Getting ready to rebarrel a 243. Would like to shoot 95gr bullets up to maybe some 115. My Gunsmith has a sammi reamer. Trying to decide if I would be better off to rent a 243 match reamer or go with the sammi reamer. Thanks for any help.
.243 what reamer
- Thread starter Mt.Boy
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Danny1788
Well-Known Member
If you want to shoot 95gr and up bullets, use a reamer with atleast .110" FB
Bob Wright
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I've had 2 match reamer jobs that I learned from after reloading for them. I do have to turn necks on the brass and the free bore was very short. So, something to think about if you don't like turning necks and running longer bullets. The barrel twist could come into play as well.
So does the match chamber have less freebore then the sammi chamber
shortgrass
Well-Known Member
You would have to compare prints to know. "Match" usually means smaller diameters, but it can also mean a longer or shorter throat, or a different than SAAMI throat, or a longer or shorter freebore. "Match" simply means 'not to SAAMI specs'. You can find SAAMI reamer/chamber prints at www.saami.org
Bob Wright
Well-Known Member
Free bore will meet SAAMI usually, but those specs were written when lighter bullets were common. Anything over 100 grain, may be problematic.
My 280AI and 7RM were also SAAMI free bore and inadequate for longer high BC bullets. I have to seat well below neck shoulder for adequate jump.
It's a good time to talk to your Smith and maybe seat a dummy round with your preffered bullet.
My 280AI and 7RM were also SAAMI free bore and inadequate for longer high BC bullets. I have to seat well below neck shoulder for adequate jump.
It's a good time to talk to your Smith and maybe seat a dummy round with your preffered bullet.
Thanks.
Zero. It (SAAMI 243) does have a 30° transition angle from neck to throat so it has near double the length that a more typical 45° angle would provide. In the .243 the 30° transition is ~.012" longer than it would be if it were 45°. Keep that in mind when comparing to someone else's reamer that may use 45°.
Capt RB
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Have a reamer made for what you want to do. If you are going to shoot 1 brand of brass exclusively and like a particular bullet make a dummy round and send it to Manson or JGS or even PTG. You can turn necks or make it so it will shoot factory ammo or improved or whatever.
SAAMI .243 Winchester has a .177" freebore.
I had a reamer made by JGS for Peterson brass and Berger 105-109s. I went with .130" freebore .244" freebore diameter and .275"-.276" no trim neck.
I've used the SAAMI chamber for 95 SST and was always able to get them to shoot really well.
I had a reamer made by JGS for Peterson brass and Berger 105-109s. I went with .130" freebore .244" freebore diameter and .275"-.276" no trim neck.
I've used the SAAMI chamber for 95 SST and was always able to get them to shoot really well.
.177 That's a lot
sierracharlie338
Well-Known Member
Not really in the grand scheme of things. Freebore of .200-.250 is common in some cartridges. I believe it was mentioned, but the SAMMI chamber will shoot anything up to 100grainers very well. If you are wanting to jump into the heavies like 108,109, or 115s call your preferred gunsmith and see what he recommends. Or you can solicit some advice here for smiths that guys have used for a 243 build with heavies in mind. Fwiw my 243 I had built I used a SAMMI reamer with 105 Amaxs and got very acceptable performance (2950fps).
jasent
Well-Known Member
Depends what mag size you run. The 115's are long and end up seated pretty deep in standard sa mags
