6.5x243wssm

[b moulds]

hello,
i have just made an experimental case for a friend, by necking up a 243wssm case to 264 and neckturning it.
the virgin case necked up has a 0.302" neck when loaded with a 142 sierra.
the neck is approx 0.3" long and it holds about 49 gn of h4350 up to the neck/shoulder junction when tapped down well.
i turned the neck to be 0.290" loaded, as it seemed a bit thick in its original form.
looks like a nice little outfit.
can anyone offer any advice from experience. am i on the right track?
how does the case cap. compare with 6.5x55 ackley,6.5x57 ackley, and 260 rem ackley? 6.5x284 is well over 50 gn, so this should be a bit easier on barrels. has anyone ackleyized this case?
is my neck thickness o.k., or would it be better thinner?
any suggested loads with 140 class bullets?
thanks in advance,
bruce moulds.

 

[marion packett]

Shoot for a loaded round that is .002-.003 under chamber neck diameter. 6.5 -284 will hold 53-54 grs of H4350 but 48-48.5 is max load with lapua brass behind Sie 142.

 

[b moulds]

marion,
thanks for your reply.
the reason for this exercise was to obtain dimensions for a reamer. neck was turned, as it is suspected that std necks are too thick for accuracy loading.
my feeling is to order a reamer with saami min spec body, but with a 0.294 neck.
comments?
bruce.

 

[Cheechako]

bruce

It's been done. Called the 6.5 Fat Cat. Based on the 25 WSSM. There are probably other versions with other names too (6.5 Heaton is one, I think). It's been used in competition in both F Class and LR Benchrest.

Dave Kiff probably made the reamers and can furnish the specs. Other forum members, if they're reading this, can talk about loads.

Fat Cat on right.

Ray

 

[b moulds]

thank you ray.
are there dimensional differences between the 243 wssm & the 25 wssm.
we are not trying to do anything fancy here, but my friend has a heap of 243 wssm brass, and a number of actions to suit, and wants a long range rifle in 6.5 mm.
regards,
bruce.

 

[Cheechako]

thank you ray.
are there dimensional differences between the 243 wssm & the 25 wssm.
we are not trying to do anything fancy here, but my friend has a heap of 243 wssm brass, and a number of actions to suit, and wants a long range rifle in 6.5 mm.
regards,
bruce.

No differences, except for bullet diameter, as far as I know.

My point was not to discourage you from doing what you are doing. It was that many of your questions had already been worked out in the Fat Cat et al and there was no sense in re-inventing the wheel. Dave Kiff probably has reamer prints that you should get. Also, I would suggest that you contact the shooters who used the Fat Cat. I don't want to bad mouth the cartridge but it didn't exactly turn out to be a sure fire winner, as I recall. One guy who used it was tillroot1. Ask him.

Ray

 

[Doug Rumbaugh]

I have a 6.5 WSSM Imp (40 degree shoulder) .292 neck that I played around with. I shot 140 Bergers and had two loads one a full case of N165 (around 50 grains) yielding 3050 fps and another with around 48 grains of H4350 yielding 2850 fps. The ES of the H4350 was very impressive but I got lower velocities. The N165 gave very tiny groups at 100 yards but much higher velocity ES. The H4350 accuracy was only like .75" groups at 100 yards. At 1000 yards, the H4350 load did best and I was able to win a 1000 yard match with it a few years ago.

I did have a problem with the case turning 180 degrees in the action without ejecting in my 7.5" BAT. If you are interested, I have the 30" Williamsport Light Gun Contour barrel chambered for a BAT with 800 rounds down the tube, a set of custom dies made with a resize reamer to match the chamber reamer. I also have 100 fire formed cases that were neck turned and fired just once. I had these in the classifieds in the past but never sold them.