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308 winny
mond
Member Posts: 6,458
Can i use .311 (303 cal) bullets for .308 ?? As an ex-engineer i am thinking .0003" of an inch (3 thou) will not be detremetal in Dia.
I would how ever NOT go the other way 308 to 303 (308/311)
Opinions please.
Atb Mond[:)]
I would how ever NOT go the other way 308 to 303 (308/311)
Opinions please.
Atb Mond[:)]
Comments
And the fatter .311" bullets will push your pressures higher, if it is just 1 psi PAST the failure point of action/barrel, Kaboom! I won't try it unless I had to, in a do or die situation. And .308 in a .311 barrel is done a lot...just with some accuracy decline.
Are you an ex-engineer because of mistakes??[:D] Three thousandths is .003 not .0003.
And the fatter .311" bullets will push your pressures higher, if it is just 1 psi PAST the failure point of action/barrel, Kaboom! I won't try it unless I had to, in a do or die situation. And .308 in a .311 barrel is done a lot...just with some accuracy decline.
A type error.003" [:D] so its a no no !
Generaly no.......but.......like you said it's only .003". if everthing else is ok (neck tension, throat dimensions, ect.) you probably could with lighter loads........but why?.
why ? ...... i have 600 sierra bullets of various weight (123-180gr) 303cal & less than 100 308cal. At almost ?30 ($49)a box , i though i would use some 303 surplus.
Atb
If the case neck is too tight in the chamber neck to expand and release the bullet, that is what will trigger excess pressure.
So, take a case fired in your rifle without resizing and see if it will accept a .311 bullet. If it won't, you should not use them.
Greetings from the other side of the big pond!
Good question, good answer. Many times, we Americans forget that shooting components are much more expensive overseas than they are here in the U.S. (Although Lapua and Norma are pushing the envelop here as well...) Trying to utilize expensive components in a crossover type application would be a natural question to ask.
The real answer, as alluded to above, is that the .311" diameter bullets have the potential to raise the pressure to a catastrophic level. Note the term potential since we are all aware of the mismatched component stories about bigger bullets being swaged down in small bores... Once is a freak accident, continuing the practice as acceptable is like playing Russian Roulette. You never know when failure is lurking in the next shot.
The .311" diameter and the .003" difference should be compared in a relative manner. In and of itself, the .003" is very small as we all know. But when it comes to the difference being propelled down a bore with a groove diameter that .003" SMALLER, we have to take the side of caution so as not to be a part of a possible failure. Reduced loads might gain you some time but the wear on the rifle will be another variable to take into account.
When building standard bolt action rifles, it's not unusual to use .30 caliber barrels (.300/.308) that have a smaller bore dimension such as 0.299" or even 0.298" in the case of some older Palma rifles. (Note here that I'm talking about bore diameter and not the groove you are asking about.) The groove dimension though remains the standard 0.308" as always. But when we build an AR10 semi-auto rifle and we try to use those barrels with the smaller bore diameter we get a distinctive over-pressure situation which leads to other failures. We have no choice but to use the standard 0.300" bore diameter since anything smaller leads to overpressure.
Common sense dictates that we just avoid these attempts and go on with our routinely boring lives without the possibility of experiencing catastrophic failures. Given the situation over there, it might be simpler to sell them or better yet, trade them for the correct components. Trading and swapping has taken on a whole new life over here with the advent of the stupid idiots playing the market with metals pricing.
Good Luck with your project!
Best.
ADDED:
While true as far as dimensions are concerned, Parker didn't take the time to mention (nor could he know) that our current factory rifle chambers often have an oversize dimension on the neck, throat and leade areas of those chambers. This then would allow the chambering of the above oversize cartridge. So your logic is that it still could be O.K.
What about lug battering, gas seepage, blown primers, excessive recoil and several other areas of concern? This does not beg an answer since the real answer is that trying to use the .311" bullets is not acceptable. End of statement.
Today's custom rifles and benchrest rifles wouldn't be affected because the chamber dimensions are usually tighter than the standard factory. You couldn't chamber such a cartridge at all. But that doesn't necessarily preclude today's sloppy factory offerings.
Best.
What you say takes every equation into fact. I'll sell the surp & buy the correct Dia heads.[;)] Many thanks for your valued opinions.
ATb Mond
Have you considered resizing your .311 bullets to .308 ?
I once had a quantity of jacketed pistol bullets which were well over the .357 required by most 38 caliber pistols. I don't remember the exact size but I think it was about .365.
I resized them using a Lee .357 sizing kit. These kits are designed for resizing cast bullets and fit any standard reloading press. I lubed the bullets with Lee Liquid Alox Bullet Lube (as I would do for cast bullets) and then ran them through the sizing die with no trouble.
Don't know if it would work with your rifle bullets but might be worth a try.
The kit and a bottle of lube is about $20 in the US.
Since I reload both .308 and .311 bullets I could try sizing a few .311s down to .308 and let you know the results if you are interested.
Just out of curiosity I decided to give it a try.
I have a quantity of CIL (Canadian Industries Limited) 180 gr. .311 bullets. These bullets are basically hollow points with a plastic plug in the hollow point to give them a nice pointed profile.
I lubed them with Lee Liquid Alox and let the lube dry overnight. This morning I ran them through a Lee .308 sizing die and they came out measuring exactly .308. Because the bullets are pushed out of the die by the nose of the following bullet the plastic noses were pretty well flattened. Round nose FMJ bullets would probably work better.
A fair amount of force was required to push the bullets through the die so if you try this you should probably have a fairly sturdy press (I used a Lee Cast Press).
Some other thoughts.
To avoid damaging the noses you could probably make up a longer punch so that you could push each individual bullet all the way through the die instead of depending on the following bullets to push it through.
These bullets have a relatively long bearing surface (about .65"). Bullets with a shorter bearing surface would probably resize more easily.
Lee also offers these sizing dies in .309 diameter so it might be easier to first run them through this .309 and then the .308.
Also, since we are talking about jacketed bullets, they need the lubricant for resizing, not for shooting. Possibly case lubricant would work as well or better than the bullet lubricant.
As for the damaged noses on the bullets I resized. Many years ago I had the chance to buy a large quantity of bullets at scrap metal prices. The problem was that the bullets were in many different calibers and weights. And many of them were obviously damaged. But I thought there were enough good bullets in calibers I could use so I bought them. After a lot of sorting I had a lot of good bullets at a very low price. I also had a lot of bullets with varying degrees of damage. Among them were a lot of 22 caliber, 45 gr. jacketed SPs, obviously intended for the 22 Hornet. The noses of these bullets were flattened as if they had been grabbed with pliers and pulled. But the bearing surface looked OK. I thought they might be usable for "plinking" loads in my .222 Rem. To my surprise they shot better groups than the brand new, fresh out of the box 50 gr. Sierras that I had been using.
So I will load these resized bullets and try them in a .308 Win. and see how they shoot.
If you try anything like this (or have tried anything like this) please post your results (good or bad) so we can all learn from your experience).
On the 303 cal dia- I have used pistol 32 cal 100gr heads in a 303 for plinking, with good results & more importantly no problems.
atb Mond[:)]
As per my earlier posts (June 2011), I did eventually load the 10 resized bullets in .308 Winchester cartridges using 37.0 grs. of IMR 4895.
The weather here yesterday was fairly mild so it seemed like time to get out and do a little shooting.
I first loaded one round in my FN/FAL and fired at a target at 50 yards. It went bang and was on the paper.
I then loaded the next five rounds one by one and fired them over the chronograph. Average velocity : 2096 fps, ES : 42 fps. Two inch group at 50 yards.
Next loaded the remaining 4 rounds in the magazine to see how they would function. Had one jam. Possibly due to the mangled plastic tip.
Bottom line: If I had a lot of .311 bullets and only .308 caliber rifles I would size down the .311s and use them.
Sorry I didn't get back to you sooner but I hope this may still be of some interest to someone.
Better late than never.
As per my earlier posts (June 2011), I did eventually load the 10 resized bullets in .308 Winchester cartridges using 37.0 grs. of IMR 4895.
The weather here yesterday was fairly mild so it seemed like time to get out and do a little shooting.
I first loaded one round in my FN/FAL and fired at a target at 50 yards. It went bang and was on the paper.
I then loaded the next five rounds one by one and fired them over the chronograph. Average velocity : 2096 fps, ES : 42 fps. Two inch group at 50 yards.
Next loaded the remaining 4 rounds in the magazine to see how they would function. Had one jam. Possibly due to the mangled plastic tip.
Bottom line: If I had a lot of .311 bullets and only .308 caliber rifles I would size down the .311s and use them.
Sorry I didn't get back to you sooner but I hope this may still be of some interest to someone.
Cheers, thanks for the info. All soaked in [;)] Best, Mond