Smith & Wesson M&P-10

[Trotter]

Thx. I think I have a lead on some PMC at Alamo Ammo, hopefully that functions better than the Tula.

http://www.sgammo.com/product/pmc/20...onze-ammo-308b

[Jake'sDad]

I personally have had problems with surplus 7.62x51 in a number of AR308 rifles, including the AR10A, AR10C, SR25 EMC, LMT 308MWSE, and LaRue OBR. I think the surplus stuff is great in a FAL where you can dial up the gas or a roller-lock gun like the HK91, but probably not so great in an AR308 with a fixed gas system tuned to function correctly with decent modern ammo.

This has been my experience as well, in 4 different AR .308 rifles, (SR25, Colt 901, Armalite and S&W), at least with foreign surplus. Lake City or Olin Winchester 7.62 runs just fine.

[MistWolf]

A couple observations-

I took the trigger out of the lower to grease it up to smooth out the pull a bit. While testing the pull, it dawned on me that it's a two stage. Rough, compared to a G trigger but smoother than most standard AR triggers I've tried. The FCG has a nice smooth coating on all the surfaces and dabbing it with grease made it a bit smoother. Still a bit of grit on the travel, however. I'm giving serious thought to an SD-E. Life is too short to put up with gritty triggers.

I really like the idea of the ambidextrous controls, but the location of the ambi bolt release makes re-installing the hammer a pain. It catches on the coils of the hammer spring. I had to fight to get the hammer in and go back three generations for cuss words before I got it back in and pinned. It came out easily enough!

The RE isn't clocked clocked correctly. I noticed the heel of the stock is canted a bit towards the left of the rifle, almost to the 7 o'clock position. Minor, really and don't affect function but annoying enough to irritate my CDO

[30 cal slut]

i'm about to plop a Geissele SSA trigger group into mine.

according to the guys over at the S&W forum, they'll drop right in, but you have to pull the ambi bolt catch out first.

looking forward to shooting this rifle with an improved trigger and handloaded ammo. you can go to stupid lengths to make very accurate .308.

gonna try some fun stuff like fitting the COAL to the chamber and turning the necks on some brass, maybe run the bullets through a concentricity comparator.

[Little Creek]

i'm about to plop a Geissele SSA trigger group into mine.

according to the guys over at the S&W forum, they'll drop right in, but you have to pull the ambi bolt catch out first.

looking forward to shooting this rifle with an improved trigger and handloaded ammo. you can go to stupid lengths to make very accurate .308.

gonna try some fun stuff like fitting the COAL to the chamber and turning the necks on some brass, maybe run the bullets through a concentricity comparator.

I have only one SSA trigger in a DDM4V7lw. It is a very good thing. I suggest you maintain sufficient bullet push as you strive for accuracy. Neck turning the shell cases could reduce bullet push and result in bullets pushing into the shell case during feeding, increasing pressures, etc. Believe me you don't want to fire a 308 in your M&P10 with the bullet deep seated.

[MistWolf]

Neck turning the shell cases could reduce bullet push

You mean it could reduce neck tension. Deeper seating actually reduces pressure because it increases bullet jump. Decreased neck tension can reduce pressure as well unless the bullet slips forward. If a powder with good load density is used, it will limit how far back the bullet can be pushed. The usual problem with low neck tension in a self loading rifle isn't the bullet being pushed deeper into the case, it's sliding forward into the rifling. This is what causes the pressure to spike

[Little Creek]

You mean it could reduce neck tension. Deeper seating actually reduces pressure because it increases bullet jump. Decreased neck tension can reduce pressure as well unless the bullet slips forward. If a powder with good load density is used, it will limit how far back the bullet can be pushed. The usual problem with low neck tension in a self loading rifle isn't the bullet being pushed deeper into the case, it's sliding forward into the rifling. This is what causes the pressure to spike

I don't want to argue, but what you are saying fails to compute.

[MistWolf]

The reason it lowers pressure is because the bullet gets more of running start before it engages the rifling to overcome the friction. A bullet seated out to engage the rifling starts with zero momentum and the gasses have to push harder, reaching an even higher pressure before the bullet can start moving.

The pressure needed to push the bullet out of the neck of the case is actually very low. Peak pressure isn't achieved until the bullet engages the rifling. Keep in mind, this is all contingent on the neck and chamber dimensions being in spec. If the brass has thickened at the neck or the neck of the chamber cut too small, it will increase the pressure needed to push the bullet out of the case, possibly to dangerous levels

[MistWolf]

It's been a cold winter this year. Not as cold as last year, or as cold as it's been in other parts of the country, but cold enough. It's also been a season of unexpected bills eating away at any extra green I was hoping to find in my wallet. I've been trying to shake a few sheckles loose to build up my stash of ammo, but things like new tires for the Battlestar Victoria and repairs to the motorhome have sucked all that spare change out of the couch.

I've been threatening to rid myself of that dem barbell hanging the end of the M&P-10 and replace it with a BABC. Only problem is cost. The BABC is a bit on the expensive side for an underpaid wolf. There one on the Par FAL and it's performance has been nothing short of outstanding, so I've been reluctant to change it. Finally, I got sick and tired of looking at S&W's version of the Mosin bayonet, removed the BABC & the adaptor from the Para and installed it on the Big Smith. The Belgian Combo Device went back on the Para and the clunky S&W flash hider retired to the parts bin. Both rifles have been shortened signicantly. Along with a reduction in length, with the loss of the BABC, the Para has lost a noticeable amount of Cool Factor but sometimes, sacrifices have to be made.

The BABC shortened the Big Smith by at least an inch. It seems lighter too, although that might be my imagination. I didn't weigh the BABC, but the S&W flash suppressor weighed 4 ozs! Some think that's not much, but that's a good 1/4 lbs. On an 18" barrel, that's 4.5 in/lbs of moment! I'll try to get photos taken and posted soon.

I haven't had a chance to shoot the Big Smith with the BABC, but I hope to soon. I need to get out of the house before I drive my poor wife crazy. I can't wait to see how the Big Smith shoots with the BABC!

[hjmpanzr]

Picked up a 308. Let's go shoot something!