While testing a BCM 14.5 carbine upper I had a bit of a surprise. I was trying to set up the carbine’s buffer/spring combination to reliably run .223 pressure ammo. I figured if it would run with that crummy 55gr Wolf it will run with anything. So, I found a combo that would reliably lock the bolt back on the Wolf and figured I was done. Just for grins I decided to test some 75gr .223 pressure Hornady ammo. This is the pretty common TAP defense load I have a good bit of. Surprise, the gun was now no longer locking back the bolt. Back to the drawing board… While Hornady is no doubt better quality in every way than the Wolf, the pressure curves must be different and so the carbine is now under gassed. The real lesson of course is: don’t assume, test any load you might use.
Wolf is also much more accurate than my reloads.
It’s a bit depressing, actually.
It could also be not locking back because the bolt speed is too fast
My new S&W M&P15TS has a 14.5" barrel, carbine length gas system and pined Vortex. It runs with all ammo I’ve tried in it, including .223… Is there any info I can get off it for you that would assist in setting up your gun?
Just wanted to offer. Not sure what I could provide that would be useful.
Jason
Wolf ammo varies quite a bit lot to lot.
I thought the m&p15ts was a middie…?? Maybe me wrong.
That’s what the photo showed on their site. But on arrival that was not the case. They must of rethought the plan after looking at retooling for those specific rifles. I got two from two different production runs that they are both carbine length. The barrel length is also a little different from the photo on their site, based on the length of the barrel vs the end of the Troy rail.
All in all, it’s still a sweet deal at less than $1100 into my hands after the rebate.
Sorry about the hijack, just thought I’d answer the question.
What in the world is your reload recipe? Something doesnt sound right.
I am just saying it could be a weird pressure curve with hornady practice ammo. It is not unheard of factory ammo to have a spiky pressure curve. [radway any one] Your chamber could also be playing a roll in this as well.
I have read that the hornady practice ammo is loaded less hot than most other rounds. Figures, for the price right?
This ammo was not the practice ammo. It is the Hornady TAP defense load, just the .223 version rather than 5.56. Top shelf stuff in every way. The only point I was really trying to make is to not make assumptions and always test every load you might use for function in the carbine. So now, I run an H buffer rather than an H2, problem solved for me.
What bullets are you using? Get some of the Hornady FMJBT W/C. Those bullets are hard to make shoot bad.
Perhaps a new bullet seating die? Have someone check your bullet runout.
I have a lesson scheduled with a friend of mine who loads fantastic ammo. He has a sexy AR that will do 1/2 MOA groups with his handloads so I am confident that I will solve the mystery.
OP I thought you were going to say being able to use a magnet after a carbine class to police up your cases;)
I’d say its a matter of pressure curve, and point well taken about testing with the loads you want to run…