Help with varmint upper build

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TEXAS222
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.204 Ruger Guns: custom build AR 15-Rem 700 .204 VARMINT- .204 Kimber Pro Var
Location: Southeast Texas

Help with varmint upper build

Post by TEXAS222 »

Hello. I'm building a .204 Ruger AR with a 24" White Oak varmint barrel, 15" Seekins SP3R V3 hand guard, and a Syrac lo profile adjustable gas block. My question is about the clearance of the gas block inside the hand guard. The top & sides are fine but the clearance on the bottom between the block & hand guard is about the thickness of a business card, I can slide a card between them. Is this enough clearance or should I try a different type gas block? Any opinions would be welcome. Thanks & have a good safe day. JD
surefire
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.204 Ruger Guns: AR-15 in 204 Ruger, CZ527
Location: Out West

Re: Help with varmint upper build

Post by surefire »

I'm not an expert on this but I think that is sufficient clearance for a free-float barrel. I base this on the test commonly used to verify a free-float barrel on a bolt rifle which is to slide a dollar bill under the barrel and down the handguard. My own varmit AR 204 is shown in the AR thread. I will tell you my bottom low block clearance is less than yours but it seems to fire and group fine.
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TEXAS222
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Posts: 291
Joined: Sun Oct 19, 2014 8:09 pm
.204 Ruger Guns: custom build AR 15-Rem 700 .204 VARMINT- .204 Kimber Pro Var
Location: Southeast Texas

Re: Help with varmint upper build

Post by TEXAS222 »

Thanks surefire, I thought the same thing but was uncertain. I went and looked at your build, very nice! My 1st build is much like it with Black Rain upper & lower & same trigger & barrel but have not had time lately for shooting. Have you found any good loads for it yet? Thanks and have a great safe day. JD
surefire
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.204 Ruger Guns: AR-15 in 204 Ruger, CZ527
Location: Out West

Re: Help with varmint upper build

Post by surefire »

TEJAS JD--BTW, I have a JD too but I'm sure mine goes back a ways (1969!). Anyway, I just took that rifle to the range today to re-sight it in after I removed the barrel to get it threaded for my suppressor. I was shooting factory Hornady 40 gr Vmaxes which I shot before. They fit my metal AR mags just fine, cycle great, and the rifle seems to like them. Put on my Surefire suppressor after I got it zeroed and re zeroed it. But my session was not a complete success. I had hand loaded some 39 and 36 gr SBKs and was anxious to try them. My OAL was the same as that of the Hornadys to fit the magazine which they did. Unfortunately, the first load I tried managed to chamber (but maybe not fully) enough that I could pull the trigger but would not fire when I pulled the trigger. I could not eject the cartridge until I took off my QD scope which allowed me to forcibly pull on the CH and eject the cartridge. Upon inspection, the BR4 primer showed a very light strike that was hardly visible. I tried a 32 gr SBK with the same result. Not sure what is wrong. I think my necks are not correct. So back to the drawing board. I'm not finding much help here on reloading the 204 Ruger for the AR. I just bought some 40 gr Vmax bullets and think I'll try to reload those to the same specs as factory ( except for the powder which I don't know). I'm using RL10x.
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TEXAS222
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Posts: 291
Joined: Sun Oct 19, 2014 8:09 pm
.204 Ruger Guns: custom build AR 15-Rem 700 .204 VARMINT- .204 Kimber Pro Var
Location: Southeast Texas

Re: Help with varmint upper build

Post by TEXAS222 »

Hi surefire, your right about not getting a lot of help on the AR forum. I had a similar experience as you with a custom .223 built just like my 204 above. WOA chambers their own barrels with short throats for optimum performance with AR magazine length ammo. Well, I loaded some 52 grain bullets that I had used in other AR's & when I loaded one in this gun I noticed it did not close all the way so I didn't pull the trigger. I had to pull hard on the charging handle but finally got it out. On inspection I could see where the bullet had jammed in the lands just above the case mouth. When I checked that bullet with my comparator I found out I wouldn't be able to use this bullet in this gun, it would have to be seated way to deep because of the particular ogive of this bullet. Hope you have good luck figuring yours out. Jim D
surefire
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.204 Ruger Guns: AR-15 in 204 Ruger, CZ527
Location: Out West

Re: Help with varmint upper build

Post by surefire »

My thought on this is that I didn't use the full-case sizing die. I have never reloaded rifle before (I shoot a lot of birds) and I had someone help me using my 3-piece Redding die set, my powder, bullets and primers in his press. I think he may have picked the wrong one from the set and we didn't do a full case resize. In trying to research this, I saw a YouTube video on neck resizing where the guy said don't use the partial neck sizing technique on ARs and other similar type rifles since it leaves the case expanded too much. The symptoms he described are exactly what happened to me. Anyway, I am going to rework those when I get my own press. I think I'll start fresh with the shells from Sunday's shoot. But right now all I have is several Mech 600 Jrs for shotgun shell reloading. I'm thinking of getting a Redding T-7 progressive but may go with something simpler.
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TEXAS222
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Posts: 291
Joined: Sun Oct 19, 2014 8:09 pm
.204 Ruger Guns: custom build AR 15-Rem 700 .204 VARMINT- .204 Kimber Pro Var
Location: Southeast Texas

Re: Help with varmint upper build

Post by TEXAS222 »

SURFIRE, your probably correct. I neck size only pushing the shoulder back .002-.003 for my bolt guns but my AR's always get a full length resize with Forster FL sizing die. By the way this JD (1952). Have a nice safe day. JD
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