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300 AR specific bore guide
Posted: Sun Jun 07, 2015 1:39 am
by skered53
Has anyone made one ? I was asked to fab one a couple years ago, a guy even sent me some spent cartridges but I lost contact with him, my prototype used a steel tube with a very this wall where it entered the chamber, or at least that was the plan. I can't find the tube or the 4 empty cases. Not sure anyone wants a steel tube entering their chamber for a snug fit. When my upper arrives, I figure I would make me a guide that doesn't enter the chamber but butts up against it, yes there will be no liquid seal, but I'm just a clp kinda guy so I'm not worried about what might dribble onto my barrel extension. Like my MP5 and 9mm AR guides it will have to be held in the receiver via a plastic bolt or easier a rubber band.
Anyhow, I Googled 300 blackout bore guide and didn't find any, so I checked here.
Re: 300 AR specific bore guide
Posted: Sun Jun 07, 2015 3:25 am
by danner
Re: 300 AR specific bore guide
Posted: Sun Jun 07, 2015 6:45 am
by Badfinger
I use Mike Lucas bore guides, they're expensive but the best I have found. They're custom made from aluminum and have an "O" ring to hold them tightly on the chamber and he'll need to know what caliber, cleaning rod size, and type of rifle, you’ll be using. I use his two piece guide with insert and was $65.50 with shipping.
Here's his contact info:
[email protected]
Re: 300 AR specific bore guide
Posted: Sun Jun 07, 2015 10:16 am
by skered53
The link to Brownell's shows my very 1st guide for a 5.56 AR , I got one back in 2000, but have since made my own. Also the .308 AR guide has to be bigger as the bolt carrier is much larger....This started when I got a HK clone ( Vector93) and built a HK specific guide for 5.56. Then got request for HK .308 and HK 9mm, I then got request to make several different AR caliber guides, ( .308, 6.8, etc. ).
The Lucas is high end, but I don't think a 300 BO can be built with the O-ring, there just isn't that much meat / difference between the case base diameter and the bullet diameter.
Re: 300 AR specific bore guide
Posted: Sun Jun 07, 2015 11:44 am
by danner
skered53 wrote:The link to Brownell's shows my very 1st guide for a 5.56 AR
Don't know what your browser shows when you click the link but for me the very first item is one for the 300blk.
Re: 300 AR specific bore guide
Posted: Sun Jun 07, 2015 11:57 am
by skered53
I see that now, a close up shows a .30 caliber tube in a small receiver spacer and a brass bushing thing on the chamber end, looks like it might engage the barrel extension inside diameter, then the entire thing is kept in the receiver via the tension of the o-ring on the spacer. That O-ring might get nicked on the receiver ??.
Good, no need for me to make them
Re: 300 AR specific bore guide
Posted: Mon Jun 08, 2015 6:35 pm
by whiskey08
been wanting one forever, I ordered some delrin the other day, gonna turn it down on a lathe. Ill post dimensions when it done.
Re: 300 AR specific bore guide
Posted: Mon Jun 08, 2015 6:46 pm
by dellet
I have the Dewey works great, seals tight.
Product Description
Product Specifications
AR-15/M-16 300 AAC Blackout Breech Rod Guide
Made from Delrin, Brass and Anodized Aluminum
For Use with Any J. Dewey Cleaning Rods
The combination of limited chamber space and the large tube inside diameter needed for brush clearance eliminates the possibility of any type of chamber sealing o-ring. We have incorporated a front brass bushing, which centers the guide in the barrel extension and butts up against the chamber opening. The large o-ring on the back end locks into the bolt opening at the rear of the receiver to reduce longitudinal movement of the guide during the cleaning process.Instructions: Keep a very light coating of non-solvent gun oil on the o-ring. Push the guide, brass end first, into and through the center of the barrel extension. At the same time, a slight twist the black delrin will ease the o-ring into the bolt opening. Twist until the guide bottoms out. To remove the guide, reverse the twist while slowly removing the guide. Thank you for selecting Dewey Products – Made in the USA by a Veteran Owned Company.
http://deweyrods.com/product/ar-15-300- ... -rod-guide
Re: 300 AR specific bore guide
Posted: Mon Jun 08, 2015 8:28 pm
by maxl
I have one 100% delrin from possum hollow if I can recall, had it a few years now and it works perfectly. It's got an o ring seal and was around 30 bucks.
Re: 300 AR specific bore guide
Posted: Thu Jun 11, 2015 9:07 pm
by skered53
o-ring in the chamber ?? or on the delrin spacer sized to the receiver ??