered the same problem. Live and learn

__________________
I believe in the wadcutter.

Then again, if the wheel works.....
I don't think the BC of a bullet is too important at self-defense ranges, typically 10 yards or less.

I'm still waiting for a reply from Atomic Ammunition. They must be busy.

__________________
I believe in the wadcutter.

I've been busy for a few weeks, too... haven't contacted them yet.

This weekend, I did get around to seeing how the rounds fit in my other .38's. I have 3: A K-frame Model 14 (no dash), and two J-frames: Model 60 (no dash), 640 (no dash).

The rounds that stuck in my 640 slid easily into my 14, and had no problems seating in the chamber, and slide back out readily with gravity alone, no need to use the extractor.

In my Model 60, they seated easier than in the 640, but felt a bit snug, and a couple of the rounds did need a slight push to get them to seat completely in the chambers.

Then I tried them again in the 640, and they went in smoother than the first time. It seems that squishing them into the 640's tight chambers probably seated the bullets or molded them just slightly so that they would fit more easily when re-inserted.

So then I reasoned I needed to re-test, chambering fresh rounds that had never been chambered before in each model. Doing so appears to confirm that the M14 has looser chambers than the M60, which has looser chambers than the M640. Fresh rounds seated easily in 2 of the M14's chambers, and required a very slight push to get them to seat in the remaining 4. Ejection wasn't overly difficult, but did require a slight amount of force on the ejector rod. The M60 was VERY tight, just like fresh rounds in the 640.

I conclude the J-frame chambers are tighter than the K-frame. Whether this is due to the frame, or the years of manufacturer, or are just random variation in tolerances and considered "normal" I can't say. Perhaps someone reading this will know. I don't have equipment to measure the precise dimensions of the chambers, either.

Given how tight they feel in the J-frames, I'm not sure I should try shooting with this ammo in them. I imagine the tight throats would make the pressure higher, and it doesn't seem wise to use them, unless someone more experienced can convince me otherwise. I can chamber them easily in my .357s so if/when I shoot them, it'll be with those.

Wouldn't all the manuals call for these bullets to be seated flush with the case?

Are they just seated shallow for show?