Slightly off COL

Reloading equipment, methods, load data, powder and projectile information.

Slightly off COL

Post by YoungBuck » 28 Mar 2018, 6:59 pm

Did my very first batch of reloads the other night for my .243 - 20 rounds with varying powder weights from 32gr to 35 gr.
I was very careful to get the right amount of powder and to ensure that I didn't go over the COL. Have only now just realised that I haven't got the rounds at the COL stated on the ADI data sheet - 2.653" (67.39mm), all of my rounds are between 66.32 - 66.44mm so I am a full mm too far into the case.
As my COL is shorter than listed, there is less space in the cartridge meaning more bang... just wanting to get advice from the experienced as to what you would do with these rounds? Pull em and restart or should they be OK to shoot?

http://www.adi-powders.com.au/handloade ... Winchester
-87gr Hornady SP
-AR2208
It'll shoot the fleas off a dog's back at five hundred yards, Tannen, and it's pointed straight at your head!
User avatar
YoungBuck
Corporal
Corporal
 
Posts: 436
Victoria

Re: Slightly off COL

Post by Cooper » 28 Mar 2018, 7:09 pm

If you have a bullet pulling hammer you probably only need to give them a whack or two until the projectile moves out a bit. Then reset the COL with your bullet seating die. So no need to pull the bullet completely apart.

Otherwise I would just start shooting from the lowest and watch for pressure signs. I would probably try AR2209 with the 87gr also. But the ar2208 might work ok for you.
Cooper
Sergeant
Sergeant
 
Posts: 539
Victoria

Re: Slightly off COL

Post by sungazer » 28 Mar 2018, 7:12 pm

How did you arrive at setting them at that length, I mean the decision to set them at that length?
sungazer
Sergeant Major
Sergeant Major
 
Posts: 1525
Other

Re: Slightly off COL

Post by Wm.Traynor » 28 Mar 2018, 7:22 pm

Start shooting the lowest charge. In theory, moving the bullet in the case forward or backwards, will abrade metal from the bullet and have an effect on pressure. Better not to do it. You should be safe with starting loads. That is metal abraded equals lower pressures leading to a false sense of security if maximum charges do not indicate excess pressure.
However, a word about COL. Did you measure this in your rifle? For a hunting rifle, COL needs to be 0.75mm less than maximum, which is when the bullet is seated touching the lands. But, if COL minus 0.75mm will not fit your magazine, because it is too long, then COL needs to be shortened to say 1.0mm less than magazine length.
Wm.Traynor
Sergeant Major
Sergeant Major
 
Posts: 1644
Queensland

Re: Slightly off COL

Post by YoungBuck » 28 Mar 2018, 7:41 pm

sungazer wrote:How did you arrive at setting them at that length, I mean the decision to set them at that length?

Was just the first length I set the die to. Checked that it wasn't past the listed .243 Max OL and went from there, forgetting about the ADI COL.

Cooper wrote:Otherwise I would just start shooting from the lowest and watch for pressure signs. I would probably try AR2209 with the 87gr also. But the ar2208 might work ok for you.

Wm.Traynor wrote:However, a word about COL. Did you measure this in your rifle? For a hunting rifle, COL needs to be 0.75mm less than maximum, which is when the bullet is seated touching the lands. But, if COL minus 0.75mm will not fit your magazine, because it is too long, then COL needs to be shortened to say 1.0mm less than magazine length.

Thx, I will start with the lowest (32gr powder) and watch closely for excess pressure signs.
No haven''t put it in the rifle yet, but my cartridges are .25mm shorter than the 90gr PPU ammo I have so they should chamber no problem.
Last edited by YoungBuck on 28 Mar 2018, 7:44 pm, edited 1 time in total.
It'll shoot the fleas off a dog's back at five hundred yards, Tannen, and it's pointed straight at your head!
User avatar
YoungBuck
Corporal
Corporal
 
Posts: 436
Victoria

Re: Slightly off COL

Post by Stix » 28 Mar 2018, 7:42 pm

Id say you're good to go...
But make sure they not touching the lands/rifling...

I dont have a 243 but there should be plenty enough room in the case to allow for that...you're a full grain under adi max & their max isnt compressed.
Just as others said--start at lower charge...!

My experience tells me as soon as you even slightly pull a proj the neck tension lessens considerably, so id either shoot em as they are or if you feel the need to pull em--do it completely & neck size again. :)
The man who knows everything, doesnt really know everything...he's just stopped learning...
Stix
Colonel
Colonel
 
Posts: 3675
South Australia

Re: Slightly off COL

Post by YoungBuck » 28 Mar 2018, 7:48 pm

Wm.Traynor wrote:In theory, moving the bullet in the case forward or backwards, will abrade metal from the bullet and have an effect on pressure. Better not to do it. You should be safe with starting loads. That is metal abraded equals lower pressures leading to a false sense of security if maximum charges do not indicate excess pressure.


Stix wrote:Id say you're good to go...My experience tells me as soon as you even slightly pull a proj the neck tension lessens considerably, so id either shoot em as they are or if you feel the need to pull em--do it completely & neck size again. :)


Thx gents, I will remember this the next time I cock up the COL and think about only semi pulling them out :thumbsup:
It'll shoot the fleas off a dog's back at five hundred yards, Tannen, and it's pointed straight at your head!
User avatar
YoungBuck
Corporal
Corporal
 
Posts: 436
Victoria

Re: Slightly off COL

Post by Norton » 29 Mar 2018, 11:13 am

That should be fine mate.

COAL is a guide, not an absolute.

Different projectiles will mean a different COAL. Flat nose vs a VLD match point will have very different COAL, the important bit is where the OGIVE and lands match up.
CZ 550 American Safari Magnum in .416 Rigby

Other puny calibre rifles... What man would want you now?
User avatar
Norton
Staff Sergeant
Staff Sergeant
 
Posts: 838
Queensland

Re: Slightly off COL

Post by marksman » 29 Mar 2018, 1:06 pm

learn to find out your rifles oal for each projectile you will use
when you are reloading you are making a tailor made load for your rifle
touching or jam is higher pressure than a jump but as you seat the projectile in deeper the pressure will rise
www.youtube.com/watch?v=TWmIwPwLyyg
“If you do not read the newspapers you are uninformed. If you do read the newspapers you are misinformed”. Mark Twain
User avatar
marksman
Colonel
Colonel
 
Posts: 3660
Victoria

Re: Slightly off COL

Post by YoungBuck » 08 Apr 2018, 10:36 am

Just rounding off this thread, I hit up little river yesterday and put the rounds to the test (4 shot groups) then had some fun putting cheap PPU rounds onto the steel plates out at 450m :D

For those interested below are the group sizes. The low powder loads surprisingly shot very well and the grouping picked up again with the 34.5gr rounds.
I suppose the next step is to experiment with smaller changes in charges at the lower end (32-33gr) and around the 34.5gr mark.

Edit: forgot to mention there was no sign of over pressure in any of the cases fired :thumbsup:
Attachments
Sizes.PNG
Sizes.PNG (14.58 KiB) Viewed 3246 times
It'll shoot the fleas off a dog's back at five hundred yards, Tannen, and it's pointed straight at your head!
User avatar
YoungBuck
Corporal
Corporal
 
Posts: 436
Victoria

Re: Slightly off COL

Post by duncan61 » 08 Apr 2018, 12:42 pm

It is a good practice to get as technical as possible to avoid errors when reloading.We standardized our .243 loads a long time ago by closing the bolt on a loose neck and setting the bullet depth .8mm from the lands. All the chambers on 4 different rifles were very close by a a few thousand inch. My main man is a precision Engineer and we did this together.We load 35gn 2208 with 80 gr projectiles and they go great.We failed to pack the rounds one trip and purchased Winchester Failsafes from the local hardware store but their POI was way out to our reloads.Enjoy the process my man it is a learniong curve
.22 winchester .22hornet .222 .243 7mm rem mag cbc 12g
User avatar
duncan61
Officer Cadet
Officer Cadet
 
Posts: 1905
Western Australia

Re: Slightly off COL

Post by duncan61 » 08 Apr 2018, 1:00 pm

Prvi Partizan Ammunition in my experience is good quality.Because it is less expensive does not mean it is not good
.22 winchester .22hornet .222 .243 7mm rem mag cbc 12g
User avatar
duncan61
Officer Cadet
Officer Cadet
 
Posts: 1905
Western Australia


Back to top
 
Return to Reloading ammunition