To crimp or not to crimp....

Alantoo

Well-Known Member
I’ve been using brasso to aid cleaning my cases for thirty six years. The most recent cases I finally junked lasted 23 reloadings over 13 years. Just ordinary Remington cases, they still looked perfectly fine when I decided to buy new brass and scrapped them. So, just how bad then is brasso/ammonia ? I’d say whoever decided that was the case, needs their lumps feeling! It’s just nonsense
Not nonsense at all. Easy to look up, try the Copper Development Association web site if you need an authoritative source.

Stress related corrosion cracking is very real. It is precipitated by, amongst other things, ammonia...even atmospheric ammonia is sufficient. As the name implies, it is stressed brass that is affected...if the brass is unstressed...ie not work hardened sufficiently, it obviously will not happen.

It is one of the reasons that stress relief annealing your brass prevents the neck splitting and extends the life. The other reason for annealing is that you can maintain a consistent (OEM) neck tension.

As far as the use of polishes like Brasso that contain ammonia, provided the brass is annealed there is no real problem...but there are better polishes out there like Autosol which do not contain ammonia, so why increase the possibility of neck splits when there is a better alternative?

Alan
 

deeangeo

Well-Known Member
Not nonsense at all. Easy to look up, try the Copper Development Association web site if you need an authoritative source.

Stress related corrosion cracking is very real. It is precipitated by, amongst other things, ammonia...even atmospheric ammonia is sufficient. As the name implies, it is stressed brass that is affected...if the brass is unstressed...ie not work hardened sufficiently, it obviously will not happen.

It is one of the reasons that stress relief annealing your brass prevents the neck splitting and extends the life. The other reason for annealing is that you can maintain a consistent (OEM) neck tension.

As far as the use of polishes like Brasso that contain ammonia, provided the brass is annealed there is no real problem...but there are better polishes out there like Autosol which do not contain ammonia, so why increase the possibility of neck splits when there is a better alternative?

Alan
As stated Alan, my experience in 36 years of reloading and the use of brasso, absolutely NO detrimental effect found.
Zero. Zilch. Perfectly fine & I shall continue its use with my latest batch of new brass.
 

Alantoo

Well-Known Member
As stated Alan, my experience in 36 years of reloading and the use of brasso, absolutely NO detrimental effect found.
Zero. Zilch. Perfectly fine & I shall continue its use with my latest batch of new brass.
I am hoping for the same result having smoked for well over 36 years...stopped a dozen years ago and okay so far!

Maybe we both will be the exceptions and get away with it... :)

If you actually try the Autosol polishes, either Shine or their standard metal polish, you will find them much more effective at their job than Brasso, irrespective of the ammonia issue. They are much faster acting and quicker to remove without smears.

Alan
 

Miki

Well-Known Member
The 'bit that flies out the barrel' is called the "bullet". The 'head' is something else and hopefully never flies out of anything
 

Dr.T.

Well-Known Member
Ah, that's good to know... must try harder!! Incidentally, based on your experience of reloading and long range shooting, was the rest of my post up to scratch, or do you have any other feedback?

Either way, now that my comments have been deciphered, hopefully they'll prove useful to the OP.
 

Miki

Well-Known Member
Ah, that's good to know... must try harder!! Incidentally, based on your experience of reloading and long range shooting, was the rest of my post up to scratch, or do you have any other feedback?
Well i'm glad you asked :)
Most of what you said made sense apart from the referral to the bullet as a 'head' or 'bullet head' or 'match head'. I was interested to read that match bullets utilise a meplat and (after further reading) that you can get a meplat trimmer tool to uniform/remove any unevenness in the nose of match bullets (that's the bit that flies out of the barrel when the gun goes bang @Dr.T. if my use of the correct terminology was creating any confusion). I always thought that 'match' bullets were made to a tighter tolerance than hunting/game or varmint designated bullets and that they always terminated in a point to offer a higher ballistic coefficient than a hollow or flat nose design.

This statement you made confused me "Saying that, you can improve concentricity by seating a head half way, rotating the bullet half way, then resting the rest." It's almost as if you have become completely discombobulated yourself with the process, perhaps you could rework that statement into a meaningful order ?

I'm also interested in what you meant by "base-to-ogive sorting" and sorting "by bearing surface and OAL," and how you measure these inconsistencies.
I don't have any experience in 'long range shooting' but am always keen to learn about these things.
 

Dr.T.

Well-Known Member
Hi Miki

Match 'bullets' are generally very accurate and consistent, but this is all about making very consistent bullets as good as they can be. I'm not sure whether match bullets are more 'consistent' than hunting bullets (partucularly those with polymer tips) but long range match bullets are more concerned with achieving a high ballistic coefficient rather than terminal performance. As i understand it, modern hunting bullets try to gain the BC advantages of match ammo (meaning less wind drift and higher retained velocity) while maintaining terminal performance.

You can buy match bullets with polymer tips, but most LR target shooters use the traditional full copper jacket design. You can uniform/ improve the tips on these, whereas the polymer ones you can't. Match bullets out 'of the box' are great and honestly you would struggle to see much benefit from this within 600 yards or so (and for anything other than top level competition, I'm not sure it's worth the extra effort). Ultimately this is about making bullets fly slightly more consistently (which is by unforming their BC). Lots of folk point only (without trimming) and many shoot them out of the box. As a side point (pun intended) the very tip of a bullet has a surprisingly small effect on BC, and pointing can only achieve a small improvement in BC (maybe 5% if you're lucky)... the main advantage to my thinking is ensuring that they fly the same (when shooting circular targets, keeping them on the 'waterline' gives you the biggest margin for wind error).

Regarding bullet seating, you just move the press handle down half way, lift the handle, rotate the case, then complete the stroke. If your setup is on the wonk then this can help keep things aligned by averaging out errors.

To take measurements involving the ogive, you'll need something like a hornady bullet comparator... to get a base to ogive measurement, you just measure the bullet as you would a loaded round . To get a sense of bearing surface you'll need two comparisors, one on each jaw of the caliper. To measure bullet OAL, you just need your calipers. You can get specialised gear to do all this (e.g. from Sinclair, which will save time) but you can achieve the same with what's already on your loading bench.

I hope this makes sense!
 

DRN

Well-Known Member
I tried 10 shots crimped and 10 without. With 223 and 243 over a chrono. Crimped had a lower spread of speed it went from about 20ftps variance to 10fps variance. That was for both calibres. Accuracy was better for both. I don't need to for my .308 as that had about 7fps total variance.
 

Dr.T.

Well-Known Member
That's an interesting observation!

Ultimately just do whatever works for you and gives you confidence in your reloads - at normal distances you're unlikely to see a difference. At long range I assure you that crimping is not the way to go (I don't know a single f class shooter who crimps; I'd be confident that benchrest shooters don't crimp either; and competition/custom dies don't even contain a crimp feature). Happy crimping (or not)!
 

Miki

Well-Known Member
"so are we bleeding crimping or not?":-|:rofl:
I crimp, mainly because I believe it gives me a consistent neck tension, which in turn offers a consistent pressure and therefore a more consistent/accurate round . I do use expander dies and have polished the expander ball (a) to make it smooth and (b) to produce an internal neck diameter of approx 2 thou smaller than the bullet. I also anneal my brass every other firing and clean with a wet tumbler. Does it make more accurate ammunition ? I don't know, but I do think it helps. The comp seating dies I use do allow me to seat with repeated accuracy and my concentricity gauge which I use occasionally to check 1 in 5 says everything is within .002" (unlike some ready-made PPU I bought a while back that was well akilter) so has almost become redundant.

To me reloading is all about being precise and consistent and measured, which when you are shooting 600yds or more is most likely much more important that sub 250yds. 1MOA @ 800yds is 8"
I need all the help I can get and the majority of 'misses' are down to me rather than the bullet or the rifle.
 

Dr.T.

Well-Known Member
Hi Miki- you can't argue with a man's belief. If crimping gives you confidence then go for it - after all, it might well be that secret sauce that competitive shooters are looking for.

Joking aside, 1MOA at 800 yards is decent performance... I think that's far better than most shooters can achieve in the real world, and (based on the abysmal display of marksmanship I witnessed at DSC1 and elsewhere) it's better than many achieve much closer than that... which is odd as their rifles all seem to shoot .25MOA 'all day' and 'if they do their part' and similar twaddle that infects shooting forums.

The steps mentioned in my earlier posts are what I (and other GB league shooters) do to consistently achieve .4-.5 MOA consistency at 1000 yards. Much less than that and you're so far from being in the running, you wouldn't believe. Outside of competition, better groups still mean a bigger margin for of error for things that are not constant (same applies to stalking in my opinion). Plus, it costs the same per bang whether you spend the extra time or not, so why wouldn't you.

Best of luck!
 

1tikka

Well-Known Member
Why add another variable in the re-loading process, I have not crimped since the semi auto-ban some 30 years ago now.
 

1tikka

Well-Known Member
Also I meant to say, neck size only, but obliviously only use the reloaded rounds in the rifle the bullet has previously been expanded in.

I can see the logic in crimping for use in a tube magazine, but that would depend on the coefficient of friction of the re-loads, in a standard magazine one head can't be inadvertently compressed by another round.
 

Orion

Well-Known Member
in a standard magazine one head can't be inadvertently compressed by another round.
Depending on the recoil of the rifle, a bullet, (obviously not a head), can be deformed in a ‘standard magazine’ by inertia causing it to hit the internal surface of the front of the magazine.

I see it with the Norma Oryx rounds in my 9.3x62 all the time, although I crimp everything I reload now.
 
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Dr.T.

Well-Known Member
So it sounds like there could be a case for running high neck tension for very high recoiling calibres, in magazine/ tube-fed rifles (I have minimal experience with rifles beyond WSM-level recoil but, like 1tikka, I can follow the logic). Honestly I'm sceptical as to whether crimping offers any benefit over e.g. using a smaller neck bushing (which would constrict more of the case neck) but perhaps crimping is the only option when using non-bushing dies? Ultimately, for high recoiling calibres, I doubt you'll really achieve enough precision to tell the difference (besides the internet 'tack drivers', of course).

Neck vs full length sizing, is another discussion altogether!
 

.243Hunter

Well-Known Member
My findings from crimping is it gives slightly accuracy improvments and reduces spread also. So I use a very slight crimp on all my rounds now and its perfect, even more so if you dont anneal for consistency .
 

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