Theoretical Question

[Kansas Ed]

This came up on another forum, and I was wondering what you folks thought about the theory.

The OP (not me) was a newby, and was wondering about a quantity of on hand .227 bullets for the .22HP and whether they could be loaded in a standard .224 bore. The most common response to his question was that it would unequivocally BLOW UP HIS GUN! Now.... MY QUESTION ISN'T ABOUT WHETHER HE SHOULD, but rather what effects this could possibly have on the loads, firearm etc. I don't want to digress in this thread about the safety cautions, or the standard reloading procedures etc. What I do want to know is: Has anyone ever run across any pressure tests which indicate measurable results from shooting slightly oversized standard makeup jacketed bullets. I only know of one test and that was by Ackley.

I'm aware that especially in the wartime Enfields, that some bores ran tight. I also had a letter at one time from Steve Hornady which had things to say on the subject.

I'm interested to hear from this forum on the subject...especially since I believe that many on here are experimenters by nature, and tend to experiment within controlled situations.

PS: The caps above aren't yelling, they are there to call attention to those statements. Don't mean to offend.

Ed

[Hobie]

I imagine that a jacketed bullet would have an effect on pressure to varying, unpredictable degrees as the diameter increases relative to the bore diameter. I would think also, that if you put one in the correct cartridge for that firearm and if the bullet still chambered one could, with proper loads, shoot those bullets. IME pressures would spike more quickly as powder charges are increased with oversize bullets rather than the commonly accepted correct diameter bullets.

Now you said you didn't want to hear about "should" but I think it is kinda dumb, when people are searching high and low for the "correct" .227 bullets for the Imp to shoot them in a .224 bore when you could sell them and get twice as many .224" bullets for the money.

[mergus]

When I bought my 32-20 Ruger from Hamilton Bowen, I learned it had a .308 bore. I emailed him to ask if that meant I should stick to .308 projectiles for handloading? He replied that I did'nt have to, that I could shoot factory 32-20 ammo, which comes with .312 projectiles.

Maybe its because factory 32-20 isin't all that heavily loaded and the pressures aren't nearly as high as some?

Mergus

[J Miller]

7.62x39 Com Block ammo uses a .311-.312" bullet. A number of American made rifles, including the early Ruger Ranch rifles used .308 bores. The Com Block ammo fired and functioned with no problems.

I doubt there would be any danger to the use of a .227" bullet in a .224" bore, but why would he want to with .224" bullets being so common is my question.

Joe

[SJPrice]

As stated twice here already, WHY? It would be one thing if we were talking apocalypse and all you had to feed yourself or family were .227 diameter for a .224 bore. But beyond that WHY?

[AJMD429]

I've always known people who shot oversized cast lead bullets that were pretty much swaged-upon-firing, and assumed the inherent properties of lead, plus the fact that they were generally large-caliber projectiles, made it reasonably safe. (Perhaps the physics contradicts it, but it just seems less 'severe' to swage a .458" bullet to .451" than to take that same .007" off a .250" to make it come out .243"

What amazes me though is the anectodal reports of folks putting say .284" down a .270", or even .308" down a .284", using jacketed bullets in what were rather high-pressure cartridges. Of course the odd-ball combinations needed to get such rounds to chamber and fire create so many variables (does the case expand so much that it lowers the pressure, is the bullet already heavily engaged by rifling, or does much gas blow-by before it does, etc., etc.) that who knows what actual pressures were involved. Still, I've read 'alleged' cases where such major swaging-upon-firing happened, even with jacketed bullets, and reportedly "didn't affect the gun" (...personally, I'd consider making such a firearm a wall-hanger after that...), that it is fascinating.

I'm with you, I'd really like to see some scientific 'data' on just what happens in those cases, especially 'pressure' data. I also wonder what velocities are gotten, since there is some energy used to deform the bullet.

[pdentrem]

PO Ackley actually tried this and it is discussed in his books. Let me find it and I will come back on this.

[Sixgun]

No big deal unless.........the loads are near max, the gun has excessive headspace or other mechanical defects. Savage routinely loaded their .303 ammo with .310-.311 jacketed bullets that were shot down a .308 bore. It was done on purpose to generate higher pressures. Who knows how many millions of .323 8mm. bullets were fired down the bores of .318 barrels.

It still does not make sense to go that route though. Another think to keep in mind is that while those bullets are 3 thou. oversized, its 100% (or near) oversized compared to shooting a bullet 3 thou. over in a 45 caliber.------------Sixgun

[Kansas Ed]

Well, I'll get to my thoughts on this. And thanks for all your opinions and experiences.

As for the "Why"...as I stated...he was a newby to reloading...and thus a newby question. No harm no foul...he asked the question and received the answers, though in general I thought that most of what I read for responses were nothing more than unsubstantiated urban legend. One person even quoted the Sierra box of Hornet .224 bullets and their CYA stance on shooting them in bores of .223 But as always, I'm open to thoughtful root cause analysis and discussion. So on to my observations and readings...Would also love to hear more of you alls thoughts and experiences.

I once had a box of .25 caliber bullets from Hornady which were .0015 to .002" oversized. Loading those bullets caused brass buckling. I wrote a nice letter to Hornady explaining the issue to let them know the lot number for quality purposes, and was promptly "rewarded" by a personal letter from Steve Hornady telling me that slightly oversized bullets do NOT cause extreme pressure variations...yea, but get them loaded....anyway, I took this with a grain of salt, until some years later when I was perusing the books of PO Ackley.

In Volume II page 76 Ackley describes the pressure tests that were by himself done to dispel the myth of slightly oversized bullets. A standard pressure barrel chambered for 30-06 was tested with a given factory 150gr load and pressure tested (57,300 psi). The chamber and throat was then opened up to 8mm (.015" oversized) and the standard .308 groove was kept. Bullets were then pulled on the factory ammo and replaced with same weight 8mm bullets. Pressure results were erratic, but averaged 16,000 psi LESS than the standard 30-06 ammo. Furthermore, the velocity dropped over 100fps. The velocity was then driven up to over 200fps above the standard 30-06 load with peak pressures remaining less than the the standard 30-06 factory ammo by 4000psi. He wanted to experiment further and push a .358 caliber bullet through the bore, but ran out of time before the printing. I would have liked to have known the results of that one too. But Ackley in general felt that the "oversized bullet" assumptions were vastly overblown. I am not saying that Ackley was the end all and be all in his theories and recommendations, but to date I have not seen any testing data which disproves his meager testing.

I have also seen evidence which suggests that high pressure revolver cartridges (55,000 cup), coupled with standard soft core handgun bullets actually pressure swage the base of the bullet oversized as the bullet enters the oversized forcing cone of the barrel. The forcing cone then swages the bullet back to the groove diameter of the barrel. In effect forcing an oversized projectile through the barrel. This is evidenced by the extreme washing of the forcing cone area when using a steady diet of soft core bullets. Hard core bullets do not exhibit this tendency.

Common sense (which in the world of ballistics and pressure means absolutely nothing) tells me that once the bullet is swaged to proper bore diameter within the first inch or so of the barrel, the pressure relative to push the bullet the remainder of the way down the bore is no different than would be generated by a proper sized bullet. In my humble mode of thinking, this would mean that the maximum pressure spike would need to coincide exactly with that swaging process to create a dangerous situation. That would mean that the pressure spike would need to be at a time point where the bullet is about 1.5" out of the case using general numbers. I'm no student of pressure curves relative to bullet position, but think that you would need to have a pretty specific set of circumstances built around a certain burn rate of powder coupled with specific bullet weights to achieve the blow up factor.

I'm glad that many of you brought up the 7.62x39 Rugers, and the 32-20 thoughts. I had forgotten about those. I was aware of the wide variations in the Enfields during the war, and some of them having groove diameters of as small as .308. The other interesting thought in this, is Hobie and AMJD's variable in the beginning caliber scenario. That is definitely something which would easily be overlooked.

What I'm saying is, there seems to be reasonable semi-scientific evidence to dispute the thought that slightly oversized bullets will wreck a firearm in and of themselves. I say semi-scientific because there are still unaccounted variables involved in the Ackley experiment (IE: chamber changes, and throat changes) But, I would like to see any published and tested pressure evidence in a controlled environment which disagrees with Ackley's findings. I would find it interesting to read.

Ed

[pdentrem]

Ackley 's Handbook for Shooters and Reloaders Vol II Pg 31 A few Causes of Blowups as well on pg 76 as mentioned by Kansas Ed. He mentions the 30-06 loaded with 8mm bullets for the 8mm Mauser conversion and somebody shooting these in a standard 30-06. No effect but no pressure info.

I would sell the 227 bullets as they are hard to find and buy 224 bullets. Period

[AJMD429]

Common sense (which in the world of ballistics and pressure means absolutely nothing) tells me that once the bullet is swaged to proper bore diameter within the first inch or so of the barrel, the pressure relative to push the bullet the remainder of the way down the bore is no different than would be generated by a proper sized bullet.

I think in some circumstances the friction might even be less, if the bullet is 'crushed' and its structure more or less crumbled, rather than just 'squeezed' but still largely intact. The "common sense" disclaimer above would apply, as I'm comparing experience with hand-squeezed dirt-clods and snow/ice 'grenades' I would squeeze by hand as a kid, so their structural properties could be a bit different than those of gilding metal and lead at 50,000 psi beinq squeezed by steel in a matter of milliseconds... Well, maybe, anhyow...

[pdentrem]

I just had a thought.
1. Artillery shells have a SOLID bronze driving ring near the base of the shell. It swages down to size on firing.
2. Barnes have SOLID copper bullets and they swage down to the fit the rifling as well.

A solid copper bullet is harder than any lead core bullet. Also remember that in past times there were steel cased bullets as well.
Do you see where this is going?

[Rusty]

A friend of mine is a RO at a range near here. One of the most recent adventures he has had was when a kid put a 7.62X39 in his dad's .270 Handi rifle. It still worked fine after the case was extracted.

[JB]

A friend of mine is a RO at a range near here. One of the most recent adventures he has had was when a kid put a 7.62X39 in his dad's .270 Handi rifle. It still worked fine after the case was extracted.

I sure wouldn't want to be the one that fired that one.

As far as the original post, I don't see the .227 bullets causing the rifle to exploded, but pressure would certainly be increased. The increased heat from the friction would accelerate barrel wear as well.

[Hobie]

I just had a thought.
1. Artillery shells have a SOLID bronze driving ring near the base of the shell. It swages down to size on firing.
2. Barnes have SOLID copper bullets and they swage down to the fit the rifling as well.

A solid copper bullet is harder than any lead core bullet. Also remember that in past times there were steel cased bullets as well.
Do you see where this is going?

Both have driving bands and the material is displaced into the intervals between the bands. That is substantially different from simple compression. In fact, before the TSX bullets, the Barnes product was known for substantially increasing pressures even over bullets of equivalent bearing surface.

We could talk about squeeze bores again. That's basically what you have with firing a 7.62x39 in the .270 Winchester. Purpose design rifles take the pressures created into account.

As I said, you CAN do it but, again, WHY? The .277-.228" bullets have been hard to source for those who want them.

PS - If you just want to try it, why not? I tend to think in terms of what works, what is "practical" (yeah, right) not the, "ooooh that's neat, wonder what this will do?" approach (even though I do that to a certain extent). My first thought was, "I know reloaders who can't find .228" bullets and gave up on the IMP," not "That'll work, just drop the charge." If those bullets were all that were available, yes, they will work, maybe very well. Gotta slug that bore!"

[Kansas Ed]

In all, I was just surprised at the amount of irrelevant information which was posted on the other forum about this topic. One was the warning label on the Sierra Hornet bullet box. One was a photo of a gun which was blown up from firing a 6mm BR in a .223WSSM chamber (which leaves at minimum .074" headspace). Others just spouted undefined statements like "You could be killed". Like I said before, the OP was new to reloading and honestly didn't know the difference..but had the good sense to ask others before forging ahead.

Sometimes thoughtless response to honest questions just drags me down......I like to discuss and read relevant thought...If I wanted Urban Legend and thoughtless rhetoric I would be a democrat...


Ed

[Old Savage]

I like to discuss and read relevant thought...If I wanted Urban Legend and thoughtless rhetoric I would be a democrat...

That's great Ed - love that.

[ollogger]

my bro. had 2 guns on the bench 1 day 25-06 & a 308 well he put a 308 in the 25 he said it sounded funny when it went off ? had to use a rubber hammer to open the bolt , it blew the primer out , thats when he discovered he had a funny looking 308 case. both guns were rugers , the 25 came out ok, but he only has 1 gun on the bench at a time now



ollogger

[Nate Kiowa Jones]

It is certainly possible to shoot excessively oversize bullets in some guns but the problem is the overwhelming number of variables from action designs to various powder types and related pressure curves and even bullet and jacket hardness. It’s just not a good idea.
That said, just to give you an idea of what you can encounter, years ago I had a very strong Arthur Brown falling block Silhouette pistol. This was a 30-20 cal gun (.308) with a 14” barrel. I decided to try my 32-20 lead loads in it just to see how well it works. These loads are 115gr RNFP lead bullets sized .312 and cronnied from my 24” relined Win. 73 at 1175 fps.
These same loads shot from the 14” A. Brown clocked 1890 fps. In order to go that fast from a 10” shorter barrel the pressure had to go up considerably. If it had been the other way round I’m not sure the 73 would have handled that kind of pressure. Probably not a catastrophic failure but certainly some extra headspace at least.

BTW, that A Brown with that lead ammo was just as accurate as my 30-20 match ammo, primers were flatted some but not to the point of enlarged pockets. But the brass OAL was growing some so 32-20 brass life at those pressures can't be very long.

[BAGTIC]

Back in the early days of the .308 Winchester cartridge an (unidentified) relative of mine bought one of the first .308 Savage 99's. He came to me one day saying something was wrong with his new gun. It wouldn't shoot worth anything and it was mangling the brass. I took a look at both and explained that his problem was that he was shooting the wrong ammo. He said No Way!. He was shooting .300 Savage ammo and should be shooting .308 Winchester. He explained that I was wrong that his gun was not a Winchester, it was a Savage and he was shooting 'Savage' ammo in it. He had fired a couple boxes with no apparent harm.