Full Length vs Neck Sizing 243

Wolfsburg1

New member
I am trying to come up with a good load for my Rem 700 SPS in 243. I switched out the SPS stock for a free floated and bedded maple custom.

Last week the following load shot to 1/2" at 100:

-Norma Brass FL sized
-39.5 and 40.0 grains of IMR-4350
-CCI-BR2 primers
-Honardy 100 grain interlock
-2.272 inches measured to ogive

Today I went to range to fine tune with 39.5, 39.8, 40.0 and 40.3 grains and my groups blew up to between 1.25 and 3.0 inches.

The only difference was that I neck sized rather than FL sized.

Has anyone else seen worse accuracy when neck sizing vs FL sizing? I fully expected the same or better accuracy with neck sizing.
 
Full length size your neck sized and fired brass. Shoot again if they shoot good, your neck sized is probably producing out of concentric ammo. Otherwise obvious changes, bag or rest issue, wind, temp, parallax setting, stock or scope screws, damage to barrel crown. If it is a new barrel, you may still be in a period of change as the barrel wears. Or your load was on the end of node either the charge or seating depth.
 
Did you fire several 5-shot groups that consistently grouped at 0.500"s or was it just one group that size? If consistently shooting a half inch at 100 yards - I would be puzzled, as neck sizing usually doesn't change group patterns/sizes.

Try going down a tad in your powder charge and see if that brings back any joy. Shooting a 0.500" group on demand with a 243 is no easy task - shooting a 0.900" to 1.250" group at 100 yards in my opinion is good enough outdoors.

Some days I must have Lady Luck with me, as I find a load that shoots 5-shot bug hole groups consistently and I'm confident I found the "wonder load" for that rifle. Problem being, I'm unable to repeat those groups next time out - sometimes close, but close only counts when using heavy artillery.
 
I shoot 41.5g in Win brass, full length sized with the 100g Hornady, seated .005 off the lands. My barrel has some wear on it, SO WORK UP TO MY LOAD!!.

Lapua brass is tough as nails, so is PMC if you can find any. Norma brass can be on the softer side, but not as bad as Federal.

My rifle is a 700, and I have shot the barrels out of many 243 rem 700's. I think that you are on the bottom end of the accuracy and powder charge, but every barrel is different so proceed with caution.

I shoot 3 shot groups, NOT 5 due to barrel heat which slows down the throat errosion.

Clean the barrel every 30 shots max, you WILL have a lot of copper, which may account for your larger groups also.

Teslong bore scope with 90* angle is $80.

Good luck, let us know how the accuracy turns out
 
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Thanks for your help everyone; I have a few ideas to try.

Ackleyman: I was working up to your load with IMR-4350 when I lucked into the two 1/2" groups.

For more info; the rifle is a new 700 SPS. Probably only 50 shots through it.

I had two 1/2" three shots groups the last time out. One at 39.5 gr and one at 40.0 gr. That's was I was so disappointed to see 2+ this time.

My fired brass fits in my Forster go/no go gauge just fine. It's like it hasn't expanded at all after firing and the brass goes through my dies with virtually no effort.

I know this is NOT the case for other calibers I reload.

I am using Norma brass because I happened to have some laying around.
 
On top of the annealing and barrel cleaning mentioned above, ck your case length. If the neck sizing is stretching the neck enough, and you are near trim length w a shorter throat, you could be "pinching" the case mouth into the bullet, and creating an unintentional crimp? Ive had issues as such when I wasnt paying attention in the past, hence my thoughts. Make sure you are lubing well also.
 
Has anyone else seen worse accuracy when neck sizing vs FL sizing?

You changed the recipe,neck-size vs full size, so you changed the 'flavor' to your rifle. I use food analogies a lot when it comes to reloading, as I think it is similar.

Remington builds in a pressure point at the front of the stock, with the theory being it helps to dampen barrel harmonics, and a wider variety of loads will shoot well. Free floating the barrel can be more accurate, but more sensitive to the load changes.

My Sako, a 1963 L461 in 222RemMag, had the pressure point when I bought it in 1996. When I free-floated the barrel, I had to re-do load development. YMMV.
 
K-22hornet,

Thanks for the info and recipe analogy makes sense.

I know the pressure point issue well. Last year a I bought a 700 ADL in 7mm Mag and it shot under 1/2" with factory ammo so....I immediately upgraded to a Boyd's stock, bedded it, upgraded the optics and started reloading for it.

I am still trying to get it to shoot as well as it did.
 
+1 to Ackleymans 'little on lower side of charge weight'. I ve typically found better accuracy a grain, maybe 2 under max loads. (Work up your charges though). When I ve loaded light, beginning charges accuracy usually not as good.
 
Well I made it back to the range yesterday. I went with same loads and FL sizing. Groups improved some but still nowhere near where I was was. I initially was at 0.94" average 3 shot shot group with a best of 0.5". Yesterday's average was 1.4" with one group at 0.75". I think I will use the 0.75" load and move on.
 
When shooting groups there are probably dozens of variables that will affect group size besides the loads themselves. You can shoot the same loads on different days and get different results.

Was the weather the same? Wind changes everything.
Dirty bore? Amazing how much it can affect group size.
Action screws tight?
Even how you hold the gun, how tight, the sandbags used, etc. will affect things.

Consistency is everything. Do everything the same.
 
Hornady sells that bullet in loaded ammo, velocity is 2960. Will need to work your way up to 42.0 gr of powder to equal factory ammo. Might be worthwhile to know if your handload shoots better than factory.
 
Some times all the voodoo of hand loading just doesn't produce any better results than factory ammo. The reason,every rifle isn't a bench gun! R.O don't have much effect on accuracy @ 100 yrds,and I doubt most rifles can take advantage of 0.003 or less R.O anyhow. Seating bullets to the lands is fine for fire forming (if you can afford it) But why would anyone want to pack such ammo to the field for hunting? Neck turning IMO is a waste of time for a factory rig, I think brass selection is a better option. I'm not trying to rain on anyone's parade! These are just my opinions. The 243 is a very accurate cartridge, it shouldn't be hard to find a load that shoots under 1 MOA.
 
Unfortunately I only shot two 0.5" groups and it was the first time out. Two trips since and the best is 0.8".

My original question was based on the fact that neck sizing only (appeared to) caused my groups to expand so much for the same load; from 0.5" to 2.5/3.0" and in average for several loads from 0.94" to 2.2".

I am sure I will manage to get the rifle dialed into acceptable levels and I guess that's the fun.
 
I appreciate everyone's insights and wanted to provide an update. I made a few changes and I am back to where I started (almost). I shot two groups today at 0.63" with the following specs:

40.0/41.5 grains of IMR-4350
0.005 off the lands
Hornady 100 grain interlock (2453)
Lapua new FL sized brass
CCI-BR2 primers

I also tried a few 0.010 off the lands and the group size increased to 1.0 to 1.5"

I am leaning towards sticking with the 41.5 grain load and will continue to FL size my brass. This is essentially Ackleyman's suggested load with a few component changes. FWIW 40.0 and 41.5 grains have both shot the best with all components.
 
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