I use that, as well…
Only thing that sucks is that you can’t use it on blowback guns, like 9mm. Those… I just go easy when I work on them.
I did have a Spikes upper with Adams Arms piston/barrel that broke the index pin that fixed the extension/barrel. Locked in the Magpul block, and barrel spun to about 1:00. Spike’s was zero help… CS asked for info/pictures, got COVID, then forgot about the situation (even though the email thread was present).
Contacted Adams Arms, and their CS was awesome. Representative didn’t work at Adams Arms when the barrel was offered (stainless 1:8”), but was professional and said they will check and see if it is a warranty issue. Got it back a week or so later, with a new production 1:7” barrel installed.
Recommend the block, but if there is a bad job with the extension pin… going to break it either way.
As does the bolt carrier with the Magpul block… in addition to the front pivot pin loop.
Even if that is the case… the pin/extension/upper were all secured during my example. The barrel, itself, spun… no tool/block/rod is going to stop it if there is an issue there (index pin that goes thru the extension to pin the barrel).
That is not saying brand X block or rod won’t do the job. You really can screw up an upper just by muscling the muzzle device. But it didn’t make my barrel break where a reaction rod would have kept it from failing.
I considered the Magpul unit, but I might not be tracking on how it would stabilize the upper? Would it be because the carrier key is up in the charging handle slot?
Not trying to argue, but my understanding was that your barrel broke the pin holding the barrel extension to the barrel?
Part of the reason I splurged (I bought the Midwest Industries) is because I liked the way that the upper is held by the fin, and the barrel (barrel extension, more accurately) is held by the lugs on the rod. So the friction of turning the barrel nut against the barrel extension is working directly against the rod in the vice. And the friction of the threads is working against the fin up in the charging handle slot. The interface of the pin to the slot in the upper is isolated.
But I might not be understanding how the barrel broke.
ETA:
Were you working the barrel nut? On or off? or a muzzle device?
https://magpul.com/firearm-accessori...obal_color=118
I mean, should be a better visual than explanation… there is contact in the charging handle slot, in addition of the bolt carrier.
When that barrel spin occurred, I pulled the block and looked at the feed ramps… were lined up perfectly to the ones on the upper. That showed that the upper and extension were secured. I rotated the barrel back to 12:00 (popped right back), and started down the road of contacting Spikes for their crappy CS… getting fed up, and luckily being taken care of by Adams Arms.
And it was the muzzle device… coming off. It has a torque value of 35 foot/pounds. Thought it was funny how I torqued it once, and occurred on the removal when I got shims to time it.
And not taking it as arguing… just giving my experience with a situation that using the right tools still gave a crappy outcome.
It’s good to have receiver blocks and there are several to choose from. While you’re making up your mind, get a couple of blocks of wood, say four to six inches long cut from a two by four. Cut a V groove in both. Use them to clamp your barrel between the gas block and muzzle in a vise. Use a rag for padding, if you like.
Or, if the AR has a front sight block, use the wood to clamp the barrel there.
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That barrel spinning is weird. Harrison Beene, the owner of AR-15 Performance, has described how barrel extensions are normally hydraulically torqued. Said he's attempted to remove them with all sorts of equipment and failed. Your experience was definitely an outlier and something that shouldn't have happened.
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Not another dime.
I have numerous vise blocks, including the magpul. However for changing a MD, I use the midwest industries reaction rod. I think it is better than the G rod.
https://www.midwestindustriesinc.com...d-p/mi-urr.htm
Hence, I second the above folks who recommend this device.
Cheers, Steve