Long Range Hunting Online Magazine

Go Back   Long Range Hunting Online Magazine > Rifles, Reloading, Optics, Equipment > Reloading

Reloading Techniques For Reloading


Split Necks when Fire Forming >243 AI

LinkBack Thread Tools Display Modes
Old 12-04-2011, 10:03 PM
Bronze Member
Join Date: Oct 2009
Location: Lawrenceville GA
Posts: 39
Split Necks when Fire Forming >243 AI

I am looking for some advice. I loaded some rounds with new Winchester brass in regular .243 Win for fireforming in my .243 AI which is a new build. Two of the 18 rounds I shot split the necks pretty bad, one on both sides. Here are the particulars:

1) 5 rounds with 41.8 gr varget - 58 gr H Vmax - no issues, and they shot 1/2" at 100 yds.

2) 10 rounds with 40.0 gr varget - 70gr speer HP - no issues, they shot about 1".

3) shot 3 rounds with 41.0 gr varget - 70 gr speer HP and they did not shoot as good as the other loads and I noticed two had necks split pretty bad and the shoulder did not blow out clean. I stopped shooting. This is only a mid-level load and is a couple of grains below max by my load books. Primers were CCI LR and WLR I did not track the placement of the different primers in the loads.

4) I have several more loaded at 41.0 and some at 42.0 varget and the 70 gr speers. It looks like I need to pull these and reduce to 40.0 to load with the 70 gr bullets or use them with the 58 grain v-max.

5) I have loaded the fire formed AI cases with all 58 gr bullets and have stepped the charges up to 41.8, 42.5 and 43.5 varget which are all well below max for regular .243 win. I will try shooting these next week.

What do you think caused the split necks, is the Win. brass too hard ?

My chamber was set .004" shorter than the regular .243 win for the crush fit for the AI. A good gunsmith set this up for me. He thought maybe we should set the chamber back a little more. Since some of the brass did not have issues I am not sure I want to do this.

My reloaded FF rounds fit snug in the chamber but eject fine. since I am using the short bullets in a 14 TW barrel I do not think the bullets are or can touch the lands.

I am sure most will agree that I should pull the loads or not shoot them in this gun but does anyone have opinions on why I would be getting split necks with less than maximum loads? Anything I should check and does anyone think the barrel should be set back. The barrel was bought used but had little use and is reportedly a shillen varmint # 5 in .243 AI. My gunsmith trued the action and checked the chamber with a go gauge. The cases that did fire form without problems look good.

Advice is appreciated.
Reply With Quote
Old 12-04-2011, 11:11 PM
Bronze Member
Join Date: Aug 2010
Location: Heath Springs SC
Posts: 59
Re: Split Necks when Fire Forming >243 AI

Did you anneal the brass first?
Reply With Quote
Old 12-04-2011, 11:26 PM
Bronze Member
Join Date: Oct 2009
Location: Lawrenceville GA
Posts: 39
Re: Split Necks when Fire Forming >243 AI

I did not anneal and do not know how to or have the equipment to do it but it sounds like I may need to learn or else buy some of the premium brass that this is already done to it ?

Last edited by gasph; 12-05-2011 at 09:33 PM.
Reply With Quote
Old 12-05-2011, 09:08 AM
Bronze Member
Join Date: Mar 2011
Location: Northern Michigan
Posts: 96
Re: Split Necks when Fire Forming >243 AI

I've have quite a few AI'd rifles and have only ran into split necks while forming one time. It was when I was using once fired brass to form for one of my 223AI's. You say that you do have the .oo4" crush fit so it's not that. (personally) I like to put the bullet in the lands when forming cases to just to make sure that I have positive headspace. I also like to form with max to near max loads for the parent chambering. It could simply be a couple pieces of brass that was harder than the rest also. I'd just form them all and not worry about losing a couple cases, but that's just me.
Reply With Quote
Old 12-05-2011, 01:18 PM
Platinum Member
Join Date: Jun 2010
Location: greenwood, IN
Posts: 3,557
Re: Split Necks when Fire Forming >243 AI

I never have had the split neck syndome with my 6/250AI during fireform, but I also build my case out of .243 brass instead of 22-250 brass. And this leads me to thinking back when several friends of mine got on the .243AI and 22-250AI kick. All were plagued with split necks as well. The guys that shot the .243AI ended up using 6mm brass or 6.5x55 brass, and making the necks as long as they could fit in the chamber (one guy reworked an older .243 barrel with a neck that was about .075" longer than the one in the good chamber. This pretty much ended the problem for them. I anneal my necks prior to fireforming, and seldom loose a case. Looking back, I think that annealing the neck and shoulder area might have solved the problem for everybody. Interestingly these same guys shooting factory loaded rounds in their rifles did not have much of a split neck issue. Still thinking back thru the years I've only had split necks with cases that have short necks. Why I don't really know for sure.

Last edited by Trickymissfit; 12-05-2011 at 01:19 PM. Reason: spelling issues
Reply With Quote
Old 12-18-2011, 06:11 PM
Bronze Member
Join Date: Oct 2009
Location: Lawrenceville GA
Posts: 39
Re: Split Necks when Fire Forming >243 AI

Update: I shot one more of the 41gr loads with the 70 gr speers and the neck split again which was no surprise. I pulled all the bullets and dumped the power and started over again. I reduced the load to 39.1 gr which is a minimum load and they are working fine and blowing the shoulder out like they should. I think this solves the problem.

I also ordered 100 Lapua cases and I will see how they do. Thanks for the replies.
Reply With Quote
Old 12-20-2011, 02:20 AM
Official LRH Spponsor
Join Date: Jun 2010
Location: utah
Posts: 124
Re: Split Necks when Fire Forming >243 AI

I just fireformed 100 Lapua cases with 40g 4831sc with Amax 105. Never had a problem. Then finally load was 47.5g of H1000 with Berger 105vld 3295fps. I anneal every time after fire forming.

Here is the 5 shot group with the Amax's

Reply With Quote


Thread Tools
Display Modes

Similar Threads for: Split Necks when Fire Forming >243 AI
Thread Thread Starter Forum Replies Last Post
turn necks before fire forming an ackley improved 1sniper Reloading 8 07-10-2011 01:11 AM
COW fire forming coupalr Reloading 1 10-07-2006 02:08 PM
270 AM Fire Forming? srhaggerty Reloading 3 10-06-2005 10:16 AM
Fire-Forming? skip AI Reloading 15 04-26-2005 07:33 AM
Help , split case necks Aussie Rifles, Bullets, Barrels and Ballistics 5 11-03-2004 10:12 AM

Current Poll
Are you on Facebook?
Yes - 46.41%
1,119 Vote
No - 19.54%
471 Votes
No, but I may join - 1.78%
43 Votes
No way, are you kidding? - 36.00%
868 Votes
Total Votes: 2,411
You may not vote on this poll.

All times are GMT -5. The time now is 09:52 PM.

Powered by vBulletin ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Management Powered by vBadvanced CMPS
All content ©2010-2014 Long Range Hunting, LLC