223 90gr 7 Twist load data

[Seddo]

Hi guys,

I got to fire some rounds over the chrono today and thought I would post the results as there isn't a lot of 90gr load data around.



RIFLE: Winchester Model 70, 30" Pacnor 7 Twist, long throated reamer.
LOAD: New Lapua Brass, 90gr Berger BT Target, AR2208, Rem 7.5 primer
OAL: watch this space as I left it in the shed, but its long. Over 2" from the base to the ogive and it isn't jammed.

CHARGE VELOCITY VELOCITY VELOCITY AVE
22.0 2425 2453 2439
22.5 2565 2506 2457 2509
23.0 2566 2575 2569 2570
23.5 2582 2620 2626 2609
24.0 2731 2732 2715 2726
24.5 2725 2742 2741 2736
25.0 2775 2783 2779

The 25gr charge wasn't compressed so there is more room for improvement before I have to try another powder. The only signs on the primer is a bit of a raise lip around the firing pin but I have put that down to the sloppy fit as there is no other deformation of the primer. I will measure the case heads over the next week and update this post.

[Seddo]

OAL: 2.575"
Base to ogive: 2.020"




When you look at the projie next to the loaded round you can see its in need of a longer throat but then the problem is the 80gr projies start only just hanging in the case so I need to be careful until I am 100% the 90's will work or I will need to set it back.



Looking at the Berger website I have chosen to use a 90gr projie they have dropped from their range so I had better use the VLD Target which has a base to ogive of approx. 2.000".

[SteveL]

Hi Seddo
Nice looking rifle. If it shoots as good as it looks your on a winner.
I have had no experience with the 90g pills but the 80g's seem to shoot better and faster with 2206H.
Have you tried that powder? Or is it too faster burning.
Steve

[Brad Y]

Seddo, might be worth looking at RL15 as well, a bit extra velocity and the 6BR and dasher shooters really rave about it. Similar in burn rate to 2208. I used to shoot 90gr VLD's in a 22BR that wore a 7 twist trueflie. Really shot well out to 600 or so. Jam them 15 thou with 1 thou tension and they will hammer.

[Seddo]

Stevel,

I shoot 80gr projies out of my 8 twist. I went with 2208 as i ran into pressure before i had a full case of of 2206H under the 80's.

Brad,
I will try RL15 if i dont get what i want with 2208. If you run the numbers on a 90gr at 2800 it is better than all of the 80's up to 3050fps (max i got in my rifle) so if i can get then going a bit faster it will be a better option for F/TR than a 223 with 80's.

[Brad Y]

I think there is merit using the longer and heavier bullets in any calibre mate. The 80's are definitely good. But the 90's puts them up into 6mm BC territory.

[saum2]

Go the whole hog & throat it out, then you can get in a lot more powder for better speed. 2770 won't cut it. You've come half way.
Geoff

[Seddo]

Its been done, here is the new throat length with a 90gr SMK that's just off the lands. The base to ogive measurement for the SMK is approx. 0.010" shorter than the Berger.



I will load up some more rounds tomorrow and run them over the chrono, this time I will keep adding 2208 until it gets compresses and stop there.

[Norm]

I will load up some more rounds tomorrow and run them over the chrono, this time I will keep adding 2208 until it gets compresses and stop there.

That's more like it.

[Steve N]

It will be very interesting to see how they go Seddo and if there is any real gain over the 80gr Berger.

[Seddo]

The whole idea of this rifle build was to see if there is any advantage shooting 90's in a 223. I have read a lot of for's and against's but there isn't a lot of hard evidence to prove which on is better. The best data I have read came out of the UK but they weren't using any of the powders I use.

I loaded up some rounds from 25gr to 26gr of 2208 and it wasn't compressed, at 26.2gr the shaking noise went away so I stopped there. Off to the range tomorrow to chrono.

[mike H]

The whole idea of this rifle build was to see if there is any advantage shooting 90's in a 223. I have read a lot of for's and against's but there isn't a lot of hard evidence to prove which on is better. The best data I have read came out of the UK but they weren't using any of the powders I use.

I loaded up some rounds from 25gr to 26gr of 2208 and it wasn't compressed, at 26.2gr the shaking noise went away so I stopped there. Off to the range tomorrow to chrono.

Well Seddo you must have good ears,I haven`t heard powder shaking noises for a long time,please look after after what hearing you have,the alternative is not so good.
Mike.

[Seddo]

Here it is, straight off the press....

PLEASE DONT TRY THIS IN YOUR RIFLE, THE LOADS LISTED ARE ABOVE THE MAX LOADS AND MAY NOT BE SAFE IN YOUR RIFLE.

Load:
POWDER: 2208
PRIMER: Rem 7 1/2
PROJIE: Sierra 90gr SMK
BASE TO OGIVE: 2.090"
BRASS: Lapua (once fired)

CHARGE VELOCITY VELOCITY
25.0 error error
25.2 2734 error
25.4 2747 error
25.6 2779 2745
25.8 2816 2814
26.0 2839 2827
26.2 2892 error

I haven't measured any case heads so I cant comment on how the pressure is effecting the case but the primers are fine, they only have a slight raised cup around the firing pin which I believe is caused by the loose fitting Winchester firing pin.

I loaded up 2 rounds for each charge for this test as I wasn't sure what was going to happen with the powder charges I was using. The next step will be a trip to the range to do some 300y testing while working back from 26.2gr to see where the node is.

PLEASE DONT TRY THIS IN YOUR RIFLE, THE LOADS LISTED ARE ABOVE THE MAX LOADS AND MAY NOT BE SAFE IN YOUR RIFLE.

[Norm]

Seddo,

It will be interesting to see how accurate those 90gn pills are in your rifle.

There seems to be quite a jump in velocity for every 0.2gn increase in powder charge. To maintain a tight water line at long range you may have to pay careful attention to the accuracy of each powder charge.

I wonder if there is a velocity node there somewhere that you can latch onto.

[flatlina]

Seddo I have some 90 grain JLK's I can send a few down for you to try.

Regards
john