Suffolk Rifle shortened MP15-22 with/without over-barrel mod

[AR15]

BTW, nice video, but the action is not the same as with rim fire rifles, as you surely know the bolt doesn't move anything like the distance that the full-bore one does and the shape of the bolt is totally different.

So are you saying that with a rimfire action it is possible to release the hammer before the bolt is fully in battery...? Because it seems like that's what you're saying...

Well, I think the theory is to add rigidity rather than attempting to free-float the barrel. There's an argument that if this didn't work better on the MP15-22 than free-floating, then S&W wouldn't have added the hand-guard cap in the first place.

I don't know what best approach or company is - that's why I started the thread :-)

Just so you know that adding rigidity to a barrel with a handguard will only cause more flexing when the firearm is loaded or pushed against something, like a bipod or a shooting bag. All the force you exert in bracing the rifle will be pushed directly into the barrel and cause it to move. This is usually considered a bad thing. That's why barrels are free floated.
The Barrel, Handguard and Upper will flex and the point of impact will move as the scope is no longer lined up. This will become more and more obvious as the range increases.
The M&P handguard endcap is a crap idea as it contacts the barrel and needs throwing in the bin, technically the rifle would be more accurate without it.
Your results will largely depend on how much pressure you apply to the handguard in the first place however. So for some shooters who gently rest the rifle they may not notice an improvement, others who are used to bracing etc will see a difference.

[nickb834]

So are you saying that with a rimfire action it is possible to release the hammer before the bolt is fully in battery...? Because it seems like that's what you're saying...

Yes it can, on both the 22 and the rim fire versions of the AR. It is easy to demonstrate with a full-bore AR but I haven't tried it with a 22.
The hammer can release before the bolt is fully closed, in the 223 this will mean it won't fire, in the 22lr version it means it could fire the round. I have witness someone firing rapidly with a 22AR and the rounds were regularly going off before the bolt had full closed, there was a lot of flash and brass bits coming out of the eject port and still it reloaded OK.

It is the use of forward assist on a rim fire round that I wouldn't advise. If you are having trouble with the bolt closing on a rim fire and take a look to see why the rifle failed to fire, if the bolt is half way back then the round most likely is bent and should be discarded as a damaged - I would also not advise attempting to shoot a damaged round.

If the bolt has ridden up over the rim then forward assist will damage the round further.
If the bullet is still in the mag and the bolt has stopped on the rim I would not advise the forward assist in this instance as it could fire the round.
Similarly if the bolt is almost home and failed to fire then the hammer has fallen, forward assist now will not work, and, depending upon the cause of the round failing to fully chamber, it could go off if attempting to force it home.

Personally if a round fails to chamber I would try to find out why and in so doing the bolt is pulled back. If it is a failure to fire then as a shooter I would have already assumed the bolt to be fully home otherwise I wouldn't have tried to fire in the first place, then perform your drills and fire on.

As someone mentioned earlier, if on a timed stage and a round fails to fire, the quickest and most likely action to take to remedy the situation is to manually cycle the action watching to see if a round clears and a new one chambers, then continue with the CoF.
Otherwise you are likely to waste more time. If the round fails to fire as sometimes happens forward assist won't help, if the round failed to fully chamber and the hammer has fallen forward assist will not help, if you are out of rounds forward assist will not help. The only situation I can think of where a failure to fire that a forward assist may help is if the bolt has not moved forward enough so that the disconnecter still has the hammer. However manually cycling the bolt and checking that a round chambers will solve the problem every time.
(If the firing pin has broken or there is another mechanical malfunction, that is another issue altogether and the forward assist won't help.)

In all instances the manual cycle of the bolt and checking of the chamber/bolt configuration will solve the problem or show up an issue needing a closer inspection, forward assist may only help in the vast minority of the cases. If I was a numbers man and playing for score then I would not use the forward assist method but the manual/check method.

I advise anyone not to use the forward assist on a 22lr round - I have seen a rim fire round go off in just this situation.
Others may say it is OK.
You chose how you want to proceed.

That's interesting regards the hammer being released before the bolt is in battery - specfically why does it mean that a 22AR could fire when a 223 won't? I don't disbelieve you but I'd genuinely like to know why. I'd be inclined to think that's a faulty rifle (trigger mech) or where the bolt didn't travel far enough backwards such that the hammer didn't latch, or one where the disconnector has been over polished such that the trigger etc auto resets.

The bolt being almost home doesn't mean that the hammer is forward at all - I explained this to you earlier, and on that topic - what makes you think the bolt doesn't reciprocate as much as on a 223? I can assure at the very least on a CMMG or an upper using a CMMG / Ciener style bolt conversion kit (as in 22LR conversion for a full bore) that there's probably not much in it (caveted with I haven't actually measured it) as the bolt completely clears the full length ejection port (I removed the gas deflector on my upper for a standard full length 223 ejection port cover) there are witness marks all over my buffer as the bolt merrily makes contact when it cycles.

Don't forget my CMMG lower can be used on a full bore, it's dimensionally accurate and functions exactly the same way (Note I didn't say mil spec as I can't vouch for the anodising being as per spec) ergo - I have a dedicated 22 upper on a multi calibre lower. So as regards fire control - it's exactly as per a full bore - therefore it cycles the hammer, disconnector and resets the trigger AS PER it's full bore brethren.

I don't know why neither myself or AR15 can get you to understand that for us forward assists work and we're happy to continue doing so - we'd hardly be advocating it if the hammer was forward would we - it'd be a waste of time and the action would have to be racked and said forward assisted round ejected - that's clearly not the case is it?

With regards the quickest action on a COF to eject the round - I think that's arguable either way as to whether my forward assist (if safe and appropriate) vs eject the round is the quickest, but what can't be argued is - my way you don't lose that round, that could be a match lost right there (although of course I never want to finish a match empty but you know how it goes sometimes).

I'm going to continue to disagree with you as regards a blanket NO to forward assists for reasons that both myself an AR15 have given, there are times when it is ok and times when it isn't, yes I too have seen instances where a round has gone off out of battery (not my rifle and not an AR at that).

I would gladly kill this debate off if you simply acknowledged that there are times when it is OK to forward assist as I have acknowledged that there are times that it isn't! Go on - it's christmas, push the boat out, good will to all men and that razz

[safetyfirst]

Cmmg make great rifles and terrible magazines, my CMMG is the most reliable .22 semi I've ever owned or seen in fact. They've had their issues but the newer ones you can buy now have solved them for the most part so I'm told. Lanner tactical used to fettle the earlier ones by reinforcing a weak join on the bolt assembly amongst other things, but I've got one of the early ones from Suffolk rifle and soon as I ditched the Cmmg mags it became a completely different rifle. I must be 15,000 rounds into this rifle now.

I see a lot of semi .22's in my travels and therefore a lot of stoppages and jams, I'd say a .22 AR is easily amongst the more reliable of options. The 15/22's included.

[nickb834]

Agreed - although black dog mags were by no means much better, it wasn't till I switched to Lantac's own mags that I got the reliability I was looking for.

To be fair, I don't clean mine as much as I should - I know when it's time as my gun tells me, as in I find I need to use the forward assit perhaps 1 in 200 rounds as opposed to ooooh 1 in 3000 rounds.

I think I'm only in for about 7000 rounds though so it's barely done any work.

[AR15]

The problem with CMMG was consistency.
Some rifles were very good and other just plain bad. Receiver dimensions would vary from gun to gun depending on who had supplied the uppers and lowers at the time. Some of the magwells were quite tight.
The mags were always crap, from the hilarious expanding follower design that just jammed inside the core to the next one with a metal feed tower and a follower that didn't fit property, you would think that it might be 3rd time lucky but they messed up the last one they did too. Now back to grey mags I see.
They went from 2 welds to 1 on the rear of the action plate in order to save money, that resulted in broken rear tabs, we re welded them with 3 welds and they never failed.
I got sick and tired of wiping the arse of a company that didn't seem to care.
Add to that a plethora of dealers who started importing them and selling them without even opening the box and you had a situation I didn't want to be part of any longer.

Our mags work well and will hold open with the CMMG BHOA but do remember that the BHOA is made by CMMG and usually needs a bit of fettling.

[nickb834]

The problem with CMMG was consistency.
Some rifles were very good and other just plain bad. Receiver dimensions would vary from gun to gun depending on who had supplied the uppers and lowers at the time. Some of the magwells were quite tight.
The mags were always crap, from the hilarious expanding follower design that just jammed inside the core to the next one with a metal feed tower and a follower that didn't fit property, you would think that it might be 3rd time lucky but they messed up the last one they did too. Now back to grey mags I see.
They went from 2 welds to 1 on the rear of the action plate in order to save money, that resulted in broken rear tabs, we re welded them with 3 welds and they never failed.
I got sick and tired of wiping the arse of a company that didn't seem to care.
Add to that a plethora of dealers who started importing them and selling them without even opening the box and you had a situation I didn't want to be part of any longer.

Our mags work well and will hold open with the CMMG BHOA but do remember that the BHOA is made by CMMG and usually needs a bit of fettling.

Haha yep - the CMMG gen 3 mags were so stiff that after cutting 6 turns out the spring I still couldn't feed even 1 round!

[AR15]

So are you saying that with a rimfire action it is possible to release the hammer before the bolt is fully in battery...? Because it seems like that's what you're saying...

Yes it can, on both the 223 and the rim fire versions of the AR. It is easy to demonstrate with a full-bore AR but I haven't tried it with a 22.

How are you going to demonstrate this on a full bore AR, I presume your are talking semi auto fire?
If not then obviously its a case of just pulling the trigger as you let go of the bolt on a Straight Pull or Semi with the bolt locked back and means nothing. Its some sort of bizarre firing technique that nobody uses.

On a semi auto 223, if you stack up the time required for your brain to tell your finger to move to reset the trigger, for the trigger and disconnector to start to rotate, for the disconnector to slip from the secondary to the primary sear, then for your brain to register such change and for it to now instruct your finger to start to pull said trigger back in the opposite direction, for the trigger to move and the sears to disengage, then for the hammer to start to accelerate and finally hit the carrier all the while the bolt is pretty much moving into battery you will have to be hyper quick.
Jerry Miculek quick. I don't think he can do it.
That's also with a custom trigger not a USGI standard setup that has quite long sear engagement and is thus a lot slower.
Or are you talking about a full auto sear trip by the carrier?

Lets say you did get the release just right, you are going to get a Hammer Follow or Hammer Follow Down scenario that very much CAN cause the full bore rifle to fire or slam fire, IN FACT IT CAN RUN FULL AUTO, as the hammer is pushing the firing pin from the rear and thus there is firing pin protrusion as the bolt goes into battery.
So what if its not OOB its still a very dangerous situation.
If the disconnector is worn, damaged or removed this can and will happen. This is a recognised Malfunction.


Notched hammers and un-shrouded firing pin carriers have been designed to solve these problems but are by no means fitted to every AR at all, in fact the majority dont have them. They also have their own problems relating to firing pin and retaining pin damage etc...


The rimfire round has to be supported from the back side of the rim in order for the firing pin to hit the rim with enough force to set the primer off reliably. Or there has to be enough resistance on the entire round so that it cannot move when struck by the firing pin.
It is entirely possible (but not recommended) for you to tap the round into the chamber by smacking it with the firing pin and hammer repeatedly. Its very unlikely to go off because a huge chunk of the energy required to fire it is being lost in its forward movement. Only when it meets enough resistance will the pin force be substantial enough to set the primer off.
I have fitted 100's of Geissele triggers to CMMGs and they all did the same thing, light strike due to the fact that the CMMG design has the case rim touch the feedramp and hold slightly out of battery. What you get (until you reshape the feedramp) is a deformed case rim that has been punched forwards through the gap, towards the breech face, but not gone off due to running out of pin/ hammer energy and resistance.

You are only ever going to use the forward assist when the hammer is cocked. The firing pin is held back by a spring on the CMMG's so with no force from the hammer its retracted, inside the bolt.
You are using the bolt face, a large surface area, to push the round home. So I have absolutely no idea what you think is going to set it off by doing this.
Based on your assumptions a round should go off every time the bolt hits one to strip it off a mag!

Watching a gun repeatedly fire OOB but reload means some fundamental problems existed. I would hazard a guess that the chamber was properly messed up. So that enough resistance was present for the pin to dump energy into the rim with the round proud of the chamber.
I would also suggest that some sort of squib even was possibly occurring that increased back pressure, allowing the reloading stroke to be long enough to continue function.
The shooter could just as easily have stopped and used the forward assist to ascertain how much resistance there was to the second round going home (after the OOB) and also confirm the bolt was fully closed.
Seeing that there was a fundamental problem he would then have stopped firing sooner.

All of this OOB stuff has noting to do with a properly used forward assist anyway.


Now this is me 'Over and Out' as I have much more important things to be doing with my time, like making my new scope mount. Watch out for a tie in with a large US optics manufacturer very soon.