22lr jacketed bullet speed limit myth busted?

[BT Sniper]

Had a very informative weekend at the range shooting both the 22 cal made from 22lr brass out of a 26" 223rem 9 twist and a 6mmbr 26" 8 twist.

I get a lot of inquires asking about the so called FPS limits on our bullets made from 22lr brass. Of course I have spent a good deal of time reaserching the matter. From what I recall the most pertant info I found was on RCE (Corbin) web site and mention it was potential for better accuracy at slower FPS not that there was any sort of limit and certain doom would come if we where to exceed it. It was one of the Corbin's sites I was reading about how they would work up a load shooting these bullets made from 22lr brass and shoot till they started getting unexpected fliers then back down in FPS till accuracy returned.

Well I am working on my theory and I believe it might not be any FPS limits at all that cause any potential bullets to break up. I think there must have been some other reason. Maybe a fold in the tip of the jacket? Maybe a slight tare in the base from the ironed out primmer strike? Maybe too much anneal or not enough? or any number of reasons. Certainly the greater FPS and higher twist rate would effect these flaws in the jacket exponentialy as we increase either or both.

If it was a set FPS/RPM/twist limit that caused the bullets to come apart after leaing the barrel we would expect to see a high number of failures any time we exceeded such parameters. This wasn't the case in any of my findings.

I shot 55 rounds of 6s ogive bullets made from 22lr brass this weekend in my Savage 26" 9 twist 223rem testing loads of H-335 from 22.5-28.0 grains. Sierra book load max is 27.5 grains (bolt action!) with a 14 twist barrel and I found their info as far as max load to be right on. At 27.5 grains I got one primmer that had been smoked from escaping gases and at 28.0 I popped 2 out of 3 primmers and stopped there. Definatly 27.5 max! But I was getting 3480 FPS with the 27.0 grain load and must have been pushing 3500+ fps with the 27.5 grain load. These numbers where faster then Sierra's by 200 FPS.

Point of the story being.... out of 55 rounds I only had two potential bullets that didn't make it to the target unless I just center punched one of the holes allready in the target, but I don't think so. If our jackets had a "blow up FPS limit" you would expect it to have occured at the highest loads and FPS but this was not the case. I had one with the 25.5 load and one with the 26.0 load, both around the 3300 FPS mark. As it turned out the 27.0 and 27.5 grain load at nearly 3500FPS in a realitivly fast 9 twist all made it to the target and the 27.5 load actually posted one of the better groups of the weekend with a 5 shot group at .70". The three shots I took with 28.0 grains also had no trouble making it to the target. Also got good groups at 25.0 grains and 22.5 grains. More later on groups.


So I am working on my theory that there is no "fps" barrer that we have to concern ourselfs with when shooting our bullets made from 22lr brass and there must be some other reason for any potential bullets not making it to the target. Granted my testing is still a bit limited yet to tell for sure but all the max loads I have ever shot with the 22 cal bullets have had no problems which would certainly go against any FPS barrier ideas. Of course all reloading precautions apply here and start low working your way up, loads listed may have been safe in my gun but not in yours!

I had similar results with the 6mmbr and 80 grain bullets made from cut 17hmr brass, with nearly 100 bullets down range and 4 potential bullets not making it to target. The full power loads did just fine so there had to have been a small flaw in the construction of the bullet somewhere on teh lighter loads. By the way, best group with the 6mmbr and these bullets went about .7 for me as well.

Anyway just thought I would pass along my findings for all of you that may have heard anything about so called FPS myths when it comes to these bullets we make from 22lr brass or 22 mag brass.

Good shooting and Swage On!

BT

[DukeInFlorida]

I dare say that NO ONE at Corbin, or elsewhere, is doing this sort of on going development work, pushing the State of the Art to newer heights all the time!!!!

You are amazing Brian. I'm glad that you afford yourself some R&R days, away from the kids, and away from the projects. Cleans out the cobwebs, and keeps you at the top of your game.

I've been convinced for a long time that the jackets on the swaged .224 bullets made from .22 LR brass are thick enough to survive the rifling on our guns. Other than too fast a twist rate, or pushing the bullet to too fast a speed for normal SAAMI pressure safety, there is no reason for a swaged .224 (or any other swaged bullet) to fail in use.

THanks for testing and confirming this.

[Lizard333]

Went shooting this weekend myself. I was depressed from last weekends dismall results, so I brought my Remington 700, with a 1:6.5 twist, chambered in 223. We had a great time shooting golf balls at 170 plus yards. This was with Sierra 90 gn HPBT. Not a good candidate for the 53HPRBT I made for a different gun. I had ten loads still loaded that I needed the brass on, as I wasn't happy with the performance. Rather than pull them, I figured I'd just fire them. These were loaded over 25 gns of Varget.

Not one made it to the target. Not surprising. But the ball ammo we had did. These were 55 gn FMJ with copper jackets.

It's my experience that the 22LR jackets, being thinner, do have limits. I'd like to try these rounds in a 22-250, and see if the the envelope can be pushed. Do I think a proper twist, and velocity are matched for the 223 are going to give bad results, no. I just don't think a 223 cartridge is going to break them down. That is unless you get stupid with them like I was. My buddy has a 22-250, so might give him bullets, and see if I can find the upper limits, if there is one.

[kweidner]

Yep did the same with my 22-250 this weekend. 30 shots 10 groups testing h380. Fastest group was nearly 3600 and had an 18fps ES. Myth busted agreed. All made it to target. All groups moa or better.

[williamwaco]

Brian,

My friends and I used to "smoke" Hornet bullets in our .22-250 and Swifts.

This was back in the '60s and I am sure bullets are better nowadays than the ones we used.

We didn't have chronographs so I don't know the velocities but the first sign that the bullet is coming apart is tiny lead "sprinkles" around the bullet hole. Sometimes, but not reliably there will be a grey spiral around the bullet hole. Then, at some point there is a visible grey smoke trail behind the bullet all the way to the target, unless the target is too far, then it just disappears around 150 yards out.

If your bullets are disintegrating, you will know it. You will not need to speculate about it.

I do not believe you can smoke them in a .223. You are going to need a lot more velocity than that.

[David2011]

Will velocity destroy a bullet in flight? No, at least not in ordinary smokeless powder rifles. Will excessive RPMs make them come apart? Yes. Excessive RPM is a function of both high velocity and a fast twist. High velocity and slow twist are not a problem. Sierra advised me against using certain bullets in an 8" twist .22-250. A .223 WSSM, an extreme example to be sure, can spin light bullets well over 400,000 rpm.

David

[Smokin7mm]

I think the twist has much more influence than speed. I have posted before about my buddies 6BR at 2600fps (bullets not making it to target) and my 6TCU at 2200fps (no problems) both with 1-7 twist as well as my 243 at 2900fps (no problems) in a 1-10 twist. I also believe that when making bullets from rimfire brass that there are known issues with thinner jackets, firing pin indentations and potentially other issues with annealing etc. Lots of variables when using rimfire cases for jackets.
Bret

[fredj338]

Back in the day I was able to get 45gr Sierra sp to come apart on occasion in my 26" bbl Swift w/ 1-12 bbl. The bullets were in the 4100fps+ range. So when I get some bullets made, I've got a buddy w/ an 'F' class savage w/ 28", I think 1-9, bbl I can run them pretty warm. The way to test would be single shots on separate targets to verify all make it. I don't plan on running them much past 3000fps anyway, but it would be good to know where the limit is. I love to experiment.

[shooterg]

I can remember when AR's were becoming "the" service rifle for HP. When folks started tossing 52 grain Sierras downrange out of 1:7 Colt barrels, many didn't make it to 200 yards. In bright sunlight you'd see the "sparks" downrange ! Sierra probably went to a thicker jacket, the ones shot now all make it. I've shot the homemade 56 gr. in a current White Oak barrel(1:7) , seem to do fine.
Maybe I should drag the old Colt upper out and see if I can explode 'em !

[SquirrelHollow]

I agree with some of the above posters - There absolutely IS a speed limit for these projectiles. However, there isn't a fixed velocity or bullet rpm figure. It will vary, depending on the brand/type of jacket, swaging methods used, core material, the barrel, and atmospheric conditions.

Having had several .220 Swift and .243 Win loads turn into 'bullet detonators' in cold, dense conditions, I've seen it first-hand.
Then again... we're also talking about up to 4,300 fps with some of those loads. ;)

[MIBULLETS]

I believe the myth is real, but it is very hard to quantify. Some guns will have it happen at slower velocities than others with the same twist barrel. Definately velocity and twist have alot to do with it, but the condition of your barrel, throat, and how clean the gun is can make a big difference as well. So, my take is, some guns do and some don't. The only way to know if a particular gun can shoot them faster is to try it. I have shot them at over 3600fps before without problems, but I have also had blow-ups from other guns. Quite spectacular too, it looked like a small cloud over the hot smoldering pieces of lead on the ground at about 40 - 50 yds out.

[runfiverun]

i know cutting a jaxket causes problems like lead flinging from the core not rpm.

if rpm caused issues i couldn't shoot regular naked cast boolits over 2700 fps in a 9 twist 223.
or 30 caliber boolits at 170,000 rpm [2250 fps] and maintain better than moa accuracy.

it's jaxket and core inconsistencies that cause the errant bullets.
velocity just makes them apparent.
otherwise target shooters would all just back their loads down to 1400 fps and shoot whatever was on the shelf the cheapest.

[Bullshop]

I have fired cast 22 cal boolit up to 4300 fps in 1/10" twist barrel without issue. Best accuracy was at 3900 to 4100 fps. Of course they rode down the barrel wrapped in a sabot. But still the speed alone didnt hurt anything.
Now going back some to my early fur hunting days I had a Styer rifle chambered for the 5.6x57 RWS cartridge with a twist fast enough to stabalise the 80gn factory bullets. When forming brass from 30/06 the cases would hold 10gn more powder than factory RWS brass. That rifle would smoke any bullets that were not of heavy jacket construction. They would make it about 30 feet then puff into a grey cloud.

[firefly1957]

Brian I have also wondered if it is the rifling twist i am told the current Corbin book says to expect 3300f/s as top velocity but my older book says about 3500f/s back them a 1-8 twist rifle was about unheard of!

I have this in another thread somewhere : I formed some 37 gr bullets to test this in my Rossi with a 23" barrel the cases were not trimmed I just formed them as hollow points. loading them at about 3300 f/s they shot okay (about 2" at 100 yds) giving them maximum book charge for about 3700 f/s the group became a pattern! All bullets did hit paper. Then i loaded some 55 grain swaged bullets in sabots and shot them from my 30-06 at or over 4000 f/s and they shot about the same as my 180 gr. hunting loads for a 2" group at 100 yds. Note that this was not great for this gun with the hunting loads so i looked it over and found a loose front action screw it is shooting better now.

[kweidner]

Just for the record mine is a 14 twist. I got to nearly 3600 with absolutley 0 issues. I really should have waited for a better day as the wind was kicking my butt in the end. Even blowing over my wind flags. If it was consistent I could have shot better. I had to rely on my Chrony to tell the real tale. The last group I feel is going to be it. Oddly it is the exact same powder charge I use with the Ed Watson bullets I have shot in .224 for 20 or so years. Still got about 1000 of those left. You put one of mine next to one of Ed's only way you know the difference is the size of the hollow point and the color of course. This is two guns that my home made and Ed's bullets end up identical as the best load and powder combination.

[BT Sniper]

As far as a clean barrel goes...... I would draw a bore snake down the barrel between the 5 shot strings in the 6mm, I know it really isn't "cleaning" a lot but what the heck I figured. With two of my loads I had the first bullet blow up in back to back loads with the remaining 4 making it to target. I figured a "clean" barrel might have acutually caused a bit more friction on the bullet vs. a barrel that had allready been shot???

A lot of factors to consider, only way to know for sure would be more testing I suppose.

Here is a thought.... Do you suppose if we where to run the bullets right on the edge they will be even more explosive on some little varmint when we hit it? Basicaly come apart with the first thing they hit? BOOM! :)

BT

[MIBULLETS]

Here is a thought.... Do you suppose if we where to run the bullets right on the edge they will be even more explosive on some little varmint when we hit it? Basicaly come apart with the first thing they hit? BOOM! :)

BT

I would absolutely think so.

[clodhopper]

If you run right on the edege. Some bullets will be flyers, an occasinal bullet slighty deformed due to centrifical force.
Like what others have said here many factors come into play, jacket thickness, prehaps a flaw in the jacket, lead hardness, twist rate coupled with velocity, the sharpness of rifleing, maybe even air density or an impact on a raindrop.
Shoot first, alibi later!

[runfiverun]

i know a hit on a rock chuck from a 9 twist and one from a 12 twist at the same velocity has some different body part distances.

oh powder fouling is a friction reducer.
we take it into account when tweaking a lube.

there is a [synopsis of] story elmer keith wrote one time about two different rifles in the same caliber performing differenty on game in africa.
one would consistently penetrate deeper than the other.
they were using the same lot of bullets from the same batch of reloaded ammo.
the difference?
one was a new rifle with sharp rifling and the other was one with a worn bore where the rifling was getting rounded over.
airc the worn rifle was borrowed to go shoot a water buffalo because of this trait.

the micro-groove rifling by marlin used to claim [airc 23%] greater accuracy because the rifling didn't damage the bullets jaxket.
this was their advertising claim when the rifling come out.

[MIBULLETS]

oh powder fouling is a friction reducer.
we take it into account when tweaking a lube.

Very true, but jacket fouling is not. The one rifle I had blow-ups in would not have any problem for the first 10 - 15 rounds, but after that almost all would blow-up. My buddy had the same rifle and his would shoot them all day long without problems. When we cleaned them up mine always had more jacket fouling than his.

[BT Sniper]

I thought the same thing...... powder fouling reduced the friction a bit and of course jacket fouling is somthing different.

BT

[freddyp]

I have pushed my rimfire bullets to 3600 fps out of a Tikka 22-250. Accuracy was very good and I did not experience any bullet blow-ups. It's a whole different story out of my stainless Mini-14. The Mini gives poor accuracy with them and bullet blow-ups are common. The same load out of a 700 PSS with a 1-9 barrel will group 3/4" or better. I think the problem with blow-ups is how smooth the barrel interior is. The Mini barrel is full of machining marks and that is scraping the jackets too much and weakening them. The other two barrels are very smooth and free of marks, this I believe is the key to speed and overall good accuracy with thin jacketed bullets.

[runfiverun]

chrome lining...

[kweidner]

The mini 14 shouldn't have a chrome lined bbl if it's stainless should it River? I too seem to think that it has to do with bore condition and jacket integrity. I cull any jackets that are suspect and leave them for my .223. I am pretty picky about fold overs even at the very tip. They go into a different box along with the ones the firing pin mark didn't completely iron out of. I will eventually test them but feel they won't make the 22-250 speed. It's funny. I can feel them when I am point forming as they have very little resistance in comparison to the others. It might also be interesting to note the majority I shot the other day were federal. I know the jacket is thicker on those. Derimming pressures are much different than the CCI etc.

[runfiverun]

no.
many of the ar's do have them now though.
it's the only way they can guarantee unlimited shots down the barell.

i went with a little story on page one illustrating barell condition effects on a bullet.
and it showing up in on target performance.
it would also explain why many rifles have a tendancy to really like one bullet over another.

it affects cast boolits the same way.
a lube can be tailored to a rough or smooth barell to make things better there too.

[BT Sniper]

I can feel them when I am point forming as they have very little resistance in comparison to the others. It might also be interesting to note the majority I shot the other day were federal. I know the jacket is thicker on those. Derimming pressures are much different than the CCI etc.

Concerning the folded tips that can somtimes happen when making bullets.......

I try to point this out to all new and long time swagers! "feel" has a lot to do with it! Just FYI, the folded tips has everthing to do with..... well %90 to do with how well the case is annealed.

Good shooting and swage on!

BT

[DukeInFlorida]

And, the Lee 20 pound electric pot is doing an amazing job annealing all my brass...... Wow