Bullet Weight

[deadelk]

I have a S&W M&P that I have using 55 grain jacketed bullets with 26 grains of H414. I have turned the necks and I am full length resizing. I have not been impressed with the accuracy of this rifle. I am shooting iron sights. I have changed out the stock trigger with a Jard 4lb. adjustable. I have a free float tube coming in. My question is, can I expect more accuracy with a heavier or lighter bullet? Thanks.

[markm]

What kind of accuracy are you getting? What kind of accuracy are you striving for? What kind of bullet are you using?

Many of us here have had great luck with Hornaday 55 gr FMJBT W/C bulk bullets.

[rat31465]

[QUOTE=deadelk;276301]I have a S&W M&P that I have using 55 grain jacketed bullets with 26 grains of H414. I have turned the necks and I am full length resizing.

deadelk,
Years ago I used to shoot an old .220 Swift and came upon a Pet Loads book listing a charge of H414 powder as an accuracy load. The same book also held a warning concerning Hard Powder Fouling when using the H414 powders.
I experienced this first hand with the Swift and thought it would make for difficulty in cleaning such residue from a gas operated mechanism.

Am curious if you have experienced any such issues yourself?

[deadelk]

You know, actually I have been thinking the carbon fouling has been excessive. I think I'll start a load using H335 and see if there is a difference. Thanks for the headsup on the 414.

[Damascus]

I've posted several posts here talking about how unbelievably accurate my M&P15T is - I'm not sure if all 15T's are as accurate as mine, or if I just got a lucky fluke. Mine averages 0.61 MOA using my pet load.
I have tried most everything in my rifle, and have gotten the best results using the 69gr. Sierra Matchking. The lightest I've tried is 55gr. M193's, 55gr. Sierra Blitzkings. The heaviest I've used it 75gr. Hornady TAP FPD (75gr. Hornady HPBT). The 55gr. rounds shoot worse than the 75's do in my rifle.
Here's about what I get with these loads, remembering them off the top of my head:
WWB M193 - 1.20 MOA
Handload 55gr. SBK - 1.05 MOA
Handload 60gr. Nosler Partition - 0.95 MOA
Lake City M855 62gr. - 0.95 MOA
Win PowerPoint 64gr. SP - 0.99 MOA
Handload 65r. Sierra Gameking SBT - 0.75 MOA
Handload 68gr. Hornady HPBT - 0.74 MOA
Handload 69gr. SMK - 0.61 MOA
Handload 70gr. Barnes TSX - 0.73 MOA
Hornady TAP FPD 75gr. HPBT - 0.90 MOA

These results are the average of ten 5 shot groups @ 100 yards, rifle clamped into a Caldwell Leadsled shooting rest, using a Nikon 4-16x42 scope. Rifle is a stock 15T, w/ Magpul CRT stock, G27 grip, 4lb. JP "tactical" FCG springs w/ self polished trigger/sear contact surfaces. All handloads use CCI Small Rifle Magnum primers, and either RL-15, TAC, or Varget powders, and Winchester brass. Always loaded to a max mag length of 2.264" (I only use Pmags).
You should see some improvement when you get that free float handguard. Also, when you are testing for accuracy, are you eliminating all possible shooter error? No wind? A quality, high powered optic, rifle in a rock-solid rest?