Once fired brass what happend?

[Adrain]

Fire formed new brass 243 win 28in PAC NOR barrel samii min chamber 1in7 twist shot great ,hit golf balls at 300 till got tied of hits. Reloaded brass neck size only ,105 nosler C.C. 4831sc 43.5gr cronod at 2958 aveg. Shot like I had a bent barrel, look like a shotgun blast ,same mount same everything,temperature was lower by 30 degree ,barrel has only 150 rounds on it so not shot out any thoughts? Winchester brass, trimmed and sized before first firing./

 

[LHSmith]

Shot like I had a bent barrel, look like a shotgun blast ,same mount same everything,temperature was lower by 30 degree ,

We need some clue as to what the target results were on the second outing?- distance?, group size?, conditions present?

 

[dkhunt14]

I think 4831SC is too slow for a 243. When the temp dropped 30 degrees the load probably slowed a lot. Maybe because of neck sizing or a lot of run out. Like Mr Smith said need more info. Was the load, bullet and seating depth the same? Maybe carbon in the barrel. Matt

 

[ebb]

Maybe copper in the barrel

 

[AckleymanII]

Adrin, copper in the barrel is the first thing to check, but going to H4350 between 41-42g is going to save the day more than likely.

 

[Larryh128]

I've used 4831 in the 243 with excellent accuracy in the heavier bullets. I would question if your load was a little soft. I run more than that without any pressure.

 

[dkhunt14]

I've used 4831 in the 243 with excellent accuracy in the heavier bullets. I would question if your load was a little soft. I run more than that without any pressure.

I have never seen 4831 outshoot 4350 in a 6mm. The 7 twist barrel is a real fast twist and he probably can't get as much in till he hits pressure. Shooting 100 yards and 300 yards is two different things. I would try cleaning the barrel good and then getting somebody to borescope it. Almost all benchrest shooters full length resize with minimum shoulder bump. Matt

 

[Ledd Slinger]

Or his scope took a dump...

 

[Adrain]

All bullets were set to same depth 3 grove barrel cleaned completely. only thing I can think of is diff neck tension caused pressure drop. went from full size new brass to once fired neck size only 100yd group went from 1/2 in to 1 in 300 yd went from 1in to2.200 in ?

 

[243winxb]

You fired new brass, then went to neck sized. The case volume changed. And FL sized brass is more accurate than neck sized. IMO.

 

[wapiti25]

I quit buying Nosler bullets when I found new bullets were .0005" smaller in dia than my old ones. I called and they told me they did not have a problem with their bullets.

 

[Dusty Stevens]

I cant believe nobody told him he shoulda annealed.
A 30deg temp drop threw your load into shambles being as it was on the edge with 4831 on the first day. Lucky node

 

[normmatzen]

Pay close attention to 243WINxb. I think he is spot on!
I used to use a full case of H1000 (46gn) in my first BR gun in 243 WIN and it worked just fine.

 

[Homerange]

You fired new brass, then went to neck sized. The case volume changed. And FL sized brass is more accurate than neck sized. IMO.

+1
Fireforming is NOT the same as firing full power loads. Yep, volumetric efficiency has changed.

 

[fguffey]

Fire formed new brass 243 win 28in PAC NOR barrel samii min chamber 1in7 twist shot great ,hit golf balls at 300 till got tied of hits. Reloaded brass neck size only ,105 nosler C.C. 4831sc 43.5gr cronod at 2958 aveg. Shot like I had a bent barrel, look like a shotgun blast ,same mount same everything,temperature was lower by 30 degree ,barrel has only 150 rounds on it so not shot out any thoughts? Winchester brass, trimmed and sized before first firing./

And I wonder, If you were hitting golf balls at 200 yards what did you have to gain by changing anything? If your cases were minimum length/full length sized I believe that would be a good place to start.

Then there are factors that change when going from fire formed to neck sized.

F. Guffey

 

[mikecr]

Develop a load w/brass -as you're going to use it -in conditions you're going to shoot in.
You changed too many things

 

[BoydAllen]

Just out of curiosity, what kind of neck die did you use? Also, do you own a concentricity gauge? I agree with the suggestion to rework the load with properly bumped, FL sized brass. The other thing that I would point out is that one piece neck dies with expanders are the absolute worst that I have seen for making cases crooked during sizing. As an alternative to a bushing FL die, for unturned necks, and chambers with factory like neck clearances, several of us have seen very good results with two stage sizing, using a Lee collet die followed by a body die set for the correct amount of shoulder bump. This combination can produce very consistent results. Just remember that with the Lee die, that you vary your neck tension by changing out the mandrel for one with a different diameter, and to carefully read the directions for setup and operation.

 

[fguffey]

Fire formed new brass 243 win 28in PAC NOR barrel samii min chamber 1in7 twist shot great ,hit golf balls at 300 till got tied of hits. Reloaded brass neck size only ,105 nosler C.C. 4831sc 43.5gr cronod at 2958 aveg. Shot like I had a bent barrel, look like a shotgun blast ,same mount same everything,temperature was lower by 30 degree ,barrel has only 150 rounds on it so not shot out any thoughts? Winchester brass, trimmed and sized before first firing./

If I was hitting golf balls at 200 years I would not change anything. I would save a few unfired cases for comparison

When going from full length sized cases to neck sized cases there are a few factors that change. I am the fan of cutting down on all that case travel.

And then there comes a time when a decision could be made. What do you want; accuracy or long case life?

F. Guffey

 

[Ledd Slinger]

FL sizing is used to 'consistently' control case dimensions. If the case dimensions are always the same when a round is fired, that is one less variable to worry about. Fired brass that is only neck sized has no control over the case body and shoulder dimensions. Head space and body width will often vary quite a bit with neck sized brass. Especially once you fire it 3 or 4 times with only neck sizing.

 

[AZHunter12]

...As an alternative to a bushing FL die, for unturned necks, and chambers with factory like neck clearances, several of us have seen very good results with two stage sizing, using a Lee collet die followed by a body die set for the correct amount of shoulder bump. This combination can produce very consistent results. Just remember that with the Lee die, that you vary your neck tension by changing out the mandrel for one with a different diameter, and to carefully read the directions for setup and operation.

Boyd, I'm interested in the details of this process. You size the necks first, then use the body die. I've read that others reverse the order of die usage. I've not used a body die, only a FL, so my knowledge is zip. Here's my question, if you size the neck first with the collet die, then use the body die, do you risk moving brass toward the neck, possibly changing the concentricity of the neck? Or does the body die restrict that brass flow? Thanks.