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Posted: 1/24/2009 10:14:40 AM EST
New here with a S&W MP 15. Can some one point me in the right direction on bullet weight verse Barrel twist. Trying to decide which one works best in a 1/8 twist. A 55 grain or 70 grain bullet. I have searched the forum and can not find the info. I believe a smaller grain tumbles more  but I am not sure. Thanks
Link Posted: 1/24/2009 10:17:20 AM EST
62 thru 70
Link Posted: 1/24/2009 7:47:18 PM EST
Quoted:
New here with a S&W MP 15. Can some one point me in the right direction on bullet weight verse Barrel twist. Trying to decide which one works best in a 1/8 twist. A 55 grain or 70 grain bullet. I have searched the forum and can not find the info. I believe a smaller grain tumbles more  but I am not sure. Thanks


1/8 will get you 77 grain bullets no problem... it's the length of the round and velocity  not the weight that determines twist..
1/7 twist was called for to stabalize traces. and is overkill for many match rounds.
If your Smith is the one with a stainless barel it will outshoot many premium rigs I know where they get the barrels and they are high quality.
Link Posted: 1/25/2009 5:44:23 AM EST
Quoted:... I believe a smaller grain tumbles more  but I am not sure.



The 55 gr will pretty much explode and fragment on impact with anything.  This is why its a bad choice for shooting through barriers and such.  The current rule of thumb is "heavier is better".

Further Reading on Ammo Choices

I myself like the 62gr Speer Gold Dot.

Link Posted: 1/25/2009 12:53:55 PM EST
Thanks guys. Right now have been stocking up on some hotshot and wolf 70 grain. I really appreciate you help. Still new here and try to listen to wisdom of the guys who know. Take care.
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