2017 Mayberry Semi-Auto Rifle Championships

steveinmd · Jan 29, 2017

Thank you shooters for coming out to the match. You were a great group of guys, not a problem was had all day. Congratulations Greg, you are now the official Intergalactic World Champion of the Universe.

Greg B.
Brian S. (by the slimmest of margins over third)
Bill S.
Steve B.
Bob K.
Brandon D.
Ling X.
Dave M.
Anthony C.
Richard P.
Elliott R. dnf
John W. dnf
John M. dnf

Thanks again and good shooting all. See you at the next match.

Steve B.

Grumpy41 · Jan 29, 2017

Great match today Steve. This format was awesome and layout avoided any confusion. Hopefully your team finds the time for another this year. Again thanks to all that made this possible.

300blkprs · Jan 30, 2017

had a lot of fun, next time I wont use a finicky cartridge

41maghunter · Jan 30, 2017

Steve,
Great shoot. Good course of fire. Next time we need a few more ROs. I can't run like I used to. Legs are hurtin' today.
Bob

DZ · Feb 5, 2017

300blkprs said:
had a lot of fun, next time I wont use a finicky cartridge

What cartridge? 300BLK? What were the issues and what was your set up?

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300blkprs · Feb 6, 2017

DZ said:
What cartridge? 300BLK? What were the issues and what was your set up?

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I had a bunch of hot h110 125gr sst loads which work flawlessly in my upper, but I ended up having issues with my last mag filled with factory loaded "PNW Arms" 147gr ammo which was wayyyy to lightly loaded and were unable to cycle the bolt fully creating double feeds. Not to mention holdovers with the 300 blk were ridiculous for 300m, looking back I should have just bought some 556 for this match.

TL/DR: stay away from pnw arms 300blk ammo

DZ · Feb 7, 2017

300blkprs said:
I had a bunch of hot h110 125gr sst loads which work flawlessly in my upper, but I ended up having issues with my last mag filled with factory loaded "PNW Arms" 147gr ammo which was wayyyy to lightly loaded and were unable to cycle the bolt fully creating double feeds. Not to mention holdovers with the 300 blk were ridiculous for 300m, looking back I should have just bought some 556 for this match.

TL/DR: stay away from pnw arms 300blk ammo

Gotcha. I would agree that a faster cartridge is best for this match. I typically shoot that match with a 14.5 and an Aimpoint ML3.

I am putting together a couple 300BLK guns, so I was curious about the issues you had.

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300blkprs · Feb 8, 2017

DZ said:
Gotcha. I would agree that a faster cartridge is best for this match. I typically shoot that match with a 14.5 and an Aimpoint ML3.

I am putting together a couple 300BLK guns, so I was curious about the issues you had.

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make sure you use pistol length gas system if you want to run heavier bullets and subs. hot loaded 110's and 125-130's are perfect as long as they have a secant ogive (125 sst w cannelure, speer 125 tnt, etc)

DZ · Feb 8, 2017

300blkprs said:
make sure you use pistol length gas system if you want to run heavier bullets and subs. hot loaded 110's and 125-130's are perfect as long as they have a secant ogive (125 sst w cannelure, speer 125 tnt, etc)

Wouldn't gas system length be dependent on barrel length(ETA: and gas port and buffer weight and action spring stiffness...)?

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300blkprs · Feb 8, 2017

DZ said:
Wouldn't gas system length be dependent on barrel length?

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normally on an AR, yes, but not on the 300. Since case capacity is very low in them and most loads use pistol powder they need the shorter gas systems to work best. 300BO doesn't gain much advantage (velocity) from barrels over 10" due to the design of the round. 16" with adjustable pistol gas system is ideal for non NFA use.

If I were to go back to when I was building mine, I would have built a 10" pistol and submitted SBR paperwork since 16" really is too long of a barrel for the round.

DZ · Feb 8, 2017

300blkprs said:
normally on an AR, yes, but not on the 300. Since case capacity is very low in them and most loads use pistol powder they need the shorter gas systems to work best. 300BO doesn't gain much advantage (velocity) from barrels over 10" due to the design of the round. 16" with adjustable pistol gas system is ideal for non NFA use.

If I were to go back to when I was building mine, I would have built a 10" pistol and submitted SBR paperwork since 16" really is too long of a barrel for the round.

Interesting. I suppose it makes sense since pistol powders are fast burning.
BCM seems to be one of the few that uses a carbine length gas system on their 16" bbl. They call for a carbine buffer for subsonic and H3 for supersonic loads. Perhaps a carbine buffer and adjustable gas block would be the ticket for that barrel.

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300blkprs · Feb 8, 2017

DZ said:
Interesting. I suppose it makes sense since pistol powders are fast burning.
BCM seems to be one of the few that uses a carbine length gas system on their 16" bbl. They call for a carbine buffer for subsonic and H3 for supersonic loads. Perhaps a carbine buffer and adjustable gas block would be the ticket for that barrel.

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My setup is a first gen 16" AAC barrel with adjustable carbine length gas, I have had zero issues with rifle buffer on good super loads with h110 and Lil gun. Has issues with subs and the previously mentioned pnw

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